Merge "Allow shared lib and package name to match"
diff --git a/Android.mk b/Android.mk
index 21bd76b..2539c3d 100644
--- a/Android.mk
+++ b/Android.mk
@@ -346,6 +346,7 @@
core/java/com/android/internal/appwidget/IAppWidgetHost.aidl \
core/java/com/android/internal/backup/IBackupTransport.aidl \
core/java/com/android/internal/backup/IObbBackupService.aidl \
+ core/java/com/android/internal/font/IFontManager.aidl \
core/java/com/android/internal/inputmethod/IInputContentUriToken.aidl \
core/java/com/android/internal/policy/IKeyguardDrawnCallback.aidl \
core/java/com/android/internal/policy/IKeyguardDismissCallback.aidl \
diff --git a/api/current.txt b/api/current.txt
index ca6f470..bca65ee 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -8476,6 +8476,7 @@
field public static final java.lang.String DOWNLOAD_SERVICE = "download";
field public static final java.lang.String DROPBOX_SERVICE = "dropbox";
field public static final java.lang.String FINGERPRINT_SERVICE = "fingerprint";
+ field public static final java.lang.String FONT_SERVICE = "font";
field public static final java.lang.String HARDWARE_PROPERTIES_SERVICE = "hardware_properties";
field public static final java.lang.String INPUT_METHOD_SERVICE = "input_method";
field public static final java.lang.String INPUT_SERVICE = "input";
@@ -37726,7 +37727,7 @@
field public static final java.lang.String ACTION_CHANGE_PHONE_ACCOUNTS = "android.telecom.action.CHANGE_PHONE_ACCOUNTS";
field public static final java.lang.String ACTION_CONFIGURE_PHONE_ACCOUNT = "android.telecom.action.CONFIGURE_PHONE_ACCOUNT";
field public static final java.lang.String ACTION_DEFAULT_DIALER_CHANGED = "android.telecom.action.DEFAULT_DIALER_CHANGED";
- field public static final java.lang.String ACTION_INCOMING_CALL = "android.telecom.action.INCOMING_CALL";
+ field public static final deprecated java.lang.String ACTION_INCOMING_CALL = "android.telecom.action.INCOMING_CALL";
field public static final java.lang.String ACTION_SHOW_CALL_ACCESSIBILITY_SETTINGS = "android.telecom.action.SHOW_CALL_ACCESSIBILITY_SETTINGS";
field public static final java.lang.String ACTION_SHOW_CALL_SETTINGS = "android.telecom.action.SHOW_CALL_SETTINGS";
field public static final java.lang.String ACTION_SHOW_MISSED_CALLS_NOTIFICATION = "android.telecom.action.SHOW_MISSED_CALLS_NOTIFICATION";
@@ -39485,6 +39486,65 @@
method public android.text.Editable newEditable(java.lang.CharSequence);
}
+ public final class FontConfig implements android.os.Parcelable {
+ ctor public FontConfig();
+ ctor public FontConfig(android.text.FontConfig);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Alias> getAliases();
+ method public java.util.List<android.text.FontConfig.Family> getFamilies();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig> CREATOR;
+ }
+
+ public static final class FontConfig.Alias implements android.os.Parcelable {
+ ctor public FontConfig.Alias(java.lang.String, java.lang.String, int);
+ method public int describeContents();
+ method public java.lang.String getName();
+ method public java.lang.String getToName();
+ method public int getWeight();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Alias> CREATOR;
+ }
+
+ public static final class FontConfig.Axis implements android.os.Parcelable {
+ ctor public FontConfig.Axis(int, float);
+ method public int describeContents();
+ method public float getStyleValue();
+ method public int getTag();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Axis> CREATOR;
+ }
+
+ public static final class FontConfig.Family implements android.os.Parcelable {
+ ctor public FontConfig.Family(java.lang.String, java.util.List<android.text.FontConfig.Font>, java.lang.String, java.lang.String);
+ ctor public FontConfig.Family(android.text.FontConfig.Family);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Font> getFonts();
+ method public java.lang.String getLanguage();
+ method public java.lang.String getName();
+ method public java.lang.String getVariant();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Family> CREATOR;
+ }
+
+ public static final class FontConfig.Font implements android.os.Parcelable {
+ ctor public FontConfig.Font(java.lang.String, int, java.util.List<android.text.FontConfig.Axis>, int, boolean);
+ ctor public FontConfig.Font(android.text.FontConfig.Font);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Axis> getAxes();
+ method public android.os.ParcelFileDescriptor getFd();
+ method public java.lang.String getFontName();
+ method public int getTtcIndex();
+ method public int getWeight();
+ method public boolean isItalic();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Font> CREATOR;
+ }
+
+ public final class FontManager {
+ method public android.text.FontConfig getSystemFonts();
+ }
+
public abstract interface GetChars implements java.lang.CharSequence {
method public abstract void getChars(int, int, char[], int);
}
diff --git a/api/system-current.txt b/api/system-current.txt
index 8e0a3e2..53552fc 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -8852,6 +8852,7 @@
field public static final java.lang.String DOWNLOAD_SERVICE = "download";
field public static final java.lang.String DROPBOX_SERVICE = "dropbox";
field public static final java.lang.String FINGERPRINT_SERVICE = "fingerprint";
+ field public static final java.lang.String FONT_SERVICE = "font";
field public static final java.lang.String HARDWARE_PROPERTIES_SERVICE = "hardware_properties";
field public static final java.lang.String HDMI_CONTROL_SERVICE = "hdmi_control";
field public static final java.lang.String INPUT_METHOD_SERVICE = "input_method";
@@ -40929,7 +40930,7 @@
field public static final java.lang.String ACTION_CHANGE_PHONE_ACCOUNTS = "android.telecom.action.CHANGE_PHONE_ACCOUNTS";
field public static final java.lang.String ACTION_CONFIGURE_PHONE_ACCOUNT = "android.telecom.action.CONFIGURE_PHONE_ACCOUNT";
field public static final java.lang.String ACTION_DEFAULT_DIALER_CHANGED = "android.telecom.action.DEFAULT_DIALER_CHANGED";
- field public static final java.lang.String ACTION_INCOMING_CALL = "android.telecom.action.INCOMING_CALL";
+ field public static final deprecated java.lang.String ACTION_INCOMING_CALL = "android.telecom.action.INCOMING_CALL";
field public static final java.lang.String ACTION_PHONE_ACCOUNT_REGISTERED = "android.telecom.action.PHONE_ACCOUNT_REGISTERED";
field public static final java.lang.String ACTION_PHONE_ACCOUNT_UNREGISTERED = "android.telecom.action.PHONE_ACCOUNT_UNREGISTERED";
field public static final java.lang.String ACTION_SHOW_CALL_ACCESSIBILITY_SETTINGS = "android.telecom.action.SHOW_CALL_ACCESSIBILITY_SETTINGS";
@@ -42786,6 +42787,65 @@
method public android.text.Editable newEditable(java.lang.CharSequence);
}
+ public final class FontConfig implements android.os.Parcelable {
+ ctor public FontConfig();
+ ctor public FontConfig(android.text.FontConfig);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Alias> getAliases();
+ method public java.util.List<android.text.FontConfig.Family> getFamilies();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig> CREATOR;
+ }
+
+ public static final class FontConfig.Alias implements android.os.Parcelable {
+ ctor public FontConfig.Alias(java.lang.String, java.lang.String, int);
+ method public int describeContents();
+ method public java.lang.String getName();
+ method public java.lang.String getToName();
+ method public int getWeight();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Alias> CREATOR;
+ }
+
+ public static final class FontConfig.Axis implements android.os.Parcelable {
+ ctor public FontConfig.Axis(int, float);
+ method public int describeContents();
+ method public float getStyleValue();
+ method public int getTag();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Axis> CREATOR;
+ }
+
+ public static final class FontConfig.Family implements android.os.Parcelable {
+ ctor public FontConfig.Family(java.lang.String, java.util.List<android.text.FontConfig.Font>, java.lang.String, java.lang.String);
+ ctor public FontConfig.Family(android.text.FontConfig.Family);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Font> getFonts();
+ method public java.lang.String getLanguage();
+ method public java.lang.String getName();
+ method public java.lang.String getVariant();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Family> CREATOR;
+ }
+
+ public static final class FontConfig.Font implements android.os.Parcelable {
+ ctor public FontConfig.Font(java.lang.String, int, java.util.List<android.text.FontConfig.Axis>, int, boolean);
+ ctor public FontConfig.Font(android.text.FontConfig.Font);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Axis> getAxes();
+ method public android.os.ParcelFileDescriptor getFd();
+ method public java.lang.String getFontName();
+ method public int getTtcIndex();
+ method public int getWeight();
+ method public boolean isItalic();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Font> CREATOR;
+ }
+
+ public final class FontManager {
+ method public android.text.FontConfig getSystemFonts();
+ }
+
public abstract interface GetChars implements java.lang.CharSequence {
method public abstract void getChars(int, int, char[], int);
}
@@ -50654,6 +50714,7 @@
method public java.lang.String getErrorString(android.content.Context, int);
method public int getPackageId(android.content.res.Resources, java.lang.String);
method public void invokeDrawGlFunctor(android.view.View, long, boolean);
+ method public boolean isMultiProcessEnabled();
method public boolean isTraceTagEnabled();
method public void setOnTraceEnabledChangeListener(android.webkit.WebViewDelegate.OnTraceEnabledChangeListener);
}
diff --git a/api/test-current.txt b/api/test-current.txt
index d579624..d18af4c 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -8500,6 +8500,7 @@
field public static final java.lang.String DOWNLOAD_SERVICE = "download";
field public static final java.lang.String DROPBOX_SERVICE = "dropbox";
field public static final java.lang.String FINGERPRINT_SERVICE = "fingerprint";
+ field public static final java.lang.String FONT_SERVICE = "font";
field public static final java.lang.String HARDWARE_PROPERTIES_SERVICE = "hardware_properties";
field public static final java.lang.String INPUT_METHOD_SERVICE = "input_method";
field public static final java.lang.String INPUT_SERVICE = "input";
@@ -37847,7 +37848,7 @@
field public static final java.lang.String ACTION_CHANGE_PHONE_ACCOUNTS = "android.telecom.action.CHANGE_PHONE_ACCOUNTS";
field public static final java.lang.String ACTION_CONFIGURE_PHONE_ACCOUNT = "android.telecom.action.CONFIGURE_PHONE_ACCOUNT";
field public static final java.lang.String ACTION_DEFAULT_DIALER_CHANGED = "android.telecom.action.DEFAULT_DIALER_CHANGED";
- field public static final java.lang.String ACTION_INCOMING_CALL = "android.telecom.action.INCOMING_CALL";
+ field public static final deprecated java.lang.String ACTION_INCOMING_CALL = "android.telecom.action.INCOMING_CALL";
field public static final java.lang.String ACTION_SHOW_CALL_ACCESSIBILITY_SETTINGS = "android.telecom.action.SHOW_CALL_ACCESSIBILITY_SETTINGS";
field public static final java.lang.String ACTION_SHOW_CALL_SETTINGS = "android.telecom.action.SHOW_CALL_SETTINGS";
field public static final java.lang.String ACTION_SHOW_MISSED_CALLS_NOTIFICATION = "android.telecom.action.SHOW_MISSED_CALLS_NOTIFICATION";
@@ -39609,6 +39610,65 @@
method public android.text.Editable newEditable(java.lang.CharSequence);
}
+ public final class FontConfig implements android.os.Parcelable {
+ ctor public FontConfig();
+ ctor public FontConfig(android.text.FontConfig);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Alias> getAliases();
+ method public java.util.List<android.text.FontConfig.Family> getFamilies();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig> CREATOR;
+ }
+
+ public static final class FontConfig.Alias implements android.os.Parcelable {
+ ctor public FontConfig.Alias(java.lang.String, java.lang.String, int);
+ method public int describeContents();
+ method public java.lang.String getName();
+ method public java.lang.String getToName();
+ method public int getWeight();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Alias> CREATOR;
+ }
+
+ public static final class FontConfig.Axis implements android.os.Parcelable {
+ ctor public FontConfig.Axis(int, float);
+ method public int describeContents();
+ method public float getStyleValue();
+ method public int getTag();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Axis> CREATOR;
+ }
+
+ public static final class FontConfig.Family implements android.os.Parcelable {
+ ctor public FontConfig.Family(java.lang.String, java.util.List<android.text.FontConfig.Font>, java.lang.String, java.lang.String);
+ ctor public FontConfig.Family(android.text.FontConfig.Family);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Font> getFonts();
+ method public java.lang.String getLanguage();
+ method public java.lang.String getName();
+ method public java.lang.String getVariant();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Family> CREATOR;
+ }
+
+ public static final class FontConfig.Font implements android.os.Parcelable {
+ ctor public FontConfig.Font(java.lang.String, int, java.util.List<android.text.FontConfig.Axis>, int, boolean);
+ ctor public FontConfig.Font(android.text.FontConfig.Font);
+ method public int describeContents();
+ method public java.util.List<android.text.FontConfig.Axis> getAxes();
+ method public android.os.ParcelFileDescriptor getFd();
+ method public java.lang.String getFontName();
+ method public int getTtcIndex();
+ method public int getWeight();
+ method public boolean isItalic();
+ method public void writeToParcel(android.os.Parcel, int);
+ field public static final android.os.Parcelable.Creator<android.text.FontConfig.Font> CREATOR;
+ }
+
+ public final class FontManager {
+ method public android.text.FontConfig getSystemFonts();
+ }
+
public abstract interface GetChars implements java.lang.CharSequence {
method public abstract void getChars(int, int, char[], int);
}
diff --git a/compiled-classes-phone b/compiled-classes-phone
index ebc54f2..ed0a4a6 100644
--- a/compiled-classes-phone
+++ b/compiled-classes-phone
@@ -1195,13 +1195,13 @@
android.graphics.DiscretePathEffect
android.graphics.DrawFilter
android.graphics.EmbossMaskFilter
+android.graphics.FontConfig
+android.graphics.FontConfig$Alias
+android.graphics.FontConfig$Axis
+android.graphics.FontConfig$Family
+android.graphics.FontConfig$Font
android.graphics.FontFamily
android.graphics.FontListParser
-android.graphics.FontListParser$Alias
-android.graphics.FontListParser$Axis
-android.graphics.FontListParser$Config
-android.graphics.FontListParser$Family
-android.graphics.FontListParser$Font
android.graphics.ImageFormat
android.graphics.Insets
android.graphics.Interpolator
diff --git a/core/java/android/app/ContextImpl.java b/core/java/android/app/ContextImpl.java
index 1658e82..b2c97f6 100644
--- a/core/java/android/app/ContextImpl.java
+++ b/core/java/android/app/ContextImpl.java
@@ -1591,12 +1591,15 @@
}
final IActivityManager am = ActivityManager.getService();
- if (am == null && UserHandle.getAppId(Binder.getCallingUid()) == Process.SYSTEM_UID) {
+ if (am == null) {
// Well this is super awkward; we somehow don't have an active
- // ActivityManager instance. If this is the system UID, then we
- // totally have whatever permission this is.
- Slog.w(TAG, "Missing ActivityManager; assuming system UID holds " + permission);
- return PackageManager.PERMISSION_GRANTED;
+ // ActivityManager instance. If we're testing a root or system
+ // UID, then they totally have whatever permission this is.
+ final int appId = UserHandle.getAppId(uid);
+ if (appId == Process.ROOT_UID || appId == Process.SYSTEM_UID) {
+ Slog.w(TAG, "Missing ActivityManager; assuming " + uid + " holds " + permission);
+ return PackageManager.PERMISSION_GRANTED;
+ }
}
try {
diff --git a/core/java/android/app/KeyguardManager.java b/core/java/android/app/KeyguardManager.java
index 036b47c..6793c90 100644
--- a/core/java/android/app/KeyguardManager.java
+++ b/core/java/android/app/KeyguardManager.java
@@ -322,7 +322,7 @@
* password.
*/
public boolean isDeviceLocked() {
- return isDeviceLocked(UserHandle.getCallingUserId());
+ return isDeviceLocked(UserHandle.myUserId());
}
/**
@@ -347,7 +347,7 @@
* @return true if a PIN, pattern or password was set.
*/
public boolean isDeviceSecure() {
- return isDeviceSecure(UserHandle.getCallingUserId());
+ return isDeviceSecure(UserHandle.myUserId());
}
/**
diff --git a/core/java/android/app/SystemServiceRegistry.java b/core/java/android/app/SystemServiceRegistry.java
index 9387019..a37f22b 100644
--- a/core/java/android/app/SystemServiceRegistry.java
+++ b/core/java/android/app/SystemServiceRegistry.java
@@ -118,6 +118,7 @@
import android.telephony.CarrierConfigManager;
import android.telephony.SubscriptionManager;
import android.telephony.TelephonyManager;
+import android.text.FontManager;
import android.text.TextClassificationManager;
import android.util.Log;
import android.view.ContextThemeWrapper;
@@ -133,6 +134,7 @@
import com.android.internal.app.IBatteryStats;
import com.android.internal.app.ISoundTriggerService;
import com.android.internal.appwidget.IAppWidgetService;
+import com.android.internal.font.IFontManager;
import com.android.internal.os.IDropBoxManagerService;
import com.android.internal.policy.PhoneLayoutInflater;
@@ -793,6 +795,15 @@
public IncidentManager createService(ContextImpl ctx) throws ServiceNotFoundException {
return new IncidentManager(ctx);
}});
+
+ registerService(Context.FONT_SERVICE, FontManager.class,
+ new CachedServiceFetcher<FontManager>() {
+ @Override
+ public FontManager createService(ContextImpl ctx)
+ throws ServiceNotFoundException {
+ IBinder b = ServiceManager.getServiceOrThrow(Context.FONT_SERVICE);
+ return new FontManager(IFontManager.Stub.asInterface(b));
+ }});
}
/**
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index 596a9fd..f41d7f2 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -3744,6 +3744,11 @@
public static final String DEVICE_IDENTIFIERS_SERVICE = "device_identifiers";
/**
+ * Service that provides System font data.
+ */
+ public static final String FONT_SERVICE = "font";
+
+ /**
* Service to report a system health "incident"
* @hide
*/
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 5dcc96a..71b9482 100755
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -7601,6 +7601,14 @@
"hdmi_control_auto_device_off_enabled";
/**
+ * The interval in milliseconds at which location requests will be throttled when they are
+ * coming from the background.
+ * @hide
+ */
+ public static final String LOCATION_BACKGROUND_THROTTLE_INTERVAL_MS =
+ "location_background_throttle_interval_ms";
+
+ /**
* Whether TV will switch to MHL port when a mobile device is plugged in.
* (0 = false, 1 = true)
* @hide
diff --git a/core/java/android/text/FontConfig.aidl b/core/java/android/text/FontConfig.aidl
new file mode 100644
index 0000000..17a5ca2
--- /dev/null
+++ b/core/java/android/text/FontConfig.aidl
@@ -0,0 +1,20 @@
+/**
+ * Copyright (c) 2017, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.text;
+
+/** @hide */
+parcelable FontConfig;
diff --git a/core/java/android/text/FontConfig.java b/core/java/android/text/FontConfig.java
new file mode 100644
index 0000000..df694ff
--- /dev/null
+++ b/core/java/android/text/FontConfig.java
@@ -0,0 +1,466 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.text;
+
+import android.os.Parcel;
+import android.os.ParcelFileDescriptor;
+import android.os.Parcelable;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Font configuration descriptions for System fonts.
+ */
+public final class FontConfig implements Parcelable {
+ private final List<Family> mFamilies = new ArrayList<>();
+ private final List<Alias> mAliases = new ArrayList<>();
+
+ public FontConfig() {
+ }
+
+ public FontConfig(FontConfig config) {
+ for (int i = 0; i < config.mFamilies.size(); i++) {
+ mFamilies.add(new Family(config.mFamilies.get(i)));
+ }
+ mAliases.addAll(config.mAliases);
+ }
+
+ /**
+ * Returns the ordered list of families included in the system fonts.
+ */
+ public List<Family> getFamilies() {
+ return mFamilies;
+ }
+
+ /**
+ * Returns the list of aliases defined for the font families in the system fonts.
+ */
+ public List<Alias> getAliases() {
+ return mAliases;
+ }
+
+ /**
+ * @hide
+ */
+ public FontConfig(Parcel in) {
+ readFromParcel(in);
+ }
+
+ @Override
+ public void writeToParcel(Parcel out, int flag) {
+ out.writeInt(mFamilies.size());
+ for (int i = 0; i < mFamilies.size(); i++) {
+ mFamilies.get(i).writeToParcel(out, flag);
+ }
+ out.writeInt(mAliases.size());
+ for (int i = 0; i < mAliases.size(); i++) {
+ mAliases.get(i).writeToParcel(out, flag);
+ }
+ }
+
+ /**
+ * @hide
+ */
+ public void readFromParcel(Parcel in) {
+ int size = in.readInt();
+ for (int i = 0; i < size; i++) {
+ mFamilies.add(new Family(in));
+ }
+ size = in.readInt();
+ for (int i = 0; i < size; i++) {
+ mAliases.add(new Alias(in));
+ }
+ }
+
+ @Override
+ public int describeContents() {
+ return 0;
+ }
+
+ public static final Parcelable.Creator<FontConfig> CREATOR = new Parcelable.Creator() {
+ public FontConfig createFromParcel(Parcel in) {
+ return new FontConfig(in);
+ }
+ public FontConfig[] newArray(int size) {
+ return new FontConfig[size];
+ }
+ };
+
+ /**
+ * Class that holds information about a Font axis.
+ */
+ public static final class Axis implements Parcelable {
+ private final int mTag;
+ private final float mStyleValue;
+
+ public Axis(int tag, float styleValue) {
+ this.mTag = tag;
+ this.mStyleValue = styleValue;
+ }
+
+ /**
+ * Returns the variable font axis tag associated to this axis.
+ */
+ public int getTag() {
+ return mTag;
+ }
+
+ /**
+ * Returns the style value associated to the given axis for this font.
+ */
+ public float getStyleValue() {
+ return mStyleValue;
+ }
+
+ /**
+ * @hide
+ */
+ public Axis(Parcel in) {
+ mTag = in.readInt();
+ mStyleValue = in.readFloat();
+ }
+
+ @Override
+ public void writeToParcel(Parcel out, int flag) {
+ out.writeInt(mTag);
+ out.writeFloat(mStyleValue);
+ }
+
+ @Override
+ public int describeContents() {
+ return 0;
+ }
+
+ public static final Creator<Axis> CREATOR = new Creator<Axis>() {
+ @Override
+ public Axis createFromParcel(Parcel in) {
+ return new Axis(in);
+ }
+
+ @Override
+ public Axis[] newArray(int size) {
+ return new Axis[size];
+ }
+ };
+ }
+
+ /**
+ * Class that holds information about a Font.
+ */
+ public static final class Font implements Parcelable {
+ private final String mFontName;
+ private final int mTtcIndex;
+ private final List<Axis> mAxes;
+ private final int mWeight;
+ private final boolean mIsItalic;
+ private ParcelFileDescriptor mFd;
+
+ public Font(String fontName, int ttcIndex, List<Axis> axes, int weight, boolean isItalic) {
+ mFontName = fontName;
+ mTtcIndex = ttcIndex;
+ mAxes = axes;
+ mWeight = weight;
+ mIsItalic = isItalic;
+ mFd = null;
+ }
+
+ public Font(Font origin) {
+ mFontName = origin.mFontName;
+ mTtcIndex = origin.mTtcIndex;
+ mAxes = new ArrayList<>(origin.mAxes);
+ mWeight = origin.mWeight;
+ mIsItalic = origin.mIsItalic;
+ if (origin.mFd != null) {
+ try {
+ mFd = origin.mFd.dup();
+ } catch (IOException e) {
+ e.printStackTrace();
+ }
+ }
+ }
+
+ /**
+ * Returns the name associated by the system to this font.
+ */
+ public String getFontName() {
+ return mFontName;
+ }
+
+ /**
+ * Returns the index to be used to access this font when accessing a TTC file.
+ */
+ public int getTtcIndex() {
+ return mTtcIndex;
+ }
+
+ /**
+ * Returns the list of axes associated to this font.
+ */
+ public List<Axis> getAxes() {
+ return mAxes;
+ }
+
+ /**
+ * Returns the weight value for this font.
+ */
+ public int getWeight() {
+ return mWeight;
+ }
+
+ /**
+ * Returns whether this font is italic.
+ */
+ public boolean isItalic() {
+ return mIsItalic;
+ }
+
+ /**
+ * Returns a file descriptor to access the specified font. This should be closed after use.
+ */
+ public ParcelFileDescriptor getFd() {
+ return mFd;
+ }
+
+ /**
+ * @hide
+ */
+ public void setFd(ParcelFileDescriptor fd) {
+ mFd = fd;
+ }
+
+ /**
+ * @hide
+ */
+ public Font(Parcel in) {
+ mFontName = in.readString();
+ mTtcIndex = in.readInt();
+ final int numAxes = in.readInt();
+ mAxes = new ArrayList<>();
+ for (int i = 0; i < numAxes; i++) {
+ mAxes.add(new Axis(in));
+ }
+ mWeight = in.readInt();
+ mIsItalic = in.readInt() == 1;
+ if (in.readInt() == 1) { /* has FD */
+ mFd = ParcelFileDescriptor.CREATOR.createFromParcel(in);
+ } else {
+ mFd = null;
+ }
+ }
+
+ @Override
+ public void writeToParcel(Parcel out, int flag) {
+ out.writeString(mFontName);
+ out.writeInt(mTtcIndex);
+ out.writeInt(mAxes.size());
+ for (int i = 0; i < mAxes.size(); i++) {
+ mAxes.get(i).writeToParcel(out, flag);
+ }
+ out.writeInt(mWeight);
+ out.writeInt(mIsItalic ? 1 : 0);
+ out.writeInt(mFd == null ? 0 : 1);
+ if (mFd != null) {
+ mFd.writeToParcel(out, flag);
+ }
+ }
+
+ @Override
+ public int describeContents() {
+ return 0;
+ }
+
+ public static final Creator<Font> CREATOR = new Creator<Font>() {
+ @Override
+ public Font createFromParcel(Parcel in) {
+ return new Font(in);
+ }
+
+ @Override
+ public Font[] newArray(int size) {
+ return new Font[size];
+ }
+ };
+ }
+
+ /**
+ * Class that holds information about a Font alias.
+ */
+ public static final class Alias implements Parcelable {
+ private final String mName;
+ private final String mToName;
+ private final int mWeight;
+
+ public Alias(String name, String toName, int weight) {
+ this.mName = name;
+ this.mToName = toName;
+ this.mWeight = weight;
+ }
+
+ /**
+ * Returns the new name for the alias.
+ */
+ public String getName() {
+ return mName;
+ }
+
+ /**
+ * Returns the existing name to which this alias points to.
+ */
+ public String getToName() {
+ return mToName;
+ }
+
+ /**
+ * Returns the weight associated with this alias.
+ */
+ public int getWeight() {
+ return mWeight;
+ }
+
+ /**
+ * @hide
+ */
+ public Alias(Parcel in) {
+ mName = in.readString();
+ mToName = in.readString();
+ mWeight = in.readInt();
+ }
+
+ @Override
+ public void writeToParcel(Parcel out, int flag) {
+ out.writeString(mName);
+ out.writeString(mToName);
+ out.writeInt(mWeight);
+ }
+
+ @Override
+ public int describeContents() {
+ return 0;
+ }
+
+ public static final Creator<Alias> CREATOR = new Creator<Alias>() {
+ @Override
+ public Alias createFromParcel(Parcel in) {
+ return new Alias(in);
+ }
+
+ @Override
+ public Alias[] newArray(int size) {
+ return new Alias[size];
+ }
+ };
+ }
+
+ /**
+ * Class that holds information about a Font family.
+ */
+ public static final class Family implements Parcelable {
+ private final String mName;
+ private final List<Font> mFonts;
+ private final String mLanguage;
+ private final String mVariant;
+
+ public Family(String name, List<Font> fonts, String language, String variant) {
+ this.mName = name;
+ this.mFonts = fonts;
+ this.mLanguage = language;
+ this.mVariant = variant;
+ }
+
+ public Family(Family origin) {
+ this.mName = origin.mName;
+ this.mLanguage = origin.mLanguage;
+ this.mVariant = origin.mVariant;
+ this.mFonts = new ArrayList<>();
+ for (int i = 0; i < origin.mFonts.size(); i++) {
+ mFonts.add(new Font(origin.mFonts.get(i)));
+ }
+ }
+
+ /**
+ * Returns the name given by the system to this font family.
+ */
+ public String getName() {
+ return mName;
+ }
+
+ /**
+ * Returns the list of fonts included in this family.
+ */
+ public List<Font> getFonts() {
+ return mFonts;
+ }
+
+ /**
+ * Returns the language for this family. May be null.
+ */
+ public String getLanguage() {
+ return mLanguage;
+ }
+
+ /**
+ * Returns the font variant for this family, e.g. "elegant" or "compact". May be null.
+ */
+ public String getVariant() {
+ return mVariant;
+ }
+
+ /**
+ * @hide
+ */
+ public Family(Parcel in) {
+ mName = in.readString();
+ final int size = in.readInt();
+ mFonts = new ArrayList<>();
+ for (int i = 0; i < size; i++) {
+ mFonts.add(new Font(in));
+ }
+ mLanguage = in.readString();
+ mVariant = in.readString();
+ }
+
+ @Override
+ public void writeToParcel(Parcel out, int flag) {
+ out.writeString(mName);
+ out.writeInt(mFonts.size());
+ for (int i = 0; i < mFonts.size(); i++) {
+ mFonts.get(i).writeToParcel(out, flag);
+ }
+ out.writeString(mLanguage);
+ out.writeString(mVariant);
+ }
+
+ @Override
+ public int describeContents() {
+ return 0;
+ }
+
+ public static final Creator<Family> CREATOR = new Creator<Family>() {
+ @Override
+ public Family createFromParcel(Parcel in) {
+ return new Family(in);
+ }
+
+ @Override
+ public Family[] newArray(int size) {
+ return new Family[size];
+ }
+ };
+ }
+}
diff --git a/core/java/android/text/FontManager.java b/core/java/android/text/FontManager.java
new file mode 100644
index 0000000..b61cbf3
--- /dev/null
+++ b/core/java/android/text/FontManager.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.text;
+
+import android.os.RemoteException;
+
+import com.android.internal.font.IFontManager;
+
+/**
+ * Interact with the Font service.
+ */
+public final class FontManager {
+ private static final String TAG = "FontManager";
+
+ private final IFontManager mService;
+
+ /**
+ * @hide
+ */
+ public FontManager(IFontManager service) {
+ mService = service;
+ }
+
+ /**
+ * Retrieve the system fonts data. This loads the fonts.xml data if needed and loads all system
+ * fonts in to memory, providing file descriptors for them.
+ */
+ public FontConfig getSystemFonts() {
+ try {
+ return mService.getSystemFonts();
+ } catch (RemoteException e) {
+ throw e.rethrowFromSystemServer();
+ }
+ }
+}
diff --git a/core/java/android/webkit/UserPackage.java b/core/java/android/webkit/UserPackage.java
new file mode 100644
index 0000000..404bcf4
--- /dev/null
+++ b/core/java/android/webkit/UserPackage.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.webkit;
+
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.pm.UserInfo;
+import android.os.UserManager;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Utility class for storing a (user,PackageInfo) mapping.
+ * @hide
+ */
+public class UserPackage {
+ private final UserInfo mUserInfo;
+ private final PackageInfo mPackageInfo;
+
+ public UserPackage(UserInfo user, PackageInfo packageInfo) {
+ this.mUserInfo = user;
+ this.mPackageInfo = packageInfo;
+ }
+
+ /**
+ * Returns a list of (User,PackageInfo) pairs corresponding to the PackageInfos for all
+ * device users for the package named {@param packageName}.
+ */
+ public static List<UserPackage> getPackageInfosAllUsers(Context context,
+ String packageName, int packageFlags) {
+ List<UserInfo> users = getAllUsers(context);
+ List<UserPackage> userPackages = new ArrayList<UserPackage>(users.size());
+ for (UserInfo user : users) {
+ PackageInfo packageInfo = null;
+ try {
+ packageInfo = context.getPackageManager().getPackageInfoAsUser(
+ packageName, packageFlags, user.id);
+ } catch (NameNotFoundException e) {
+ }
+ userPackages.add(new UserPackage(user, packageInfo));
+ }
+ return userPackages;
+ }
+
+ /**
+ * Returns whether the given package is enabled.
+ * This state can be changed by the user from Settings->Apps
+ */
+ public boolean isEnabledPackage() {
+ if (mPackageInfo == null) return false;
+ return mPackageInfo.applicationInfo.enabled;
+ }
+
+ /**
+ * Return true if the package is installed and not hidden
+ */
+ public boolean isInstalledPackage() {
+ if (mPackageInfo == null) return false;
+ return (((mPackageInfo.applicationInfo.flags & ApplicationInfo.FLAG_INSTALLED) != 0)
+ && ((mPackageInfo.applicationInfo.privateFlags
+ & ApplicationInfo.PRIVATE_FLAG_HIDDEN) == 0));
+ }
+
+ public UserInfo getUserInfo() {
+ return mUserInfo;
+ }
+
+ public PackageInfo getPackageInfo() {
+ return mPackageInfo;
+ }
+
+
+ private static List<UserInfo> getAllUsers(Context context) {
+ UserManager userManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
+ return userManager.getUsers(false);
+ }
+
+}
diff --git a/core/java/android/webkit/WebViewDelegate.java b/core/java/android/webkit/WebViewDelegate.java
index 2cdff79..92d0d71 100644
--- a/core/java/android/webkit/WebViewDelegate.java
+++ b/core/java/android/webkit/WebViewDelegate.java
@@ -26,6 +26,7 @@
import android.content.pm.ApplicationInfo;
import android.content.res.Resources;
import android.graphics.Canvas;
+import android.os.RemoteException;
import android.os.SystemProperties;
import android.os.Trace;
import android.util.SparseArray;
@@ -206,4 +207,15 @@
appInfo.getBaseResourcePath(), newAssetPath);
}
}
+
+ /**
+ * Returns whether WebView should run in multiprocess mode.
+ */
+ public boolean isMultiProcessEnabled() {
+ try {
+ return WebViewFactory.getUpdateService().isMultiProcessEnabled();
+ } catch (RemoteException e) {
+ throw e.rethrowFromSystemServer();
+ }
+ }
}
diff --git a/core/java/com/android/internal/app/ResolverActivity.java b/core/java/com/android/internal/app/ResolverActivity.java
index d734d17..ab1d9b9 100644
--- a/core/java/com/android/internal/app/ResolverActivity.java
+++ b/core/java/com/android/internal/app/ResolverActivity.java
@@ -749,10 +749,7 @@
}
} else {
try {
- AppGlobals.getPackageManager().setLastChosenActivity(intent,
- intent.resolveType(getContentResolver()),
- PackageManager.MATCH_DEFAULT_ONLY,
- filter, bestMatch, intent.getComponent());
+ mAdapter.mResolverListController.setLastChosen(intent, filter, bestMatch);
} catch (RemoteException re) {
Log.d(TAG, "Error calling setLastChosenActivity\n" + re);
}
@@ -1312,10 +1309,7 @@
protected boolean rebuildList() {
List<ResolvedComponentInfo> currentResolveList = null;
try {
- final Intent primaryIntent = getTargetIntent();
- mLastChosen = AppGlobals.getPackageManager().getLastChosenActivity(
- primaryIntent, primaryIntent.resolveTypeIfNeeded(getContentResolver()),
- PackageManager.MATCH_DEFAULT_ONLY);
+ mLastChosen = mResolverListController.getLastChosen();
} catch (RemoteException re) {
Log.d(TAG, "Error calling getLastChosenActivity\n" + re);
}
diff --git a/core/java/com/android/internal/app/ResolverListController.java b/core/java/com/android/internal/app/ResolverListController.java
index f88f6f9..00faf65 100644
--- a/core/java/com/android/internal/app/ResolverListController.java
+++ b/core/java/com/android/internal/app/ResolverListController.java
@@ -19,13 +19,16 @@
import android.annotation.WorkerThread;
import android.app.ActivityManager;
+import android.app.AppGlobals;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
+import android.content.IntentFilter;
import android.content.pm.ActivityInfo;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
+import android.os.RemoteException;
import android.util.Log;
import com.android.internal.annotations.VisibleForTesting;
@@ -66,6 +69,22 @@
}
@VisibleForTesting
+ ResolveInfo getLastChosen() throws RemoteException {
+ return AppGlobals.getPackageManager().getLastChosenActivity(
+ mTargetIntent, mTargetIntent.resolveTypeIfNeeded(mContext.getContentResolver()),
+ PackageManager.MATCH_DEFAULT_ONLY);
+ }
+
+ @VisibleForTesting
+ void setLastChosen(Intent intent, IntentFilter filter, int match)
+ throws RemoteException {
+ AppGlobals.getPackageManager().setLastChosenActivity(intent,
+ intent.resolveType(mContext.getContentResolver()),
+ PackageManager.MATCH_DEFAULT_ONLY,
+ filter, match, intent.getComponent());
+ }
+
+ @VisibleForTesting
public List<ResolverActivity.ResolvedComponentInfo> getResolversForIntent(
boolean shouldGetResolvedFilter,
boolean shouldGetActivityMetadata,
diff --git a/core/java/com/android/internal/font/IFontManager.aidl b/core/java/com/android/internal/font/IFontManager.aidl
new file mode 100644
index 0000000..52a6262
--- /dev/null
+++ b/core/java/com/android/internal/font/IFontManager.aidl
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.font;
+
+import android.text.FontConfig;
+
+/**
+ * Interface to the font manager.
+ * @hide
+ */
+interface IFontManager {
+ FontConfig getSystemFonts();
+}
diff --git a/core/java/com/android/internal/widget/AdapterHelper.java b/core/java/com/android/internal/widget/AdapterHelper.java
new file mode 100644
index 0000000..f47d430
--- /dev/null
+++ b/core/java/com/android/internal/widget/AdapterHelper.java
@@ -0,0 +1,775 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.util.Log;
+import android.util.Pools;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Helper class that can enqueue and process adapter update operations.
+ * <p>
+ * To support animations, RecyclerView presents an older version the Adapter to best represent
+ * previous state of the layout. Sometimes, this is not trivial when items are removed that were
+ * not laid out, in which case, RecyclerView has no way of providing that item's view for
+ * animations.
+ * <p>
+ * AdapterHelper creates an UpdateOp for each adapter data change then pre-processes them. During
+ * pre processing, AdapterHelper finds out which UpdateOps can be deferred to second layout pass
+ * and which cannot. For the UpdateOps that cannot be deferred, AdapterHelper will change them
+ * according to previously deferred operation and dispatch them before the first layout pass. It
+ * also takes care of updating deferred UpdateOps since order of operations is changed by this
+ * process.
+ * <p>
+ * Although operations may be forwarded to LayoutManager in different orders, resulting data set
+ * is guaranteed to be the consistent.
+ */
+class AdapterHelper implements OpReorderer.Callback {
+
+ static final int POSITION_TYPE_INVISIBLE = 0;
+
+ static final int POSITION_TYPE_NEW_OR_LAID_OUT = 1;
+
+ private static final boolean DEBUG = false;
+
+ private static final String TAG = "AHT";
+
+ private Pools.Pool<UpdateOp> mUpdateOpPool = new Pools.SimplePool<UpdateOp>(UpdateOp.POOL_SIZE);
+
+ final ArrayList<UpdateOp> mPendingUpdates = new ArrayList<UpdateOp>();
+
+ final ArrayList<UpdateOp> mPostponedList = new ArrayList<UpdateOp>();
+
+ final Callback mCallback;
+
+ Runnable mOnItemProcessedCallback;
+
+ final boolean mDisableRecycler;
+
+ final OpReorderer mOpReorderer;
+
+ private int mExistingUpdateTypes = 0;
+
+ AdapterHelper(Callback callback) {
+ this(callback, false);
+ }
+
+ AdapterHelper(Callback callback, boolean disableRecycler) {
+ mCallback = callback;
+ mDisableRecycler = disableRecycler;
+ mOpReorderer = new OpReorderer(this);
+ }
+
+ AdapterHelper addUpdateOp(UpdateOp... ops) {
+ Collections.addAll(mPendingUpdates, ops);
+ return this;
+ }
+
+ void reset() {
+ recycleUpdateOpsAndClearList(mPendingUpdates);
+ recycleUpdateOpsAndClearList(mPostponedList);
+ mExistingUpdateTypes = 0;
+ }
+
+ void preProcess() {
+ mOpReorderer.reorderOps(mPendingUpdates);
+ final int count = mPendingUpdates.size();
+ for (int i = 0; i < count; i++) {
+ UpdateOp op = mPendingUpdates.get(i);
+ switch (op.cmd) {
+ case UpdateOp.ADD:
+ applyAdd(op);
+ break;
+ case UpdateOp.REMOVE:
+ applyRemove(op);
+ break;
+ case UpdateOp.UPDATE:
+ applyUpdate(op);
+ break;
+ case UpdateOp.MOVE:
+ applyMove(op);
+ break;
+ }
+ if (mOnItemProcessedCallback != null) {
+ mOnItemProcessedCallback.run();
+ }
+ }
+ mPendingUpdates.clear();
+ }
+
+ void consumePostponedUpdates() {
+ final int count = mPostponedList.size();
+ for (int i = 0; i < count; i++) {
+ mCallback.onDispatchSecondPass(mPostponedList.get(i));
+ }
+ recycleUpdateOpsAndClearList(mPostponedList);
+ mExistingUpdateTypes = 0;
+ }
+
+ private void applyMove(UpdateOp op) {
+ // MOVE ops are pre-processed so at this point, we know that item is still in the adapter.
+ // otherwise, it would be converted into a REMOVE operation
+ postponeAndUpdateViewHolders(op);
+ }
+
+ private void applyRemove(UpdateOp op) {
+ int tmpStart = op.positionStart;
+ int tmpCount = 0;
+ int tmpEnd = op.positionStart + op.itemCount;
+ int type = -1;
+ for (int position = op.positionStart; position < tmpEnd; position++) {
+ boolean typeChanged = false;
+ RecyclerView.ViewHolder vh = mCallback.findViewHolder(position);
+ if (vh != null || canFindInPreLayout(position)) {
+ // If a ViewHolder exists or this is a newly added item, we can defer this update
+ // to post layout stage.
+ // * For existing ViewHolders, we'll fake its existence in the pre-layout phase.
+ // * For items that are added and removed in the same process cycle, they won't
+ // have any effect in pre-layout since their add ops are already deferred to
+ // post-layout pass.
+ if (type == POSITION_TYPE_INVISIBLE) {
+ // Looks like we have other updates that we cannot merge with this one.
+ // Create an UpdateOp and dispatch it to LayoutManager.
+ UpdateOp newOp = obtainUpdateOp(UpdateOp.REMOVE, tmpStart, tmpCount, null);
+ dispatchAndUpdateViewHolders(newOp);
+ typeChanged = true;
+ }
+ type = POSITION_TYPE_NEW_OR_LAID_OUT;
+ } else {
+ // This update cannot be recovered because we don't have a ViewHolder representing
+ // this position. Instead, post it to LayoutManager immediately
+ if (type == POSITION_TYPE_NEW_OR_LAID_OUT) {
+ // Looks like we have other updates that we cannot merge with this one.
+ // Create UpdateOp op and dispatch it to LayoutManager.
+ UpdateOp newOp = obtainUpdateOp(UpdateOp.REMOVE, tmpStart, tmpCount, null);
+ postponeAndUpdateViewHolders(newOp);
+ typeChanged = true;
+ }
+ type = POSITION_TYPE_INVISIBLE;
+ }
+ if (typeChanged) {
+ position -= tmpCount; // also equal to tmpStart
+ tmpEnd -= tmpCount;
+ tmpCount = 1;
+ } else {
+ tmpCount++;
+ }
+ }
+ if (tmpCount != op.itemCount) { // all 1 effect
+ recycleUpdateOp(op);
+ op = obtainUpdateOp(UpdateOp.REMOVE, tmpStart, tmpCount, null);
+ }
+ if (type == POSITION_TYPE_INVISIBLE) {
+ dispatchAndUpdateViewHolders(op);
+ } else {
+ postponeAndUpdateViewHolders(op);
+ }
+ }
+
+ private void applyUpdate(UpdateOp op) {
+ int tmpStart = op.positionStart;
+ int tmpCount = 0;
+ int tmpEnd = op.positionStart + op.itemCount;
+ int type = -1;
+ for (int position = op.positionStart; position < tmpEnd; position++) {
+ RecyclerView.ViewHolder vh = mCallback.findViewHolder(position);
+ if (vh != null || canFindInPreLayout(position)) { // deferred
+ if (type == POSITION_TYPE_INVISIBLE) {
+ UpdateOp newOp = obtainUpdateOp(UpdateOp.UPDATE, tmpStart, tmpCount,
+ op.payload);
+ dispatchAndUpdateViewHolders(newOp);
+ tmpCount = 0;
+ tmpStart = position;
+ }
+ type = POSITION_TYPE_NEW_OR_LAID_OUT;
+ } else { // applied
+ if (type == POSITION_TYPE_NEW_OR_LAID_OUT) {
+ UpdateOp newOp = obtainUpdateOp(UpdateOp.UPDATE, tmpStart, tmpCount,
+ op.payload);
+ postponeAndUpdateViewHolders(newOp);
+ tmpCount = 0;
+ tmpStart = position;
+ }
+ type = POSITION_TYPE_INVISIBLE;
+ }
+ tmpCount++;
+ }
+ if (tmpCount != op.itemCount) { // all 1 effect
+ Object payload = op.payload;
+ recycleUpdateOp(op);
+ op = obtainUpdateOp(UpdateOp.UPDATE, tmpStart, tmpCount, payload);
+ }
+ if (type == POSITION_TYPE_INVISIBLE) {
+ dispatchAndUpdateViewHolders(op);
+ } else {
+ postponeAndUpdateViewHolders(op);
+ }
+ }
+
+ private void dispatchAndUpdateViewHolders(UpdateOp op) {
+ // tricky part.
+ // traverse all postpones and revert their changes on this op if necessary, apply updated
+ // dispatch to them since now they are after this op.
+ if (op.cmd == UpdateOp.ADD || op.cmd == UpdateOp.MOVE) {
+ throw new IllegalArgumentException("should not dispatch add or move for pre layout");
+ }
+ if (DEBUG) {
+ Log.d(TAG, "dispatch (pre)" + op);
+ Log.d(TAG, "postponed state before:");
+ for (UpdateOp updateOp : mPostponedList) {
+ Log.d(TAG, updateOp.toString());
+ }
+ Log.d(TAG, "----");
+ }
+
+ // handle each pos 1 by 1 to ensure continuity. If it breaks, dispatch partial
+ // TODO Since move ops are pushed to end, we should not need this anymore
+ int tmpStart = updatePositionWithPostponed(op.positionStart, op.cmd);
+ if (DEBUG) {
+ Log.d(TAG, "pos:" + op.positionStart + ",updatedPos:" + tmpStart);
+ }
+ int tmpCnt = 1;
+ int offsetPositionForPartial = op.positionStart;
+ final int positionMultiplier;
+ switch (op.cmd) {
+ case UpdateOp.UPDATE:
+ positionMultiplier = 1;
+ break;
+ case UpdateOp.REMOVE:
+ positionMultiplier = 0;
+ break;
+ default:
+ throw new IllegalArgumentException("op should be remove or update." + op);
+ }
+ for (int p = 1; p < op.itemCount; p++) {
+ final int pos = op.positionStart + (positionMultiplier * p);
+ int updatedPos = updatePositionWithPostponed(pos, op.cmd);
+ if (DEBUG) {
+ Log.d(TAG, "pos:" + pos + ",updatedPos:" + updatedPos);
+ }
+ boolean continuous = false;
+ switch (op.cmd) {
+ case UpdateOp.UPDATE:
+ continuous = updatedPos == tmpStart + 1;
+ break;
+ case UpdateOp.REMOVE:
+ continuous = updatedPos == tmpStart;
+ break;
+ }
+ if (continuous) {
+ tmpCnt++;
+ } else {
+ // need to dispatch this separately
+ UpdateOp tmp = obtainUpdateOp(op.cmd, tmpStart, tmpCnt, op.payload);
+ if (DEBUG) {
+ Log.d(TAG, "need to dispatch separately " + tmp);
+ }
+ dispatchFirstPassAndUpdateViewHolders(tmp, offsetPositionForPartial);
+ recycleUpdateOp(tmp);
+ if (op.cmd == UpdateOp.UPDATE) {
+ offsetPositionForPartial += tmpCnt;
+ }
+ tmpStart = updatedPos; // need to remove previously dispatched
+ tmpCnt = 1;
+ }
+ }
+ Object payload = op.payload;
+ recycleUpdateOp(op);
+ if (tmpCnt > 0) {
+ UpdateOp tmp = obtainUpdateOp(op.cmd, tmpStart, tmpCnt, payload);
+ if (DEBUG) {
+ Log.d(TAG, "dispatching:" + tmp);
+ }
+ dispatchFirstPassAndUpdateViewHolders(tmp, offsetPositionForPartial);
+ recycleUpdateOp(tmp);
+ }
+ if (DEBUG) {
+ Log.d(TAG, "post dispatch");
+ Log.d(TAG, "postponed state after:");
+ for (UpdateOp updateOp : mPostponedList) {
+ Log.d(TAG, updateOp.toString());
+ }
+ Log.d(TAG, "----");
+ }
+ }
+
+ void dispatchFirstPassAndUpdateViewHolders(UpdateOp op, int offsetStart) {
+ mCallback.onDispatchFirstPass(op);
+ switch (op.cmd) {
+ case UpdateOp.REMOVE:
+ mCallback.offsetPositionsForRemovingInvisible(offsetStart, op.itemCount);
+ break;
+ case UpdateOp.UPDATE:
+ mCallback.markViewHoldersUpdated(offsetStart, op.itemCount, op.payload);
+ break;
+ default:
+ throw new IllegalArgumentException("only remove and update ops can be dispatched"
+ + " in first pass");
+ }
+ }
+
+ private int updatePositionWithPostponed(int pos, int cmd) {
+ final int count = mPostponedList.size();
+ for (int i = count - 1; i >= 0; i--) {
+ UpdateOp postponed = mPostponedList.get(i);
+ if (postponed.cmd == UpdateOp.MOVE) {
+ int start, end;
+ if (postponed.positionStart < postponed.itemCount) {
+ start = postponed.positionStart;
+ end = postponed.itemCount;
+ } else {
+ start = postponed.itemCount;
+ end = postponed.positionStart;
+ }
+ if (pos >= start && pos <= end) {
+ //i'm affected
+ if (start == postponed.positionStart) {
+ if (cmd == UpdateOp.ADD) {
+ postponed.itemCount++;
+ } else if (cmd == UpdateOp.REMOVE) {
+ postponed.itemCount--;
+ }
+ // op moved to left, move it right to revert
+ pos++;
+ } else {
+ if (cmd == UpdateOp.ADD) {
+ postponed.positionStart++;
+ } else if (cmd == UpdateOp.REMOVE) {
+ postponed.positionStart--;
+ }
+ // op was moved right, move left to revert
+ pos--;
+ }
+ } else if (pos < postponed.positionStart) {
+ // postponed MV is outside the dispatched OP. if it is before, offset
+ if (cmd == UpdateOp.ADD) {
+ postponed.positionStart++;
+ postponed.itemCount++;
+ } else if (cmd == UpdateOp.REMOVE) {
+ postponed.positionStart--;
+ postponed.itemCount--;
+ }
+ }
+ } else {
+ if (postponed.positionStart <= pos) {
+ if (postponed.cmd == UpdateOp.ADD) {
+ pos -= postponed.itemCount;
+ } else if (postponed.cmd == UpdateOp.REMOVE) {
+ pos += postponed.itemCount;
+ }
+ } else {
+ if (cmd == UpdateOp.ADD) {
+ postponed.positionStart++;
+ } else if (cmd == UpdateOp.REMOVE) {
+ postponed.positionStart--;
+ }
+ }
+ }
+ if (DEBUG) {
+ Log.d(TAG, "dispath (step" + i + ")");
+ Log.d(TAG, "postponed state:" + i + ", pos:" + pos);
+ for (UpdateOp updateOp : mPostponedList) {
+ Log.d(TAG, updateOp.toString());
+ }
+ Log.d(TAG, "----");
+ }
+ }
+ for (int i = mPostponedList.size() - 1; i >= 0; i--) {
+ UpdateOp op = mPostponedList.get(i);
+ if (op.cmd == UpdateOp.MOVE) {
+ if (op.itemCount == op.positionStart || op.itemCount < 0) {
+ mPostponedList.remove(i);
+ recycleUpdateOp(op);
+ }
+ } else if (op.itemCount <= 0) {
+ mPostponedList.remove(i);
+ recycleUpdateOp(op);
+ }
+ }
+ return pos;
+ }
+
+ private boolean canFindInPreLayout(int position) {
+ final int count = mPostponedList.size();
+ for (int i = 0; i < count; i++) {
+ UpdateOp op = mPostponedList.get(i);
+ if (op.cmd == UpdateOp.MOVE) {
+ if (findPositionOffset(op.itemCount, i + 1) == position) {
+ return true;
+ }
+ } else if (op.cmd == UpdateOp.ADD) {
+ // TODO optimize.
+ final int end = op.positionStart + op.itemCount;
+ for (int pos = op.positionStart; pos < end; pos++) {
+ if (findPositionOffset(pos, i + 1) == position) {
+ return true;
+ }
+ }
+ }
+ }
+ return false;
+ }
+
+ private void applyAdd(UpdateOp op) {
+ postponeAndUpdateViewHolders(op);
+ }
+
+ private void postponeAndUpdateViewHolders(UpdateOp op) {
+ if (DEBUG) {
+ Log.d(TAG, "postponing " + op);
+ }
+ mPostponedList.add(op);
+ switch (op.cmd) {
+ case UpdateOp.ADD:
+ mCallback.offsetPositionsForAdd(op.positionStart, op.itemCount);
+ break;
+ case UpdateOp.MOVE:
+ mCallback.offsetPositionsForMove(op.positionStart, op.itemCount);
+ break;
+ case UpdateOp.REMOVE:
+ mCallback.offsetPositionsForRemovingLaidOutOrNewView(op.positionStart,
+ op.itemCount);
+ break;
+ case UpdateOp.UPDATE:
+ mCallback.markViewHoldersUpdated(op.positionStart, op.itemCount, op.payload);
+ break;
+ default:
+ throw new IllegalArgumentException("Unknown update op type for " + op);
+ }
+ }
+
+ boolean hasPendingUpdates() {
+ return mPendingUpdates.size() > 0;
+ }
+
+ boolean hasAnyUpdateTypes(int updateTypes) {
+ return (mExistingUpdateTypes & updateTypes) != 0;
+ }
+
+ int findPositionOffset(int position) {
+ return findPositionOffset(position, 0);
+ }
+
+ int findPositionOffset(int position, int firstPostponedItem) {
+ int count = mPostponedList.size();
+ for (int i = firstPostponedItem; i < count; ++i) {
+ UpdateOp op = mPostponedList.get(i);
+ if (op.cmd == UpdateOp.MOVE) {
+ if (op.positionStart == position) {
+ position = op.itemCount;
+ } else {
+ if (op.positionStart < position) {
+ position--; // like a remove
+ }
+ if (op.itemCount <= position) {
+ position++; // like an add
+ }
+ }
+ } else if (op.positionStart <= position) {
+ if (op.cmd == UpdateOp.REMOVE) {
+ if (position < op.positionStart + op.itemCount) {
+ return -1;
+ }
+ position -= op.itemCount;
+ } else if (op.cmd == UpdateOp.ADD) {
+ position += op.itemCount;
+ }
+ }
+ }
+ return position;
+ }
+
+ /**
+ * @return True if updates should be processed.
+ */
+ boolean onItemRangeChanged(int positionStart, int itemCount, Object payload) {
+ if (itemCount < 1) {
+ return false;
+ }
+ mPendingUpdates.add(obtainUpdateOp(UpdateOp.UPDATE, positionStart, itemCount, payload));
+ mExistingUpdateTypes |= UpdateOp.UPDATE;
+ return mPendingUpdates.size() == 1;
+ }
+
+ /**
+ * @return True if updates should be processed.
+ */
+ boolean onItemRangeInserted(int positionStart, int itemCount) {
+ if (itemCount < 1) {
+ return false;
+ }
+ mPendingUpdates.add(obtainUpdateOp(UpdateOp.ADD, positionStart, itemCount, null));
+ mExistingUpdateTypes |= UpdateOp.ADD;
+ return mPendingUpdates.size() == 1;
+ }
+
+ /**
+ * @return True if updates should be processed.
+ */
+ boolean onItemRangeRemoved(int positionStart, int itemCount) {
+ if (itemCount < 1) {
+ return false;
+ }
+ mPendingUpdates.add(obtainUpdateOp(UpdateOp.REMOVE, positionStart, itemCount, null));
+ mExistingUpdateTypes |= UpdateOp.REMOVE;
+ return mPendingUpdates.size() == 1;
+ }
+
+ /**
+ * @return True if updates should be processed.
+ */
+ boolean onItemRangeMoved(int from, int to, int itemCount) {
+ if (from == to) {
+ return false; // no-op
+ }
+ if (itemCount != 1) {
+ throw new IllegalArgumentException("Moving more than 1 item is not supported yet");
+ }
+ mPendingUpdates.add(obtainUpdateOp(UpdateOp.MOVE, from, to, null));
+ mExistingUpdateTypes |= UpdateOp.MOVE;
+ return mPendingUpdates.size() == 1;
+ }
+
+ /**
+ * Skips pre-processing and applies all updates in one pass.
+ */
+ void consumeUpdatesInOnePass() {
+ // we still consume postponed updates (if there is) in case there was a pre-process call
+ // w/o a matching consumePostponedUpdates.
+ consumePostponedUpdates();
+ final int count = mPendingUpdates.size();
+ for (int i = 0; i < count; i++) {
+ UpdateOp op = mPendingUpdates.get(i);
+ switch (op.cmd) {
+ case UpdateOp.ADD:
+ mCallback.onDispatchSecondPass(op);
+ mCallback.offsetPositionsForAdd(op.positionStart, op.itemCount);
+ break;
+ case UpdateOp.REMOVE:
+ mCallback.onDispatchSecondPass(op);
+ mCallback.offsetPositionsForRemovingInvisible(op.positionStart, op.itemCount);
+ break;
+ case UpdateOp.UPDATE:
+ mCallback.onDispatchSecondPass(op);
+ mCallback.markViewHoldersUpdated(op.positionStart, op.itemCount, op.payload);
+ break;
+ case UpdateOp.MOVE:
+ mCallback.onDispatchSecondPass(op);
+ mCallback.offsetPositionsForMove(op.positionStart, op.itemCount);
+ break;
+ }
+ if (mOnItemProcessedCallback != null) {
+ mOnItemProcessedCallback.run();
+ }
+ }
+ recycleUpdateOpsAndClearList(mPendingUpdates);
+ mExistingUpdateTypes = 0;
+ }
+
+ public int applyPendingUpdatesToPosition(int position) {
+ final int size = mPendingUpdates.size();
+ for (int i = 0; i < size; i++) {
+ UpdateOp op = mPendingUpdates.get(i);
+ switch (op.cmd) {
+ case UpdateOp.ADD:
+ if (op.positionStart <= position) {
+ position += op.itemCount;
+ }
+ break;
+ case UpdateOp.REMOVE:
+ if (op.positionStart <= position) {
+ final int end = op.positionStart + op.itemCount;
+ if (end > position) {
+ return RecyclerView.NO_POSITION;
+ }
+ position -= op.itemCount;
+ }
+ break;
+ case UpdateOp.MOVE:
+ if (op.positionStart == position) {
+ position = op.itemCount; //position end
+ } else {
+ if (op.positionStart < position) {
+ position -= 1;
+ }
+ if (op.itemCount <= position) {
+ position += 1;
+ }
+ }
+ break;
+ }
+ }
+ return position;
+ }
+
+ boolean hasUpdates() {
+ return !mPostponedList.isEmpty() && !mPendingUpdates.isEmpty();
+ }
+
+ /**
+ * Queued operation to happen when child views are updated.
+ */
+ static class UpdateOp {
+
+ static final int ADD = 1;
+
+ static final int REMOVE = 1 << 1;
+
+ static final int UPDATE = 1 << 2;
+
+ static final int MOVE = 1 << 3;
+
+ static final int POOL_SIZE = 30;
+
+ int cmd;
+
+ int positionStart;
+
+ Object payload;
+
+ // holds the target position if this is a MOVE
+ int itemCount;
+
+ UpdateOp(int cmd, int positionStart, int itemCount, Object payload) {
+ this.cmd = cmd;
+ this.positionStart = positionStart;
+ this.itemCount = itemCount;
+ this.payload = payload;
+ }
+
+ String cmdToString() {
+ switch (cmd) {
+ case ADD:
+ return "add";
+ case REMOVE:
+ return "rm";
+ case UPDATE:
+ return "up";
+ case MOVE:
+ return "mv";
+ }
+ return "??";
+ }
+
+ @Override
+ public String toString() {
+ return Integer.toHexString(System.identityHashCode(this))
+ + "[" + cmdToString() + ",s:" + positionStart + "c:" + itemCount
+ + ",p:" + payload + "]";
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) {
+ return true;
+ }
+ if (o == null || getClass() != o.getClass()) {
+ return false;
+ }
+
+ UpdateOp op = (UpdateOp) o;
+
+ if (cmd != op.cmd) {
+ return false;
+ }
+ if (cmd == MOVE && Math.abs(itemCount - positionStart) == 1) {
+ // reverse of this is also true
+ if (itemCount == op.positionStart && positionStart == op.itemCount) {
+ return true;
+ }
+ }
+ if (itemCount != op.itemCount) {
+ return false;
+ }
+ if (positionStart != op.positionStart) {
+ return false;
+ }
+ if (payload != null) {
+ if (!payload.equals(op.payload)) {
+ return false;
+ }
+ } else if (op.payload != null) {
+ return false;
+ }
+
+ return true;
+ }
+
+ @Override
+ public int hashCode() {
+ int result = cmd;
+ result = 31 * result + positionStart;
+ result = 31 * result + itemCount;
+ return result;
+ }
+ }
+
+ @Override
+ public UpdateOp obtainUpdateOp(int cmd, int positionStart, int itemCount, Object payload) {
+ UpdateOp op = mUpdateOpPool.acquire();
+ if (op == null) {
+ op = new UpdateOp(cmd, positionStart, itemCount, payload);
+ } else {
+ op.cmd = cmd;
+ op.positionStart = positionStart;
+ op.itemCount = itemCount;
+ op.payload = payload;
+ }
+ return op;
+ }
+
+ @Override
+ public void recycleUpdateOp(UpdateOp op) {
+ if (!mDisableRecycler) {
+ op.payload = null;
+ mUpdateOpPool.release(op);
+ }
+ }
+
+ void recycleUpdateOpsAndClearList(List<UpdateOp> ops) {
+ final int count = ops.size();
+ for (int i = 0; i < count; i++) {
+ recycleUpdateOp(ops.get(i));
+ }
+ ops.clear();
+ }
+
+ /**
+ * Contract between AdapterHelper and RecyclerView.
+ */
+ interface Callback {
+
+ RecyclerView.ViewHolder findViewHolder(int position);
+
+ void offsetPositionsForRemovingInvisible(int positionStart, int itemCount);
+
+ void offsetPositionsForRemovingLaidOutOrNewView(int positionStart, int itemCount);
+
+ void markViewHoldersUpdated(int positionStart, int itemCount, Object payloads);
+
+ void onDispatchFirstPass(UpdateOp updateOp);
+
+ void onDispatchSecondPass(UpdateOp updateOp);
+
+ void offsetPositionsForAdd(int positionStart, int itemCount);
+
+ void offsetPositionsForMove(int from, int to);
+ }
+}
diff --git a/core/java/com/android/internal/widget/ChildHelper.java b/core/java/com/android/internal/widget/ChildHelper.java
new file mode 100644
index 0000000..e9136d0
--- /dev/null
+++ b/core/java/com/android/internal/widget/ChildHelper.java
@@ -0,0 +1,538 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.util.Log;
+import android.view.View;
+import android.view.ViewGroup;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Helper class to manage children.
+ * <p>
+ * It wraps a RecyclerView and adds ability to hide some children. There are two sets of methods
+ * provided by this class. <b>Regular</b> methods are the ones that replicate ViewGroup methods
+ * like getChildAt, getChildCount etc. These methods ignore hidden children.
+ * <p>
+ * When RecyclerView needs direct access to the view group children, it can call unfiltered
+ * methods like get getUnfilteredChildCount or getUnfilteredChildAt.
+ */
+class ChildHelper {
+
+ private static final boolean DEBUG = false;
+
+ private static final String TAG = "ChildrenHelper";
+
+ final Callback mCallback;
+
+ final Bucket mBucket;
+
+ final List<View> mHiddenViews;
+
+ ChildHelper(Callback callback) {
+ mCallback = callback;
+ mBucket = new Bucket();
+ mHiddenViews = new ArrayList<View>();
+ }
+
+ /**
+ * Marks a child view as hidden
+ *
+ * @param child View to hide.
+ */
+ private void hideViewInternal(View child) {
+ mHiddenViews.add(child);
+ mCallback.onEnteredHiddenState(child);
+ }
+
+ /**
+ * Unmarks a child view as hidden.
+ *
+ * @param child View to hide.
+ */
+ private boolean unhideViewInternal(View child) {
+ if (mHiddenViews.remove(child)) {
+ mCallback.onLeftHiddenState(child);
+ return true;
+ } else {
+ return false;
+ }
+ }
+
+ /**
+ * Adds a view to the ViewGroup
+ *
+ * @param child View to add.
+ * @param hidden If set to true, this item will be invisible from regular methods.
+ */
+ void addView(View child, boolean hidden) {
+ addView(child, -1, hidden);
+ }
+
+ /**
+ * Add a view to the ViewGroup at an index
+ *
+ * @param child View to add.
+ * @param index Index of the child from the regular perspective (excluding hidden views).
+ * ChildHelper offsets this index to actual ViewGroup index.
+ * @param hidden If set to true, this item will be invisible from regular methods.
+ */
+ void addView(View child, int index, boolean hidden) {
+ final int offset;
+ if (index < 0) {
+ offset = mCallback.getChildCount();
+ } else {
+ offset = getOffset(index);
+ }
+ mBucket.insert(offset, hidden);
+ if (hidden) {
+ hideViewInternal(child);
+ }
+ mCallback.addView(child, offset);
+ if (DEBUG) {
+ Log.d(TAG, "addViewAt " + index + ",h:" + hidden + ", " + this);
+ }
+ }
+
+ private int getOffset(int index) {
+ if (index < 0) {
+ return -1; //anything below 0 won't work as diff will be undefined.
+ }
+ final int limit = mCallback.getChildCount();
+ int offset = index;
+ while (offset < limit) {
+ final int removedBefore = mBucket.countOnesBefore(offset);
+ final int diff = index - (offset - removedBefore);
+ if (diff == 0) {
+ while (mBucket.get(offset)) { // ensure this offset is not hidden
+ offset++;
+ }
+ return offset;
+ } else {
+ offset += diff;
+ }
+ }
+ return -1;
+ }
+
+ /**
+ * Removes the provided View from underlying RecyclerView.
+ *
+ * @param view The view to remove.
+ */
+ void removeView(View view) {
+ int index = mCallback.indexOfChild(view);
+ if (index < 0) {
+ return;
+ }
+ if (mBucket.remove(index)) {
+ unhideViewInternal(view);
+ }
+ mCallback.removeViewAt(index);
+ if (DEBUG) {
+ Log.d(TAG, "remove View off:" + index + "," + this);
+ }
+ }
+
+ /**
+ * Removes the view at the provided index from RecyclerView.
+ *
+ * @param index Index of the child from the regular perspective (excluding hidden views).
+ * ChildHelper offsets this index to actual ViewGroup index.
+ */
+ void removeViewAt(int index) {
+ final int offset = getOffset(index);
+ final View view = mCallback.getChildAt(offset);
+ if (view == null) {
+ return;
+ }
+ if (mBucket.remove(offset)) {
+ unhideViewInternal(view);
+ }
+ mCallback.removeViewAt(offset);
+ if (DEBUG) {
+ Log.d(TAG, "removeViewAt " + index + ", off:" + offset + ", " + this);
+ }
+ }
+
+ /**
+ * Returns the child at provided index.
+ *
+ * @param index Index of the child to return in regular perspective.
+ */
+ View getChildAt(int index) {
+ final int offset = getOffset(index);
+ return mCallback.getChildAt(offset);
+ }
+
+ /**
+ * Removes all views from the ViewGroup including the hidden ones.
+ */
+ void removeAllViewsUnfiltered() {
+ mBucket.reset();
+ for (int i = mHiddenViews.size() - 1; i >= 0; i--) {
+ mCallback.onLeftHiddenState(mHiddenViews.get(i));
+ mHiddenViews.remove(i);
+ }
+ mCallback.removeAllViews();
+ if (DEBUG) {
+ Log.d(TAG, "removeAllViewsUnfiltered");
+ }
+ }
+
+ /**
+ * This can be used to find a disappearing view by position.
+ *
+ * @param position The adapter position of the item.
+ * @return A hidden view with a valid ViewHolder that matches the position.
+ */
+ View findHiddenNonRemovedView(int position) {
+ final int count = mHiddenViews.size();
+ for (int i = 0; i < count; i++) {
+ final View view = mHiddenViews.get(i);
+ RecyclerView.ViewHolder holder = mCallback.getChildViewHolder(view);
+ if (holder.getLayoutPosition() == position
+ && !holder.isInvalid()
+ && !holder.isRemoved()) {
+ return view;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Attaches the provided view to the underlying ViewGroup.
+ *
+ * @param child Child to attach.
+ * @param index Index of the child to attach in regular perspective.
+ * @param layoutParams LayoutParams for the child.
+ * @param hidden If set to true, this item will be invisible to the regular methods.
+ */
+ void attachViewToParent(View child, int index, ViewGroup.LayoutParams layoutParams,
+ boolean hidden) {
+ final int offset;
+ if (index < 0) {
+ offset = mCallback.getChildCount();
+ } else {
+ offset = getOffset(index);
+ }
+ mBucket.insert(offset, hidden);
+ if (hidden) {
+ hideViewInternal(child);
+ }
+ mCallback.attachViewToParent(child, offset, layoutParams);
+ if (DEBUG) {
+ Log.d(TAG, "attach view to parent index:" + index + ",off:" + offset + ","
+ + "h:" + hidden + ", " + this);
+ }
+ }
+
+ /**
+ * Returns the number of children that are not hidden.
+ *
+ * @return Number of children that are not hidden.
+ * @see #getChildAt(int)
+ */
+ int getChildCount() {
+ return mCallback.getChildCount() - mHiddenViews.size();
+ }
+
+ /**
+ * Returns the total number of children.
+ *
+ * @return The total number of children including the hidden views.
+ * @see #getUnfilteredChildAt(int)
+ */
+ int getUnfilteredChildCount() {
+ return mCallback.getChildCount();
+ }
+
+ /**
+ * Returns a child by ViewGroup offset. ChildHelper won't offset this index.
+ *
+ * @param index ViewGroup index of the child to return.
+ * @return The view in the provided index.
+ */
+ View getUnfilteredChildAt(int index) {
+ return mCallback.getChildAt(index);
+ }
+
+ /**
+ * Detaches the view at the provided index.
+ *
+ * @param index Index of the child to return in regular perspective.
+ */
+ void detachViewFromParent(int index) {
+ final int offset = getOffset(index);
+ mBucket.remove(offset);
+ mCallback.detachViewFromParent(offset);
+ if (DEBUG) {
+ Log.d(TAG, "detach view from parent " + index + ", off:" + offset);
+ }
+ }
+
+ /**
+ * Returns the index of the child in regular perspective.
+ *
+ * @param child The child whose index will be returned.
+ * @return The regular perspective index of the child or -1 if it does not exists.
+ */
+ int indexOfChild(View child) {
+ final int index = mCallback.indexOfChild(child);
+ if (index == -1) {
+ return -1;
+ }
+ if (mBucket.get(index)) {
+ if (DEBUG) {
+ throw new IllegalArgumentException("cannot get index of a hidden child");
+ } else {
+ return -1;
+ }
+ }
+ // reverse the index
+ return index - mBucket.countOnesBefore(index);
+ }
+
+ /**
+ * Returns whether a View is visible to LayoutManager or not.
+ *
+ * @param view The child view to check. Should be a child of the Callback.
+ * @return True if the View is not visible to LayoutManager
+ */
+ boolean isHidden(View view) {
+ return mHiddenViews.contains(view);
+ }
+
+ /**
+ * Marks a child view as hidden.
+ *
+ * @param view The view to hide.
+ */
+ void hide(View view) {
+ final int offset = mCallback.indexOfChild(view);
+ if (offset < 0) {
+ throw new IllegalArgumentException("view is not a child, cannot hide " + view);
+ }
+ if (DEBUG && mBucket.get(offset)) {
+ throw new RuntimeException("trying to hide same view twice, how come ? " + view);
+ }
+ mBucket.set(offset);
+ hideViewInternal(view);
+ if (DEBUG) {
+ Log.d(TAG, "hiding child " + view + " at offset " + offset + ", " + this);
+ }
+ }
+
+ /**
+ * Moves a child view from hidden list to regular list.
+ * Calling this method should probably be followed by a detach, otherwise, it will suddenly
+ * show up in LayoutManager's children list.
+ *
+ * @param view The hidden View to unhide
+ */
+ void unhide(View view) {
+ final int offset = mCallback.indexOfChild(view);
+ if (offset < 0) {
+ throw new IllegalArgumentException("view is not a child, cannot hide " + view);
+ }
+ if (!mBucket.get(offset)) {
+ throw new RuntimeException("trying to unhide a view that was not hidden" + view);
+ }
+ mBucket.clear(offset);
+ unhideViewInternal(view);
+ }
+
+ @Override
+ public String toString() {
+ return mBucket.toString() + ", hidden list:" + mHiddenViews.size();
+ }
+
+ /**
+ * Removes a view from the ViewGroup if it is hidden.
+ *
+ * @param view The view to remove.
+ * @return True if the View is found and it is hidden. False otherwise.
+ */
+ boolean removeViewIfHidden(View view) {
+ final int index = mCallback.indexOfChild(view);
+ if (index == -1) {
+ if (unhideViewInternal(view) && DEBUG) {
+ throw new IllegalStateException("view is in hidden list but not in view group");
+ }
+ return true;
+ }
+ if (mBucket.get(index)) {
+ mBucket.remove(index);
+ if (!unhideViewInternal(view) && DEBUG) {
+ throw new IllegalStateException(
+ "removed a hidden view but it is not in hidden views list");
+ }
+ mCallback.removeViewAt(index);
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Bitset implementation that provides methods to offset indices.
+ */
+ static class Bucket {
+
+ static final int BITS_PER_WORD = Long.SIZE;
+
+ static final long LAST_BIT = 1L << (Long.SIZE - 1);
+
+ long mData = 0;
+
+ Bucket mNext;
+
+ void set(int index) {
+ if (index >= BITS_PER_WORD) {
+ ensureNext();
+ mNext.set(index - BITS_PER_WORD);
+ } else {
+ mData |= 1L << index;
+ }
+ }
+
+ private void ensureNext() {
+ if (mNext == null) {
+ mNext = new Bucket();
+ }
+ }
+
+ void clear(int index) {
+ if (index >= BITS_PER_WORD) {
+ if (mNext != null) {
+ mNext.clear(index - BITS_PER_WORD);
+ }
+ } else {
+ mData &= ~(1L << index);
+ }
+
+ }
+
+ boolean get(int index) {
+ if (index >= BITS_PER_WORD) {
+ ensureNext();
+ return mNext.get(index - BITS_PER_WORD);
+ } else {
+ return (mData & (1L << index)) != 0;
+ }
+ }
+
+ void reset() {
+ mData = 0;
+ if (mNext != null) {
+ mNext.reset();
+ }
+ }
+
+ void insert(int index, boolean value) {
+ if (index >= BITS_PER_WORD) {
+ ensureNext();
+ mNext.insert(index - BITS_PER_WORD, value);
+ } else {
+ final boolean lastBit = (mData & LAST_BIT) != 0;
+ long mask = (1L << index) - 1;
+ final long before = mData & mask;
+ final long after = ((mData & ~mask)) << 1;
+ mData = before | after;
+ if (value) {
+ set(index);
+ } else {
+ clear(index);
+ }
+ if (lastBit || mNext != null) {
+ ensureNext();
+ mNext.insert(0, lastBit);
+ }
+ }
+ }
+
+ boolean remove(int index) {
+ if (index >= BITS_PER_WORD) {
+ ensureNext();
+ return mNext.remove(index - BITS_PER_WORD);
+ } else {
+ long mask = (1L << index);
+ final boolean value = (mData & mask) != 0;
+ mData &= ~mask;
+ mask = mask - 1;
+ final long before = mData & mask;
+ // cannot use >> because it adds one.
+ final long after = Long.rotateRight(mData & ~mask, 1);
+ mData = before | after;
+ if (mNext != null) {
+ if (mNext.get(0)) {
+ set(BITS_PER_WORD - 1);
+ }
+ mNext.remove(0);
+ }
+ return value;
+ }
+ }
+
+ int countOnesBefore(int index) {
+ if (mNext == null) {
+ if (index >= BITS_PER_WORD) {
+ return Long.bitCount(mData);
+ }
+ return Long.bitCount(mData & ((1L << index) - 1));
+ }
+ if (index < BITS_PER_WORD) {
+ return Long.bitCount(mData & ((1L << index) - 1));
+ } else {
+ return mNext.countOnesBefore(index - BITS_PER_WORD) + Long.bitCount(mData);
+ }
+ }
+
+ @Override
+ public String toString() {
+ return mNext == null ? Long.toBinaryString(mData)
+ : mNext.toString() + "xx" + Long.toBinaryString(mData);
+ }
+ }
+
+ interface Callback {
+
+ int getChildCount();
+
+ void addView(View child, int index);
+
+ int indexOfChild(View view);
+
+ void removeViewAt(int index);
+
+ View getChildAt(int offset);
+
+ void removeAllViews();
+
+ RecyclerView.ViewHolder getChildViewHolder(View view);
+
+ void attachViewToParent(View child, int index, ViewGroup.LayoutParams layoutParams);
+
+ void detachViewFromParent(int offset);
+
+ void onEnteredHiddenState(View child);
+
+ void onLeftHiddenState(View child);
+ }
+}
+
diff --git a/core/java/com/android/internal/widget/DefaultItemAnimator.java b/core/java/com/android/internal/widget/DefaultItemAnimator.java
new file mode 100644
index 0000000..92345af
--- /dev/null
+++ b/core/java/com/android/internal/widget/DefaultItemAnimator.java
@@ -0,0 +1,668 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.TimeInterpolator;
+import android.animation.ValueAnimator;
+import android.annotation.NonNull;
+import android.view.View;
+import android.view.ViewPropertyAnimator;
+
+import com.android.internal.widget.RecyclerView.ViewHolder;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * This implementation of {@link RecyclerView.ItemAnimator} provides basic
+ * animations on remove, add, and move events that happen to the items in
+ * a RecyclerView. RecyclerView uses a DefaultItemAnimator by default.
+ *
+ * @see RecyclerView#setItemAnimator(RecyclerView.ItemAnimator)
+ */
+public class DefaultItemAnimator extends SimpleItemAnimator {
+ private static final boolean DEBUG = false;
+
+ private static TimeInterpolator sDefaultInterpolator;
+
+ private ArrayList<ViewHolder> mPendingRemovals = new ArrayList<>();
+ private ArrayList<ViewHolder> mPendingAdditions = new ArrayList<>();
+ private ArrayList<MoveInfo> mPendingMoves = new ArrayList<>();
+ private ArrayList<ChangeInfo> mPendingChanges = new ArrayList<>();
+
+ ArrayList<ArrayList<ViewHolder>> mAdditionsList = new ArrayList<>();
+ ArrayList<ArrayList<MoveInfo>> mMovesList = new ArrayList<>();
+ ArrayList<ArrayList<ChangeInfo>> mChangesList = new ArrayList<>();
+
+ ArrayList<ViewHolder> mAddAnimations = new ArrayList<>();
+ ArrayList<ViewHolder> mMoveAnimations = new ArrayList<>();
+ ArrayList<ViewHolder> mRemoveAnimations = new ArrayList<>();
+ ArrayList<ViewHolder> mChangeAnimations = new ArrayList<>();
+
+ private static class MoveInfo {
+ public ViewHolder holder;
+ public int fromX, fromY, toX, toY;
+
+ MoveInfo(ViewHolder holder, int fromX, int fromY, int toX, int toY) {
+ this.holder = holder;
+ this.fromX = fromX;
+ this.fromY = fromY;
+ this.toX = toX;
+ this.toY = toY;
+ }
+ }
+
+ private static class ChangeInfo {
+ public ViewHolder oldHolder, newHolder;
+ public int fromX, fromY, toX, toY;
+ private ChangeInfo(ViewHolder oldHolder, ViewHolder newHolder) {
+ this.oldHolder = oldHolder;
+ this.newHolder = newHolder;
+ }
+
+ ChangeInfo(ViewHolder oldHolder, ViewHolder newHolder,
+ int fromX, int fromY, int toX, int toY) {
+ this(oldHolder, newHolder);
+ this.fromX = fromX;
+ this.fromY = fromY;
+ this.toX = toX;
+ this.toY = toY;
+ }
+
+ @Override
+ public String toString() {
+ return "ChangeInfo{"
+ + "oldHolder=" + oldHolder
+ + ", newHolder=" + newHolder
+ + ", fromX=" + fromX
+ + ", fromY=" + fromY
+ + ", toX=" + toX
+ + ", toY=" + toY
+ + '}';
+ }
+ }
+
+ @Override
+ public void runPendingAnimations() {
+ boolean removalsPending = !mPendingRemovals.isEmpty();
+ boolean movesPending = !mPendingMoves.isEmpty();
+ boolean changesPending = !mPendingChanges.isEmpty();
+ boolean additionsPending = !mPendingAdditions.isEmpty();
+ if (!removalsPending && !movesPending && !additionsPending && !changesPending) {
+ // nothing to animate
+ return;
+ }
+ // First, remove stuff
+ for (ViewHolder holder : mPendingRemovals) {
+ animateRemoveImpl(holder);
+ }
+ mPendingRemovals.clear();
+ // Next, move stuff
+ if (movesPending) {
+ final ArrayList<MoveInfo> moves = new ArrayList<>();
+ moves.addAll(mPendingMoves);
+ mMovesList.add(moves);
+ mPendingMoves.clear();
+ Runnable mover = new Runnable() {
+ @Override
+ public void run() {
+ for (MoveInfo moveInfo : moves) {
+ animateMoveImpl(moveInfo.holder, moveInfo.fromX, moveInfo.fromY,
+ moveInfo.toX, moveInfo.toY);
+ }
+ moves.clear();
+ mMovesList.remove(moves);
+ }
+ };
+ if (removalsPending) {
+ View view = moves.get(0).holder.itemView;
+ view.postOnAnimationDelayed(mover, getRemoveDuration());
+ } else {
+ mover.run();
+ }
+ }
+ // Next, change stuff, to run in parallel with move animations
+ if (changesPending) {
+ final ArrayList<ChangeInfo> changes = new ArrayList<>();
+ changes.addAll(mPendingChanges);
+ mChangesList.add(changes);
+ mPendingChanges.clear();
+ Runnable changer = new Runnable() {
+ @Override
+ public void run() {
+ for (ChangeInfo change : changes) {
+ animateChangeImpl(change);
+ }
+ changes.clear();
+ mChangesList.remove(changes);
+ }
+ };
+ if (removalsPending) {
+ ViewHolder holder = changes.get(0).oldHolder;
+ holder.itemView.postOnAnimationDelayed(changer, getRemoveDuration());
+ } else {
+ changer.run();
+ }
+ }
+ // Next, add stuff
+ if (additionsPending) {
+ final ArrayList<ViewHolder> additions = new ArrayList<>();
+ additions.addAll(mPendingAdditions);
+ mAdditionsList.add(additions);
+ mPendingAdditions.clear();
+ Runnable adder = new Runnable() {
+ @Override
+ public void run() {
+ for (ViewHolder holder : additions) {
+ animateAddImpl(holder);
+ }
+ additions.clear();
+ mAdditionsList.remove(additions);
+ }
+ };
+ if (removalsPending || movesPending || changesPending) {
+ long removeDuration = removalsPending ? getRemoveDuration() : 0;
+ long moveDuration = movesPending ? getMoveDuration() : 0;
+ long changeDuration = changesPending ? getChangeDuration() : 0;
+ long totalDelay = removeDuration + Math.max(moveDuration, changeDuration);
+ View view = additions.get(0).itemView;
+ view.postOnAnimationDelayed(adder, totalDelay);
+ } else {
+ adder.run();
+ }
+ }
+ }
+
+ @Override
+ public boolean animateRemove(final ViewHolder holder) {
+ resetAnimation(holder);
+ mPendingRemovals.add(holder);
+ return true;
+ }
+
+ private void animateRemoveImpl(final ViewHolder holder) {
+ final View view = holder.itemView;
+ final ViewPropertyAnimator animation = view.animate();
+ mRemoveAnimations.add(holder);
+ animation.setDuration(getRemoveDuration()).alpha(0).setListener(
+ new AnimatorListenerAdapter() {
+ @Override
+ public void onAnimationStart(Animator animator) {
+ dispatchRemoveStarting(holder);
+ }
+
+ @Override
+ public void onAnimationEnd(Animator animator) {
+ animation.setListener(null);
+ view.setAlpha(1);
+ dispatchRemoveFinished(holder);
+ mRemoveAnimations.remove(holder);
+ dispatchFinishedWhenDone();
+ }
+ }).start();
+ }
+
+ @Override
+ public boolean animateAdd(final ViewHolder holder) {
+ resetAnimation(holder);
+ holder.itemView.setAlpha(0);
+ mPendingAdditions.add(holder);
+ return true;
+ }
+
+ void animateAddImpl(final ViewHolder holder) {
+ final View view = holder.itemView;
+ final ViewPropertyAnimator animation = view.animate();
+ mAddAnimations.add(holder);
+ animation.alpha(1).setDuration(getAddDuration())
+ .setListener(new AnimatorListenerAdapter() {
+ @Override
+ public void onAnimationStart(Animator animator) {
+ dispatchAddStarting(holder);
+ }
+
+ @Override
+ public void onAnimationCancel(Animator animator) {
+ view.setAlpha(1);
+ }
+
+ @Override
+ public void onAnimationEnd(Animator animator) {
+ animation.setListener(null);
+ dispatchAddFinished(holder);
+ mAddAnimations.remove(holder);
+ dispatchFinishedWhenDone();
+ }
+ }).start();
+ }
+
+ @Override
+ public boolean animateMove(final ViewHolder holder, int fromX, int fromY,
+ int toX, int toY) {
+ final View view = holder.itemView;
+ fromX += holder.itemView.getTranslationX();
+ fromY += holder.itemView.getTranslationY();
+ resetAnimation(holder);
+ int deltaX = toX - fromX;
+ int deltaY = toY - fromY;
+ if (deltaX == 0 && deltaY == 0) {
+ dispatchMoveFinished(holder);
+ return false;
+ }
+ if (deltaX != 0) {
+ view.setTranslationX(-deltaX);
+ }
+ if (deltaY != 0) {
+ view.setTranslationY(-deltaY);
+ }
+ mPendingMoves.add(new MoveInfo(holder, fromX, fromY, toX, toY));
+ return true;
+ }
+
+ void animateMoveImpl(final ViewHolder holder, int fromX, int fromY, int toX, int toY) {
+ final View view = holder.itemView;
+ final int deltaX = toX - fromX;
+ final int deltaY = toY - fromY;
+ if (deltaX != 0) {
+ view.animate().translationX(0);
+ }
+ if (deltaY != 0) {
+ view.animate().translationY(0);
+ }
+ // TODO: make EndActions end listeners instead, since end actions aren't called when
+ // vpas are canceled (and can't end them. why?)
+ // need listener functionality in VPACompat for this. Ick.
+ final ViewPropertyAnimator animation = view.animate();
+ mMoveAnimations.add(holder);
+ animation.setDuration(getMoveDuration()).setListener(new AnimatorListenerAdapter() {
+ @Override
+ public void onAnimationStart(Animator animator) {
+ dispatchMoveStarting(holder);
+ }
+
+ @Override
+ public void onAnimationCancel(Animator animator) {
+ if (deltaX != 0) {
+ view.setTranslationX(0);
+ }
+ if (deltaY != 0) {
+ view.setTranslationY(0);
+ }
+ }
+
+ @Override
+ public void onAnimationEnd(Animator animator) {
+ animation.setListener(null);
+ dispatchMoveFinished(holder);
+ mMoveAnimations.remove(holder);
+ dispatchFinishedWhenDone();
+ }
+ }).start();
+ }
+
+ @Override
+ public boolean animateChange(ViewHolder oldHolder, ViewHolder newHolder,
+ int fromX, int fromY, int toX, int toY) {
+ if (oldHolder == newHolder) {
+ // Don't know how to run change animations when the same view holder is re-used.
+ // run a move animation to handle position changes.
+ return animateMove(oldHolder, fromX, fromY, toX, toY);
+ }
+ final float prevTranslationX = oldHolder.itemView.getTranslationX();
+ final float prevTranslationY = oldHolder.itemView.getTranslationY();
+ final float prevAlpha = oldHolder.itemView.getAlpha();
+ resetAnimation(oldHolder);
+ int deltaX = (int) (toX - fromX - prevTranslationX);
+ int deltaY = (int) (toY - fromY - prevTranslationY);
+ // recover prev translation state after ending animation
+ oldHolder.itemView.setTranslationX(prevTranslationX);
+ oldHolder.itemView.setTranslationY(prevTranslationY);
+ oldHolder.itemView.setAlpha(prevAlpha);
+ if (newHolder != null) {
+ // carry over translation values
+ resetAnimation(newHolder);
+ newHolder.itemView.setTranslationX(-deltaX);
+ newHolder.itemView.setTranslationY(-deltaY);
+ newHolder.itemView.setAlpha(0);
+ }
+ mPendingChanges.add(new ChangeInfo(oldHolder, newHolder, fromX, fromY, toX, toY));
+ return true;
+ }
+
+ void animateChangeImpl(final ChangeInfo changeInfo) {
+ final ViewHolder holder = changeInfo.oldHolder;
+ final View view = holder == null ? null : holder.itemView;
+ final ViewHolder newHolder = changeInfo.newHolder;
+ final View newView = newHolder != null ? newHolder.itemView : null;
+ if (view != null) {
+ final ViewPropertyAnimator oldViewAnim = view.animate().setDuration(
+ getChangeDuration());
+ mChangeAnimations.add(changeInfo.oldHolder);
+ oldViewAnim.translationX(changeInfo.toX - changeInfo.fromX);
+ oldViewAnim.translationY(changeInfo.toY - changeInfo.fromY);
+ oldViewAnim.alpha(0).setListener(new AnimatorListenerAdapter() {
+ @Override
+ public void onAnimationStart(Animator animator) {
+ dispatchChangeStarting(changeInfo.oldHolder, true);
+ }
+
+ @Override
+ public void onAnimationEnd(Animator animator) {
+ oldViewAnim.setListener(null);
+ view.setAlpha(1);
+ view.setTranslationX(0);
+ view.setTranslationY(0);
+ dispatchChangeFinished(changeInfo.oldHolder, true);
+ mChangeAnimations.remove(changeInfo.oldHolder);
+ dispatchFinishedWhenDone();
+ }
+ }).start();
+ }
+ if (newView != null) {
+ final ViewPropertyAnimator newViewAnimation = newView.animate();
+ mChangeAnimations.add(changeInfo.newHolder);
+ newViewAnimation.translationX(0).translationY(0).setDuration(getChangeDuration())
+ .alpha(1).setListener(new AnimatorListenerAdapter() {
+ @Override
+ public void onAnimationStart(Animator animator) {
+ dispatchChangeStarting(changeInfo.newHolder, false);
+ }
+ @Override
+ public void onAnimationEnd(Animator animator) {
+ newViewAnimation.setListener(null);
+ newView.setAlpha(1);
+ newView.setTranslationX(0);
+ newView.setTranslationY(0);
+ dispatchChangeFinished(changeInfo.newHolder, false);
+ mChangeAnimations.remove(changeInfo.newHolder);
+ dispatchFinishedWhenDone();
+ }
+ }).start();
+ }
+ }
+
+ private void endChangeAnimation(List<ChangeInfo> infoList, ViewHolder item) {
+ for (int i = infoList.size() - 1; i >= 0; i--) {
+ ChangeInfo changeInfo = infoList.get(i);
+ if (endChangeAnimationIfNecessary(changeInfo, item)) {
+ if (changeInfo.oldHolder == null && changeInfo.newHolder == null) {
+ infoList.remove(changeInfo);
+ }
+ }
+ }
+ }
+
+ private void endChangeAnimationIfNecessary(ChangeInfo changeInfo) {
+ if (changeInfo.oldHolder != null) {
+ endChangeAnimationIfNecessary(changeInfo, changeInfo.oldHolder);
+ }
+ if (changeInfo.newHolder != null) {
+ endChangeAnimationIfNecessary(changeInfo, changeInfo.newHolder);
+ }
+ }
+ private boolean endChangeAnimationIfNecessary(ChangeInfo changeInfo, ViewHolder item) {
+ boolean oldItem = false;
+ if (changeInfo.newHolder == item) {
+ changeInfo.newHolder = null;
+ } else if (changeInfo.oldHolder == item) {
+ changeInfo.oldHolder = null;
+ oldItem = true;
+ } else {
+ return false;
+ }
+ item.itemView.setAlpha(1);
+ item.itemView.setTranslationX(0);
+ item.itemView.setTranslationY(0);
+ dispatchChangeFinished(item, oldItem);
+ return true;
+ }
+
+ @Override
+ public void endAnimation(ViewHolder item) {
+ final View view = item.itemView;
+ // this will trigger end callback which should set properties to their target values.
+ view.animate().cancel();
+ // TODO if some other animations are chained to end, how do we cancel them as well?
+ for (int i = mPendingMoves.size() - 1; i >= 0; i--) {
+ MoveInfo moveInfo = mPendingMoves.get(i);
+ if (moveInfo.holder == item) {
+ view.setTranslationY(0);
+ view.setTranslationX(0);
+ dispatchMoveFinished(item);
+ mPendingMoves.remove(i);
+ }
+ }
+ endChangeAnimation(mPendingChanges, item);
+ if (mPendingRemovals.remove(item)) {
+ view.setAlpha(1);
+ dispatchRemoveFinished(item);
+ }
+ if (mPendingAdditions.remove(item)) {
+ view.setAlpha(1);
+ dispatchAddFinished(item);
+ }
+
+ for (int i = mChangesList.size() - 1; i >= 0; i--) {
+ ArrayList<ChangeInfo> changes = mChangesList.get(i);
+ endChangeAnimation(changes, item);
+ if (changes.isEmpty()) {
+ mChangesList.remove(i);
+ }
+ }
+ for (int i = mMovesList.size() - 1; i >= 0; i--) {
+ ArrayList<MoveInfo> moves = mMovesList.get(i);
+ for (int j = moves.size() - 1; j >= 0; j--) {
+ MoveInfo moveInfo = moves.get(j);
+ if (moveInfo.holder == item) {
+ view.setTranslationY(0);
+ view.setTranslationX(0);
+ dispatchMoveFinished(item);
+ moves.remove(j);
+ if (moves.isEmpty()) {
+ mMovesList.remove(i);
+ }
+ break;
+ }
+ }
+ }
+ for (int i = mAdditionsList.size() - 1; i >= 0; i--) {
+ ArrayList<ViewHolder> additions = mAdditionsList.get(i);
+ if (additions.remove(item)) {
+ view.setAlpha(1);
+ dispatchAddFinished(item);
+ if (additions.isEmpty()) {
+ mAdditionsList.remove(i);
+ }
+ }
+ }
+
+ // animations should be ended by the cancel above.
+ //noinspection PointlessBooleanExpression,ConstantConditions
+ if (mRemoveAnimations.remove(item) && DEBUG) {
+ throw new IllegalStateException("after animation is cancelled, item should not be in "
+ + "mRemoveAnimations list");
+ }
+
+ //noinspection PointlessBooleanExpression,ConstantConditions
+ if (mAddAnimations.remove(item) && DEBUG) {
+ throw new IllegalStateException("after animation is cancelled, item should not be in "
+ + "mAddAnimations list");
+ }
+
+ //noinspection PointlessBooleanExpression,ConstantConditions
+ if (mChangeAnimations.remove(item) && DEBUG) {
+ throw new IllegalStateException("after animation is cancelled, item should not be in "
+ + "mChangeAnimations list");
+ }
+
+ //noinspection PointlessBooleanExpression,ConstantConditions
+ if (mMoveAnimations.remove(item) && DEBUG) {
+ throw new IllegalStateException("after animation is cancelled, item should not be in "
+ + "mMoveAnimations list");
+ }
+ dispatchFinishedWhenDone();
+ }
+
+ private void resetAnimation(ViewHolder holder) {
+ if (sDefaultInterpolator == null) {
+ sDefaultInterpolator = new ValueAnimator().getInterpolator();
+ }
+ holder.itemView.animate().setInterpolator(sDefaultInterpolator);
+ endAnimation(holder);
+ }
+
+ @Override
+ public boolean isRunning() {
+ return (!mPendingAdditions.isEmpty()
+ || !mPendingChanges.isEmpty()
+ || !mPendingMoves.isEmpty()
+ || !mPendingRemovals.isEmpty()
+ || !mMoveAnimations.isEmpty()
+ || !mRemoveAnimations.isEmpty()
+ || !mAddAnimations.isEmpty()
+ || !mChangeAnimations.isEmpty()
+ || !mMovesList.isEmpty()
+ || !mAdditionsList.isEmpty()
+ || !mChangesList.isEmpty());
+ }
+
+ /**
+ * Check the state of currently pending and running animations. If there are none
+ * pending/running, call {@link #dispatchAnimationsFinished()} to notify any
+ * listeners.
+ */
+ void dispatchFinishedWhenDone() {
+ if (!isRunning()) {
+ dispatchAnimationsFinished();
+ }
+ }
+
+ @Override
+ public void endAnimations() {
+ int count = mPendingMoves.size();
+ for (int i = count - 1; i >= 0; i--) {
+ MoveInfo item = mPendingMoves.get(i);
+ View view = item.holder.itemView;
+ view.setTranslationY(0);
+ view.setTranslationX(0);
+ dispatchMoveFinished(item.holder);
+ mPendingMoves.remove(i);
+ }
+ count = mPendingRemovals.size();
+ for (int i = count - 1; i >= 0; i--) {
+ ViewHolder item = mPendingRemovals.get(i);
+ dispatchRemoveFinished(item);
+ mPendingRemovals.remove(i);
+ }
+ count = mPendingAdditions.size();
+ for (int i = count - 1; i >= 0; i--) {
+ ViewHolder item = mPendingAdditions.get(i);
+ item.itemView.setAlpha(1);
+ dispatchAddFinished(item);
+ mPendingAdditions.remove(i);
+ }
+ count = mPendingChanges.size();
+ for (int i = count - 1; i >= 0; i--) {
+ endChangeAnimationIfNecessary(mPendingChanges.get(i));
+ }
+ mPendingChanges.clear();
+ if (!isRunning()) {
+ return;
+ }
+
+ int listCount = mMovesList.size();
+ for (int i = listCount - 1; i >= 0; i--) {
+ ArrayList<MoveInfo> moves = mMovesList.get(i);
+ count = moves.size();
+ for (int j = count - 1; j >= 0; j--) {
+ MoveInfo moveInfo = moves.get(j);
+ ViewHolder item = moveInfo.holder;
+ View view = item.itemView;
+ view.setTranslationY(0);
+ view.setTranslationX(0);
+ dispatchMoveFinished(moveInfo.holder);
+ moves.remove(j);
+ if (moves.isEmpty()) {
+ mMovesList.remove(moves);
+ }
+ }
+ }
+ listCount = mAdditionsList.size();
+ for (int i = listCount - 1; i >= 0; i--) {
+ ArrayList<ViewHolder> additions = mAdditionsList.get(i);
+ count = additions.size();
+ for (int j = count - 1; j >= 0; j--) {
+ ViewHolder item = additions.get(j);
+ View view = item.itemView;
+ view.setAlpha(1);
+ dispatchAddFinished(item);
+ additions.remove(j);
+ if (additions.isEmpty()) {
+ mAdditionsList.remove(additions);
+ }
+ }
+ }
+ listCount = mChangesList.size();
+ for (int i = listCount - 1; i >= 0; i--) {
+ ArrayList<ChangeInfo> changes = mChangesList.get(i);
+ count = changes.size();
+ for (int j = count - 1; j >= 0; j--) {
+ endChangeAnimationIfNecessary(changes.get(j));
+ if (changes.isEmpty()) {
+ mChangesList.remove(changes);
+ }
+ }
+ }
+
+ cancelAll(mRemoveAnimations);
+ cancelAll(mMoveAnimations);
+ cancelAll(mAddAnimations);
+ cancelAll(mChangeAnimations);
+
+ dispatchAnimationsFinished();
+ }
+
+ void cancelAll(List<ViewHolder> viewHolders) {
+ for (int i = viewHolders.size() - 1; i >= 0; i--) {
+ viewHolders.get(i).itemView.animate().cancel();
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ * <p>
+ * If the payload list is not empty, DefaultItemAnimator returns <code>true</code>.
+ * When this is the case:
+ * <ul>
+ * <li>If you override {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)}, both
+ * ViewHolder arguments will be the same instance.
+ * </li>
+ * <li>
+ * If you are not overriding {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)},
+ * then DefaultItemAnimator will call {@link #animateMove(ViewHolder, int, int, int, int)} and
+ * run a move animation instead.
+ * </li>
+ * </ul>
+ */
+ @Override
+ public boolean canReuseUpdatedViewHolder(@NonNull ViewHolder viewHolder,
+ @NonNull List<Object> payloads) {
+ return !payloads.isEmpty() || super.canReuseUpdatedViewHolder(viewHolder, payloads);
+ }
+}
diff --git a/core/java/com/android/internal/widget/GapWorker.java b/core/java/com/android/internal/widget/GapWorker.java
new file mode 100644
index 0000000..5972396
--- /dev/null
+++ b/core/java/com/android/internal/widget/GapWorker.java
@@ -0,0 +1,379 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.annotation.Nullable;
+import android.os.Trace;
+import android.view.View;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.concurrent.TimeUnit;
+
+final class GapWorker implements Runnable {
+
+ static final ThreadLocal<GapWorker> sGapWorker = new ThreadLocal<>();
+
+ ArrayList<RecyclerView> mRecyclerViews = new ArrayList<>();
+ long mPostTimeNs;
+ long mFrameIntervalNs;
+
+ static class Task {
+ public boolean immediate;
+ public int viewVelocity;
+ public int distanceToItem;
+ public RecyclerView view;
+ public int position;
+
+ public void clear() {
+ immediate = false;
+ viewVelocity = 0;
+ distanceToItem = 0;
+ view = null;
+ position = 0;
+ }
+ }
+
+ /**
+ * Temporary storage for prefetch Tasks that execute in {@link #prefetch(long)}. Task objects
+ * are pooled in the ArrayList, and never removed to avoid allocations, but always cleared
+ * in between calls.
+ */
+ private ArrayList<Task> mTasks = new ArrayList<>();
+
+ /**
+ * Prefetch information associated with a specific RecyclerView.
+ */
+ static class LayoutPrefetchRegistryImpl
+ implements RecyclerView.LayoutManager.LayoutPrefetchRegistry {
+ int mPrefetchDx;
+ int mPrefetchDy;
+ int[] mPrefetchArray;
+
+ int mCount;
+
+ void setPrefetchVector(int dx, int dy) {
+ mPrefetchDx = dx;
+ mPrefetchDy = dy;
+ }
+
+ void collectPrefetchPositionsFromView(RecyclerView view, boolean nested) {
+ mCount = 0;
+ if (mPrefetchArray != null) {
+ Arrays.fill(mPrefetchArray, -1);
+ }
+
+ final RecyclerView.LayoutManager layout = view.mLayout;
+ if (view.mAdapter != null
+ && layout != null
+ && layout.isItemPrefetchEnabled()) {
+ if (nested) {
+ // nested prefetch, only if no adapter updates pending. Note: we don't query
+ // view.hasPendingAdapterUpdates(), as first layout may not have occurred
+ if (!view.mAdapterHelper.hasPendingUpdates()) {
+ layout.collectInitialPrefetchPositions(view.mAdapter.getItemCount(), this);
+ }
+ } else {
+ // momentum based prefetch, only if we trust current child/adapter state
+ if (!view.hasPendingAdapterUpdates()) {
+ layout.collectAdjacentPrefetchPositions(mPrefetchDx, mPrefetchDy,
+ view.mState, this);
+ }
+ }
+
+ if (mCount > layout.mPrefetchMaxCountObserved) {
+ layout.mPrefetchMaxCountObserved = mCount;
+ layout.mPrefetchMaxObservedInInitialPrefetch = nested;
+ view.mRecycler.updateViewCacheSize();
+ }
+ }
+ }
+
+ @Override
+ public void addPosition(int layoutPosition, int pixelDistance) {
+ if (pixelDistance < 0) {
+ throw new IllegalArgumentException("Pixel distance must be non-negative");
+ }
+
+ // allocate or expand array as needed, doubling when needed
+ final int storagePosition = mCount * 2;
+ if (mPrefetchArray == null) {
+ mPrefetchArray = new int[4];
+ Arrays.fill(mPrefetchArray, -1);
+ } else if (storagePosition >= mPrefetchArray.length) {
+ final int[] oldArray = mPrefetchArray;
+ mPrefetchArray = new int[storagePosition * 2];
+ System.arraycopy(oldArray, 0, mPrefetchArray, 0, oldArray.length);
+ }
+
+ // add position
+ mPrefetchArray[storagePosition] = layoutPosition;
+ mPrefetchArray[storagePosition + 1] = pixelDistance;
+
+ mCount++;
+ }
+
+ boolean lastPrefetchIncludedPosition(int position) {
+ if (mPrefetchArray != null) {
+ final int count = mCount * 2;
+ for (int i = 0; i < count; i += 2) {
+ if (mPrefetchArray[i] == position) return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Called when prefetch indices are no longer valid for cache prioritization.
+ */
+ void clearPrefetchPositions() {
+ if (mPrefetchArray != null) {
+ Arrays.fill(mPrefetchArray, -1);
+ }
+ }
+ }
+
+ public void add(RecyclerView recyclerView) {
+ if (RecyclerView.DEBUG && mRecyclerViews.contains(recyclerView)) {
+ throw new IllegalStateException("RecyclerView already present in worker list!");
+ }
+ mRecyclerViews.add(recyclerView);
+ }
+
+ public void remove(RecyclerView recyclerView) {
+ boolean removeSuccess = mRecyclerViews.remove(recyclerView);
+ if (RecyclerView.DEBUG && !removeSuccess) {
+ throw new IllegalStateException("RecyclerView removal failed!");
+ }
+ }
+
+ /**
+ * Schedule a prefetch immediately after the current traversal.
+ */
+ void postFromTraversal(RecyclerView recyclerView, int prefetchDx, int prefetchDy) {
+ if (recyclerView.isAttachedToWindow()) {
+ if (RecyclerView.DEBUG && !mRecyclerViews.contains(recyclerView)) {
+ throw new IllegalStateException("attempting to post unregistered view!");
+ }
+ if (mPostTimeNs == 0) {
+ mPostTimeNs = recyclerView.getNanoTime();
+ recyclerView.post(this);
+ }
+ }
+
+ recyclerView.mPrefetchRegistry.setPrefetchVector(prefetchDx, prefetchDy);
+ }
+
+ static Comparator<Task> sTaskComparator = new Comparator<Task>() {
+ @Override
+ public int compare(Task lhs, Task rhs) {
+ // first, prioritize non-cleared tasks
+ if ((lhs.view == null) != (rhs.view == null)) {
+ return lhs.view == null ? 1 : -1;
+ }
+
+ // then prioritize immediate
+ if (lhs.immediate != rhs.immediate) {
+ return lhs.immediate ? -1 : 1;
+ }
+
+ // then prioritize _highest_ view velocity
+ int deltaViewVelocity = rhs.viewVelocity - lhs.viewVelocity;
+ if (deltaViewVelocity != 0) return deltaViewVelocity;
+
+ // then prioritize _lowest_ distance to item
+ int deltaDistanceToItem = lhs.distanceToItem - rhs.distanceToItem;
+ if (deltaDistanceToItem != 0) return deltaDistanceToItem;
+
+ return 0;
+ }
+ };
+
+ private void buildTaskList() {
+ // Update PrefetchRegistry in each view
+ final int viewCount = mRecyclerViews.size();
+ int totalTaskCount = 0;
+ for (int i = 0; i < viewCount; i++) {
+ RecyclerView view = mRecyclerViews.get(i);
+ view.mPrefetchRegistry.collectPrefetchPositionsFromView(view, false);
+ totalTaskCount += view.mPrefetchRegistry.mCount;
+ }
+
+ // Populate task list from prefetch data...
+ mTasks.ensureCapacity(totalTaskCount);
+ int totalTaskIndex = 0;
+ for (int i = 0; i < viewCount; i++) {
+ RecyclerView view = mRecyclerViews.get(i);
+ LayoutPrefetchRegistryImpl prefetchRegistry = view.mPrefetchRegistry;
+ final int viewVelocity = Math.abs(prefetchRegistry.mPrefetchDx)
+ + Math.abs(prefetchRegistry.mPrefetchDy);
+ for (int j = 0; j < prefetchRegistry.mCount * 2; j += 2) {
+ final Task task;
+ if (totalTaskIndex >= mTasks.size()) {
+ task = new Task();
+ mTasks.add(task);
+ } else {
+ task = mTasks.get(totalTaskIndex);
+ }
+ final int distanceToItem = prefetchRegistry.mPrefetchArray[j + 1];
+
+ task.immediate = distanceToItem <= viewVelocity;
+ task.viewVelocity = viewVelocity;
+ task.distanceToItem = distanceToItem;
+ task.view = view;
+ task.position = prefetchRegistry.mPrefetchArray[j];
+
+ totalTaskIndex++;
+ }
+ }
+
+ // ... and priority sort
+ Collections.sort(mTasks, sTaskComparator);
+ }
+
+ static boolean isPrefetchPositionAttached(RecyclerView view, int position) {
+ final int childCount = view.mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ View attachedView = view.mChildHelper.getUnfilteredChildAt(i);
+ RecyclerView.ViewHolder holder = RecyclerView.getChildViewHolderInt(attachedView);
+ // Note: can use mPosition here because adapter doesn't have pending updates
+ if (holder.mPosition == position && !holder.isInvalid()) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ private RecyclerView.ViewHolder prefetchPositionWithDeadline(RecyclerView view,
+ int position, long deadlineNs) {
+ if (isPrefetchPositionAttached(view, position)) {
+ // don't attempt to prefetch attached views
+ return null;
+ }
+
+ RecyclerView.Recycler recycler = view.mRecycler;
+ RecyclerView.ViewHolder holder = recycler.tryGetViewHolderForPositionByDeadline(
+ position, false, deadlineNs);
+
+ if (holder != null) {
+ if (holder.isBound()) {
+ // Only give the view a chance to go into the cache if binding succeeded
+ // Note that we must use public method, since item may need cleanup
+ recycler.recycleView(holder.itemView);
+ } else {
+ // Didn't bind, so we can't cache the view, but it will stay in the pool until
+ // next prefetch/traversal. If a View fails to bind, it means we didn't have
+ // enough time prior to the deadline (and won't for other instances of this
+ // type, during this GapWorker prefetch pass).
+ recycler.addViewHolderToRecycledViewPool(holder, false);
+ }
+ }
+ return holder;
+ }
+
+ private void prefetchInnerRecyclerViewWithDeadline(@Nullable RecyclerView innerView,
+ long deadlineNs) {
+ if (innerView == null) {
+ return;
+ }
+
+ if (innerView.mDataSetHasChangedAfterLayout
+ && innerView.mChildHelper.getUnfilteredChildCount() != 0) {
+ // RecyclerView has new data, but old attached views. Clear everything, so that
+ // we can prefetch without partially stale data.
+ innerView.removeAndRecycleViews();
+ }
+
+ // do nested prefetch!
+ final LayoutPrefetchRegistryImpl innerPrefetchRegistry = innerView.mPrefetchRegistry;
+ innerPrefetchRegistry.collectPrefetchPositionsFromView(innerView, true);
+
+ if (innerPrefetchRegistry.mCount != 0) {
+ try {
+ Trace.beginSection(RecyclerView.TRACE_NESTED_PREFETCH_TAG);
+ innerView.mState.prepareForNestedPrefetch(innerView.mAdapter);
+ for (int i = 0; i < innerPrefetchRegistry.mCount * 2; i += 2) {
+ // Note that we ignore immediate flag for inner items because
+ // we have lower confidence they're needed next frame.
+ final int innerPosition = innerPrefetchRegistry.mPrefetchArray[i];
+ prefetchPositionWithDeadline(innerView, innerPosition, deadlineNs);
+ }
+ } finally {
+ Trace.endSection();
+ }
+ }
+ }
+
+ private void flushTaskWithDeadline(Task task, long deadlineNs) {
+ long taskDeadlineNs = task.immediate ? RecyclerView.FOREVER_NS : deadlineNs;
+ RecyclerView.ViewHolder holder = prefetchPositionWithDeadline(task.view,
+ task.position, taskDeadlineNs);
+ if (holder != null && holder.mNestedRecyclerView != null) {
+ prefetchInnerRecyclerViewWithDeadline(holder.mNestedRecyclerView.get(), deadlineNs);
+ }
+ }
+
+ private void flushTasksWithDeadline(long deadlineNs) {
+ for (int i = 0; i < mTasks.size(); i++) {
+ final Task task = mTasks.get(i);
+ if (task.view == null) {
+ break; // done with populated tasks
+ }
+ flushTaskWithDeadline(task, deadlineNs);
+ task.clear();
+ }
+ }
+
+ void prefetch(long deadlineNs) {
+ buildTaskList();
+ flushTasksWithDeadline(deadlineNs);
+ }
+
+ @Override
+ public void run() {
+ try {
+ Trace.beginSection(RecyclerView.TRACE_PREFETCH_TAG);
+
+ if (mRecyclerViews.isEmpty()) {
+ // abort - no work to do
+ return;
+ }
+
+ // Query last vsync so we can predict next one. Note that drawing time not yet
+ // valid in animation/input callbacks, so query it here to be safe.
+ long lastFrameVsyncNs = TimeUnit.MILLISECONDS.toNanos(
+ mRecyclerViews.get(0).getDrawingTime());
+ if (lastFrameVsyncNs == 0) {
+ // abort - couldn't get last vsync for estimating next
+ return;
+ }
+
+ // TODO: consider rebasing deadline if frame was already dropped due to long UI work.
+ // Next frame will still wait for VSYNC, so we can still use the gap if it exists.
+ long nextFrameNs = lastFrameVsyncNs + mFrameIntervalNs;
+
+ prefetch(nextFrameNs);
+
+ // TODO: consider rescheduling self, if there's more work to do
+ } finally {
+ mPostTimeNs = 0;
+ Trace.endSection();
+ }
+ }
+}
diff --git a/core/java/com/android/internal/widget/LinearLayoutManager.java b/core/java/com/android/internal/widget/LinearLayoutManager.java
new file mode 100644
index 0000000..d82c746
--- /dev/null
+++ b/core/java/com/android/internal/widget/LinearLayoutManager.java
@@ -0,0 +1,2398 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import static com.android.internal.widget.RecyclerView.NO_POSITION;
+
+import android.content.Context;
+import android.graphics.PointF;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.accessibility.AccessibilityEvent;
+
+import com.android.internal.widget.RecyclerView.LayoutParams;
+import com.android.internal.widget.helper.ItemTouchHelper;
+
+import java.util.List;
+
+/**
+ * A {@link com.android.internal.widget.RecyclerView.LayoutManager} implementation which provides
+ * similar functionality to {@link android.widget.ListView}.
+ */
+public class LinearLayoutManager extends RecyclerView.LayoutManager implements
+ ItemTouchHelper.ViewDropHandler, RecyclerView.SmoothScroller.ScrollVectorProvider {
+
+ private static final String TAG = "LinearLayoutManager";
+
+ static final boolean DEBUG = false;
+
+ public static final int HORIZONTAL = OrientationHelper.HORIZONTAL;
+
+ public static final int VERTICAL = OrientationHelper.VERTICAL;
+
+ public static final int INVALID_OFFSET = Integer.MIN_VALUE;
+
+
+ /**
+ * While trying to find next view to focus, LayoutManager will not try to scroll more
+ * than this factor times the total space of the list. If layout is vertical, total space is the
+ * height minus padding, if layout is horizontal, total space is the width minus padding.
+ */
+ private static final float MAX_SCROLL_FACTOR = 1 / 3f;
+
+
+ /**
+ * Current orientation. Either {@link #HORIZONTAL} or {@link #VERTICAL}
+ */
+ int mOrientation;
+
+ /**
+ * Helper class that keeps temporary layout state.
+ * It does not keep state after layout is complete but we still keep a reference to re-use
+ * the same object.
+ */
+ private LayoutState mLayoutState;
+
+ /**
+ * Many calculations are made depending on orientation. To keep it clean, this interface
+ * helps {@link LinearLayoutManager} make those decisions.
+ * Based on {@link #mOrientation}, an implementation is lazily created in
+ * {@link #ensureLayoutState} method.
+ */
+ OrientationHelper mOrientationHelper;
+
+ /**
+ * We need to track this so that we can ignore current position when it changes.
+ */
+ private boolean mLastStackFromEnd;
+
+
+ /**
+ * Defines if layout should be calculated from end to start.
+ *
+ * @see #mShouldReverseLayout
+ */
+ private boolean mReverseLayout = false;
+
+ /**
+ * This keeps the final value for how LayoutManager should start laying out views.
+ * It is calculated by checking {@link #getReverseLayout()} and View's layout direction.
+ * {@link #onLayoutChildren(RecyclerView.Recycler, RecyclerView.State)} is run.
+ */
+ boolean mShouldReverseLayout = false;
+
+ /**
+ * Works the same way as {@link android.widget.AbsListView#setStackFromBottom(boolean)} and
+ * it supports both orientations.
+ * see {@link android.widget.AbsListView#setStackFromBottom(boolean)}
+ */
+ private boolean mStackFromEnd = false;
+
+ /**
+ * Works the same way as {@link android.widget.AbsListView#setSmoothScrollbarEnabled(boolean)}.
+ * see {@link android.widget.AbsListView#setSmoothScrollbarEnabled(boolean)}
+ */
+ private boolean mSmoothScrollbarEnabled = true;
+
+ /**
+ * When LayoutManager needs to scroll to a position, it sets this variable and requests a
+ * layout which will check this variable and re-layout accordingly.
+ */
+ int mPendingScrollPosition = NO_POSITION;
+
+ /**
+ * Used to keep the offset value when {@link #scrollToPositionWithOffset(int, int)} is
+ * called.
+ */
+ int mPendingScrollPositionOffset = INVALID_OFFSET;
+
+ private boolean mRecycleChildrenOnDetach;
+
+ SavedState mPendingSavedState = null;
+
+ /**
+ * Re-used variable to keep anchor information on re-layout.
+ * Anchor position and coordinate defines the reference point for LLM while doing a layout.
+ * */
+ final AnchorInfo mAnchorInfo = new AnchorInfo();
+
+ /**
+ * Stashed to avoid allocation, currently only used in #fill()
+ */
+ private final LayoutChunkResult mLayoutChunkResult = new LayoutChunkResult();
+
+ /**
+ * Number of items to prefetch when first coming on screen with new data.
+ */
+ private int mInitialItemPrefetchCount = 2;
+
+ /**
+ * Creates a vertical LinearLayoutManager
+ *
+ * @param context Current context, will be used to access resources.
+ */
+ public LinearLayoutManager(Context context) {
+ this(context, VERTICAL, false);
+ }
+
+ /**
+ * @param context Current context, will be used to access resources.
+ * @param orientation Layout orientation. Should be {@link #HORIZONTAL} or {@link
+ * #VERTICAL}.
+ * @param reverseLayout When set to true, layouts from end to start.
+ */
+ public LinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
+ setOrientation(orientation);
+ setReverseLayout(reverseLayout);
+ setAutoMeasureEnabled(true);
+ }
+
+ /**
+ * Constructor used when layout manager is set in XML by RecyclerView attribute
+ * "layoutManager". Defaults to vertical orientation.
+ *
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_android_orientation
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_reverseLayout
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_stackFromEnd
+ */
+ public LinearLayoutManager(Context context, AttributeSet attrs, int defStyleAttr,
+ int defStyleRes) {
+ Properties properties = getProperties(context, attrs, defStyleAttr, defStyleRes);
+ setOrientation(properties.orientation);
+ setReverseLayout(properties.reverseLayout);
+ setStackFromEnd(properties.stackFromEnd);
+ setAutoMeasureEnabled(true);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public LayoutParams generateDefaultLayoutParams() {
+ return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
+ ViewGroup.LayoutParams.WRAP_CONTENT);
+ }
+
+ /**
+ * Returns whether LayoutManager will recycle its children when it is detached from
+ * RecyclerView.
+ *
+ * @return true if LayoutManager will recycle its children when it is detached from
+ * RecyclerView.
+ */
+ public boolean getRecycleChildrenOnDetach() {
+ return mRecycleChildrenOnDetach;
+ }
+
+ /**
+ * Set whether LayoutManager will recycle its children when it is detached from
+ * RecyclerView.
+ * <p>
+ * If you are using a {@link RecyclerView.RecycledViewPool}, it might be a good idea to set
+ * this flag to <code>true</code> so that views will be available to other RecyclerViews
+ * immediately.
+ * <p>
+ * Note that, setting this flag will result in a performance drop if RecyclerView
+ * is restored.
+ *
+ * @param recycleChildrenOnDetach Whether children should be recycled in detach or not.
+ */
+ public void setRecycleChildrenOnDetach(boolean recycleChildrenOnDetach) {
+ mRecycleChildrenOnDetach = recycleChildrenOnDetach;
+ }
+
+ @Override
+ public void onDetachedFromWindow(RecyclerView view, RecyclerView.Recycler recycler) {
+ super.onDetachedFromWindow(view, recycler);
+ if (mRecycleChildrenOnDetach) {
+ removeAndRecycleAllViews(recycler);
+ recycler.clear();
+ }
+ }
+
+ @Override
+ public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
+ super.onInitializeAccessibilityEvent(event);
+ if (getChildCount() > 0) {
+ event.setFromIndex(findFirstVisibleItemPosition());
+ event.setToIndex(findLastVisibleItemPosition());
+ }
+ }
+
+ @Override
+ public Parcelable onSaveInstanceState() {
+ if (mPendingSavedState != null) {
+ return new SavedState(mPendingSavedState);
+ }
+ SavedState state = new SavedState();
+ if (getChildCount() > 0) {
+ ensureLayoutState();
+ boolean didLayoutFromEnd = mLastStackFromEnd ^ mShouldReverseLayout;
+ state.mAnchorLayoutFromEnd = didLayoutFromEnd;
+ if (didLayoutFromEnd) {
+ final View refChild = getChildClosestToEnd();
+ state.mAnchorOffset = mOrientationHelper.getEndAfterPadding()
+ - mOrientationHelper.getDecoratedEnd(refChild);
+ state.mAnchorPosition = getPosition(refChild);
+ } else {
+ final View refChild = getChildClosestToStart();
+ state.mAnchorPosition = getPosition(refChild);
+ state.mAnchorOffset = mOrientationHelper.getDecoratedStart(refChild)
+ - mOrientationHelper.getStartAfterPadding();
+ }
+ } else {
+ state.invalidateAnchor();
+ }
+ return state;
+ }
+
+ @Override
+ public void onRestoreInstanceState(Parcelable state) {
+ if (state instanceof SavedState) {
+ mPendingSavedState = (SavedState) state;
+ requestLayout();
+ if (DEBUG) {
+ Log.d(TAG, "loaded saved state");
+ }
+ } else if (DEBUG) {
+ Log.d(TAG, "invalid saved state class");
+ }
+ }
+
+ /**
+ * @return true if {@link #getOrientation()} is {@link #HORIZONTAL}
+ */
+ @Override
+ public boolean canScrollHorizontally() {
+ return mOrientation == HORIZONTAL;
+ }
+
+ /**
+ * @return true if {@link #getOrientation()} is {@link #VERTICAL}
+ */
+ @Override
+ public boolean canScrollVertically() {
+ return mOrientation == VERTICAL;
+ }
+
+ /**
+ * Compatibility support for {@link android.widget.AbsListView#setStackFromBottom(boolean)}
+ */
+ public void setStackFromEnd(boolean stackFromEnd) {
+ assertNotInLayoutOrScroll(null);
+ if (mStackFromEnd == stackFromEnd) {
+ return;
+ }
+ mStackFromEnd = stackFromEnd;
+ requestLayout();
+ }
+
+ public boolean getStackFromEnd() {
+ return mStackFromEnd;
+ }
+
+ /**
+ * Returns the current orientation of the layout.
+ *
+ * @return Current orientation, either {@link #HORIZONTAL} or {@link #VERTICAL}
+ * @see #setOrientation(int)
+ */
+ public int getOrientation() {
+ return mOrientation;
+ }
+
+ /**
+ * Sets the orientation of the layout. {@link com.android.internal.widget.LinearLayoutManager}
+ * will do its best to keep scroll position.
+ *
+ * @param orientation {@link #HORIZONTAL} or {@link #VERTICAL}
+ */
+ public void setOrientation(int orientation) {
+ if (orientation != HORIZONTAL && orientation != VERTICAL) {
+ throw new IllegalArgumentException("invalid orientation:" + orientation);
+ }
+ assertNotInLayoutOrScroll(null);
+ if (orientation == mOrientation) {
+ return;
+ }
+ mOrientation = orientation;
+ mOrientationHelper = null;
+ requestLayout();
+ }
+
+ /**
+ * Calculates the view layout order. (e.g. from end to start or start to end)
+ * RTL layout support is applied automatically. So if layout is RTL and
+ * {@link #getReverseLayout()} is {@code true}, elements will be laid out starting from left.
+ */
+ private void resolveShouldLayoutReverse() {
+ // A == B is the same result, but we rather keep it readable
+ if (mOrientation == VERTICAL || !isLayoutRTL()) {
+ mShouldReverseLayout = mReverseLayout;
+ } else {
+ mShouldReverseLayout = !mReverseLayout;
+ }
+ }
+
+ /**
+ * Returns if views are laid out from the opposite direction of the layout.
+ *
+ * @return If layout is reversed or not.
+ * @see #setReverseLayout(boolean)
+ */
+ public boolean getReverseLayout() {
+ return mReverseLayout;
+ }
+
+ /**
+ * Used to reverse item traversal and layout order.
+ * This behaves similar to the layout change for RTL views. When set to true, first item is
+ * laid out at the end of the UI, second item is laid out before it etc.
+ *
+ * For horizontal layouts, it depends on the layout direction.
+ * When set to true, If {@link com.android.internal.widget.RecyclerView} is LTR, than it will
+ * layout from RTL, if {@link com.android.internal.widget.RecyclerView}} is RTL, it will layout
+ * from LTR.
+ *
+ * If you are looking for the exact same behavior of
+ * {@link android.widget.AbsListView#setStackFromBottom(boolean)}, use
+ * {@link #setStackFromEnd(boolean)}
+ */
+ public void setReverseLayout(boolean reverseLayout) {
+ assertNotInLayoutOrScroll(null);
+ if (reverseLayout == mReverseLayout) {
+ return;
+ }
+ mReverseLayout = reverseLayout;
+ requestLayout();
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public View findViewByPosition(int position) {
+ final int childCount = getChildCount();
+ if (childCount == 0) {
+ return null;
+ }
+ final int firstChild = getPosition(getChildAt(0));
+ final int viewPosition = position - firstChild;
+ if (viewPosition >= 0 && viewPosition < childCount) {
+ final View child = getChildAt(viewPosition);
+ if (getPosition(child) == position) {
+ return child; // in pre-layout, this may not match
+ }
+ }
+ // fallback to traversal. This might be necessary in pre-layout.
+ return super.findViewByPosition(position);
+ }
+
+ /**
+ * <p>Returns the amount of extra space that should be laid out by LayoutManager.</p>
+ *
+ * <p>By default, {@link com.android.internal.widget.LinearLayoutManager} lays out 1 extra page
+ * of items while smooth scrolling and 0 otherwise. You can override this method to implement
+ * your custom layout pre-cache logic.</p>
+ *
+ * <p><strong>Note:</strong>Laying out invisible elements generally comes with significant
+ * performance cost. It's typically only desirable in places like smooth scrolling to an unknown
+ * location, where 1) the extra content helps LinearLayoutManager know in advance when its
+ * target is approaching, so it can decelerate early and smoothly and 2) while motion is
+ * continuous.</p>
+ *
+ * <p>Extending the extra layout space is especially expensive if done while the user may change
+ * scrolling direction. Changing direction will cause the extra layout space to swap to the
+ * opposite side of the viewport, incurring many rebinds/recycles, unless the cache is large
+ * enough to handle it.</p>
+ *
+ * @return The extra space that should be laid out (in pixels).
+ */
+ protected int getExtraLayoutSpace(RecyclerView.State state) {
+ if (state.hasTargetScrollPosition()) {
+ return mOrientationHelper.getTotalSpace();
+ } else {
+ return 0;
+ }
+ }
+
+ @Override
+ public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state,
+ int position) {
+ LinearSmoothScroller linearSmoothScroller =
+ new LinearSmoothScroller(recyclerView.getContext());
+ linearSmoothScroller.setTargetPosition(position);
+ startSmoothScroll(linearSmoothScroller);
+ }
+
+ @Override
+ public PointF computeScrollVectorForPosition(int targetPosition) {
+ if (getChildCount() == 0) {
+ return null;
+ }
+ final int firstChildPos = getPosition(getChildAt(0));
+ final int direction = targetPosition < firstChildPos != mShouldReverseLayout ? -1 : 1;
+ if (mOrientation == HORIZONTAL) {
+ return new PointF(direction, 0);
+ } else {
+ return new PointF(0, direction);
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
+ // layout algorithm:
+ // 1) by checking children and other variables, find an anchor coordinate and an anchor
+ // item position.
+ // 2) fill towards start, stacking from bottom
+ // 3) fill towards end, stacking from top
+ // 4) scroll to fulfill requirements like stack from bottom.
+ // create layout state
+ if (DEBUG) {
+ Log.d(TAG, "is pre layout:" + state.isPreLayout());
+ }
+ if (mPendingSavedState != null || mPendingScrollPosition != NO_POSITION) {
+ if (state.getItemCount() == 0) {
+ removeAndRecycleAllViews(recycler);
+ return;
+ }
+ }
+ if (mPendingSavedState != null && mPendingSavedState.hasValidAnchor()) {
+ mPendingScrollPosition = mPendingSavedState.mAnchorPosition;
+ }
+
+ ensureLayoutState();
+ mLayoutState.mRecycle = false;
+ // resolve layout direction
+ resolveShouldLayoutReverse();
+
+ if (!mAnchorInfo.mValid || mPendingScrollPosition != NO_POSITION
+ || mPendingSavedState != null) {
+ mAnchorInfo.reset();
+ mAnchorInfo.mLayoutFromEnd = mShouldReverseLayout ^ mStackFromEnd;
+ // calculate anchor position and coordinate
+ updateAnchorInfoForLayout(recycler, state, mAnchorInfo);
+ mAnchorInfo.mValid = true;
+ }
+ if (DEBUG) {
+ Log.d(TAG, "Anchor info:" + mAnchorInfo);
+ }
+
+ // LLM may decide to layout items for "extra" pixels to account for scrolling target,
+ // caching or predictive animations.
+ int extraForStart;
+ int extraForEnd;
+ final int extra = getExtraLayoutSpace(state);
+ // If the previous scroll delta was less than zero, the extra space should be laid out
+ // at the start. Otherwise, it should be at the end.
+ if (mLayoutState.mLastScrollDelta >= 0) {
+ extraForEnd = extra;
+ extraForStart = 0;
+ } else {
+ extraForStart = extra;
+ extraForEnd = 0;
+ }
+ extraForStart += mOrientationHelper.getStartAfterPadding();
+ extraForEnd += mOrientationHelper.getEndPadding();
+ if (state.isPreLayout() && mPendingScrollPosition != NO_POSITION
+ && mPendingScrollPositionOffset != INVALID_OFFSET) {
+ // if the child is visible and we are going to move it around, we should layout
+ // extra items in the opposite direction to make sure new items animate nicely
+ // instead of just fading in
+ final View existing = findViewByPosition(mPendingScrollPosition);
+ if (existing != null) {
+ final int current;
+ final int upcomingOffset;
+ if (mShouldReverseLayout) {
+ current = mOrientationHelper.getEndAfterPadding()
+ - mOrientationHelper.getDecoratedEnd(existing);
+ upcomingOffset = current - mPendingScrollPositionOffset;
+ } else {
+ current = mOrientationHelper.getDecoratedStart(existing)
+ - mOrientationHelper.getStartAfterPadding();
+ upcomingOffset = mPendingScrollPositionOffset - current;
+ }
+ if (upcomingOffset > 0) {
+ extraForStart += upcomingOffset;
+ } else {
+ extraForEnd -= upcomingOffset;
+ }
+ }
+ }
+ int startOffset;
+ int endOffset;
+ final int firstLayoutDirection;
+ if (mAnchorInfo.mLayoutFromEnd) {
+ firstLayoutDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_TAIL
+ : LayoutState.ITEM_DIRECTION_HEAD;
+ } else {
+ firstLayoutDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_HEAD
+ : LayoutState.ITEM_DIRECTION_TAIL;
+ }
+
+ onAnchorReady(recycler, state, mAnchorInfo, firstLayoutDirection);
+ detachAndScrapAttachedViews(recycler);
+ mLayoutState.mInfinite = resolveIsInfinite();
+ mLayoutState.mIsPreLayout = state.isPreLayout();
+ if (mAnchorInfo.mLayoutFromEnd) {
+ // fill towards start
+ updateLayoutStateToFillStart(mAnchorInfo);
+ mLayoutState.mExtra = extraForStart;
+ fill(recycler, mLayoutState, state, false);
+ startOffset = mLayoutState.mOffset;
+ final int firstElement = mLayoutState.mCurrentPosition;
+ if (mLayoutState.mAvailable > 0) {
+ extraForEnd += mLayoutState.mAvailable;
+ }
+ // fill towards end
+ updateLayoutStateToFillEnd(mAnchorInfo);
+ mLayoutState.mExtra = extraForEnd;
+ mLayoutState.mCurrentPosition += mLayoutState.mItemDirection;
+ fill(recycler, mLayoutState, state, false);
+ endOffset = mLayoutState.mOffset;
+
+ if (mLayoutState.mAvailable > 0) {
+ // end could not consume all. add more items towards start
+ extraForStart = mLayoutState.mAvailable;
+ updateLayoutStateToFillStart(firstElement, startOffset);
+ mLayoutState.mExtra = extraForStart;
+ fill(recycler, mLayoutState, state, false);
+ startOffset = mLayoutState.mOffset;
+ }
+ } else {
+ // fill towards end
+ updateLayoutStateToFillEnd(mAnchorInfo);
+ mLayoutState.mExtra = extraForEnd;
+ fill(recycler, mLayoutState, state, false);
+ endOffset = mLayoutState.mOffset;
+ final int lastElement = mLayoutState.mCurrentPosition;
+ if (mLayoutState.mAvailable > 0) {
+ extraForStart += mLayoutState.mAvailable;
+ }
+ // fill towards start
+ updateLayoutStateToFillStart(mAnchorInfo);
+ mLayoutState.mExtra = extraForStart;
+ mLayoutState.mCurrentPosition += mLayoutState.mItemDirection;
+ fill(recycler, mLayoutState, state, false);
+ startOffset = mLayoutState.mOffset;
+
+ if (mLayoutState.mAvailable > 0) {
+ extraForEnd = mLayoutState.mAvailable;
+ // start could not consume all it should. add more items towards end
+ updateLayoutStateToFillEnd(lastElement, endOffset);
+ mLayoutState.mExtra = extraForEnd;
+ fill(recycler, mLayoutState, state, false);
+ endOffset = mLayoutState.mOffset;
+ }
+ }
+
+ // changes may cause gaps on the UI, try to fix them.
+ // TODO we can probably avoid this if neither stackFromEnd/reverseLayout/RTL values have
+ // changed
+ if (getChildCount() > 0) {
+ // because layout from end may be changed by scroll to position
+ // we re-calculate it.
+ // find which side we should check for gaps.
+ if (mShouldReverseLayout ^ mStackFromEnd) {
+ int fixOffset = fixLayoutEndGap(endOffset, recycler, state, true);
+ startOffset += fixOffset;
+ endOffset += fixOffset;
+ fixOffset = fixLayoutStartGap(startOffset, recycler, state, false);
+ startOffset += fixOffset;
+ endOffset += fixOffset;
+ } else {
+ int fixOffset = fixLayoutStartGap(startOffset, recycler, state, true);
+ startOffset += fixOffset;
+ endOffset += fixOffset;
+ fixOffset = fixLayoutEndGap(endOffset, recycler, state, false);
+ startOffset += fixOffset;
+ endOffset += fixOffset;
+ }
+ }
+ layoutForPredictiveAnimations(recycler, state, startOffset, endOffset);
+ if (!state.isPreLayout()) {
+ mOrientationHelper.onLayoutComplete();
+ } else {
+ mAnchorInfo.reset();
+ }
+ mLastStackFromEnd = mStackFromEnd;
+ if (DEBUG) {
+ validateChildOrder();
+ }
+ }
+
+ @Override
+ public void onLayoutCompleted(RecyclerView.State state) {
+ super.onLayoutCompleted(state);
+ mPendingSavedState = null; // we don't need this anymore
+ mPendingScrollPosition = NO_POSITION;
+ mPendingScrollPositionOffset = INVALID_OFFSET;
+ mAnchorInfo.reset();
+ }
+
+ /**
+ * Method called when Anchor position is decided. Extending class can setup accordingly or
+ * even update anchor info if necessary.
+ * @param recycler The recycler for the layout
+ * @param state The layout state
+ * @param anchorInfo The mutable POJO that keeps the position and offset.
+ * @param firstLayoutItemDirection The direction of the first layout filling in terms of adapter
+ * indices.
+ */
+ void onAnchorReady(RecyclerView.Recycler recycler, RecyclerView.State state,
+ AnchorInfo anchorInfo, int firstLayoutItemDirection) {
+ }
+
+ /**
+ * If necessary, layouts new items for predictive animations
+ */
+ private void layoutForPredictiveAnimations(RecyclerView.Recycler recycler,
+ RecyclerView.State state, int startOffset, int endOffset) {
+ // If there are scrap children that we did not layout, we need to find where they did go
+ // and layout them accordingly so that animations can work as expected.
+ // This case may happen if new views are added or an existing view expands and pushes
+ // another view out of bounds.
+ if (!state.willRunPredictiveAnimations() || getChildCount() == 0 || state.isPreLayout()
+ || !supportsPredictiveItemAnimations()) {
+ return;
+ }
+ // to make the logic simpler, we calculate the size of children and call fill.
+ int scrapExtraStart = 0, scrapExtraEnd = 0;
+ final List<RecyclerView.ViewHolder> scrapList = recycler.getScrapList();
+ final int scrapSize = scrapList.size();
+ final int firstChildPos = getPosition(getChildAt(0));
+ for (int i = 0; i < scrapSize; i++) {
+ RecyclerView.ViewHolder scrap = scrapList.get(i);
+ if (scrap.isRemoved()) {
+ continue;
+ }
+ final int position = scrap.getLayoutPosition();
+ final int direction = position < firstChildPos != mShouldReverseLayout
+ ? LayoutState.LAYOUT_START : LayoutState.LAYOUT_END;
+ if (direction == LayoutState.LAYOUT_START) {
+ scrapExtraStart += mOrientationHelper.getDecoratedMeasurement(scrap.itemView);
+ } else {
+ scrapExtraEnd += mOrientationHelper.getDecoratedMeasurement(scrap.itemView);
+ }
+ }
+
+ if (DEBUG) {
+ Log.d(TAG, "for unused scrap, decided to add " + scrapExtraStart
+ + " towards start and " + scrapExtraEnd + " towards end");
+ }
+ mLayoutState.mScrapList = scrapList;
+ if (scrapExtraStart > 0) {
+ View anchor = getChildClosestToStart();
+ updateLayoutStateToFillStart(getPosition(anchor), startOffset);
+ mLayoutState.mExtra = scrapExtraStart;
+ mLayoutState.mAvailable = 0;
+ mLayoutState.assignPositionFromScrapList();
+ fill(recycler, mLayoutState, state, false);
+ }
+
+ if (scrapExtraEnd > 0) {
+ View anchor = getChildClosestToEnd();
+ updateLayoutStateToFillEnd(getPosition(anchor), endOffset);
+ mLayoutState.mExtra = scrapExtraEnd;
+ mLayoutState.mAvailable = 0;
+ mLayoutState.assignPositionFromScrapList();
+ fill(recycler, mLayoutState, state, false);
+ }
+ mLayoutState.mScrapList = null;
+ }
+
+ private void updateAnchorInfoForLayout(RecyclerView.Recycler recycler, RecyclerView.State state,
+ AnchorInfo anchorInfo) {
+ if (updateAnchorFromPendingData(state, anchorInfo)) {
+ if (DEBUG) {
+ Log.d(TAG, "updated anchor info from pending information");
+ }
+ return;
+ }
+
+ if (updateAnchorFromChildren(recycler, state, anchorInfo)) {
+ if (DEBUG) {
+ Log.d(TAG, "updated anchor info from existing children");
+ }
+ return;
+ }
+ if (DEBUG) {
+ Log.d(TAG, "deciding anchor info for fresh state");
+ }
+ anchorInfo.assignCoordinateFromPadding();
+ anchorInfo.mPosition = mStackFromEnd ? state.getItemCount() - 1 : 0;
+ }
+
+ /**
+ * Finds an anchor child from existing Views. Most of the time, this is the view closest to
+ * start or end that has a valid position (e.g. not removed).
+ * <p>
+ * If a child has focus, it is given priority.
+ */
+ private boolean updateAnchorFromChildren(RecyclerView.Recycler recycler,
+ RecyclerView.State state, AnchorInfo anchorInfo) {
+ if (getChildCount() == 0) {
+ return false;
+ }
+ final View focused = getFocusedChild();
+ if (focused != null && anchorInfo.isViewValidAsAnchor(focused, state)) {
+ anchorInfo.assignFromViewAndKeepVisibleRect(focused);
+ return true;
+ }
+ if (mLastStackFromEnd != mStackFromEnd) {
+ return false;
+ }
+ View referenceChild = anchorInfo.mLayoutFromEnd
+ ? findReferenceChildClosestToEnd(recycler, state)
+ : findReferenceChildClosestToStart(recycler, state);
+ if (referenceChild != null) {
+ anchorInfo.assignFromView(referenceChild);
+ // If all visible views are removed in 1 pass, reference child might be out of bounds.
+ // If that is the case, offset it back to 0 so that we use these pre-layout children.
+ if (!state.isPreLayout() && supportsPredictiveItemAnimations()) {
+ // validate this child is at least partially visible. if not, offset it to start
+ final boolean notVisible =
+ mOrientationHelper.getDecoratedStart(referenceChild) >= mOrientationHelper
+ .getEndAfterPadding()
+ || mOrientationHelper.getDecoratedEnd(referenceChild)
+ < mOrientationHelper.getStartAfterPadding();
+ if (notVisible) {
+ anchorInfo.mCoordinate = anchorInfo.mLayoutFromEnd
+ ? mOrientationHelper.getEndAfterPadding()
+ : mOrientationHelper.getStartAfterPadding();
+ }
+ }
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * If there is a pending scroll position or saved states, updates the anchor info from that
+ * data and returns true
+ */
+ private boolean updateAnchorFromPendingData(RecyclerView.State state, AnchorInfo anchorInfo) {
+ if (state.isPreLayout() || mPendingScrollPosition == NO_POSITION) {
+ return false;
+ }
+ // validate scroll position
+ if (mPendingScrollPosition < 0 || mPendingScrollPosition >= state.getItemCount()) {
+ mPendingScrollPosition = NO_POSITION;
+ mPendingScrollPositionOffset = INVALID_OFFSET;
+ if (DEBUG) {
+ Log.e(TAG, "ignoring invalid scroll position " + mPendingScrollPosition);
+ }
+ return false;
+ }
+
+ // if child is visible, try to make it a reference child and ensure it is fully visible.
+ // if child is not visible, align it depending on its virtual position.
+ anchorInfo.mPosition = mPendingScrollPosition;
+ if (mPendingSavedState != null && mPendingSavedState.hasValidAnchor()) {
+ // Anchor offset depends on how that child was laid out. Here, we update it
+ // according to our current view bounds
+ anchorInfo.mLayoutFromEnd = mPendingSavedState.mAnchorLayoutFromEnd;
+ if (anchorInfo.mLayoutFromEnd) {
+ anchorInfo.mCoordinate = mOrientationHelper.getEndAfterPadding()
+ - mPendingSavedState.mAnchorOffset;
+ } else {
+ anchorInfo.mCoordinate = mOrientationHelper.getStartAfterPadding()
+ + mPendingSavedState.mAnchorOffset;
+ }
+ return true;
+ }
+
+ if (mPendingScrollPositionOffset == INVALID_OFFSET) {
+ View child = findViewByPosition(mPendingScrollPosition);
+ if (child != null) {
+ final int childSize = mOrientationHelper.getDecoratedMeasurement(child);
+ if (childSize > mOrientationHelper.getTotalSpace()) {
+ // item does not fit. fix depending on layout direction
+ anchorInfo.assignCoordinateFromPadding();
+ return true;
+ }
+ final int startGap = mOrientationHelper.getDecoratedStart(child)
+ - mOrientationHelper.getStartAfterPadding();
+ if (startGap < 0) {
+ anchorInfo.mCoordinate = mOrientationHelper.getStartAfterPadding();
+ anchorInfo.mLayoutFromEnd = false;
+ return true;
+ }
+ final int endGap = mOrientationHelper.getEndAfterPadding()
+ - mOrientationHelper.getDecoratedEnd(child);
+ if (endGap < 0) {
+ anchorInfo.mCoordinate = mOrientationHelper.getEndAfterPadding();
+ anchorInfo.mLayoutFromEnd = true;
+ return true;
+ }
+ anchorInfo.mCoordinate = anchorInfo.mLayoutFromEnd
+ ? (mOrientationHelper.getDecoratedEnd(child) + mOrientationHelper
+ .getTotalSpaceChange())
+ : mOrientationHelper.getDecoratedStart(child);
+ } else { // item is not visible.
+ if (getChildCount() > 0) {
+ // get position of any child, does not matter
+ int pos = getPosition(getChildAt(0));
+ anchorInfo.mLayoutFromEnd = mPendingScrollPosition < pos
+ == mShouldReverseLayout;
+ }
+ anchorInfo.assignCoordinateFromPadding();
+ }
+ return true;
+ }
+ // override layout from end values for consistency
+ anchorInfo.mLayoutFromEnd = mShouldReverseLayout;
+ // if this changes, we should update prepareForDrop as well
+ if (mShouldReverseLayout) {
+ anchorInfo.mCoordinate = mOrientationHelper.getEndAfterPadding()
+ - mPendingScrollPositionOffset;
+ } else {
+ anchorInfo.mCoordinate = mOrientationHelper.getStartAfterPadding()
+ + mPendingScrollPositionOffset;
+ }
+ return true;
+ }
+
+ /**
+ * @return The final offset amount for children
+ */
+ private int fixLayoutEndGap(int endOffset, RecyclerView.Recycler recycler,
+ RecyclerView.State state, boolean canOffsetChildren) {
+ int gap = mOrientationHelper.getEndAfterPadding() - endOffset;
+ int fixOffset = 0;
+ if (gap > 0) {
+ fixOffset = -scrollBy(-gap, recycler, state);
+ } else {
+ return 0; // nothing to fix
+ }
+ // move offset according to scroll amount
+ endOffset += fixOffset;
+ if (canOffsetChildren) {
+ // re-calculate gap, see if we could fix it
+ gap = mOrientationHelper.getEndAfterPadding() - endOffset;
+ if (gap > 0) {
+ mOrientationHelper.offsetChildren(gap);
+ return gap + fixOffset;
+ }
+ }
+ return fixOffset;
+ }
+
+ /**
+ * @return The final offset amount for children
+ */
+ private int fixLayoutStartGap(int startOffset, RecyclerView.Recycler recycler,
+ RecyclerView.State state, boolean canOffsetChildren) {
+ int gap = startOffset - mOrientationHelper.getStartAfterPadding();
+ int fixOffset = 0;
+ if (gap > 0) {
+ // check if we should fix this gap.
+ fixOffset = -scrollBy(gap, recycler, state);
+ } else {
+ return 0; // nothing to fix
+ }
+ startOffset += fixOffset;
+ if (canOffsetChildren) {
+ // re-calculate gap, see if we could fix it
+ gap = startOffset - mOrientationHelper.getStartAfterPadding();
+ if (gap > 0) {
+ mOrientationHelper.offsetChildren(-gap);
+ return fixOffset - gap;
+ }
+ }
+ return fixOffset;
+ }
+
+ private void updateLayoutStateToFillEnd(AnchorInfo anchorInfo) {
+ updateLayoutStateToFillEnd(anchorInfo.mPosition, anchorInfo.mCoordinate);
+ }
+
+ private void updateLayoutStateToFillEnd(int itemPosition, int offset) {
+ mLayoutState.mAvailable = mOrientationHelper.getEndAfterPadding() - offset;
+ mLayoutState.mItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_HEAD :
+ LayoutState.ITEM_DIRECTION_TAIL;
+ mLayoutState.mCurrentPosition = itemPosition;
+ mLayoutState.mLayoutDirection = LayoutState.LAYOUT_END;
+ mLayoutState.mOffset = offset;
+ mLayoutState.mScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
+ }
+
+ private void updateLayoutStateToFillStart(AnchorInfo anchorInfo) {
+ updateLayoutStateToFillStart(anchorInfo.mPosition, anchorInfo.mCoordinate);
+ }
+
+ private void updateLayoutStateToFillStart(int itemPosition, int offset) {
+ mLayoutState.mAvailable = offset - mOrientationHelper.getStartAfterPadding();
+ mLayoutState.mCurrentPosition = itemPosition;
+ mLayoutState.mItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_TAIL :
+ LayoutState.ITEM_DIRECTION_HEAD;
+ mLayoutState.mLayoutDirection = LayoutState.LAYOUT_START;
+ mLayoutState.mOffset = offset;
+ mLayoutState.mScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
+
+ }
+
+ protected boolean isLayoutRTL() {
+ return getLayoutDirection() == View.LAYOUT_DIRECTION_RTL;
+ }
+
+ void ensureLayoutState() {
+ if (mLayoutState == null) {
+ mLayoutState = createLayoutState();
+ }
+ if (mOrientationHelper == null) {
+ mOrientationHelper = OrientationHelper.createOrientationHelper(this, mOrientation);
+ }
+ }
+
+ /**
+ * Test overrides this to plug some tracking and verification.
+ *
+ * @return A new LayoutState
+ */
+ LayoutState createLayoutState() {
+ return new LayoutState();
+ }
+
+ /**
+ * <p>Scroll the RecyclerView to make the position visible.</p>
+ *
+ * <p>RecyclerView will scroll the minimum amount that is necessary to make the
+ * target position visible. If you are looking for a similar behavior to
+ * {@link android.widget.ListView#setSelection(int)} or
+ * {@link android.widget.ListView#setSelectionFromTop(int, int)}, use
+ * {@link #scrollToPositionWithOffset(int, int)}.</p>
+ *
+ * <p>Note that scroll position change will not be reflected until the next layout call.</p>
+ *
+ * @param position Scroll to this adapter position
+ * @see #scrollToPositionWithOffset(int, int)
+ */
+ @Override
+ public void scrollToPosition(int position) {
+ mPendingScrollPosition = position;
+ mPendingScrollPositionOffset = INVALID_OFFSET;
+ if (mPendingSavedState != null) {
+ mPendingSavedState.invalidateAnchor();
+ }
+ requestLayout();
+ }
+
+ /**
+ * Scroll to the specified adapter position with the given offset from resolved layout
+ * start. Resolved layout start depends on {@link #getReverseLayout()},
+ * {@link View#getLayoutDirection()} and {@link #getStackFromEnd()}.
+ * <p>
+ * For example, if layout is {@link #VERTICAL} and {@link #getStackFromEnd()} is true, calling
+ * <code>scrollToPositionWithOffset(10, 20)</code> will layout such that
+ * <code>item[10]</code>'s bottom is 20 pixels above the RecyclerView's bottom.
+ * <p>
+ * Note that scroll position change will not be reflected until the next layout call.
+ * <p>
+ * If you are just trying to make a position visible, use {@link #scrollToPosition(int)}.
+ *
+ * @param position Index (starting at 0) of the reference item.
+ * @param offset The distance (in pixels) between the start edge of the item view and
+ * start edge of the RecyclerView.
+ * @see #setReverseLayout(boolean)
+ * @see #scrollToPosition(int)
+ */
+ public void scrollToPositionWithOffset(int position, int offset) {
+ mPendingScrollPosition = position;
+ mPendingScrollPositionOffset = offset;
+ if (mPendingSavedState != null) {
+ mPendingSavedState.invalidateAnchor();
+ }
+ requestLayout();
+ }
+
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public int scrollHorizontallyBy(int dx, RecyclerView.Recycler recycler,
+ RecyclerView.State state) {
+ if (mOrientation == VERTICAL) {
+ return 0;
+ }
+ return scrollBy(dx, recycler, state);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler,
+ RecyclerView.State state) {
+ if (mOrientation == HORIZONTAL) {
+ return 0;
+ }
+ return scrollBy(dy, recycler, state);
+ }
+
+ @Override
+ public int computeHorizontalScrollOffset(RecyclerView.State state) {
+ return computeScrollOffset(state);
+ }
+
+ @Override
+ public int computeVerticalScrollOffset(RecyclerView.State state) {
+ return computeScrollOffset(state);
+ }
+
+ @Override
+ public int computeHorizontalScrollExtent(RecyclerView.State state) {
+ return computeScrollExtent(state);
+ }
+
+ @Override
+ public int computeVerticalScrollExtent(RecyclerView.State state) {
+ return computeScrollExtent(state);
+ }
+
+ @Override
+ public int computeHorizontalScrollRange(RecyclerView.State state) {
+ return computeScrollRange(state);
+ }
+
+ @Override
+ public int computeVerticalScrollRange(RecyclerView.State state) {
+ return computeScrollRange(state);
+ }
+
+ private int computeScrollOffset(RecyclerView.State state) {
+ if (getChildCount() == 0) {
+ return 0;
+ }
+ ensureLayoutState();
+ return ScrollbarHelper.computeScrollOffset(state, mOrientationHelper,
+ findFirstVisibleChildClosestToStart(!mSmoothScrollbarEnabled, true),
+ findFirstVisibleChildClosestToEnd(!mSmoothScrollbarEnabled, true),
+ this, mSmoothScrollbarEnabled, mShouldReverseLayout);
+ }
+
+ private int computeScrollExtent(RecyclerView.State state) {
+ if (getChildCount() == 0) {
+ return 0;
+ }
+ ensureLayoutState();
+ return ScrollbarHelper.computeScrollExtent(state, mOrientationHelper,
+ findFirstVisibleChildClosestToStart(!mSmoothScrollbarEnabled, true),
+ findFirstVisibleChildClosestToEnd(!mSmoothScrollbarEnabled, true),
+ this, mSmoothScrollbarEnabled);
+ }
+
+ private int computeScrollRange(RecyclerView.State state) {
+ if (getChildCount() == 0) {
+ return 0;
+ }
+ ensureLayoutState();
+ return ScrollbarHelper.computeScrollRange(state, mOrientationHelper,
+ findFirstVisibleChildClosestToStart(!mSmoothScrollbarEnabled, true),
+ findFirstVisibleChildClosestToEnd(!mSmoothScrollbarEnabled, true),
+ this, mSmoothScrollbarEnabled);
+ }
+
+ /**
+ * When smooth scrollbar is enabled, the position and size of the scrollbar thumb is computed
+ * based on the number of visible pixels in the visible items. This however assumes that all
+ * list items have similar or equal widths or heights (depending on list orientation).
+ * If you use a list in which items have different dimensions, the scrollbar will change
+ * appearance as the user scrolls through the list. To avoid this issue, you need to disable
+ * this property.
+ *
+ * When smooth scrollbar is disabled, the position and size of the scrollbar thumb is based
+ * solely on the number of items in the adapter and the position of the visible items inside
+ * the adapter. This provides a stable scrollbar as the user navigates through a list of items
+ * with varying widths / heights.
+ *
+ * @param enabled Whether or not to enable smooth scrollbar.
+ *
+ * @see #setSmoothScrollbarEnabled(boolean)
+ */
+ public void setSmoothScrollbarEnabled(boolean enabled) {
+ mSmoothScrollbarEnabled = enabled;
+ }
+
+ /**
+ * Returns the current state of the smooth scrollbar feature. It is enabled by default.
+ *
+ * @return True if smooth scrollbar is enabled, false otherwise.
+ *
+ * @see #setSmoothScrollbarEnabled(boolean)
+ */
+ public boolean isSmoothScrollbarEnabled() {
+ return mSmoothScrollbarEnabled;
+ }
+
+ private void updateLayoutState(int layoutDirection, int requiredSpace,
+ boolean canUseExistingSpace, RecyclerView.State state) {
+ // If parent provides a hint, don't measure unlimited.
+ mLayoutState.mInfinite = resolveIsInfinite();
+ mLayoutState.mExtra = getExtraLayoutSpace(state);
+ mLayoutState.mLayoutDirection = layoutDirection;
+ int scrollingOffset;
+ if (layoutDirection == LayoutState.LAYOUT_END) {
+ mLayoutState.mExtra += mOrientationHelper.getEndPadding();
+ // get the first child in the direction we are going
+ final View child = getChildClosestToEnd();
+ // the direction in which we are traversing children
+ mLayoutState.mItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_HEAD
+ : LayoutState.ITEM_DIRECTION_TAIL;
+ mLayoutState.mCurrentPosition = getPosition(child) + mLayoutState.mItemDirection;
+ mLayoutState.mOffset = mOrientationHelper.getDecoratedEnd(child);
+ // calculate how much we can scroll without adding new children (independent of layout)
+ scrollingOffset = mOrientationHelper.getDecoratedEnd(child)
+ - mOrientationHelper.getEndAfterPadding();
+
+ } else {
+ final View child = getChildClosestToStart();
+ mLayoutState.mExtra += mOrientationHelper.getStartAfterPadding();
+ mLayoutState.mItemDirection = mShouldReverseLayout ? LayoutState.ITEM_DIRECTION_TAIL
+ : LayoutState.ITEM_DIRECTION_HEAD;
+ mLayoutState.mCurrentPosition = getPosition(child) + mLayoutState.mItemDirection;
+ mLayoutState.mOffset = mOrientationHelper.getDecoratedStart(child);
+ scrollingOffset = -mOrientationHelper.getDecoratedStart(child)
+ + mOrientationHelper.getStartAfterPadding();
+ }
+ mLayoutState.mAvailable = requiredSpace;
+ if (canUseExistingSpace) {
+ mLayoutState.mAvailable -= scrollingOffset;
+ }
+ mLayoutState.mScrollingOffset = scrollingOffset;
+ }
+
+ boolean resolveIsInfinite() {
+ return mOrientationHelper.getMode() == View.MeasureSpec.UNSPECIFIED
+ && mOrientationHelper.getEnd() == 0;
+ }
+
+ void collectPrefetchPositionsForLayoutState(RecyclerView.State state, LayoutState layoutState,
+ LayoutPrefetchRegistry layoutPrefetchRegistry) {
+ final int pos = layoutState.mCurrentPosition;
+ if (pos >= 0 && pos < state.getItemCount()) {
+ layoutPrefetchRegistry.addPosition(pos, layoutState.mScrollingOffset);
+ }
+ }
+
+ @Override
+ public void collectInitialPrefetchPositions(int adapterItemCount,
+ LayoutPrefetchRegistry layoutPrefetchRegistry) {
+ final boolean fromEnd;
+ final int anchorPos;
+ if (mPendingSavedState != null && mPendingSavedState.hasValidAnchor()) {
+ // use restored state, since it hasn't been resolved yet
+ fromEnd = mPendingSavedState.mAnchorLayoutFromEnd;
+ anchorPos = mPendingSavedState.mAnchorPosition;
+ } else {
+ resolveShouldLayoutReverse();
+ fromEnd = mShouldReverseLayout;
+ if (mPendingScrollPosition == NO_POSITION) {
+ anchorPos = fromEnd ? adapterItemCount - 1 : 0;
+ } else {
+ anchorPos = mPendingScrollPosition;
+ }
+ }
+
+ final int direction = fromEnd
+ ? LayoutState.ITEM_DIRECTION_HEAD
+ : LayoutState.ITEM_DIRECTION_TAIL;
+ int targetPos = anchorPos;
+ for (int i = 0; i < mInitialItemPrefetchCount; i++) {
+ if (targetPos >= 0 && targetPos < adapterItemCount) {
+ layoutPrefetchRegistry.addPosition(targetPos, 0);
+ } else {
+ break; // no more to prefetch
+ }
+ targetPos += direction;
+ }
+ }
+
+ /**
+ * Sets the number of items to prefetch in
+ * {@link #collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)}, which defines
+ * how many inner items should be prefetched when this LayoutManager's RecyclerView
+ * is nested inside another RecyclerView.
+ *
+ * <p>Set this value to the number of items this inner LayoutManager will display when it is
+ * first scrolled into the viewport. RecyclerView will attempt to prefetch that number of items
+ * so they are ready, avoiding jank as the inner RecyclerView is scrolled into the viewport.</p>
+ *
+ * <p>For example, take a vertically scrolling RecyclerView with horizontally scrolling inner
+ * RecyclerViews. The rows always have 4 items visible in them (or 5 if not aligned). Passing
+ * <code>4</code> to this method for each inner RecyclerView's LinearLayoutManager will enable
+ * RecyclerView's prefetching feature to do create/bind work for 4 views within a row early,
+ * before it is scrolled on screen, instead of just the default 2.</p>
+ *
+ * <p>Calling this method does nothing unless the LayoutManager is in a RecyclerView
+ * nested in another RecyclerView.</p>
+ *
+ * <p class="note"><strong>Note:</strong> Setting this value to be larger than the number of
+ * views that will be visible in this view can incur unnecessary bind work, and an increase to
+ * the number of Views created and in active use.</p>
+ *
+ * @param itemCount Number of items to prefetch
+ *
+ * @see #isItemPrefetchEnabled()
+ * @see #getInitialItemPrefetchCount()
+ * @see #collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)
+ */
+ public void setInitialPrefetchItemCount(int itemCount) {
+ mInitialItemPrefetchCount = itemCount;
+ }
+
+ /**
+ * Gets the number of items to prefetch in
+ * {@link #collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)}, which defines
+ * how many inner items should be prefetched when this LayoutManager's RecyclerView
+ * is nested inside another RecyclerView.
+ *
+ * @see #isItemPrefetchEnabled()
+ * @see #setInitialPrefetchItemCount(int)
+ * @see #collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)
+ *
+ * @return number of items to prefetch.
+ */
+ public int getInitialItemPrefetchCount() {
+ return mInitialItemPrefetchCount;
+ }
+
+ @Override
+ public void collectAdjacentPrefetchPositions(int dx, int dy, RecyclerView.State state,
+ LayoutPrefetchRegistry layoutPrefetchRegistry) {
+ int delta = (mOrientation == HORIZONTAL) ? dx : dy;
+ if (getChildCount() == 0 || delta == 0) {
+ // can't support this scroll, so don't bother prefetching
+ return;
+ }
+
+ final int layoutDirection = delta > 0 ? LayoutState.LAYOUT_END : LayoutState.LAYOUT_START;
+ final int absDy = Math.abs(delta);
+ updateLayoutState(layoutDirection, absDy, true, state);
+ collectPrefetchPositionsForLayoutState(state, mLayoutState, layoutPrefetchRegistry);
+ }
+
+ int scrollBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {
+ if (getChildCount() == 0 || dy == 0) {
+ return 0;
+ }
+ mLayoutState.mRecycle = true;
+ ensureLayoutState();
+ final int layoutDirection = dy > 0 ? LayoutState.LAYOUT_END : LayoutState.LAYOUT_START;
+ final int absDy = Math.abs(dy);
+ updateLayoutState(layoutDirection, absDy, true, state);
+ final int consumed = mLayoutState.mScrollingOffset
+ + fill(recycler, mLayoutState, state, false);
+ if (consumed < 0) {
+ if (DEBUG) {
+ Log.d(TAG, "Don't have any more elements to scroll");
+ }
+ return 0;
+ }
+ final int scrolled = absDy > consumed ? layoutDirection * consumed : dy;
+ mOrientationHelper.offsetChildren(-scrolled);
+ if (DEBUG) {
+ Log.d(TAG, "scroll req: " + dy + " scrolled: " + scrolled);
+ }
+ mLayoutState.mLastScrollDelta = scrolled;
+ return scrolled;
+ }
+
+ @Override
+ public void assertNotInLayoutOrScroll(String message) {
+ if (mPendingSavedState == null) {
+ super.assertNotInLayoutOrScroll(message);
+ }
+ }
+
+ /**
+ * Recycles children between given indices.
+ *
+ * @param startIndex inclusive
+ * @param endIndex exclusive
+ */
+ private void recycleChildren(RecyclerView.Recycler recycler, int startIndex, int endIndex) {
+ if (startIndex == endIndex) {
+ return;
+ }
+ if (DEBUG) {
+ Log.d(TAG, "Recycling " + Math.abs(startIndex - endIndex) + " items");
+ }
+ if (endIndex > startIndex) {
+ for (int i = endIndex - 1; i >= startIndex; i--) {
+ removeAndRecycleViewAt(i, recycler);
+ }
+ } else {
+ for (int i = startIndex; i > endIndex; i--) {
+ removeAndRecycleViewAt(i, recycler);
+ }
+ }
+ }
+
+ /**
+ * Recycles views that went out of bounds after scrolling towards the end of the layout.
+ * <p>
+ * Checks both layout position and visible position to guarantee that the view is not visible.
+ *
+ * @param recycler Recycler instance of {@link com.android.internal.widget.RecyclerView}
+ * @param dt This can be used to add additional padding to the visible area. This is used
+ * to detect children that will go out of bounds after scrolling, without
+ * actually moving them.
+ */
+ private void recycleViewsFromStart(RecyclerView.Recycler recycler, int dt) {
+ if (dt < 0) {
+ if (DEBUG) {
+ Log.d(TAG, "Called recycle from start with a negative value. This might happen"
+ + " during layout changes but may be sign of a bug");
+ }
+ return;
+ }
+ // ignore padding, ViewGroup may not clip children.
+ final int limit = dt;
+ final int childCount = getChildCount();
+ if (mShouldReverseLayout) {
+ for (int i = childCount - 1; i >= 0; i--) {
+ View child = getChildAt(i);
+ if (mOrientationHelper.getDecoratedEnd(child) > limit
+ || mOrientationHelper.getTransformedEndWithDecoration(child) > limit) {
+ // stop here
+ recycleChildren(recycler, childCount - 1, i);
+ return;
+ }
+ }
+ } else {
+ for (int i = 0; i < childCount; i++) {
+ View child = getChildAt(i);
+ if (mOrientationHelper.getDecoratedEnd(child) > limit
+ || mOrientationHelper.getTransformedEndWithDecoration(child) > limit) {
+ // stop here
+ recycleChildren(recycler, 0, i);
+ return;
+ }
+ }
+ }
+ }
+
+
+ /**
+ * Recycles views that went out of bounds after scrolling towards the start of the layout.
+ * <p>
+ * Checks both layout position and visible position to guarantee that the view is not visible.
+ *
+ * @param recycler Recycler instance of {@link com.android.internal.widget.RecyclerView}
+ * @param dt This can be used to add additional padding to the visible area. This is used
+ * to detect children that will go out of bounds after scrolling, without
+ * actually moving them.
+ */
+ private void recycleViewsFromEnd(RecyclerView.Recycler recycler, int dt) {
+ final int childCount = getChildCount();
+ if (dt < 0) {
+ if (DEBUG) {
+ Log.d(TAG, "Called recycle from end with a negative value. This might happen"
+ + " during layout changes but may be sign of a bug");
+ }
+ return;
+ }
+ final int limit = mOrientationHelper.getEnd() - dt;
+ if (mShouldReverseLayout) {
+ for (int i = 0; i < childCount; i++) {
+ View child = getChildAt(i);
+ if (mOrientationHelper.getDecoratedStart(child) < limit
+ || mOrientationHelper.getTransformedStartWithDecoration(child) < limit) {
+ // stop here
+ recycleChildren(recycler, 0, i);
+ return;
+ }
+ }
+ } else {
+ for (int i = childCount - 1; i >= 0; i--) {
+ View child = getChildAt(i);
+ if (mOrientationHelper.getDecoratedStart(child) < limit
+ || mOrientationHelper.getTransformedStartWithDecoration(child) < limit) {
+ // stop here
+ recycleChildren(recycler, childCount - 1, i);
+ return;
+ }
+ }
+ }
+ }
+
+ /**
+ * Helper method to call appropriate recycle method depending on current layout direction
+ *
+ * @param recycler Current recycler that is attached to RecyclerView
+ * @param layoutState Current layout state. Right now, this object does not change but
+ * we may consider moving it out of this view so passing around as a
+ * parameter for now, rather than accessing {@link #mLayoutState}
+ * @see #recycleViewsFromStart(com.android.internal.widget.RecyclerView.Recycler, int)
+ * @see #recycleViewsFromEnd(com.android.internal.widget.RecyclerView.Recycler, int)
+ * @see com.android.internal.widget.LinearLayoutManager.LayoutState#mLayoutDirection
+ */
+ private void recycleByLayoutState(RecyclerView.Recycler recycler, LayoutState layoutState) {
+ if (!layoutState.mRecycle || layoutState.mInfinite) {
+ return;
+ }
+ if (layoutState.mLayoutDirection == LayoutState.LAYOUT_START) {
+ recycleViewsFromEnd(recycler, layoutState.mScrollingOffset);
+ } else {
+ recycleViewsFromStart(recycler, layoutState.mScrollingOffset);
+ }
+ }
+
+ /**
+ * The magic functions :). Fills the given layout, defined by the layoutState. This is fairly
+ * independent from the rest of the {@link com.android.internal.widget.LinearLayoutManager}
+ * and with little change, can be made publicly available as a helper class.
+ *
+ * @param recycler Current recycler that is attached to RecyclerView
+ * @param layoutState Configuration on how we should fill out the available space.
+ * @param state Context passed by the RecyclerView to control scroll steps.
+ * @param stopOnFocusable If true, filling stops in the first focusable new child
+ * @return Number of pixels that it added. Useful for scroll functions.
+ */
+ int fill(RecyclerView.Recycler recycler, LayoutState layoutState,
+ RecyclerView.State state, boolean stopOnFocusable) {
+ // max offset we should set is mFastScroll + available
+ final int start = layoutState.mAvailable;
+ if (layoutState.mScrollingOffset != LayoutState.SCROLLING_OFFSET_NaN) {
+ // TODO ugly bug fix. should not happen
+ if (layoutState.mAvailable < 0) {
+ layoutState.mScrollingOffset += layoutState.mAvailable;
+ }
+ recycleByLayoutState(recycler, layoutState);
+ }
+ int remainingSpace = layoutState.mAvailable + layoutState.mExtra;
+ LayoutChunkResult layoutChunkResult = mLayoutChunkResult;
+ while ((layoutState.mInfinite || remainingSpace > 0) && layoutState.hasMore(state)) {
+ layoutChunkResult.resetInternal();
+ layoutChunk(recycler, state, layoutState, layoutChunkResult);
+ if (layoutChunkResult.mFinished) {
+ break;
+ }
+ layoutState.mOffset += layoutChunkResult.mConsumed * layoutState.mLayoutDirection;
+ /**
+ * Consume the available space if:
+ * * layoutChunk did not request to be ignored
+ * * OR we are laying out scrap children
+ * * OR we are not doing pre-layout
+ */
+ if (!layoutChunkResult.mIgnoreConsumed || mLayoutState.mScrapList != null
+ || !state.isPreLayout()) {
+ layoutState.mAvailable -= layoutChunkResult.mConsumed;
+ // we keep a separate remaining space because mAvailable is important for recycling
+ remainingSpace -= layoutChunkResult.mConsumed;
+ }
+
+ if (layoutState.mScrollingOffset != LayoutState.SCROLLING_OFFSET_NaN) {
+ layoutState.mScrollingOffset += layoutChunkResult.mConsumed;
+ if (layoutState.mAvailable < 0) {
+ layoutState.mScrollingOffset += layoutState.mAvailable;
+ }
+ recycleByLayoutState(recycler, layoutState);
+ }
+ if (stopOnFocusable && layoutChunkResult.mFocusable) {
+ break;
+ }
+ }
+ if (DEBUG) {
+ validateChildOrder();
+ }
+ return start - layoutState.mAvailable;
+ }
+
+ void layoutChunk(RecyclerView.Recycler recycler, RecyclerView.State state,
+ LayoutState layoutState, LayoutChunkResult result) {
+ View view = layoutState.next(recycler);
+ if (view == null) {
+ if (DEBUG && layoutState.mScrapList == null) {
+ throw new RuntimeException("received null view when unexpected");
+ }
+ // if we are laying out views in scrap, this may return null which means there is
+ // no more items to layout.
+ result.mFinished = true;
+ return;
+ }
+ LayoutParams params = (LayoutParams) view.getLayoutParams();
+ if (layoutState.mScrapList == null) {
+ if (mShouldReverseLayout == (layoutState.mLayoutDirection
+ == LayoutState.LAYOUT_START)) {
+ addView(view);
+ } else {
+ addView(view, 0);
+ }
+ } else {
+ if (mShouldReverseLayout == (layoutState.mLayoutDirection
+ == LayoutState.LAYOUT_START)) {
+ addDisappearingView(view);
+ } else {
+ addDisappearingView(view, 0);
+ }
+ }
+ measureChildWithMargins(view, 0, 0);
+ result.mConsumed = mOrientationHelper.getDecoratedMeasurement(view);
+ int left, top, right, bottom;
+ if (mOrientation == VERTICAL) {
+ if (isLayoutRTL()) {
+ right = getWidth() - getPaddingRight();
+ left = right - mOrientationHelper.getDecoratedMeasurementInOther(view);
+ } else {
+ left = getPaddingLeft();
+ right = left + mOrientationHelper.getDecoratedMeasurementInOther(view);
+ }
+ if (layoutState.mLayoutDirection == LayoutState.LAYOUT_START) {
+ bottom = layoutState.mOffset;
+ top = layoutState.mOffset - result.mConsumed;
+ } else {
+ top = layoutState.mOffset;
+ bottom = layoutState.mOffset + result.mConsumed;
+ }
+ } else {
+ top = getPaddingTop();
+ bottom = top + mOrientationHelper.getDecoratedMeasurementInOther(view);
+
+ if (layoutState.mLayoutDirection == LayoutState.LAYOUT_START) {
+ right = layoutState.mOffset;
+ left = layoutState.mOffset - result.mConsumed;
+ } else {
+ left = layoutState.mOffset;
+ right = layoutState.mOffset + result.mConsumed;
+ }
+ }
+ // We calculate everything with View's bounding box (which includes decor and margins)
+ // To calculate correct layout position, we subtract margins.
+ layoutDecoratedWithMargins(view, left, top, right, bottom);
+ if (DEBUG) {
+ Log.d(TAG, "laid out child at position " + getPosition(view) + ", with l:"
+ + (left + params.leftMargin) + ", t:" + (top + params.topMargin) + ", r:"
+ + (right - params.rightMargin) + ", b:" + (bottom - params.bottomMargin));
+ }
+ // Consume the available space if the view is not removed OR changed
+ if (params.isItemRemoved() || params.isItemChanged()) {
+ result.mIgnoreConsumed = true;
+ }
+ result.mFocusable = view.isFocusable();
+ }
+
+ @Override
+ boolean shouldMeasureTwice() {
+ return getHeightMode() != View.MeasureSpec.EXACTLY
+ && getWidthMode() != View.MeasureSpec.EXACTLY
+ && hasFlexibleChildInBothOrientations();
+ }
+
+ /**
+ * Converts a focusDirection to orientation.
+ *
+ * @param focusDirection One of {@link View#FOCUS_UP}, {@link View#FOCUS_DOWN},
+ * {@link View#FOCUS_LEFT}, {@link View#FOCUS_RIGHT},
+ * {@link View#FOCUS_BACKWARD}, {@link View#FOCUS_FORWARD}
+ * or 0 for not applicable
+ * @return {@link LayoutState#LAYOUT_START} or {@link LayoutState#LAYOUT_END} if focus direction
+ * is applicable to current state, {@link LayoutState#INVALID_LAYOUT} otherwise.
+ */
+ int convertFocusDirectionToLayoutDirection(int focusDirection) {
+ switch (focusDirection) {
+ case View.FOCUS_BACKWARD:
+ if (mOrientation == VERTICAL) {
+ return LayoutState.LAYOUT_START;
+ } else if (isLayoutRTL()) {
+ return LayoutState.LAYOUT_END;
+ } else {
+ return LayoutState.LAYOUT_START;
+ }
+ case View.FOCUS_FORWARD:
+ if (mOrientation == VERTICAL) {
+ return LayoutState.LAYOUT_END;
+ } else if (isLayoutRTL()) {
+ return LayoutState.LAYOUT_START;
+ } else {
+ return LayoutState.LAYOUT_END;
+ }
+ case View.FOCUS_UP:
+ return mOrientation == VERTICAL ? LayoutState.LAYOUT_START
+ : LayoutState.INVALID_LAYOUT;
+ case View.FOCUS_DOWN:
+ return mOrientation == VERTICAL ? LayoutState.LAYOUT_END
+ : LayoutState.INVALID_LAYOUT;
+ case View.FOCUS_LEFT:
+ return mOrientation == HORIZONTAL ? LayoutState.LAYOUT_START
+ : LayoutState.INVALID_LAYOUT;
+ case View.FOCUS_RIGHT:
+ return mOrientation == HORIZONTAL ? LayoutState.LAYOUT_END
+ : LayoutState.INVALID_LAYOUT;
+ default:
+ if (DEBUG) {
+ Log.d(TAG, "Unknown focus request:" + focusDirection);
+ }
+ return LayoutState.INVALID_LAYOUT;
+ }
+
+ }
+
+ /**
+ * Convenience method to find the child closes to start. Caller should check it has enough
+ * children.
+ *
+ * @return The child closes to start of the layout from user's perspective.
+ */
+ private View getChildClosestToStart() {
+ return getChildAt(mShouldReverseLayout ? getChildCount() - 1 : 0);
+ }
+
+ /**
+ * Convenience method to find the child closes to end. Caller should check it has enough
+ * children.
+ *
+ * @return The child closes to end of the layout from user's perspective.
+ */
+ private View getChildClosestToEnd() {
+ return getChildAt(mShouldReverseLayout ? 0 : getChildCount() - 1);
+ }
+
+ /**
+ * Convenience method to find the visible child closes to start. Caller should check if it has
+ * enough children.
+ *
+ * @param completelyVisible Whether child should be completely visible or not
+ * @return The first visible child closest to start of the layout from user's perspective.
+ */
+ private View findFirstVisibleChildClosestToStart(boolean completelyVisible,
+ boolean acceptPartiallyVisible) {
+ if (mShouldReverseLayout) {
+ return findOneVisibleChild(getChildCount() - 1, -1, completelyVisible,
+ acceptPartiallyVisible);
+ } else {
+ return findOneVisibleChild(0, getChildCount(), completelyVisible,
+ acceptPartiallyVisible);
+ }
+ }
+
+ /**
+ * Convenience method to find the visible child closes to end. Caller should check if it has
+ * enough children.
+ *
+ * @param completelyVisible Whether child should be completely visible or not
+ * @return The first visible child closest to end of the layout from user's perspective.
+ */
+ private View findFirstVisibleChildClosestToEnd(boolean completelyVisible,
+ boolean acceptPartiallyVisible) {
+ if (mShouldReverseLayout) {
+ return findOneVisibleChild(0, getChildCount(), completelyVisible,
+ acceptPartiallyVisible);
+ } else {
+ return findOneVisibleChild(getChildCount() - 1, -1, completelyVisible,
+ acceptPartiallyVisible);
+ }
+ }
+
+
+ /**
+ * Among the children that are suitable to be considered as an anchor child, returns the one
+ * closest to the end of the layout.
+ * <p>
+ * Due to ambiguous adapter updates or children being removed, some children's positions may be
+ * invalid. This method is a best effort to find a position within adapter bounds if possible.
+ * <p>
+ * It also prioritizes children that are within the visible bounds.
+ * @return A View that can be used an an anchor View.
+ */
+ private View findReferenceChildClosestToEnd(RecyclerView.Recycler recycler,
+ RecyclerView.State state) {
+ return mShouldReverseLayout ? findFirstReferenceChild(recycler, state) :
+ findLastReferenceChild(recycler, state);
+ }
+
+ /**
+ * Among the children that are suitable to be considered as an anchor child, returns the one
+ * closest to the start of the layout.
+ * <p>
+ * Due to ambiguous adapter updates or children being removed, some children's positions may be
+ * invalid. This method is a best effort to find a position within adapter bounds if possible.
+ * <p>
+ * It also prioritizes children that are within the visible bounds.
+ *
+ * @return A View that can be used an an anchor View.
+ */
+ private View findReferenceChildClosestToStart(RecyclerView.Recycler recycler,
+ RecyclerView.State state) {
+ return mShouldReverseLayout ? findLastReferenceChild(recycler, state) :
+ findFirstReferenceChild(recycler, state);
+ }
+
+ private View findFirstReferenceChild(RecyclerView.Recycler recycler, RecyclerView.State state) {
+ return findReferenceChild(recycler, state, 0, getChildCount(), state.getItemCount());
+ }
+
+ private View findLastReferenceChild(RecyclerView.Recycler recycler, RecyclerView.State state) {
+ return findReferenceChild(recycler, state, getChildCount() - 1, -1, state.getItemCount());
+ }
+
+ // overridden by GridLayoutManager
+ View findReferenceChild(RecyclerView.Recycler recycler, RecyclerView.State state,
+ int start, int end, int itemCount) {
+ ensureLayoutState();
+ View invalidMatch = null;
+ View outOfBoundsMatch = null;
+ final int boundsStart = mOrientationHelper.getStartAfterPadding();
+ final int boundsEnd = mOrientationHelper.getEndAfterPadding();
+ final int diff = end > start ? 1 : -1;
+ for (int i = start; i != end; i += diff) {
+ final View view = getChildAt(i);
+ final int position = getPosition(view);
+ if (position >= 0 && position < itemCount) {
+ if (((LayoutParams) view.getLayoutParams()).isItemRemoved()) {
+ if (invalidMatch == null) {
+ invalidMatch = view; // removed item, least preferred
+ }
+ } else if (mOrientationHelper.getDecoratedStart(view) >= boundsEnd
+ || mOrientationHelper.getDecoratedEnd(view) < boundsStart) {
+ if (outOfBoundsMatch == null) {
+ outOfBoundsMatch = view; // item is not visible, less preferred
+ }
+ } else {
+ return view;
+ }
+ }
+ }
+ return outOfBoundsMatch != null ? outOfBoundsMatch : invalidMatch;
+ }
+
+ /**
+ * Returns the adapter position of the first visible view. This position does not include
+ * adapter changes that were dispatched after the last layout pass.
+ * <p>
+ * Note that, this value is not affected by layout orientation or item order traversal.
+ * ({@link #setReverseLayout(boolean)}). Views are sorted by their positions in the adapter,
+ * not in the layout.
+ * <p>
+ * If RecyclerView has item decorators, they will be considered in calculations as well.
+ * <p>
+ * LayoutManager may pre-cache some views that are not necessarily visible. Those views
+ * are ignored in this method.
+ *
+ * @return The adapter position of the first visible item or {@link RecyclerView#NO_POSITION} if
+ * there aren't any visible items.
+ * @see #findFirstCompletelyVisibleItemPosition()
+ * @see #findLastVisibleItemPosition()
+ */
+ public int findFirstVisibleItemPosition() {
+ final View child = findOneVisibleChild(0, getChildCount(), false, true);
+ return child == null ? NO_POSITION : getPosition(child);
+ }
+
+ /**
+ * Returns the adapter position of the first fully visible view. This position does not include
+ * adapter changes that were dispatched after the last layout pass.
+ * <p>
+ * Note that bounds check is only performed in the current orientation. That means, if
+ * LayoutManager is horizontal, it will only check the view's left and right edges.
+ *
+ * @return The adapter position of the first fully visible item or
+ * {@link RecyclerView#NO_POSITION} if there aren't any visible items.
+ * @see #findFirstVisibleItemPosition()
+ * @see #findLastCompletelyVisibleItemPosition()
+ */
+ public int findFirstCompletelyVisibleItemPosition() {
+ final View child = findOneVisibleChild(0, getChildCount(), true, false);
+ return child == null ? NO_POSITION : getPosition(child);
+ }
+
+ /**
+ * Returns the adapter position of the last visible view. This position does not include
+ * adapter changes that were dispatched after the last layout pass.
+ * <p>
+ * Note that, this value is not affected by layout orientation or item order traversal.
+ * ({@link #setReverseLayout(boolean)}). Views are sorted by their positions in the adapter,
+ * not in the layout.
+ * <p>
+ * If RecyclerView has item decorators, they will be considered in calculations as well.
+ * <p>
+ * LayoutManager may pre-cache some views that are not necessarily visible. Those views
+ * are ignored in this method.
+ *
+ * @return The adapter position of the last visible view or {@link RecyclerView#NO_POSITION} if
+ * there aren't any visible items.
+ * @see #findLastCompletelyVisibleItemPosition()
+ * @see #findFirstVisibleItemPosition()
+ */
+ public int findLastVisibleItemPosition() {
+ final View child = findOneVisibleChild(getChildCount() - 1, -1, false, true);
+ return child == null ? NO_POSITION : getPosition(child);
+ }
+
+ /**
+ * Returns the adapter position of the last fully visible view. This position does not include
+ * adapter changes that were dispatched after the last layout pass.
+ * <p>
+ * Note that bounds check is only performed in the current orientation. That means, if
+ * LayoutManager is horizontal, it will only check the view's left and right edges.
+ *
+ * @return The adapter position of the last fully visible view or
+ * {@link RecyclerView#NO_POSITION} if there aren't any visible items.
+ * @see #findLastVisibleItemPosition()
+ * @see #findFirstCompletelyVisibleItemPosition()
+ */
+ public int findLastCompletelyVisibleItemPosition() {
+ final View child = findOneVisibleChild(getChildCount() - 1, -1, true, false);
+ return child == null ? NO_POSITION : getPosition(child);
+ }
+
+ View findOneVisibleChild(int fromIndex, int toIndex, boolean completelyVisible,
+ boolean acceptPartiallyVisible) {
+ ensureLayoutState();
+ final int start = mOrientationHelper.getStartAfterPadding();
+ final int end = mOrientationHelper.getEndAfterPadding();
+ final int next = toIndex > fromIndex ? 1 : -1;
+ View partiallyVisible = null;
+ for (int i = fromIndex; i != toIndex; i += next) {
+ final View child = getChildAt(i);
+ final int childStart = mOrientationHelper.getDecoratedStart(child);
+ final int childEnd = mOrientationHelper.getDecoratedEnd(child);
+ if (childStart < end && childEnd > start) {
+ if (completelyVisible) {
+ if (childStart >= start && childEnd <= end) {
+ return child;
+ } else if (acceptPartiallyVisible && partiallyVisible == null) {
+ partiallyVisible = child;
+ }
+ } else {
+ return child;
+ }
+ }
+ }
+ return partiallyVisible;
+ }
+
+ @Override
+ public View onFocusSearchFailed(View focused, int focusDirection,
+ RecyclerView.Recycler recycler, RecyclerView.State state) {
+ resolveShouldLayoutReverse();
+ if (getChildCount() == 0) {
+ return null;
+ }
+
+ final int layoutDir = convertFocusDirectionToLayoutDirection(focusDirection);
+ if (layoutDir == LayoutState.INVALID_LAYOUT) {
+ return null;
+ }
+ ensureLayoutState();
+ final View referenceChild;
+ if (layoutDir == LayoutState.LAYOUT_START) {
+ referenceChild = findReferenceChildClosestToStart(recycler, state);
+ } else {
+ referenceChild = findReferenceChildClosestToEnd(recycler, state);
+ }
+ if (referenceChild == null) {
+ if (DEBUG) {
+ Log.d(TAG,
+ "Cannot find a child with a valid position to be used for focus search.");
+ }
+ return null;
+ }
+ ensureLayoutState();
+ final int maxScroll = (int) (MAX_SCROLL_FACTOR * mOrientationHelper.getTotalSpace());
+ updateLayoutState(layoutDir, maxScroll, false, state);
+ mLayoutState.mScrollingOffset = LayoutState.SCROLLING_OFFSET_NaN;
+ mLayoutState.mRecycle = false;
+ fill(recycler, mLayoutState, state, true);
+ final View nextFocus;
+ if (layoutDir == LayoutState.LAYOUT_START) {
+ nextFocus = getChildClosestToStart();
+ } else {
+ nextFocus = getChildClosestToEnd();
+ }
+ if (nextFocus == referenceChild || !nextFocus.isFocusable()) {
+ return null;
+ }
+ return nextFocus;
+ }
+
+ /**
+ * Used for debugging.
+ * Logs the internal representation of children to default logger.
+ */
+ private void logChildren() {
+ Log.d(TAG, "internal representation of views on the screen");
+ for (int i = 0; i < getChildCount(); i++) {
+ View child = getChildAt(i);
+ Log.d(TAG, "item " + getPosition(child) + ", coord:"
+ + mOrientationHelper.getDecoratedStart(child));
+ }
+ Log.d(TAG, "==============");
+ }
+
+ /**
+ * Used for debugging.
+ * Validates that child views are laid out in correct order. This is important because rest of
+ * the algorithm relies on this constraint.
+ *
+ * In default layout, child 0 should be closest to screen position 0 and last child should be
+ * closest to position WIDTH or HEIGHT.
+ * In reverse layout, last child should be closes to screen position 0 and first child should
+ * be closest to position WIDTH or HEIGHT
+ */
+ void validateChildOrder() {
+ Log.d(TAG, "validating child count " + getChildCount());
+ if (getChildCount() < 1) {
+ return;
+ }
+ int lastPos = getPosition(getChildAt(0));
+ int lastScreenLoc = mOrientationHelper.getDecoratedStart(getChildAt(0));
+ if (mShouldReverseLayout) {
+ for (int i = 1; i < getChildCount(); i++) {
+ View child = getChildAt(i);
+ int pos = getPosition(child);
+ int screenLoc = mOrientationHelper.getDecoratedStart(child);
+ if (pos < lastPos) {
+ logChildren();
+ throw new RuntimeException("detected invalid position. loc invalid? "
+ + (screenLoc < lastScreenLoc));
+ }
+ if (screenLoc > lastScreenLoc) {
+ logChildren();
+ throw new RuntimeException("detected invalid location");
+ }
+ }
+ } else {
+ for (int i = 1; i < getChildCount(); i++) {
+ View child = getChildAt(i);
+ int pos = getPosition(child);
+ int screenLoc = mOrientationHelper.getDecoratedStart(child);
+ if (pos < lastPos) {
+ logChildren();
+ throw new RuntimeException("detected invalid position. loc invalid? "
+ + (screenLoc < lastScreenLoc));
+ }
+ if (screenLoc < lastScreenLoc) {
+ logChildren();
+ throw new RuntimeException("detected invalid location");
+ }
+ }
+ }
+ }
+
+ @Override
+ public boolean supportsPredictiveItemAnimations() {
+ return mPendingSavedState == null && mLastStackFromEnd == mStackFromEnd;
+ }
+
+ /**
+ * @hide This method should be called by ItemTouchHelper only.
+ */
+ @Override
+ public void prepareForDrop(View view, View target, int x, int y) {
+ assertNotInLayoutOrScroll("Cannot drop a view during a scroll or layout calculation");
+ ensureLayoutState();
+ resolveShouldLayoutReverse();
+ final int myPos = getPosition(view);
+ final int targetPos = getPosition(target);
+ final int dropDirection = myPos < targetPos ? LayoutState.ITEM_DIRECTION_TAIL
+ : LayoutState.ITEM_DIRECTION_HEAD;
+ if (mShouldReverseLayout) {
+ if (dropDirection == LayoutState.ITEM_DIRECTION_TAIL) {
+ scrollToPositionWithOffset(targetPos,
+ mOrientationHelper.getEndAfterPadding()
+ - (mOrientationHelper.getDecoratedStart(target)
+ + mOrientationHelper.getDecoratedMeasurement(view)));
+ } else {
+ scrollToPositionWithOffset(targetPos,
+ mOrientationHelper.getEndAfterPadding()
+ - mOrientationHelper.getDecoratedEnd(target));
+ }
+ } else {
+ if (dropDirection == LayoutState.ITEM_DIRECTION_HEAD) {
+ scrollToPositionWithOffset(targetPos, mOrientationHelper.getDecoratedStart(target));
+ } else {
+ scrollToPositionWithOffset(targetPos,
+ mOrientationHelper.getDecoratedEnd(target)
+ - mOrientationHelper.getDecoratedMeasurement(view));
+ }
+ }
+ }
+
+ /**
+ * Helper class that keeps temporary state while {LayoutManager} is filling out the empty
+ * space.
+ */
+ static class LayoutState {
+
+ static final String TAG = "LLM#LayoutState";
+
+ static final int LAYOUT_START = -1;
+
+ static final int LAYOUT_END = 1;
+
+ static final int INVALID_LAYOUT = Integer.MIN_VALUE;
+
+ static final int ITEM_DIRECTION_HEAD = -1;
+
+ static final int ITEM_DIRECTION_TAIL = 1;
+
+ static final int SCROLLING_OFFSET_NaN = Integer.MIN_VALUE;
+
+ /**
+ * We may not want to recycle children in some cases (e.g. layout)
+ */
+ boolean mRecycle = true;
+
+ /**
+ * Pixel offset where layout should start
+ */
+ int mOffset;
+
+ /**
+ * Number of pixels that we should fill, in the layout direction.
+ */
+ int mAvailable;
+
+ /**
+ * Current position on the adapter to get the next item.
+ */
+ int mCurrentPosition;
+
+ /**
+ * Defines the direction in which the data adapter is traversed.
+ * Should be {@link #ITEM_DIRECTION_HEAD} or {@link #ITEM_DIRECTION_TAIL}
+ */
+ int mItemDirection;
+
+ /**
+ * Defines the direction in which the layout is filled.
+ * Should be {@link #LAYOUT_START} or {@link #LAYOUT_END}
+ */
+ int mLayoutDirection;
+
+ /**
+ * Used when LayoutState is constructed in a scrolling state.
+ * It should be set the amount of scrolling we can make without creating a new view.
+ * Settings this is required for efficient view recycling.
+ */
+ int mScrollingOffset;
+
+ /**
+ * Used if you want to pre-layout items that are not yet visible.
+ * The difference with {@link #mAvailable} is that, when recycling, distance laid out for
+ * {@link #mExtra} is not considered to avoid recycling visible children.
+ */
+ int mExtra = 0;
+
+ /**
+ * Equal to {@link RecyclerView.State#isPreLayout()}. When consuming scrap, if this value
+ * is set to true, we skip removed views since they should not be laid out in post layout
+ * step.
+ */
+ boolean mIsPreLayout = false;
+
+ /**
+ * The most recent {@link #scrollBy(int, RecyclerView.Recycler, RecyclerView.State)}
+ * amount.
+ */
+ int mLastScrollDelta;
+
+ /**
+ * When LLM needs to layout particular views, it sets this list in which case, LayoutState
+ * will only return views from this list and return null if it cannot find an item.
+ */
+ List<RecyclerView.ViewHolder> mScrapList = null;
+
+ /**
+ * Used when there is no limit in how many views can be laid out.
+ */
+ boolean mInfinite;
+
+ /**
+ * @return true if there are more items in the data adapter
+ */
+ boolean hasMore(RecyclerView.State state) {
+ return mCurrentPosition >= 0 && mCurrentPosition < state.getItemCount();
+ }
+
+ /**
+ * Gets the view for the next element that we should layout.
+ * Also updates current item index to the next item, based on {@link #mItemDirection}
+ *
+ * @return The next element that we should layout.
+ */
+ View next(RecyclerView.Recycler recycler) {
+ if (mScrapList != null) {
+ return nextViewFromScrapList();
+ }
+ final View view = recycler.getViewForPosition(mCurrentPosition);
+ mCurrentPosition += mItemDirection;
+ return view;
+ }
+
+ /**
+ * Returns the next item from the scrap list.
+ * <p>
+ * Upon finding a valid VH, sets current item position to VH.itemPosition + mItemDirection
+ *
+ * @return View if an item in the current position or direction exists if not null.
+ */
+ private View nextViewFromScrapList() {
+ final int size = mScrapList.size();
+ for (int i = 0; i < size; i++) {
+ final View view = mScrapList.get(i).itemView;
+ final LayoutParams lp = (LayoutParams) view.getLayoutParams();
+ if (lp.isItemRemoved()) {
+ continue;
+ }
+ if (mCurrentPosition == lp.getViewLayoutPosition()) {
+ assignPositionFromScrapList(view);
+ return view;
+ }
+ }
+ return null;
+ }
+
+ public void assignPositionFromScrapList() {
+ assignPositionFromScrapList(null);
+ }
+
+ public void assignPositionFromScrapList(View ignore) {
+ final View closest = nextViewInLimitedList(ignore);
+ if (closest == null) {
+ mCurrentPosition = NO_POSITION;
+ } else {
+ mCurrentPosition = ((LayoutParams) closest.getLayoutParams())
+ .getViewLayoutPosition();
+ }
+ }
+
+ public View nextViewInLimitedList(View ignore) {
+ int size = mScrapList.size();
+ View closest = null;
+ int closestDistance = Integer.MAX_VALUE;
+ if (DEBUG && mIsPreLayout) {
+ throw new IllegalStateException("Scrap list cannot be used in pre layout");
+ }
+ for (int i = 0; i < size; i++) {
+ View view = mScrapList.get(i).itemView;
+ final LayoutParams lp = (LayoutParams) view.getLayoutParams();
+ if (view == ignore || lp.isItemRemoved()) {
+ continue;
+ }
+ final int distance = (lp.getViewLayoutPosition() - mCurrentPosition)
+ * mItemDirection;
+ if (distance < 0) {
+ continue; // item is not in current direction
+ }
+ if (distance < closestDistance) {
+ closest = view;
+ closestDistance = distance;
+ if (distance == 0) {
+ break;
+ }
+ }
+ }
+ return closest;
+ }
+
+ void log() {
+ Log.d(TAG, "avail:" + mAvailable + ", ind:" + mCurrentPosition + ", dir:"
+ + mItemDirection + ", offset:" + mOffset + ", layoutDir:" + mLayoutDirection);
+ }
+ }
+
+ /**
+ * @hide
+ */
+ public static class SavedState implements Parcelable {
+
+ int mAnchorPosition;
+
+ int mAnchorOffset;
+
+ boolean mAnchorLayoutFromEnd;
+
+ public SavedState() {
+
+ }
+
+ SavedState(Parcel in) {
+ mAnchorPosition = in.readInt();
+ mAnchorOffset = in.readInt();
+ mAnchorLayoutFromEnd = in.readInt() == 1;
+ }
+
+ public SavedState(SavedState other) {
+ mAnchorPosition = other.mAnchorPosition;
+ mAnchorOffset = other.mAnchorOffset;
+ mAnchorLayoutFromEnd = other.mAnchorLayoutFromEnd;
+ }
+
+ boolean hasValidAnchor() {
+ return mAnchorPosition >= 0;
+ }
+
+ void invalidateAnchor() {
+ mAnchorPosition = NO_POSITION;
+ }
+
+ @Override
+ public int describeContents() {
+ return 0;
+ }
+
+ @Override
+ public void writeToParcel(Parcel dest, int flags) {
+ dest.writeInt(mAnchorPosition);
+ dest.writeInt(mAnchorOffset);
+ dest.writeInt(mAnchorLayoutFromEnd ? 1 : 0);
+ }
+
+ public static final Parcelable.Creator<SavedState> CREATOR =
+ new Parcelable.Creator<SavedState>() {
+ @Override
+ public SavedState createFromParcel(Parcel in) {
+ return new SavedState(in);
+ }
+
+ @Override
+ public SavedState[] newArray(int size) {
+ return new SavedState[size];
+ }
+ };
+ }
+
+ /**
+ * Simple data class to keep Anchor information
+ */
+ class AnchorInfo {
+ int mPosition;
+ int mCoordinate;
+ boolean mLayoutFromEnd;
+ boolean mValid;
+
+ AnchorInfo() {
+ reset();
+ }
+
+ void reset() {
+ mPosition = NO_POSITION;
+ mCoordinate = INVALID_OFFSET;
+ mLayoutFromEnd = false;
+ mValid = false;
+ }
+
+ /**
+ * assigns anchor coordinate from the RecyclerView's padding depending on current
+ * layoutFromEnd value
+ */
+ void assignCoordinateFromPadding() {
+ mCoordinate = mLayoutFromEnd
+ ? mOrientationHelper.getEndAfterPadding()
+ : mOrientationHelper.getStartAfterPadding();
+ }
+
+ @Override
+ public String toString() {
+ return "AnchorInfo{"
+ + "mPosition=" + mPosition
+ + ", mCoordinate=" + mCoordinate
+ + ", mLayoutFromEnd=" + mLayoutFromEnd
+ + ", mValid=" + mValid
+ + '}';
+ }
+
+ boolean isViewValidAsAnchor(View child, RecyclerView.State state) {
+ LayoutParams lp = (LayoutParams) child.getLayoutParams();
+ return !lp.isItemRemoved() && lp.getViewLayoutPosition() >= 0
+ && lp.getViewLayoutPosition() < state.getItemCount();
+ }
+
+ public void assignFromViewAndKeepVisibleRect(View child) {
+ final int spaceChange = mOrientationHelper.getTotalSpaceChange();
+ if (spaceChange >= 0) {
+ assignFromView(child);
+ return;
+ }
+ mPosition = getPosition(child);
+ if (mLayoutFromEnd) {
+ final int prevLayoutEnd = mOrientationHelper.getEndAfterPadding() - spaceChange;
+ final int childEnd = mOrientationHelper.getDecoratedEnd(child);
+ final int previousEndMargin = prevLayoutEnd - childEnd;
+ mCoordinate = mOrientationHelper.getEndAfterPadding() - previousEndMargin;
+ // ensure we did not push child's top out of bounds because of this
+ if (previousEndMargin > 0) { // we have room to shift bottom if necessary
+ final int childSize = mOrientationHelper.getDecoratedMeasurement(child);
+ final int estimatedChildStart = mCoordinate - childSize;
+ final int layoutStart = mOrientationHelper.getStartAfterPadding();
+ final int previousStartMargin = mOrientationHelper.getDecoratedStart(child)
+ - layoutStart;
+ final int startReference = layoutStart + Math.min(previousStartMargin, 0);
+ final int startMargin = estimatedChildStart - startReference;
+ if (startMargin < 0) {
+ // offset to make top visible but not too much
+ mCoordinate += Math.min(previousEndMargin, -startMargin);
+ }
+ }
+ } else {
+ final int childStart = mOrientationHelper.getDecoratedStart(child);
+ final int startMargin = childStart - mOrientationHelper.getStartAfterPadding();
+ mCoordinate = childStart;
+ if (startMargin > 0) { // we have room to fix end as well
+ final int estimatedEnd = childStart
+ + mOrientationHelper.getDecoratedMeasurement(child);
+ final int previousLayoutEnd = mOrientationHelper.getEndAfterPadding()
+ - spaceChange;
+ final int previousEndMargin = previousLayoutEnd
+ - mOrientationHelper.getDecoratedEnd(child);
+ final int endReference = mOrientationHelper.getEndAfterPadding()
+ - Math.min(0, previousEndMargin);
+ final int endMargin = endReference - estimatedEnd;
+ if (endMargin < 0) {
+ mCoordinate -= Math.min(startMargin, -endMargin);
+ }
+ }
+ }
+ }
+
+ public void assignFromView(View child) {
+ if (mLayoutFromEnd) {
+ mCoordinate = mOrientationHelper.getDecoratedEnd(child)
+ + mOrientationHelper.getTotalSpaceChange();
+ } else {
+ mCoordinate = mOrientationHelper.getDecoratedStart(child);
+ }
+
+ mPosition = getPosition(child);
+ }
+ }
+
+ protected static class LayoutChunkResult {
+ public int mConsumed;
+ public boolean mFinished;
+ public boolean mIgnoreConsumed;
+ public boolean mFocusable;
+
+ void resetInternal() {
+ mConsumed = 0;
+ mFinished = false;
+ mIgnoreConsumed = false;
+ mFocusable = false;
+ }
+ }
+}
diff --git a/core/java/com/android/internal/widget/LinearSmoothScroller.java b/core/java/com/android/internal/widget/LinearSmoothScroller.java
new file mode 100644
index 0000000..d024f21
--- /dev/null
+++ b/core/java/com/android/internal/widget/LinearSmoothScroller.java
@@ -0,0 +1,361 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.graphics.PointF;
+import android.util.DisplayMetrics;
+import android.util.Log;
+import android.view.View;
+import android.view.animation.DecelerateInterpolator;
+import android.view.animation.LinearInterpolator;
+
+/**
+ * {@link RecyclerView.SmoothScroller} implementation which uses a {@link LinearInterpolator} until
+ * the target position becomes a child of the RecyclerView and then uses a
+ * {@link DecelerateInterpolator} to slowly approach to target position.
+ * <p>
+ * If the {@link RecyclerView.LayoutManager} you are using does not implement the
+ * {@link RecyclerView.SmoothScroller.ScrollVectorProvider} interface, then you must override the
+ * {@link #computeScrollVectorForPosition(int)} method. All the LayoutManagers bundled with
+ * the support library implement this interface.
+ */
+public class LinearSmoothScroller extends RecyclerView.SmoothScroller {
+
+ private static final String TAG = "LinearSmoothScroller";
+
+ private static final boolean DEBUG = false;
+
+ private static final float MILLISECONDS_PER_INCH = 25f;
+
+ private static final int TARGET_SEEK_SCROLL_DISTANCE_PX = 10000;
+
+ /**
+ * Align child view's left or top with parent view's left or top
+ *
+ * @see #calculateDtToFit(int, int, int, int, int)
+ * @see #calculateDxToMakeVisible(android.view.View, int)
+ * @see #calculateDyToMakeVisible(android.view.View, int)
+ */
+ public static final int SNAP_TO_START = -1;
+
+ /**
+ * Align child view's right or bottom with parent view's right or bottom
+ *
+ * @see #calculateDtToFit(int, int, int, int, int)
+ * @see #calculateDxToMakeVisible(android.view.View, int)
+ * @see #calculateDyToMakeVisible(android.view.View, int)
+ */
+ public static final int SNAP_TO_END = 1;
+
+ /**
+ * <p>Decides if the child should be snapped from start or end, depending on where it
+ * currently is in relation to its parent.</p>
+ * <p>For instance, if the view is virtually on the left of RecyclerView, using
+ * {@code SNAP_TO_ANY} is the same as using {@code SNAP_TO_START}</p>
+ *
+ * @see #calculateDtToFit(int, int, int, int, int)
+ * @see #calculateDxToMakeVisible(android.view.View, int)
+ * @see #calculateDyToMakeVisible(android.view.View, int)
+ */
+ public static final int SNAP_TO_ANY = 0;
+
+ // Trigger a scroll to a further distance than TARGET_SEEK_SCROLL_DISTANCE_PX so that if target
+ // view is not laid out until interim target position is reached, we can detect the case before
+ // scrolling slows down and reschedule another interim target scroll
+ private static final float TARGET_SEEK_EXTRA_SCROLL_RATIO = 1.2f;
+
+ protected final LinearInterpolator mLinearInterpolator = new LinearInterpolator();
+
+ protected final DecelerateInterpolator mDecelerateInterpolator = new DecelerateInterpolator();
+
+ protected PointF mTargetVector;
+
+ private final float MILLISECONDS_PER_PX;
+
+ // Temporary variables to keep track of the interim scroll target. These values do not
+ // point to a real item position, rather point to an estimated location pixels.
+ protected int mInterimTargetDx = 0, mInterimTargetDy = 0;
+
+ public LinearSmoothScroller(Context context) {
+ MILLISECONDS_PER_PX = calculateSpeedPerPixel(context.getResources().getDisplayMetrics());
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ protected void onStart() {
+
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ protected void onTargetFound(View targetView, RecyclerView.State state, Action action) {
+ final int dx = calculateDxToMakeVisible(targetView, getHorizontalSnapPreference());
+ final int dy = calculateDyToMakeVisible(targetView, getVerticalSnapPreference());
+ final int distance = (int) Math.sqrt(dx * dx + dy * dy);
+ final int time = calculateTimeForDeceleration(distance);
+ if (time > 0) {
+ action.update(-dx, -dy, time, mDecelerateInterpolator);
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ protected void onSeekTargetStep(int dx, int dy, RecyclerView.State state, Action action) {
+ if (getChildCount() == 0) {
+ stop();
+ return;
+ }
+ //noinspection PointlessBooleanExpression
+ if (DEBUG && mTargetVector != null
+ && ((mTargetVector.x * dx < 0 || mTargetVector.y * dy < 0))) {
+ throw new IllegalStateException("Scroll happened in the opposite direction"
+ + " of the target. Some calculations are wrong");
+ }
+ mInterimTargetDx = clampApplyScroll(mInterimTargetDx, dx);
+ mInterimTargetDy = clampApplyScroll(mInterimTargetDy, dy);
+
+ if (mInterimTargetDx == 0 && mInterimTargetDy == 0) {
+ updateActionForInterimTarget(action);
+ } // everything is valid, keep going
+
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ protected void onStop() {
+ mInterimTargetDx = mInterimTargetDy = 0;
+ mTargetVector = null;
+ }
+
+ /**
+ * Calculates the scroll speed.
+ *
+ * @param displayMetrics DisplayMetrics to be used for real dimension calculations
+ * @return The time (in ms) it should take for each pixel. For instance, if returned value is
+ * 2 ms, it means scrolling 1000 pixels with LinearInterpolation should take 2 seconds.
+ */
+ protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
+ return MILLISECONDS_PER_INCH / displayMetrics.densityDpi;
+ }
+
+ /**
+ * <p>Calculates the time for deceleration so that transition from LinearInterpolator to
+ * DecelerateInterpolator looks smooth.</p>
+ *
+ * @param dx Distance to scroll
+ * @return Time for DecelerateInterpolator to smoothly traverse the distance when transitioning
+ * from LinearInterpolation
+ */
+ protected int calculateTimeForDeceleration(int dx) {
+ // we want to cover same area with the linear interpolator for the first 10% of the
+ // interpolation. After that, deceleration will take control.
+ // area under curve (1-(1-x)^2) can be calculated as (1 - x/3) * x * x
+ // which gives 0.100028 when x = .3356
+ // this is why we divide linear scrolling time with .3356
+ return (int) Math.ceil(calculateTimeForScrolling(dx) / .3356);
+ }
+
+ /**
+ * Calculates the time it should take to scroll the given distance (in pixels)
+ *
+ * @param dx Distance in pixels that we want to scroll
+ * @return Time in milliseconds
+ * @see #calculateSpeedPerPixel(android.util.DisplayMetrics)
+ */
+ protected int calculateTimeForScrolling(int dx) {
+ // In a case where dx is very small, rounding may return 0 although dx > 0.
+ // To avoid that issue, ceil the result so that if dx > 0, we'll always return positive
+ // time.
+ return (int) Math.ceil(Math.abs(dx) * MILLISECONDS_PER_PX);
+ }
+
+ /**
+ * When scrolling towards a child view, this method defines whether we should align the left
+ * or the right edge of the child with the parent RecyclerView.
+ *
+ * @return SNAP_TO_START, SNAP_TO_END or SNAP_TO_ANY; depending on the current target vector
+ * @see #SNAP_TO_START
+ * @see #SNAP_TO_END
+ * @see #SNAP_TO_ANY
+ */
+ protected int getHorizontalSnapPreference() {
+ return mTargetVector == null || mTargetVector.x == 0 ? SNAP_TO_ANY :
+ mTargetVector.x > 0 ? SNAP_TO_END : SNAP_TO_START;
+ }
+
+ /**
+ * When scrolling towards a child view, this method defines whether we should align the top
+ * or the bottom edge of the child with the parent RecyclerView.
+ *
+ * @return SNAP_TO_START, SNAP_TO_END or SNAP_TO_ANY; depending on the current target vector
+ * @see #SNAP_TO_START
+ * @see #SNAP_TO_END
+ * @see #SNAP_TO_ANY
+ */
+ protected int getVerticalSnapPreference() {
+ return mTargetVector == null || mTargetVector.y == 0 ? SNAP_TO_ANY :
+ mTargetVector.y > 0 ? SNAP_TO_END : SNAP_TO_START;
+ }
+
+ /**
+ * When the target scroll position is not a child of the RecyclerView, this method calculates
+ * a direction vector towards that child and triggers a smooth scroll.
+ *
+ * @see #computeScrollVectorForPosition(int)
+ */
+ protected void updateActionForInterimTarget(Action action) {
+ // find an interim target position
+ PointF scrollVector = computeScrollVectorForPosition(getTargetPosition());
+ if (scrollVector == null || (scrollVector.x == 0 && scrollVector.y == 0)) {
+ final int target = getTargetPosition();
+ action.jumpTo(target);
+ stop();
+ return;
+ }
+ normalize(scrollVector);
+ mTargetVector = scrollVector;
+
+ mInterimTargetDx = (int) (TARGET_SEEK_SCROLL_DISTANCE_PX * scrollVector.x);
+ mInterimTargetDy = (int) (TARGET_SEEK_SCROLL_DISTANCE_PX * scrollVector.y);
+ final int time = calculateTimeForScrolling(TARGET_SEEK_SCROLL_DISTANCE_PX);
+ // To avoid UI hiccups, trigger a smooth scroll to a distance little further than the
+ // interim target. Since we track the distance travelled in onSeekTargetStep callback, it
+ // won't actually scroll more than what we need.
+ action.update((int) (mInterimTargetDx * TARGET_SEEK_EXTRA_SCROLL_RATIO),
+ (int) (mInterimTargetDy * TARGET_SEEK_EXTRA_SCROLL_RATIO),
+ (int) (time * TARGET_SEEK_EXTRA_SCROLL_RATIO), mLinearInterpolator);
+ }
+
+ private int clampApplyScroll(int tmpDt, int dt) {
+ final int before = tmpDt;
+ tmpDt -= dt;
+ if (before * tmpDt <= 0) { // changed sign, reached 0 or was 0, reset
+ return 0;
+ }
+ return tmpDt;
+ }
+
+ /**
+ * Helper method for {@link #calculateDxToMakeVisible(android.view.View, int)} and
+ * {@link #calculateDyToMakeVisible(android.view.View, int)}
+ */
+ public int calculateDtToFit(int viewStart, int viewEnd, int boxStart, int boxEnd, int
+ snapPreference) {
+ switch (snapPreference) {
+ case SNAP_TO_START:
+ return boxStart - viewStart;
+ case SNAP_TO_END:
+ return boxEnd - viewEnd;
+ case SNAP_TO_ANY:
+ final int dtStart = boxStart - viewStart;
+ if (dtStart > 0) {
+ return dtStart;
+ }
+ final int dtEnd = boxEnd - viewEnd;
+ if (dtEnd < 0) {
+ return dtEnd;
+ }
+ break;
+ default:
+ throw new IllegalArgumentException("snap preference should be one of the"
+ + " constants defined in SmoothScroller, starting with SNAP_");
+ }
+ return 0;
+ }
+
+ /**
+ * Calculates the vertical scroll amount necessary to make the given view fully visible
+ * inside the RecyclerView.
+ *
+ * @param view The view which we want to make fully visible
+ * @param snapPreference The edge which the view should snap to when entering the visible
+ * area. One of {@link #SNAP_TO_START}, {@link #SNAP_TO_END} or
+ * {@link #SNAP_TO_ANY}.
+ * @return The vertical scroll amount necessary to make the view visible with the given
+ * snap preference.
+ */
+ public int calculateDyToMakeVisible(View view, int snapPreference) {
+ final RecyclerView.LayoutManager layoutManager = getLayoutManager();
+ if (layoutManager == null || !layoutManager.canScrollVertically()) {
+ return 0;
+ }
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ final int top = layoutManager.getDecoratedTop(view) - params.topMargin;
+ final int bottom = layoutManager.getDecoratedBottom(view) + params.bottomMargin;
+ final int start = layoutManager.getPaddingTop();
+ final int end = layoutManager.getHeight() - layoutManager.getPaddingBottom();
+ return calculateDtToFit(top, bottom, start, end, snapPreference);
+ }
+
+ /**
+ * Calculates the horizontal scroll amount necessary to make the given view fully visible
+ * inside the RecyclerView.
+ *
+ * @param view The view which we want to make fully visible
+ * @param snapPreference The edge which the view should snap to when entering the visible
+ * area. One of {@link #SNAP_TO_START}, {@link #SNAP_TO_END} or
+ * {@link #SNAP_TO_END}
+ * @return The vertical scroll amount necessary to make the view visible with the given
+ * snap preference.
+ */
+ public int calculateDxToMakeVisible(View view, int snapPreference) {
+ final RecyclerView.LayoutManager layoutManager = getLayoutManager();
+ if (layoutManager == null || !layoutManager.canScrollHorizontally()) {
+ return 0;
+ }
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ final int left = layoutManager.getDecoratedLeft(view) - params.leftMargin;
+ final int right = layoutManager.getDecoratedRight(view) + params.rightMargin;
+ final int start = layoutManager.getPaddingLeft();
+ final int end = layoutManager.getWidth() - layoutManager.getPaddingRight();
+ return calculateDtToFit(left, right, start, end, snapPreference);
+ }
+
+ /**
+ * Compute the scroll vector for a given target position.
+ * <p>
+ * This method can return null if the layout manager cannot calculate a scroll vector
+ * for the given position (e.g. it has no current scroll position).
+ *
+ * @param targetPosition the position to which the scroller is scrolling
+ *
+ * @return the scroll vector for a given target position
+ */
+ @Nullable
+ public PointF computeScrollVectorForPosition(int targetPosition) {
+ RecyclerView.LayoutManager layoutManager = getLayoutManager();
+ if (layoutManager instanceof ScrollVectorProvider) {
+ return ((ScrollVectorProvider) layoutManager)
+ .computeScrollVectorForPosition(targetPosition);
+ }
+ Log.w(TAG, "You should override computeScrollVectorForPosition when the LayoutManager"
+ + " does not implement " + ScrollVectorProvider.class.getCanonicalName());
+ return null;
+ }
+}
diff --git a/core/java/com/android/internal/widget/NestedScrollingChild.java b/core/java/com/android/internal/widget/NestedScrollingChild.java
new file mode 100644
index 0000000..20285b5
--- /dev/null
+++ b/core/java/com/android/internal/widget/NestedScrollingChild.java
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.view.MotionEvent;
+import android.view.VelocityTracker;
+import android.view.View;
+import android.view.ViewConfiguration;
+import android.view.ViewParent;
+
+/**
+ * This interface should be implemented by {@link android.view.View View} subclasses that wish
+ * to support dispatching nested scrolling operations to a cooperating parent
+ * {@link android.view.ViewGroup ViewGroup}.
+ *
+ * <p>Classes implementing this interface should create a final instance of a
+ * {@link NestedScrollingChildHelper} as a field and delegate any View methods to the
+ * <code>NestedScrollingChildHelper</code> methods of the same signature.</p>
+ *
+ * <p>Views invoking nested scrolling functionality should always do so from the relevant
+ * {@link ViewCompat}, {@link ViewGroupCompat} or {@link ViewParentCompat} compatibility
+ * shim static methods. This ensures interoperability with nested scrolling views on Android
+ * 5.0 Lollipop and newer.</p>
+ */
+public interface NestedScrollingChild {
+ /**
+ * Enable or disable nested scrolling for this view.
+ *
+ * <p>If this property is set to true the view will be permitted to initiate nested
+ * scrolling operations with a compatible parent view in the current hierarchy. If this
+ * view does not implement nested scrolling this will have no effect. Disabling nested scrolling
+ * while a nested scroll is in progress has the effect of {@link #stopNestedScroll() stopping}
+ * the nested scroll.</p>
+ *
+ * @param enabled true to enable nested scrolling, false to disable
+ *
+ * @see #isNestedScrollingEnabled()
+ */
+ void setNestedScrollingEnabled(boolean enabled);
+
+ /**
+ * Returns true if nested scrolling is enabled for this view.
+ *
+ * <p>If nested scrolling is enabled and this View class implementation supports it,
+ * this view will act as a nested scrolling child view when applicable, forwarding data
+ * about the scroll operation in progress to a compatible and cooperating nested scrolling
+ * parent.</p>
+ *
+ * @return true if nested scrolling is enabled
+ *
+ * @see #setNestedScrollingEnabled(boolean)
+ */
+ boolean isNestedScrollingEnabled();
+
+ /**
+ * Begin a nestable scroll operation along the given axes.
+ *
+ * <p>A view starting a nested scroll promises to abide by the following contract:</p>
+ *
+ * <p>The view will call startNestedScroll upon initiating a scroll operation. In the case
+ * of a touch scroll this corresponds to the initial {@link MotionEvent#ACTION_DOWN}.
+ * In the case of touch scrolling the nested scroll will be terminated automatically in
+ * the same manner as {@link ViewParent#requestDisallowInterceptTouchEvent(boolean)}.
+ * In the event of programmatic scrolling the caller must explicitly call
+ * {@link #stopNestedScroll()} to indicate the end of the nested scroll.</p>
+ *
+ * <p>If <code>startNestedScroll</code> returns true, a cooperative parent was found.
+ * If it returns false the caller may ignore the rest of this contract until the next scroll.
+ * Calling startNestedScroll while a nested scroll is already in progress will return true.</p>
+ *
+ * <p>At each incremental step of the scroll the caller should invoke
+ * {@link #dispatchNestedPreScroll(int, int, int[], int[]) dispatchNestedPreScroll}
+ * once it has calculated the requested scrolling delta. If it returns true the nested scrolling
+ * parent at least partially consumed the scroll and the caller should adjust the amount it
+ * scrolls by.</p>
+ *
+ * <p>After applying the remainder of the scroll delta the caller should invoke
+ * {@link #dispatchNestedScroll(int, int, int, int, int[]) dispatchNestedScroll}, passing
+ * both the delta consumed and the delta unconsumed. A nested scrolling parent may treat
+ * these values differently. See
+ * {@link NestedScrollingParent#onNestedScroll(View, int, int, int, int)}.
+ * </p>
+ *
+ * @param axes Flags consisting of a combination of {@link ViewCompat#SCROLL_AXIS_HORIZONTAL}
+ * and/or {@link ViewCompat#SCROLL_AXIS_VERTICAL}.
+ * @return true if a cooperative parent was found and nested scrolling has been enabled for
+ * the current gesture.
+ *
+ * @see #stopNestedScroll()
+ * @see #dispatchNestedPreScroll(int, int, int[], int[])
+ * @see #dispatchNestedScroll(int, int, int, int, int[])
+ */
+ boolean startNestedScroll(int axes);
+
+ /**
+ * Stop a nested scroll in progress.
+ *
+ * <p>Calling this method when a nested scroll is not currently in progress is harmless.</p>
+ *
+ * @see #startNestedScroll(int)
+ */
+ void stopNestedScroll();
+
+ /**
+ * Returns true if this view has a nested scrolling parent.
+ *
+ * <p>The presence of a nested scrolling parent indicates that this view has initiated
+ * a nested scroll and it was accepted by an ancestor view further up the view hierarchy.</p>
+ *
+ * @return whether this view has a nested scrolling parent
+ */
+ boolean hasNestedScrollingParent();
+
+ /**
+ * Dispatch one step of a nested scroll in progress.
+ *
+ * <p>Implementations of views that support nested scrolling should call this to report
+ * info about a scroll in progress to the current nested scrolling parent. If a nested scroll
+ * is not currently in progress or nested scrolling is not
+ * {@link #isNestedScrollingEnabled() enabled} for this view this method does nothing.</p>
+ *
+ * <p>Compatible View implementations should also call
+ * {@link #dispatchNestedPreScroll(int, int, int[], int[]) dispatchNestedPreScroll} before
+ * consuming a component of the scroll event themselves.</p>
+ *
+ * @param dxConsumed Horizontal distance in pixels consumed by this view during this scroll step
+ * @param dyConsumed Vertical distance in pixels consumed by this view during this scroll step
+ * @param dxUnconsumed Horizontal scroll distance in pixels not consumed by this view
+ * @param dyUnconsumed Horizontal scroll distance in pixels not consumed by this view
+ * @param offsetInWindow Optional. If not null, on return this will contain the offset
+ * in local view coordinates of this view from before this operation
+ * to after it completes. View implementations may use this to adjust
+ * expected input coordinate tracking.
+ * @return true if the event was dispatched, false if it could not be dispatched.
+ * @see #dispatchNestedPreScroll(int, int, int[], int[])
+ */
+ boolean dispatchNestedScroll(int dxConsumed, int dyConsumed,
+ int dxUnconsumed, int dyUnconsumed, int[] offsetInWindow);
+
+ /**
+ * Dispatch one step of a nested scroll in progress before this view consumes any portion of it.
+ *
+ * <p>Nested pre-scroll events are to nested scroll events what touch intercept is to touch.
+ * <code>dispatchNestedPreScroll</code> offers an opportunity for the parent view in a nested
+ * scrolling operation to consume some or all of the scroll operation before the child view
+ * consumes it.</p>
+ *
+ * @param dx Horizontal scroll distance in pixels
+ * @param dy Vertical scroll distance in pixels
+ * @param consumed Output. If not null, consumed[0] will contain the consumed component of dx
+ * and consumed[1] the consumed dy.
+ * @param offsetInWindow Optional. If not null, on return this will contain the offset
+ * in local view coordinates of this view from before this operation
+ * to after it completes. View implementations may use this to adjust
+ * expected input coordinate tracking.
+ * @return true if the parent consumed some or all of the scroll delta
+ * @see #dispatchNestedScroll(int, int, int, int, int[])
+ */
+ boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow);
+
+ /**
+ * Dispatch a fling to a nested scrolling parent.
+ *
+ * <p>This method should be used to indicate that a nested scrolling child has detected
+ * suitable conditions for a fling. Generally this means that a touch scroll has ended with a
+ * {@link VelocityTracker velocity} in the direction of scrolling that meets or exceeds
+ * the {@link ViewConfiguration#getScaledMinimumFlingVelocity() minimum fling velocity}
+ * along a scrollable axis.</p>
+ *
+ * <p>If a nested scrolling child view would normally fling but it is at the edge of
+ * its own content, it can use this method to delegate the fling to its nested scrolling
+ * parent instead. The parent may optionally consume the fling or observe a child fling.</p>
+ *
+ * @param velocityX Horizontal fling velocity in pixels per second
+ * @param velocityY Vertical fling velocity in pixels per second
+ * @param consumed true if the child consumed the fling, false otherwise
+ * @return true if the nested scrolling parent consumed or otherwise reacted to the fling
+ */
+ boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed);
+
+ /**
+ * Dispatch a fling to a nested scrolling parent before it is processed by this view.
+ *
+ * <p>Nested pre-fling events are to nested fling events what touch intercept is to touch
+ * and what nested pre-scroll is to nested scroll. <code>dispatchNestedPreFling</code>
+ * offsets an opportunity for the parent view in a nested fling to fully consume the fling
+ * before the child view consumes it. If this method returns <code>true</code>, a nested
+ * parent view consumed the fling and this view should not scroll as a result.</p>
+ *
+ * <p>For a better user experience, only one view in a nested scrolling chain should consume
+ * the fling at a time. If a parent view consumed the fling this method will return false.
+ * Custom view implementations should account for this in two ways:</p>
+ *
+ * <ul>
+ * <li>If a custom view is paged and needs to settle to a fixed page-point, do not
+ * call <code>dispatchNestedPreFling</code>; consume the fling and settle to a valid
+ * position regardless.</li>
+ * <li>If a nested parent does consume the fling, this view should not scroll at all,
+ * even to settle back to a valid idle position.</li>
+ * </ul>
+ *
+ * <p>Views should also not offer fling velocities to nested parent views along an axis
+ * where scrolling is not currently supported; a {@link android.widget.ScrollView ScrollView}
+ * should not offer a horizontal fling velocity to its parents since scrolling along that
+ * axis is not permitted and carrying velocity along that motion does not make sense.</p>
+ *
+ * @param velocityX Horizontal fling velocity in pixels per second
+ * @param velocityY Vertical fling velocity in pixels per second
+ * @return true if a nested scrolling parent consumed the fling
+ */
+ boolean dispatchNestedPreFling(float velocityX, float velocityY);
+}
diff --git a/core/java/com/android/internal/widget/OpReorderer.java b/core/java/com/android/internal/widget/OpReorderer.java
new file mode 100644
index 0000000..babb087
--- /dev/null
+++ b/core/java/com/android/internal/widget/OpReorderer.java
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import static com.android.internal.widget.AdapterHelper.UpdateOp.ADD;
+import static com.android.internal.widget.AdapterHelper.UpdateOp.MOVE;
+import static com.android.internal.widget.AdapterHelper.UpdateOp.REMOVE;
+import static com.android.internal.widget.AdapterHelper.UpdateOp.UPDATE;
+
+import com.android.internal.widget.AdapterHelper.UpdateOp;
+
+import java.util.List;
+
+class OpReorderer {
+
+ final Callback mCallback;
+
+ OpReorderer(Callback callback) {
+ mCallback = callback;
+ }
+
+ void reorderOps(List<UpdateOp> ops) {
+ // since move operations breaks continuity, their effects on ADD/RM are hard to handle.
+ // we push them to the end of the list so that they can be handled easily.
+ int badMove;
+ while ((badMove = getLastMoveOutOfOrder(ops)) != -1) {
+ swapMoveOp(ops, badMove, badMove + 1);
+ }
+ }
+
+ private void swapMoveOp(List<UpdateOp> list, int badMove, int next) {
+ final UpdateOp moveOp = list.get(badMove);
+ final UpdateOp nextOp = list.get(next);
+ switch (nextOp.cmd) {
+ case REMOVE:
+ swapMoveRemove(list, badMove, moveOp, next, nextOp);
+ break;
+ case ADD:
+ swapMoveAdd(list, badMove, moveOp, next, nextOp);
+ break;
+ case UPDATE:
+ swapMoveUpdate(list, badMove, moveOp, next, nextOp);
+ break;
+ }
+ }
+
+ void swapMoveRemove(List<UpdateOp> list, int movePos, UpdateOp moveOp,
+ int removePos, UpdateOp removeOp) {
+ UpdateOp extraRm = null;
+ // check if move is nulled out by remove
+ boolean revertedMove = false;
+ final boolean moveIsBackwards;
+
+ if (moveOp.positionStart < moveOp.itemCount) {
+ moveIsBackwards = false;
+ if (removeOp.positionStart == moveOp.positionStart
+ && removeOp.itemCount == moveOp.itemCount - moveOp.positionStart) {
+ revertedMove = true;
+ }
+ } else {
+ moveIsBackwards = true;
+ if (removeOp.positionStart == moveOp.itemCount + 1
+ && removeOp.itemCount == moveOp.positionStart - moveOp.itemCount) {
+ revertedMove = true;
+ }
+ }
+
+ // going in reverse, first revert the effect of add
+ if (moveOp.itemCount < removeOp.positionStart) {
+ removeOp.positionStart--;
+ } else if (moveOp.itemCount < removeOp.positionStart + removeOp.itemCount) {
+ // move is removed.
+ removeOp.itemCount--;
+ moveOp.cmd = REMOVE;
+ moveOp.itemCount = 1;
+ if (removeOp.itemCount == 0) {
+ list.remove(removePos);
+ mCallback.recycleUpdateOp(removeOp);
+ }
+ // no need to swap, it is already a remove
+ return;
+ }
+
+ // now affect of add is consumed. now apply effect of first remove
+ if (moveOp.positionStart <= removeOp.positionStart) {
+ removeOp.positionStart++;
+ } else if (moveOp.positionStart < removeOp.positionStart + removeOp.itemCount) {
+ final int remaining = removeOp.positionStart + removeOp.itemCount
+ - moveOp.positionStart;
+ extraRm = mCallback.obtainUpdateOp(REMOVE, moveOp.positionStart + 1, remaining, null);
+ removeOp.itemCount = moveOp.positionStart - removeOp.positionStart;
+ }
+
+ // if effects of move is reverted by remove, we are done.
+ if (revertedMove) {
+ list.set(movePos, removeOp);
+ list.remove(removePos);
+ mCallback.recycleUpdateOp(moveOp);
+ return;
+ }
+
+ // now find out the new locations for move actions
+ if (moveIsBackwards) {
+ if (extraRm != null) {
+ if (moveOp.positionStart > extraRm.positionStart) {
+ moveOp.positionStart -= extraRm.itemCount;
+ }
+ if (moveOp.itemCount > extraRm.positionStart) {
+ moveOp.itemCount -= extraRm.itemCount;
+ }
+ }
+ if (moveOp.positionStart > removeOp.positionStart) {
+ moveOp.positionStart -= removeOp.itemCount;
+ }
+ if (moveOp.itemCount > removeOp.positionStart) {
+ moveOp.itemCount -= removeOp.itemCount;
+ }
+ } else {
+ if (extraRm != null) {
+ if (moveOp.positionStart >= extraRm.positionStart) {
+ moveOp.positionStart -= extraRm.itemCount;
+ }
+ if (moveOp.itemCount >= extraRm.positionStart) {
+ moveOp.itemCount -= extraRm.itemCount;
+ }
+ }
+ if (moveOp.positionStart >= removeOp.positionStart) {
+ moveOp.positionStart -= removeOp.itemCount;
+ }
+ if (moveOp.itemCount >= removeOp.positionStart) {
+ moveOp.itemCount -= removeOp.itemCount;
+ }
+ }
+
+ list.set(movePos, removeOp);
+ if (moveOp.positionStart != moveOp.itemCount) {
+ list.set(removePos, moveOp);
+ } else {
+ list.remove(removePos);
+ }
+ if (extraRm != null) {
+ list.add(movePos, extraRm);
+ }
+ }
+
+ private void swapMoveAdd(List<UpdateOp> list, int move, UpdateOp moveOp, int add,
+ UpdateOp addOp) {
+ int offset = 0;
+ // going in reverse, first revert the effect of add
+ if (moveOp.itemCount < addOp.positionStart) {
+ offset--;
+ }
+ if (moveOp.positionStart < addOp.positionStart) {
+ offset++;
+ }
+ if (addOp.positionStart <= moveOp.positionStart) {
+ moveOp.positionStart += addOp.itemCount;
+ }
+ if (addOp.positionStart <= moveOp.itemCount) {
+ moveOp.itemCount += addOp.itemCount;
+ }
+ addOp.positionStart += offset;
+ list.set(move, addOp);
+ list.set(add, moveOp);
+ }
+
+ void swapMoveUpdate(List<UpdateOp> list, int move, UpdateOp moveOp, int update,
+ UpdateOp updateOp) {
+ UpdateOp extraUp1 = null;
+ UpdateOp extraUp2 = null;
+ // going in reverse, first revert the effect of add
+ if (moveOp.itemCount < updateOp.positionStart) {
+ updateOp.positionStart--;
+ } else if (moveOp.itemCount < updateOp.positionStart + updateOp.itemCount) {
+ // moved item is updated. add an update for it
+ updateOp.itemCount--;
+ extraUp1 = mCallback.obtainUpdateOp(UPDATE, moveOp.positionStart, 1, updateOp.payload);
+ }
+ // now affect of add is consumed. now apply effect of first remove
+ if (moveOp.positionStart <= updateOp.positionStart) {
+ updateOp.positionStart++;
+ } else if (moveOp.positionStart < updateOp.positionStart + updateOp.itemCount) {
+ final int remaining = updateOp.positionStart + updateOp.itemCount
+ - moveOp.positionStart;
+ extraUp2 = mCallback.obtainUpdateOp(UPDATE, moveOp.positionStart + 1, remaining,
+ updateOp.payload);
+ updateOp.itemCount -= remaining;
+ }
+ list.set(update, moveOp);
+ if (updateOp.itemCount > 0) {
+ list.set(move, updateOp);
+ } else {
+ list.remove(move);
+ mCallback.recycleUpdateOp(updateOp);
+ }
+ if (extraUp1 != null) {
+ list.add(move, extraUp1);
+ }
+ if (extraUp2 != null) {
+ list.add(move, extraUp2);
+ }
+ }
+
+ private int getLastMoveOutOfOrder(List<UpdateOp> list) {
+ boolean foundNonMove = false;
+ for (int i = list.size() - 1; i >= 0; i--) {
+ final UpdateOp op1 = list.get(i);
+ if (op1.cmd == MOVE) {
+ if (foundNonMove) {
+ return i;
+ }
+ } else {
+ foundNonMove = true;
+ }
+ }
+ return -1;
+ }
+
+ interface Callback {
+
+ UpdateOp obtainUpdateOp(int cmd, int startPosition, int itemCount, Object payload);
+
+ void recycleUpdateOp(UpdateOp op);
+ }
+}
diff --git a/core/java/com/android/internal/widget/OrientationHelper.java b/core/java/com/android/internal/widget/OrientationHelper.java
new file mode 100644
index 0000000..1b02c88
--- /dev/null
+++ b/core/java/com/android/internal/widget/OrientationHelper.java
@@ -0,0 +1,439 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.graphics.Rect;
+import android.view.View;
+import android.widget.LinearLayout;
+
+/**
+ * Helper class for LayoutManagers to abstract measurements depending on the View's orientation.
+ * <p>
+ * It is developed to easily support vertical and horizontal orientations in a LayoutManager but
+ * can also be used to abstract calls around view bounds and child measurements with margins and
+ * decorations.
+ *
+ * @see #createHorizontalHelper(RecyclerView.LayoutManager)
+ * @see #createVerticalHelper(RecyclerView.LayoutManager)
+ */
+public abstract class OrientationHelper {
+
+ private static final int INVALID_SIZE = Integer.MIN_VALUE;
+
+ protected final RecyclerView.LayoutManager mLayoutManager;
+
+ public static final int HORIZONTAL = LinearLayout.HORIZONTAL;
+
+ public static final int VERTICAL = LinearLayout.VERTICAL;
+
+ private int mLastTotalSpace = INVALID_SIZE;
+
+ final Rect mTmpRect = new Rect();
+
+ private OrientationHelper(RecyclerView.LayoutManager layoutManager) {
+ mLayoutManager = layoutManager;
+ }
+
+ /**
+ * Call this method after onLayout method is complete if state is NOT pre-layout.
+ * This method records information like layout bounds that might be useful in the next layout
+ * calculations.
+ */
+ public void onLayoutComplete() {
+ mLastTotalSpace = getTotalSpace();
+ }
+
+ /**
+ * Returns the layout space change between the previous layout pass and current layout pass.
+ * <p>
+ * Make sure you call {@link #onLayoutComplete()} at the end of your LayoutManager's
+ * {@link RecyclerView.LayoutManager#onLayoutChildren(RecyclerView.Recycler,
+ * RecyclerView.State)} method.
+ *
+ * @return The difference between the current total space and previous layout's total space.
+ * @see #onLayoutComplete()
+ */
+ public int getTotalSpaceChange() {
+ return INVALID_SIZE == mLastTotalSpace ? 0 : getTotalSpace() - mLastTotalSpace;
+ }
+
+ /**
+ * Returns the start of the view including its decoration and margin.
+ * <p>
+ * For example, for the horizontal helper, if a View's left is at pixel 20, has 2px left
+ * decoration and 3px left margin, returned value will be 15px.
+ *
+ * @param view The view element to check
+ * @return The first pixel of the element
+ * @see #getDecoratedEnd(android.view.View)
+ */
+ public abstract int getDecoratedStart(View view);
+
+ /**
+ * Returns the end of the view including its decoration and margin.
+ * <p>
+ * For example, for the horizontal helper, if a View's right is at pixel 200, has 2px right
+ * decoration and 3px right margin, returned value will be 205.
+ *
+ * @param view The view element to check
+ * @return The last pixel of the element
+ * @see #getDecoratedStart(android.view.View)
+ */
+ public abstract int getDecoratedEnd(View view);
+
+ /**
+ * Returns the end of the View after its matrix transformations are applied to its layout
+ * position.
+ * <p>
+ * This method is useful when trying to detect the visible edge of a View.
+ * <p>
+ * It includes the decorations but does not include the margins.
+ *
+ * @param view The view whose transformed end will be returned
+ * @return The end of the View after its decor insets and transformation matrix is applied to
+ * its position
+ *
+ * @see RecyclerView.LayoutManager#getTransformedBoundingBox(View, boolean, Rect)
+ */
+ public abstract int getTransformedEndWithDecoration(View view);
+
+ /**
+ * Returns the start of the View after its matrix transformations are applied to its layout
+ * position.
+ * <p>
+ * This method is useful when trying to detect the visible edge of a View.
+ * <p>
+ * It includes the decorations but does not include the margins.
+ *
+ * @param view The view whose transformed start will be returned
+ * @return The start of the View after its decor insets and transformation matrix is applied to
+ * its position
+ *
+ * @see RecyclerView.LayoutManager#getTransformedBoundingBox(View, boolean, Rect)
+ */
+ public abstract int getTransformedStartWithDecoration(View view);
+
+ /**
+ * Returns the space occupied by this View in the current orientation including decorations and
+ * margins.
+ *
+ * @param view The view element to check
+ * @return Total space occupied by this view
+ * @see #getDecoratedMeasurementInOther(View)
+ */
+ public abstract int getDecoratedMeasurement(View view);
+
+ /**
+ * Returns the space occupied by this View in the perpendicular orientation including
+ * decorations and margins.
+ *
+ * @param view The view element to check
+ * @return Total space occupied by this view in the perpendicular orientation to current one
+ * @see #getDecoratedMeasurement(View)
+ */
+ public abstract int getDecoratedMeasurementInOther(View view);
+
+ /**
+ * Returns the start position of the layout after the start padding is added.
+ *
+ * @return The very first pixel we can draw.
+ */
+ public abstract int getStartAfterPadding();
+
+ /**
+ * Returns the end position of the layout after the end padding is removed.
+ *
+ * @return The end boundary for this layout.
+ */
+ public abstract int getEndAfterPadding();
+
+ /**
+ * Returns the end position of the layout without taking padding into account.
+ *
+ * @return The end boundary for this layout without considering padding.
+ */
+ public abstract int getEnd();
+
+ /**
+ * Offsets all children's positions by the given amount.
+ *
+ * @param amount Value to add to each child's layout parameters
+ */
+ public abstract void offsetChildren(int amount);
+
+ /**
+ * Returns the total space to layout. This number is the difference between
+ * {@link #getEndAfterPadding()} and {@link #getStartAfterPadding()}.
+ *
+ * @return Total space to layout children
+ */
+ public abstract int getTotalSpace();
+
+ /**
+ * Offsets the child in this orientation.
+ *
+ * @param view View to offset
+ * @param offset offset amount
+ */
+ public abstract void offsetChild(View view, int offset);
+
+ /**
+ * Returns the padding at the end of the layout. For horizontal helper, this is the right
+ * padding and for vertical helper, this is the bottom padding. This method does not check
+ * whether the layout is RTL or not.
+ *
+ * @return The padding at the end of the layout.
+ */
+ public abstract int getEndPadding();
+
+ /**
+ * Returns the MeasureSpec mode for the current orientation from the LayoutManager.
+ *
+ * @return The current measure spec mode.
+ *
+ * @see View.MeasureSpec
+ * @see RecyclerView.LayoutManager#getWidthMode()
+ * @see RecyclerView.LayoutManager#getHeightMode()
+ */
+ public abstract int getMode();
+
+ /**
+ * Returns the MeasureSpec mode for the perpendicular orientation from the LayoutManager.
+ *
+ * @return The current measure spec mode.
+ *
+ * @see View.MeasureSpec
+ * @see RecyclerView.LayoutManager#getWidthMode()
+ * @see RecyclerView.LayoutManager#getHeightMode()
+ */
+ public abstract int getModeInOther();
+
+ /**
+ * Creates an OrientationHelper for the given LayoutManager and orientation.
+ *
+ * @param layoutManager LayoutManager to attach to
+ * @param orientation Desired orientation. Should be {@link #HORIZONTAL} or {@link #VERTICAL}
+ * @return A new OrientationHelper
+ */
+ public static OrientationHelper createOrientationHelper(
+ RecyclerView.LayoutManager layoutManager, int orientation) {
+ switch (orientation) {
+ case HORIZONTAL:
+ return createHorizontalHelper(layoutManager);
+ case VERTICAL:
+ return createVerticalHelper(layoutManager);
+ }
+ throw new IllegalArgumentException("invalid orientation");
+ }
+
+ /**
+ * Creates a horizontal OrientationHelper for the given LayoutManager.
+ *
+ * @param layoutManager The LayoutManager to attach to.
+ * @return A new OrientationHelper
+ */
+ public static OrientationHelper createHorizontalHelper(
+ RecyclerView.LayoutManager layoutManager) {
+ return new OrientationHelper(layoutManager) {
+ @Override
+ public int getEndAfterPadding() {
+ return mLayoutManager.getWidth() - mLayoutManager.getPaddingRight();
+ }
+
+ @Override
+ public int getEnd() {
+ return mLayoutManager.getWidth();
+ }
+
+ @Override
+ public void offsetChildren(int amount) {
+ mLayoutManager.offsetChildrenHorizontal(amount);
+ }
+
+ @Override
+ public int getStartAfterPadding() {
+ return mLayoutManager.getPaddingLeft();
+ }
+
+ @Override
+ public int getDecoratedMeasurement(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedMeasuredWidth(view) + params.leftMargin
+ + params.rightMargin;
+ }
+
+ @Override
+ public int getDecoratedMeasurementInOther(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedMeasuredHeight(view) + params.topMargin
+ + params.bottomMargin;
+ }
+
+ @Override
+ public int getDecoratedEnd(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedRight(view) + params.rightMargin;
+ }
+
+ @Override
+ public int getDecoratedStart(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedLeft(view) - params.leftMargin;
+ }
+
+ @Override
+ public int getTransformedEndWithDecoration(View view) {
+ mLayoutManager.getTransformedBoundingBox(view, true, mTmpRect);
+ return mTmpRect.right;
+ }
+
+ @Override
+ public int getTransformedStartWithDecoration(View view) {
+ mLayoutManager.getTransformedBoundingBox(view, true, mTmpRect);
+ return mTmpRect.left;
+ }
+
+ @Override
+ public int getTotalSpace() {
+ return mLayoutManager.getWidth() - mLayoutManager.getPaddingLeft()
+ - mLayoutManager.getPaddingRight();
+ }
+
+ @Override
+ public void offsetChild(View view, int offset) {
+ view.offsetLeftAndRight(offset);
+ }
+
+ @Override
+ public int getEndPadding() {
+ return mLayoutManager.getPaddingRight();
+ }
+
+ @Override
+ public int getMode() {
+ return mLayoutManager.getWidthMode();
+ }
+
+ @Override
+ public int getModeInOther() {
+ return mLayoutManager.getHeightMode();
+ }
+ };
+ }
+
+ /**
+ * Creates a vertical OrientationHelper for the given LayoutManager.
+ *
+ * @param layoutManager The LayoutManager to attach to.
+ * @return A new OrientationHelper
+ */
+ public static OrientationHelper createVerticalHelper(RecyclerView.LayoutManager layoutManager) {
+ return new OrientationHelper(layoutManager) {
+ @Override
+ public int getEndAfterPadding() {
+ return mLayoutManager.getHeight() - mLayoutManager.getPaddingBottom();
+ }
+
+ @Override
+ public int getEnd() {
+ return mLayoutManager.getHeight();
+ }
+
+ @Override
+ public void offsetChildren(int amount) {
+ mLayoutManager.offsetChildrenVertical(amount);
+ }
+
+ @Override
+ public int getStartAfterPadding() {
+ return mLayoutManager.getPaddingTop();
+ }
+
+ @Override
+ public int getDecoratedMeasurement(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedMeasuredHeight(view) + params.topMargin
+ + params.bottomMargin;
+ }
+
+ @Override
+ public int getDecoratedMeasurementInOther(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedMeasuredWidth(view) + params.leftMargin
+ + params.rightMargin;
+ }
+
+ @Override
+ public int getDecoratedEnd(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedBottom(view) + params.bottomMargin;
+ }
+
+ @Override
+ public int getDecoratedStart(View view) {
+ final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams)
+ view.getLayoutParams();
+ return mLayoutManager.getDecoratedTop(view) - params.topMargin;
+ }
+
+ @Override
+ public int getTransformedEndWithDecoration(View view) {
+ mLayoutManager.getTransformedBoundingBox(view, true, mTmpRect);
+ return mTmpRect.bottom;
+ }
+
+ @Override
+ public int getTransformedStartWithDecoration(View view) {
+ mLayoutManager.getTransformedBoundingBox(view, true, mTmpRect);
+ return mTmpRect.top;
+ }
+
+ @Override
+ public int getTotalSpace() {
+ return mLayoutManager.getHeight() - mLayoutManager.getPaddingTop()
+ - mLayoutManager.getPaddingBottom();
+ }
+
+ @Override
+ public void offsetChild(View view, int offset) {
+ view.offsetTopAndBottom(offset);
+ }
+
+ @Override
+ public int getEndPadding() {
+ return mLayoutManager.getPaddingBottom();
+ }
+
+ @Override
+ public int getMode() {
+ return mLayoutManager.getHeightMode();
+ }
+
+ @Override
+ public int getModeInOther() {
+ return mLayoutManager.getWidthMode();
+ }
+ };
+ }
+}
diff --git a/core/java/com/android/internal/widget/RecyclerView.java b/core/java/com/android/internal/widget/RecyclerView.java
new file mode 100644
index 0000000..0cf3164
--- /dev/null
+++ b/core/java/com/android/internal/widget/RecyclerView.java
@@ -0,0 +1,12255 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.annotation.CallSuper;
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.database.Observable;
+import android.graphics.Canvas;
+import android.graphics.Matrix;
+import android.graphics.PointF;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.os.SystemClock;
+import android.os.Trace;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.util.SparseArray;
+import android.util.TypedValue;
+import android.view.AbsSavedState;
+import android.view.Display;
+import android.view.FocusFinder;
+import android.view.InputDevice;
+import android.view.MotionEvent;
+import android.view.VelocityTracker;
+import android.view.View;
+import android.view.ViewConfiguration;
+import android.view.ViewGroup;
+import android.view.ViewParent;
+import android.view.accessibility.AccessibilityEvent;
+import android.view.accessibility.AccessibilityManager;
+import android.view.accessibility.AccessibilityNodeInfo;
+import android.view.animation.Interpolator;
+import android.widget.EdgeEffect;
+import android.widget.OverScroller;
+
+import com.android.internal.R;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.widget.RecyclerView.ItemAnimator.ItemHolderInfo;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.ref.WeakReference;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A flexible view for providing a limited window into a large data set.
+ *
+ * <h3>Glossary of terms:</h3>
+ *
+ * <ul>
+ * <li><em>Adapter:</em> A subclass of {@link Adapter} responsible for providing views
+ * that represent items in a data set.</li>
+ * <li><em>Position:</em> The position of a data item within an <em>Adapter</em>.</li>
+ * <li><em>Index:</em> The index of an attached child view as used in a call to
+ * {@link ViewGroup#getChildAt}. Contrast with <em>Position.</em></li>
+ * <li><em>Binding:</em> The process of preparing a child view to display data corresponding
+ * to a <em>position</em> within the adapter.</li>
+ * <li><em>Recycle (view):</em> A view previously used to display data for a specific adapter
+ * position may be placed in a cache for later reuse to display the same type of data again
+ * later. This can drastically improve performance by skipping initial layout inflation
+ * or construction.</li>
+ * <li><em>Scrap (view):</em> A child view that has entered into a temporarily detached
+ * state during layout. Scrap views may be reused without becoming fully detached
+ * from the parent RecyclerView, either unmodified if no rebinding is required or modified
+ * by the adapter if the view was considered <em>dirty</em>.</li>
+ * <li><em>Dirty (view):</em> A child view that must be rebound by the adapter before
+ * being displayed.</li>
+ * </ul>
+ *
+ * <h4>Positions in RecyclerView:</h4>
+ * <p>
+ * RecyclerView introduces an additional level of abstraction between the {@link Adapter} and
+ * {@link LayoutManager} to be able to detect data set changes in batches during a layout
+ * calculation. This saves LayoutManager from tracking adapter changes to calculate animations.
+ * It also helps with performance because all view bindings happen at the same time and unnecessary
+ * bindings are avoided.
+ * <p>
+ * For this reason, there are two types of <code>position</code> related methods in RecyclerView:
+ * <ul>
+ * <li>layout position: Position of an item in the latest layout calculation. This is the
+ * position from the LayoutManager's perspective.</li>
+ * <li>adapter position: Position of an item in the adapter. This is the position from
+ * the Adapter's perspective.</li>
+ * </ul>
+ * <p>
+ * These two positions are the same except the time between dispatching <code>adapter.notify*
+ * </code> events and calculating the updated layout.
+ * <p>
+ * Methods that return or receive <code>*LayoutPosition*</code> use position as of the latest
+ * layout calculation (e.g. {@link ViewHolder#getLayoutPosition()},
+ * {@link #findViewHolderForLayoutPosition(int)}). These positions include all changes until the
+ * last layout calculation. You can rely on these positions to be consistent with what user is
+ * currently seeing on the screen. For example, if you have a list of items on the screen and user
+ * asks for the 5<sup>th</sup> element, you should use these methods as they'll match what user
+ * is seeing.
+ * <p>
+ * The other set of position related methods are in the form of
+ * <code>*AdapterPosition*</code>. (e.g. {@link ViewHolder#getAdapterPosition()},
+ * {@link #findViewHolderForAdapterPosition(int)}) You should use these methods when you need to
+ * work with up-to-date adapter positions even if they may not have been reflected to layout yet.
+ * For example, if you want to access the item in the adapter on a ViewHolder click, you should use
+ * {@link ViewHolder#getAdapterPosition()}. Beware that these methods may not be able to calculate
+ * adapter positions if {@link Adapter#notifyDataSetChanged()} has been called and new layout has
+ * not yet been calculated. For this reasons, you should carefully handle {@link #NO_POSITION} or
+ * <code>null</code> results from these methods.
+ * <p>
+ * When writing a {@link LayoutManager} you almost always want to use layout positions whereas when
+ * writing an {@link Adapter}, you probably want to use adapter positions.
+ *
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_layoutManager
+ */
+public class RecyclerView extends ViewGroup implements ScrollingView, NestedScrollingChild {
+
+ static final String TAG = "RecyclerView";
+
+ static final boolean DEBUG = false;
+
+ private static final int[] NESTED_SCROLLING_ATTRS = { android.R.attr.nestedScrollingEnabled };
+
+ private static final int[] CLIP_TO_PADDING_ATTR = {android.R.attr.clipToPadding};
+
+ /**
+ * On Kitkat and JB MR2, there is a bug which prevents DisplayList from being invalidated if
+ * a View is two levels deep(wrt to ViewHolder.itemView). DisplayList can be invalidated by
+ * setting View's visibility to INVISIBLE when View is detached. On Kitkat and JB MR2, Recycler
+ * recursively traverses itemView and invalidates display list for each ViewGroup that matches
+ * this criteria.
+ */
+ static final boolean FORCE_INVALIDATE_DISPLAY_LIST = Build.VERSION.SDK_INT == 18
+ || Build.VERSION.SDK_INT == 19 || Build.VERSION.SDK_INT == 20;
+ /**
+ * On M+, an unspecified measure spec may include a hint which we can use. On older platforms,
+ * this value might be garbage. To save LayoutManagers from it, RecyclerView sets the size to
+ * 0 when mode is unspecified.
+ */
+ static final boolean ALLOW_SIZE_IN_UNSPECIFIED_SPEC = Build.VERSION.SDK_INT >= 23;
+
+ static final boolean POST_UPDATES_ON_ANIMATION = Build.VERSION.SDK_INT >= 16;
+
+ /**
+ * On L+, with RenderThread, the UI thread has idle time after it has passed a frame off to
+ * RenderThread but before the next frame begins. We schedule prefetch work in this window.
+ */
+ private static final boolean ALLOW_THREAD_GAP_WORK = Build.VERSION.SDK_INT >= 21;
+
+ /**
+ * FocusFinder#findNextFocus is broken on ICS MR1 and older for View.FOCUS_BACKWARD direction.
+ * We convert it to an absolute direction such as FOCUS_DOWN or FOCUS_LEFT.
+ */
+ private static final boolean FORCE_ABS_FOCUS_SEARCH_DIRECTION = Build.VERSION.SDK_INT <= 15;
+
+ /**
+ * on API 15-, a focused child can still be considered a focused child of RV even after
+ * it's being removed or its focusable flag is set to false. This is because when this focused
+ * child is detached, the reference to this child is not removed in clearFocus. API 16 and above
+ * properly handle this case by calling ensureInputFocusOnFirstFocusable or rootViewRequestFocus
+ * to request focus on a new child, which will clear the focus on the old (detached) child as a
+ * side-effect.
+ */
+ private static final boolean IGNORE_DETACHED_FOCUSED_CHILD = Build.VERSION.SDK_INT <= 15;
+
+ static final boolean DISPATCH_TEMP_DETACH = false;
+ public static final int HORIZONTAL = 0;
+ public static final int VERTICAL = 1;
+
+ public static final int NO_POSITION = -1;
+ public static final long NO_ID = -1;
+ public static final int INVALID_TYPE = -1;
+
+ /**
+ * Constant for use with {@link #setScrollingTouchSlop(int)}. Indicates
+ * that the RecyclerView should use the standard touch slop for smooth,
+ * continuous scrolling.
+ */
+ public static final int TOUCH_SLOP_DEFAULT = 0;
+
+ /**
+ * Constant for use with {@link #setScrollingTouchSlop(int)}. Indicates
+ * that the RecyclerView should use the standard touch slop for scrolling
+ * widgets that snap to a page or other coarse-grained barrier.
+ */
+ public static final int TOUCH_SLOP_PAGING = 1;
+
+ static final int MAX_SCROLL_DURATION = 2000;
+
+ /**
+ * RecyclerView is calculating a scroll.
+ * If there are too many of these in Systrace, some Views inside RecyclerView might be causing
+ * it. Try to avoid using EditText, focusable views or handle them with care.
+ */
+ static final String TRACE_SCROLL_TAG = "RV Scroll";
+
+ /**
+ * OnLayout has been called by the View system.
+ * If this shows up too many times in Systrace, make sure the children of RecyclerView do not
+ * update themselves directly. This will cause a full re-layout but when it happens via the
+ * Adapter notifyItemChanged, RecyclerView can avoid full layout calculation.
+ */
+ private static final String TRACE_ON_LAYOUT_TAG = "RV OnLayout";
+
+ /**
+ * NotifyDataSetChanged or equal has been called.
+ * If this is taking a long time, try sending granular notify adapter changes instead of just
+ * calling notifyDataSetChanged or setAdapter / swapAdapter. Adding stable ids to your adapter
+ * might help.
+ */
+ private static final String TRACE_ON_DATA_SET_CHANGE_LAYOUT_TAG = "RV FullInvalidate";
+
+ /**
+ * RecyclerView is doing a layout for partial adapter updates (we know what has changed)
+ * If this is taking a long time, you may have dispatched too many Adapter updates causing too
+ * many Views being rebind. Make sure all are necessary and also prefer using notify*Range
+ * methods.
+ */
+ private static final String TRACE_HANDLE_ADAPTER_UPDATES_TAG = "RV PartialInvalidate";
+
+ /**
+ * RecyclerView is rebinding a View.
+ * If this is taking a lot of time, consider optimizing your layout or make sure you are not
+ * doing extra operations in onBindViewHolder call.
+ */
+ static final String TRACE_BIND_VIEW_TAG = "RV OnBindView";
+
+ /**
+ * RecyclerView is attempting to pre-populate off screen views.
+ */
+ static final String TRACE_PREFETCH_TAG = "RV Prefetch";
+
+ /**
+ * RecyclerView is attempting to pre-populate off screen itemviews within an off screen
+ * RecyclerView.
+ */
+ static final String TRACE_NESTED_PREFETCH_TAG = "RV Nested Prefetch";
+
+ /**
+ * RecyclerView is creating a new View.
+ * If too many of these present in Systrace:
+ * - There might be a problem in Recycling (e.g. custom Animations that set transient state and
+ * prevent recycling or ItemAnimator not implementing the contract properly. ({@link
+ * > Adapter#onFailedToRecycleView(ViewHolder)})
+ *
+ * - There might be too many item view types.
+ * > Try merging them
+ *
+ * - There might be too many itemChange animations and not enough space in RecyclerPool.
+ * >Try increasing your pool size and item cache size.
+ */
+ static final String TRACE_CREATE_VIEW_TAG = "RV CreateView";
+ private static final Class<?>[] LAYOUT_MANAGER_CONSTRUCTOR_SIGNATURE =
+ new Class[]{Context.class, AttributeSet.class, int.class, int.class};
+
+ private final RecyclerViewDataObserver mObserver = new RecyclerViewDataObserver();
+
+ final Recycler mRecycler = new Recycler();
+
+ private SavedState mPendingSavedState;
+
+ /**
+ * Handles adapter updates
+ */
+ AdapterHelper mAdapterHelper;
+
+ /**
+ * Handles abstraction between LayoutManager children and RecyclerView children
+ */
+ ChildHelper mChildHelper;
+
+ /**
+ * Keeps data about views to be used for animations
+ */
+ final ViewInfoStore mViewInfoStore = new ViewInfoStore();
+
+ /**
+ * Prior to L, there is no way to query this variable which is why we override the setter and
+ * track it here.
+ */
+ boolean mClipToPadding;
+
+ /**
+ * Note: this Runnable is only ever posted if:
+ * 1) We've been through first layout
+ * 2) We know we have a fixed size (mHasFixedSize)
+ * 3) We're attached
+ */
+ final Runnable mUpdateChildViewsRunnable = new Runnable() {
+ @Override
+ public void run() {
+ if (!mFirstLayoutComplete || isLayoutRequested()) {
+ // a layout request will happen, we should not do layout here.
+ return;
+ }
+ if (!mIsAttached) {
+ requestLayout();
+ // if we are not attached yet, mark us as requiring layout and skip
+ return;
+ }
+ if (mLayoutFrozen) {
+ mLayoutRequestEaten = true;
+ return; //we'll process updates when ice age ends.
+ }
+ consumePendingUpdateOperations();
+ }
+ };
+
+ final Rect mTempRect = new Rect();
+ private final Rect mTempRect2 = new Rect();
+ final RectF mTempRectF = new RectF();
+ Adapter mAdapter;
+ @VisibleForTesting LayoutManager mLayout;
+ RecyclerListener mRecyclerListener;
+ final ArrayList<ItemDecoration> mItemDecorations = new ArrayList<>();
+ private final ArrayList<OnItemTouchListener> mOnItemTouchListeners =
+ new ArrayList<>();
+ private OnItemTouchListener mActiveOnItemTouchListener;
+ boolean mIsAttached;
+ boolean mHasFixedSize;
+ @VisibleForTesting boolean mFirstLayoutComplete;
+
+ // Counting lock to control whether we should ignore requestLayout calls from children or not.
+ private int mEatRequestLayout = 0;
+
+ boolean mLayoutRequestEaten;
+ boolean mLayoutFrozen;
+ private boolean mIgnoreMotionEventTillDown;
+
+ // binary OR of change events that were eaten during a layout or scroll.
+ private int mEatenAccessibilityChangeFlags;
+ boolean mAdapterUpdateDuringMeasure;
+
+ private final AccessibilityManager mAccessibilityManager;
+ private List<OnChildAttachStateChangeListener> mOnChildAttachStateListeners;
+
+ /**
+ * Set to true when an adapter data set changed notification is received.
+ * In that case, we cannot run any animations since we don't know what happened until layout.
+ *
+ * Attached items are invalid until next layout, at which point layout will animate/replace
+ * items as necessary, building up content from the (effectively) new adapter from scratch.
+ *
+ * Cached items must be discarded when setting this to true, so that the cache may be freely
+ * used by prefetching until the next layout occurs.
+ *
+ * @see #setDataSetChangedAfterLayout()
+ */
+ boolean mDataSetHasChangedAfterLayout = false;
+
+ /**
+ * This variable is incremented during a dispatchLayout and/or scroll.
+ * Some methods should not be called during these periods (e.g. adapter data change).
+ * Doing so will create hard to find bugs so we better check it and throw an exception.
+ *
+ * @see #assertInLayoutOrScroll(String)
+ * @see #assertNotInLayoutOrScroll(String)
+ */
+ private int mLayoutOrScrollCounter = 0;
+
+ /**
+ * Similar to mLayoutOrScrollCounter but logs a warning instead of throwing an exception
+ * (for API compatibility).
+ * <p>
+ * It is a bad practice for a developer to update the data in a scroll callback since it is
+ * potentially called during a layout.
+ */
+ private int mDispatchScrollCounter = 0;
+
+ private EdgeEffect mLeftGlow, mTopGlow, mRightGlow, mBottomGlow;
+
+ ItemAnimator mItemAnimator = new DefaultItemAnimator();
+
+ private static final int INVALID_POINTER = -1;
+
+ /**
+ * The RecyclerView is not currently scrolling.
+ * @see #getScrollState()
+ */
+ public static final int SCROLL_STATE_IDLE = 0;
+
+ /**
+ * The RecyclerView is currently being dragged by outside input such as user touch input.
+ * @see #getScrollState()
+ */
+ public static final int SCROLL_STATE_DRAGGING = 1;
+
+ /**
+ * The RecyclerView is currently animating to a final position while not under
+ * outside control.
+ * @see #getScrollState()
+ */
+ public static final int SCROLL_STATE_SETTLING = 2;
+
+ static final long FOREVER_NS = Long.MAX_VALUE;
+
+ // Touch/scrolling handling
+
+ private int mScrollState = SCROLL_STATE_IDLE;
+ private int mScrollPointerId = INVALID_POINTER;
+ private VelocityTracker mVelocityTracker;
+ private int mInitialTouchX;
+ private int mInitialTouchY;
+ private int mLastTouchX;
+ private int mLastTouchY;
+ private int mTouchSlop;
+ private OnFlingListener mOnFlingListener;
+ private final int mMinFlingVelocity;
+ private final int mMaxFlingVelocity;
+ // This value is used when handling generic motion events.
+ private float mScrollFactor = Float.MIN_VALUE;
+ private boolean mPreserveFocusAfterLayout = true;
+
+ final ViewFlinger mViewFlinger = new ViewFlinger();
+
+ GapWorker mGapWorker;
+ GapWorker.LayoutPrefetchRegistryImpl mPrefetchRegistry =
+ ALLOW_THREAD_GAP_WORK ? new GapWorker.LayoutPrefetchRegistryImpl() : null;
+
+ final State mState = new State();
+
+ private OnScrollListener mScrollListener;
+ private List<OnScrollListener> mScrollListeners;
+
+ // For use in item animations
+ boolean mItemsAddedOrRemoved = false;
+ boolean mItemsChanged = false;
+ private ItemAnimator.ItemAnimatorListener mItemAnimatorListener =
+ new ItemAnimatorRestoreListener();
+ boolean mPostedAnimatorRunner = false;
+ RecyclerViewAccessibilityDelegate mAccessibilityDelegate;
+ private ChildDrawingOrderCallback mChildDrawingOrderCallback;
+
+ // simple array to keep min and max child position during a layout calculation
+ // preserved not to create a new one in each layout pass
+ private final int[] mMinMaxLayoutPositions = new int[2];
+
+ private final int[] mScrollOffset = new int[2];
+ private final int[] mScrollConsumed = new int[2];
+ private final int[] mNestedOffsets = new int[2];
+
+ /**
+ * These are views that had their a11y importance changed during a layout. We defer these events
+ * until the end of the layout because a11y service may make sync calls back to the RV while
+ * the View's state is undefined.
+ */
+ @VisibleForTesting
+ final List<ViewHolder> mPendingAccessibilityImportanceChange = new ArrayList();
+
+ private Runnable mItemAnimatorRunner = new Runnable() {
+ @Override
+ public void run() {
+ if (mItemAnimator != null) {
+ mItemAnimator.runPendingAnimations();
+ }
+ mPostedAnimatorRunner = false;
+ }
+ };
+
+ static final Interpolator sQuinticInterpolator = new Interpolator() {
+ @Override
+ public float getInterpolation(float t) {
+ t -= 1.0f;
+ return t * t * t * t * t + 1.0f;
+ }
+ };
+
+ /**
+ * The callback to convert view info diffs into animations.
+ */
+ private final ViewInfoStore.ProcessCallback mViewInfoProcessCallback =
+ new ViewInfoStore.ProcessCallback() {
+ @Override
+ public void processDisappeared(ViewHolder viewHolder, @NonNull ItemHolderInfo info,
+ @Nullable ItemHolderInfo postInfo) {
+ mRecycler.unscrapView(viewHolder);
+ animateDisappearance(viewHolder, info, postInfo);
+ }
+ @Override
+ public void processAppeared(ViewHolder viewHolder,
+ ItemHolderInfo preInfo, ItemHolderInfo info) {
+ animateAppearance(viewHolder, preInfo, info);
+ }
+
+ @Override
+ public void processPersistent(ViewHolder viewHolder,
+ @NonNull ItemHolderInfo preInfo, @NonNull ItemHolderInfo postInfo) {
+ viewHolder.setIsRecyclable(false);
+ if (mDataSetHasChangedAfterLayout) {
+ // since it was rebound, use change instead as we'll be mapping them from
+ // stable ids. If stable ids were false, we would not be running any
+ // animations
+ if (mItemAnimator.animateChange(viewHolder, viewHolder, preInfo, postInfo)) {
+ postAnimationRunner();
+ }
+ } else if (mItemAnimator.animatePersistence(viewHolder, preInfo, postInfo)) {
+ postAnimationRunner();
+ }
+ }
+ @Override
+ public void unused(ViewHolder viewHolder) {
+ mLayout.removeAndRecycleView(viewHolder.itemView, mRecycler);
+ }
+ };
+
+ public RecyclerView(Context context) {
+ this(context, null);
+ }
+
+ public RecyclerView(Context context, @Nullable AttributeSet attrs) {
+ this(context, attrs, 0);
+ }
+
+ public RecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
+ super(context, attrs, defStyle);
+ if (attrs != null) {
+ TypedArray a = context.obtainStyledAttributes(attrs, CLIP_TO_PADDING_ATTR, defStyle, 0);
+ mClipToPadding = a.getBoolean(0, true);
+ a.recycle();
+ } else {
+ mClipToPadding = true;
+ }
+ setScrollContainer(true);
+ setFocusableInTouchMode(true);
+
+ final ViewConfiguration vc = ViewConfiguration.get(context);
+ mTouchSlop = vc.getScaledTouchSlop();
+ mMinFlingVelocity = vc.getScaledMinimumFlingVelocity();
+ mMaxFlingVelocity = vc.getScaledMaximumFlingVelocity();
+ setWillNotDraw(getOverScrollMode() == View.OVER_SCROLL_NEVER);
+
+ mItemAnimator.setListener(mItemAnimatorListener);
+ initAdapterManager();
+ initChildrenHelper();
+ // If not explicitly specified this view is important for accessibility.
+ if (getImportantForAccessibility() == View.IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
+ setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
+ }
+ mAccessibilityManager = (AccessibilityManager) getContext()
+ .getSystemService(Context.ACCESSIBILITY_SERVICE);
+ setAccessibilityDelegateCompat(new RecyclerViewAccessibilityDelegate(this));
+ // Create the layoutManager if specified.
+
+ boolean nestedScrollingEnabled = true;
+
+ if (attrs != null) {
+ int defStyleRes = 0;
+ TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RecyclerView,
+ defStyle, defStyleRes);
+ String layoutManagerName = a.getString(R.styleable.RecyclerView_layoutManager);
+ int descendantFocusability = a.getInt(
+ R.styleable.RecyclerView_descendantFocusability, -1);
+ if (descendantFocusability == -1) {
+ setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
+ }
+ a.recycle();
+ createLayoutManager(context, layoutManagerName, attrs, defStyle, defStyleRes);
+
+ if (Build.VERSION.SDK_INT >= 21) {
+ a = context.obtainStyledAttributes(attrs, NESTED_SCROLLING_ATTRS,
+ defStyle, defStyleRes);
+ nestedScrollingEnabled = a.getBoolean(0, true);
+ a.recycle();
+ }
+ } else {
+ setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
+ }
+
+ // Re-set whether nested scrolling is enabled so that it is set on all API levels
+ setNestedScrollingEnabled(nestedScrollingEnabled);
+ }
+
+ /**
+ * Returns the accessibility delegate compatibility implementation used by the RecyclerView.
+ * @return An instance of AccessibilityDelegateCompat used by RecyclerView
+ */
+ public RecyclerViewAccessibilityDelegate getCompatAccessibilityDelegate() {
+ return mAccessibilityDelegate;
+ }
+
+ /**
+ * Sets the accessibility delegate compatibility implementation used by RecyclerView.
+ * @param accessibilityDelegate The accessibility delegate to be used by RecyclerView.
+ */
+ public void setAccessibilityDelegateCompat(
+ RecyclerViewAccessibilityDelegate accessibilityDelegate) {
+ mAccessibilityDelegate = accessibilityDelegate;
+ setAccessibilityDelegate(mAccessibilityDelegate);
+ }
+
+ /**
+ * Instantiate and set a LayoutManager, if specified in the attributes.
+ */
+ private void createLayoutManager(Context context, String className, AttributeSet attrs,
+ int defStyleAttr, int defStyleRes) {
+ if (className != null) {
+ className = className.trim();
+ if (className.length() != 0) { // Can't use isEmpty since it was added in API 9.
+ className = getFullClassName(context, className);
+ try {
+ ClassLoader classLoader;
+ if (isInEditMode()) {
+ // Stupid layoutlib cannot handle simple class loaders.
+ classLoader = this.getClass().getClassLoader();
+ } else {
+ classLoader = context.getClassLoader();
+ }
+ Class<? extends LayoutManager> layoutManagerClass =
+ classLoader.loadClass(className).asSubclass(LayoutManager.class);
+ Constructor<? extends LayoutManager> constructor;
+ Object[] constructorArgs = null;
+ try {
+ constructor = layoutManagerClass
+ .getConstructor(LAYOUT_MANAGER_CONSTRUCTOR_SIGNATURE);
+ constructorArgs = new Object[]{context, attrs, defStyleAttr, defStyleRes};
+ } catch (NoSuchMethodException e) {
+ try {
+ constructor = layoutManagerClass.getConstructor();
+ } catch (NoSuchMethodException e1) {
+ e1.initCause(e);
+ throw new IllegalStateException(attrs.getPositionDescription()
+ + ": Error creating LayoutManager " + className, e1);
+ }
+ }
+ constructor.setAccessible(true);
+ setLayoutManager(constructor.newInstance(constructorArgs));
+ } catch (ClassNotFoundException e) {
+ throw new IllegalStateException(attrs.getPositionDescription()
+ + ": Unable to find LayoutManager " + className, e);
+ } catch (InvocationTargetException e) {
+ throw new IllegalStateException(attrs.getPositionDescription()
+ + ": Could not instantiate the LayoutManager: " + className, e);
+ } catch (InstantiationException e) {
+ throw new IllegalStateException(attrs.getPositionDescription()
+ + ": Could not instantiate the LayoutManager: " + className, e);
+ } catch (IllegalAccessException e) {
+ throw new IllegalStateException(attrs.getPositionDescription()
+ + ": Cannot access non-public constructor " + className, e);
+ } catch (ClassCastException e) {
+ throw new IllegalStateException(attrs.getPositionDescription()
+ + ": Class is not a LayoutManager " + className, e);
+ }
+ }
+ }
+ }
+
+ private String getFullClassName(Context context, String className) {
+ if (className.charAt(0) == '.') {
+ return context.getPackageName() + className;
+ }
+ if (className.contains(".")) {
+ return className;
+ }
+ return RecyclerView.class.getPackage().getName() + '.' + className;
+ }
+
+ private void initChildrenHelper() {
+ mChildHelper = new ChildHelper(new ChildHelper.Callback() {
+ @Override
+ public int getChildCount() {
+ return RecyclerView.this.getChildCount();
+ }
+
+ @Override
+ public void addView(View child, int index) {
+ RecyclerView.this.addView(child, index);
+ dispatchChildAttached(child);
+ }
+
+ @Override
+ public int indexOfChild(View view) {
+ return RecyclerView.this.indexOfChild(view);
+ }
+
+ @Override
+ public void removeViewAt(int index) {
+ final View child = RecyclerView.this.getChildAt(index);
+ if (child != null) {
+ dispatchChildDetached(child);
+ }
+ RecyclerView.this.removeViewAt(index);
+ }
+
+ @Override
+ public View getChildAt(int offset) {
+ return RecyclerView.this.getChildAt(offset);
+ }
+
+ @Override
+ public void removeAllViews() {
+ final int count = getChildCount();
+ for (int i = 0; i < count; i++) {
+ dispatchChildDetached(getChildAt(i));
+ }
+ RecyclerView.this.removeAllViews();
+ }
+
+ @Override
+ public ViewHolder getChildViewHolder(View view) {
+ return getChildViewHolderInt(view);
+ }
+
+ @Override
+ public void attachViewToParent(View child, int index,
+ ViewGroup.LayoutParams layoutParams) {
+ final ViewHolder vh = getChildViewHolderInt(child);
+ if (vh != null) {
+ if (!vh.isTmpDetached() && !vh.shouldIgnore()) {
+ throw new IllegalArgumentException("Called attach on a child which is not"
+ + " detached: " + vh);
+ }
+ if (DEBUG) {
+ Log.d(TAG, "reAttach " + vh);
+ }
+ vh.clearTmpDetachFlag();
+ }
+ RecyclerView.this.attachViewToParent(child, index, layoutParams);
+ }
+
+ @Override
+ public void detachViewFromParent(int offset) {
+ final View view = getChildAt(offset);
+ if (view != null) {
+ final ViewHolder vh = getChildViewHolderInt(view);
+ if (vh != null) {
+ if (vh.isTmpDetached() && !vh.shouldIgnore()) {
+ throw new IllegalArgumentException("called detach on an already"
+ + " detached child " + vh);
+ }
+ if (DEBUG) {
+ Log.d(TAG, "tmpDetach " + vh);
+ }
+ vh.addFlags(ViewHolder.FLAG_TMP_DETACHED);
+ }
+ }
+ RecyclerView.this.detachViewFromParent(offset);
+ }
+
+ @Override
+ public void onEnteredHiddenState(View child) {
+ final ViewHolder vh = getChildViewHolderInt(child);
+ if (vh != null) {
+ vh.onEnteredHiddenState(RecyclerView.this);
+ }
+ }
+
+ @Override
+ public void onLeftHiddenState(View child) {
+ final ViewHolder vh = getChildViewHolderInt(child);
+ if (vh != null) {
+ vh.onLeftHiddenState(RecyclerView.this);
+ }
+ }
+ });
+ }
+
+ void initAdapterManager() {
+ mAdapterHelper = new AdapterHelper(new AdapterHelper.Callback() {
+ @Override
+ public ViewHolder findViewHolder(int position) {
+ final ViewHolder vh = findViewHolderForPosition(position, true);
+ if (vh == null) {
+ return null;
+ }
+ // ensure it is not hidden because for adapter helper, the only thing matter is that
+ // LM thinks view is a child.
+ if (mChildHelper.isHidden(vh.itemView)) {
+ if (DEBUG) {
+ Log.d(TAG, "assuming view holder cannot be find because it is hidden");
+ }
+ return null;
+ }
+ return vh;
+ }
+
+ @Override
+ public void offsetPositionsForRemovingInvisible(int start, int count) {
+ offsetPositionRecordsForRemove(start, count, true);
+ mItemsAddedOrRemoved = true;
+ mState.mDeletedInvisibleItemCountSincePreviousLayout += count;
+ }
+
+ @Override
+ public void offsetPositionsForRemovingLaidOutOrNewView(
+ int positionStart, int itemCount) {
+ offsetPositionRecordsForRemove(positionStart, itemCount, false);
+ mItemsAddedOrRemoved = true;
+ }
+
+ @Override
+ public void markViewHoldersUpdated(int positionStart, int itemCount, Object payload) {
+ viewRangeUpdate(positionStart, itemCount, payload);
+ mItemsChanged = true;
+ }
+
+ @Override
+ public void onDispatchFirstPass(AdapterHelper.UpdateOp op) {
+ dispatchUpdate(op);
+ }
+
+ void dispatchUpdate(AdapterHelper.UpdateOp op) {
+ switch (op.cmd) {
+ case AdapterHelper.UpdateOp.ADD:
+ mLayout.onItemsAdded(RecyclerView.this, op.positionStart, op.itemCount);
+ break;
+ case AdapterHelper.UpdateOp.REMOVE:
+ mLayout.onItemsRemoved(RecyclerView.this, op.positionStart, op.itemCount);
+ break;
+ case AdapterHelper.UpdateOp.UPDATE:
+ mLayout.onItemsUpdated(RecyclerView.this, op.positionStart, op.itemCount,
+ op.payload);
+ break;
+ case AdapterHelper.UpdateOp.MOVE:
+ mLayout.onItemsMoved(RecyclerView.this, op.positionStart, op.itemCount, 1);
+ break;
+ }
+ }
+
+ @Override
+ public void onDispatchSecondPass(AdapterHelper.UpdateOp op) {
+ dispatchUpdate(op);
+ }
+
+ @Override
+ public void offsetPositionsForAdd(int positionStart, int itemCount) {
+ offsetPositionRecordsForInsert(positionStart, itemCount);
+ mItemsAddedOrRemoved = true;
+ }
+
+ @Override
+ public void offsetPositionsForMove(int from, int to) {
+ offsetPositionRecordsForMove(from, to);
+ // should we create mItemsMoved ?
+ mItemsAddedOrRemoved = true;
+ }
+ });
+ }
+
+ /**
+ * RecyclerView can perform several optimizations if it can know in advance that RecyclerView's
+ * size is not affected by the adapter contents. RecyclerView can still change its size based
+ * on other factors (e.g. its parent's size) but this size calculation cannot depend on the
+ * size of its children or contents of its adapter (except the number of items in the adapter).
+ * <p>
+ * If your use of RecyclerView falls into this category, set this to {@code true}. It will allow
+ * RecyclerView to avoid invalidating the whole layout when its adapter contents change.
+ *
+ * @param hasFixedSize true if adapter changes cannot affect the size of the RecyclerView.
+ */
+ public void setHasFixedSize(boolean hasFixedSize) {
+ mHasFixedSize = hasFixedSize;
+ }
+
+ /**
+ * @return true if the app has specified that changes in adapter content cannot change
+ * the size of the RecyclerView itself.
+ */
+ public boolean hasFixedSize() {
+ return mHasFixedSize;
+ }
+
+ @Override
+ public void setClipToPadding(boolean clipToPadding) {
+ if (clipToPadding != mClipToPadding) {
+ invalidateGlows();
+ }
+ mClipToPadding = clipToPadding;
+ super.setClipToPadding(clipToPadding);
+ if (mFirstLayoutComplete) {
+ requestLayout();
+ }
+ }
+
+ /**
+ * Returns whether this RecyclerView will clip its children to its padding, and resize (but
+ * not clip) any EdgeEffect to the padded region, if padding is present.
+ * <p>
+ * By default, children are clipped to the padding of their parent
+ * RecyclerView. This clipping behavior is only enabled if padding is non-zero.
+ *
+ * @return true if this RecyclerView clips children to its padding and resizes (but doesn't
+ * clip) any EdgeEffect to the padded region, false otherwise.
+ *
+ * @attr name android:clipToPadding
+ */
+ @Override
+ public boolean getClipToPadding() {
+ return mClipToPadding;
+ }
+
+ /**
+ * Configure the scrolling touch slop for a specific use case.
+ *
+ * Set up the RecyclerView's scrolling motion threshold based on common usages.
+ * Valid arguments are {@link #TOUCH_SLOP_DEFAULT} and {@link #TOUCH_SLOP_PAGING}.
+ *
+ * @param slopConstant One of the <code>TOUCH_SLOP_</code> constants representing
+ * the intended usage of this RecyclerView
+ */
+ public void setScrollingTouchSlop(int slopConstant) {
+ final ViewConfiguration vc = ViewConfiguration.get(getContext());
+ switch (slopConstant) {
+ default:
+ Log.w(TAG, "setScrollingTouchSlop(): bad argument constant "
+ + slopConstant + "; using default value");
+ // fall-through
+ case TOUCH_SLOP_DEFAULT:
+ mTouchSlop = vc.getScaledTouchSlop();
+ break;
+
+ case TOUCH_SLOP_PAGING:
+ mTouchSlop = vc.getScaledPagingTouchSlop();
+ break;
+ }
+ }
+
+ /**
+ * Swaps the current adapter with the provided one. It is similar to
+ * {@link #setAdapter(Adapter)} but assumes existing adapter and the new adapter uses the same
+ * {@link ViewHolder} and does not clear the RecycledViewPool.
+ * <p>
+ * Note that it still calls onAdapterChanged callbacks.
+ *
+ * @param adapter The new adapter to set, or null to set no adapter.
+ * @param removeAndRecycleExistingViews If set to true, RecyclerView will recycle all existing
+ * Views. If adapters have stable ids and/or you want to
+ * animate the disappearing views, you may prefer to set
+ * this to false.
+ * @see #setAdapter(Adapter)
+ */
+ public void swapAdapter(Adapter adapter, boolean removeAndRecycleExistingViews) {
+ // bail out if layout is frozen
+ setLayoutFrozen(false);
+ setAdapterInternal(adapter, true, removeAndRecycleExistingViews);
+ setDataSetChangedAfterLayout();
+ requestLayout();
+ }
+ /**
+ * Set a new adapter to provide child views on demand.
+ * <p>
+ * When adapter is changed, all existing views are recycled back to the pool. If the pool has
+ * only one adapter, it will be cleared.
+ *
+ * @param adapter The new adapter to set, or null to set no adapter.
+ * @see #swapAdapter(Adapter, boolean)
+ */
+ public void setAdapter(Adapter adapter) {
+ // bail out if layout is frozen
+ setLayoutFrozen(false);
+ setAdapterInternal(adapter, false, true);
+ requestLayout();
+ }
+
+ /**
+ * Removes and recycles all views - both those currently attached, and those in the Recycler.
+ */
+ void removeAndRecycleViews() {
+ // end all running animations
+ if (mItemAnimator != null) {
+ mItemAnimator.endAnimations();
+ }
+ // Since animations are ended, mLayout.children should be equal to
+ // recyclerView.children. This may not be true if item animator's end does not work as
+ // expected. (e.g. not release children instantly). It is safer to use mLayout's child
+ // count.
+ if (mLayout != null) {
+ mLayout.removeAndRecycleAllViews(mRecycler);
+ mLayout.removeAndRecycleScrapInt(mRecycler);
+ }
+ // we should clear it here before adapters are swapped to ensure correct callbacks.
+ mRecycler.clear();
+ }
+
+ /**
+ * Replaces the current adapter with the new one and triggers listeners.
+ * @param adapter The new adapter
+ * @param compatibleWithPrevious If true, the new adapter is using the same View Holders and
+ * item types with the current adapter (helps us avoid cache
+ * invalidation).
+ * @param removeAndRecycleViews If true, we'll remove and recycle all existing views. If
+ * compatibleWithPrevious is false, this parameter is ignored.
+ */
+ private void setAdapterInternal(Adapter adapter, boolean compatibleWithPrevious,
+ boolean removeAndRecycleViews) {
+ if (mAdapter != null) {
+ mAdapter.unregisterAdapterDataObserver(mObserver);
+ mAdapter.onDetachedFromRecyclerView(this);
+ }
+ if (!compatibleWithPrevious || removeAndRecycleViews) {
+ removeAndRecycleViews();
+ }
+ mAdapterHelper.reset();
+ final Adapter oldAdapter = mAdapter;
+ mAdapter = adapter;
+ if (adapter != null) {
+ adapter.registerAdapterDataObserver(mObserver);
+ adapter.onAttachedToRecyclerView(this);
+ }
+ if (mLayout != null) {
+ mLayout.onAdapterChanged(oldAdapter, mAdapter);
+ }
+ mRecycler.onAdapterChanged(oldAdapter, mAdapter, compatibleWithPrevious);
+ mState.mStructureChanged = true;
+ markKnownViewsInvalid();
+ }
+
+ /**
+ * Retrieves the previously set adapter or null if no adapter is set.
+ *
+ * @return The previously set adapter
+ * @see #setAdapter(Adapter)
+ */
+ public Adapter getAdapter() {
+ return mAdapter;
+ }
+
+ /**
+ * Register a listener that will be notified whenever a child view is recycled.
+ *
+ * <p>This listener will be called when a LayoutManager or the RecyclerView decides
+ * that a child view is no longer needed. If an application associates expensive
+ * or heavyweight data with item views, this may be a good place to release
+ * or free those resources.</p>
+ *
+ * @param listener Listener to register, or null to clear
+ */
+ public void setRecyclerListener(RecyclerListener listener) {
+ mRecyclerListener = listener;
+ }
+
+ /**
+ * <p>Return the offset of the RecyclerView's text baseline from the its top
+ * boundary. If the LayoutManager of this RecyclerView does not support baseline alignment,
+ * this method returns -1.</p>
+ *
+ * @return the offset of the baseline within the RecyclerView's bounds or -1
+ * if baseline alignment is not supported
+ */
+ @Override
+ public int getBaseline() {
+ if (mLayout != null) {
+ return mLayout.getBaseline();
+ } else {
+ return super.getBaseline();
+ }
+ }
+
+ /**
+ * Register a listener that will be notified whenever a child view is attached to or detached
+ * from RecyclerView.
+ *
+ * <p>This listener will be called when a LayoutManager or the RecyclerView decides
+ * that a child view is no longer needed. If an application associates expensive
+ * or heavyweight data with item views, this may be a good place to release
+ * or free those resources.</p>
+ *
+ * @param listener Listener to register
+ */
+ public void addOnChildAttachStateChangeListener(OnChildAttachStateChangeListener listener) {
+ if (mOnChildAttachStateListeners == null) {
+ mOnChildAttachStateListeners = new ArrayList<>();
+ }
+ mOnChildAttachStateListeners.add(listener);
+ }
+
+ /**
+ * Removes the provided listener from child attached state listeners list.
+ *
+ * @param listener Listener to unregister
+ */
+ public void removeOnChildAttachStateChangeListener(OnChildAttachStateChangeListener listener) {
+ if (mOnChildAttachStateListeners == null) {
+ return;
+ }
+ mOnChildAttachStateListeners.remove(listener);
+ }
+
+ /**
+ * Removes all listeners that were added via
+ * {@link #addOnChildAttachStateChangeListener(OnChildAttachStateChangeListener)}.
+ */
+ public void clearOnChildAttachStateChangeListeners() {
+ if (mOnChildAttachStateListeners != null) {
+ mOnChildAttachStateListeners.clear();
+ }
+ }
+
+ /**
+ * Set the {@link LayoutManager} that this RecyclerView will use.
+ *
+ * <p>In contrast to other adapter-backed views such as {@link android.widget.ListView}
+ * or {@link android.widget.GridView}, RecyclerView allows client code to provide custom
+ * layout arrangements for child views. These arrangements are controlled by the
+ * {@link LayoutManager}. A LayoutManager must be provided for RecyclerView to function.</p>
+ *
+ * <p>Several default strategies are provided for common uses such as lists and grids.</p>
+ *
+ * @param layout LayoutManager to use
+ */
+ public void setLayoutManager(LayoutManager layout) {
+ if (layout == mLayout) {
+ return;
+ }
+ stopScroll();
+ // TODO We should do this switch a dispatchLayout pass and animate children. There is a good
+ // chance that LayoutManagers will re-use views.
+ if (mLayout != null) {
+ // end all running animations
+ if (mItemAnimator != null) {
+ mItemAnimator.endAnimations();
+ }
+ mLayout.removeAndRecycleAllViews(mRecycler);
+ mLayout.removeAndRecycleScrapInt(mRecycler);
+ mRecycler.clear();
+
+ if (mIsAttached) {
+ mLayout.dispatchDetachedFromWindow(this, mRecycler);
+ }
+ mLayout.setRecyclerView(null);
+ mLayout = null;
+ } else {
+ mRecycler.clear();
+ }
+ // this is just a defensive measure for faulty item animators.
+ mChildHelper.removeAllViewsUnfiltered();
+ mLayout = layout;
+ if (layout != null) {
+ if (layout.mRecyclerView != null) {
+ throw new IllegalArgumentException("LayoutManager " + layout
+ + " is already attached to a RecyclerView: " + layout.mRecyclerView);
+ }
+ mLayout.setRecyclerView(this);
+ if (mIsAttached) {
+ mLayout.dispatchAttachedToWindow(this);
+ }
+ }
+ mRecycler.updateViewCacheSize();
+ requestLayout();
+ }
+
+ /**
+ * Set a {@link OnFlingListener} for this {@link RecyclerView}.
+ * <p>
+ * If the {@link OnFlingListener} is set then it will receive
+ * calls to {@link #fling(int,int)} and will be able to intercept them.
+ *
+ * @param onFlingListener The {@link OnFlingListener} instance.
+ */
+ public void setOnFlingListener(@Nullable OnFlingListener onFlingListener) {
+ mOnFlingListener = onFlingListener;
+ }
+
+ /**
+ * Get the current {@link OnFlingListener} from this {@link RecyclerView}.
+ *
+ * @return The {@link OnFlingListener} instance currently set (can be null).
+ */
+ @Nullable
+ public OnFlingListener getOnFlingListener() {
+ return mOnFlingListener;
+ }
+
+ @Override
+ protected Parcelable onSaveInstanceState() {
+ SavedState state = new SavedState(super.onSaveInstanceState());
+ if (mPendingSavedState != null) {
+ state.copyFrom(mPendingSavedState);
+ } else if (mLayout != null) {
+ state.mLayoutState = mLayout.onSaveInstanceState();
+ } else {
+ state.mLayoutState = null;
+ }
+
+ return state;
+ }
+
+ @Override
+ protected void onRestoreInstanceState(Parcelable state) {
+ if (!(state instanceof SavedState)) {
+ super.onRestoreInstanceState(state);
+ return;
+ }
+
+ mPendingSavedState = (SavedState) state;
+ super.onRestoreInstanceState(mPendingSavedState.getSuperState());
+ if (mLayout != null && mPendingSavedState.mLayoutState != null) {
+ mLayout.onRestoreInstanceState(mPendingSavedState.mLayoutState);
+ }
+ }
+
+ /**
+ * Override to prevent freezing of any views created by the adapter.
+ */
+ @Override
+ protected void dispatchSaveInstanceState(SparseArray<Parcelable> container) {
+ dispatchFreezeSelfOnly(container);
+ }
+
+ /**
+ * Override to prevent thawing of any views created by the adapter.
+ */
+ @Override
+ protected void dispatchRestoreInstanceState(SparseArray<Parcelable> container) {
+ dispatchThawSelfOnly(container);
+ }
+
+ /**
+ * Adds a view to the animatingViews list.
+ * mAnimatingViews holds the child views that are currently being kept around
+ * purely for the purpose of being animated out of view. They are drawn as a regular
+ * part of the child list of the RecyclerView, but they are invisible to the LayoutManager
+ * as they are managed separately from the regular child views.
+ * @param viewHolder The ViewHolder to be removed
+ */
+ private void addAnimatingView(ViewHolder viewHolder) {
+ final View view = viewHolder.itemView;
+ final boolean alreadyParented = view.getParent() == this;
+ mRecycler.unscrapView(getChildViewHolder(view));
+ if (viewHolder.isTmpDetached()) {
+ // re-attach
+ mChildHelper.attachViewToParent(view, -1, view.getLayoutParams(), true);
+ } else if (!alreadyParented) {
+ mChildHelper.addView(view, true);
+ } else {
+ mChildHelper.hide(view);
+ }
+ }
+
+ /**
+ * Removes a view from the animatingViews list.
+ * @param view The view to be removed
+ * @see #addAnimatingView(RecyclerView.ViewHolder)
+ * @return true if an animating view is removed
+ */
+ boolean removeAnimatingView(View view) {
+ eatRequestLayout();
+ final boolean removed = mChildHelper.removeViewIfHidden(view);
+ if (removed) {
+ final ViewHolder viewHolder = getChildViewHolderInt(view);
+ mRecycler.unscrapView(viewHolder);
+ mRecycler.recycleViewHolderInternal(viewHolder);
+ if (DEBUG) {
+ Log.d(TAG, "after removing animated view: " + view + ", " + this);
+ }
+ }
+ // only clear request eaten flag if we removed the view.
+ resumeRequestLayout(!removed);
+ return removed;
+ }
+
+ /**
+ * Return the {@link LayoutManager} currently responsible for
+ * layout policy for this RecyclerView.
+ *
+ * @return The currently bound LayoutManager
+ */
+ public LayoutManager getLayoutManager() {
+ return mLayout;
+ }
+
+ /**
+ * Retrieve this RecyclerView's {@link RecycledViewPool}. This method will never return null;
+ * if no pool is set for this view a new one will be created. See
+ * {@link #setRecycledViewPool(RecycledViewPool) setRecycledViewPool} for more information.
+ *
+ * @return The pool used to store recycled item views for reuse.
+ * @see #setRecycledViewPool(RecycledViewPool)
+ */
+ public RecycledViewPool getRecycledViewPool() {
+ return mRecycler.getRecycledViewPool();
+ }
+
+ /**
+ * Recycled view pools allow multiple RecyclerViews to share a common pool of scrap views.
+ * This can be useful if you have multiple RecyclerViews with adapters that use the same
+ * view types, for example if you have several data sets with the same kinds of item views
+ * displayed by a {@link android.support.v4.view.ViewPager ViewPager}.
+ *
+ * @param pool Pool to set. If this parameter is null a new pool will be created and used.
+ */
+ public void setRecycledViewPool(RecycledViewPool pool) {
+ mRecycler.setRecycledViewPool(pool);
+ }
+
+ /**
+ * Sets a new {@link ViewCacheExtension} to be used by the Recycler.
+ *
+ * @param extension ViewCacheExtension to be used or null if you want to clear the existing one.
+ *
+ * @see {@link ViewCacheExtension#getViewForPositionAndType(Recycler, int, int)}
+ */
+ public void setViewCacheExtension(ViewCacheExtension extension) {
+ mRecycler.setViewCacheExtension(extension);
+ }
+
+ /**
+ * Set the number of offscreen views to retain before adding them to the potentially shared
+ * {@link #getRecycledViewPool() recycled view pool}.
+ *
+ * <p>The offscreen view cache stays aware of changes in the attached adapter, allowing
+ * a LayoutManager to reuse those views unmodified without needing to return to the adapter
+ * to rebind them.</p>
+ *
+ * @param size Number of views to cache offscreen before returning them to the general
+ * recycled view pool
+ */
+ public void setItemViewCacheSize(int size) {
+ mRecycler.setViewCacheSize(size);
+ }
+
+ /**
+ * Return the current scrolling state of the RecyclerView.
+ *
+ * @return {@link #SCROLL_STATE_IDLE}, {@link #SCROLL_STATE_DRAGGING} or
+ * {@link #SCROLL_STATE_SETTLING}
+ */
+ public int getScrollState() {
+ return mScrollState;
+ }
+
+ void setScrollState(int state) {
+ if (state == mScrollState) {
+ return;
+ }
+ if (DEBUG) {
+ Log.d(TAG, "setting scroll state to " + state + " from " + mScrollState,
+ new Exception());
+ }
+ mScrollState = state;
+ if (state != SCROLL_STATE_SETTLING) {
+ stopScrollersInternal();
+ }
+ dispatchOnScrollStateChanged(state);
+ }
+
+ /**
+ * Add an {@link ItemDecoration} to this RecyclerView. Item decorations can
+ * affect both measurement and drawing of individual item views.
+ *
+ * <p>Item decorations are ordered. Decorations placed earlier in the list will
+ * be run/queried/drawn first for their effects on item views. Padding added to views
+ * will be nested; a padding added by an earlier decoration will mean further
+ * item decorations in the list will be asked to draw/pad within the previous decoration's
+ * given area.</p>
+ *
+ * @param decor Decoration to add
+ * @param index Position in the decoration chain to insert this decoration at. If this value
+ * is negative the decoration will be added at the end.
+ */
+ public void addItemDecoration(ItemDecoration decor, int index) {
+ if (mLayout != null) {
+ mLayout.assertNotInLayoutOrScroll("Cannot add item decoration during a scroll or"
+ + " layout");
+ }
+ if (mItemDecorations.isEmpty()) {
+ setWillNotDraw(false);
+ }
+ if (index < 0) {
+ mItemDecorations.add(decor);
+ } else {
+ mItemDecorations.add(index, decor);
+ }
+ markItemDecorInsetsDirty();
+ requestLayout();
+ }
+
+ /**
+ * Add an {@link ItemDecoration} to this RecyclerView. Item decorations can
+ * affect both measurement and drawing of individual item views.
+ *
+ * <p>Item decorations are ordered. Decorations placed earlier in the list will
+ * be run/queried/drawn first for their effects on item views. Padding added to views
+ * will be nested; a padding added by an earlier decoration will mean further
+ * item decorations in the list will be asked to draw/pad within the previous decoration's
+ * given area.</p>
+ *
+ * @param decor Decoration to add
+ */
+ public void addItemDecoration(ItemDecoration decor) {
+ addItemDecoration(decor, -1);
+ }
+
+ /**
+ * Remove an {@link ItemDecoration} from this RecyclerView.
+ *
+ * <p>The given decoration will no longer impact the measurement and drawing of
+ * item views.</p>
+ *
+ * @param decor Decoration to remove
+ * @see #addItemDecoration(ItemDecoration)
+ */
+ public void removeItemDecoration(ItemDecoration decor) {
+ if (mLayout != null) {
+ mLayout.assertNotInLayoutOrScroll("Cannot remove item decoration during a scroll or"
+ + " layout");
+ }
+ mItemDecorations.remove(decor);
+ if (mItemDecorations.isEmpty()) {
+ setWillNotDraw(getOverScrollMode() == View.OVER_SCROLL_NEVER);
+ }
+ markItemDecorInsetsDirty();
+ requestLayout();
+ }
+
+ /**
+ * Sets the {@link ChildDrawingOrderCallback} to be used for drawing children.
+ * <p>
+ * See {@link ViewGroup#getChildDrawingOrder(int, int)} for details. Calling this method will
+ * always call {@link ViewGroup#setChildrenDrawingOrderEnabled(boolean)}. The parameter will be
+ * true if childDrawingOrderCallback is not null, false otherwise.
+ * <p>
+ * Note that child drawing order may be overridden by View's elevation.
+ *
+ * @param childDrawingOrderCallback The ChildDrawingOrderCallback to be used by the drawing
+ * system.
+ */
+ public void setChildDrawingOrderCallback(ChildDrawingOrderCallback childDrawingOrderCallback) {
+ if (childDrawingOrderCallback == mChildDrawingOrderCallback) {
+ return;
+ }
+ mChildDrawingOrderCallback = childDrawingOrderCallback;
+ setChildrenDrawingOrderEnabled(mChildDrawingOrderCallback != null);
+ }
+
+ /**
+ * Set a listener that will be notified of any changes in scroll state or position.
+ *
+ * @param listener Listener to set or null to clear
+ *
+ * @deprecated Use {@link #addOnScrollListener(OnScrollListener)} and
+ * {@link #removeOnScrollListener(OnScrollListener)}
+ */
+ @Deprecated
+ public void setOnScrollListener(OnScrollListener listener) {
+ mScrollListener = listener;
+ }
+
+ /**
+ * Add a listener that will be notified of any changes in scroll state or position.
+ *
+ * <p>Components that add a listener should take care to remove it when finished.
+ * Other components that take ownership of a view may call {@link #clearOnScrollListeners()}
+ * to remove all attached listeners.</p>
+ *
+ * @param listener listener to set or null to clear
+ */
+ public void addOnScrollListener(OnScrollListener listener) {
+ if (mScrollListeners == null) {
+ mScrollListeners = new ArrayList<>();
+ }
+ mScrollListeners.add(listener);
+ }
+
+ /**
+ * Remove a listener that was notified of any changes in scroll state or position.
+ *
+ * @param listener listener to set or null to clear
+ */
+ public void removeOnScrollListener(OnScrollListener listener) {
+ if (mScrollListeners != null) {
+ mScrollListeners.remove(listener);
+ }
+ }
+
+ /**
+ * Remove all secondary listener that were notified of any changes in scroll state or position.
+ */
+ public void clearOnScrollListeners() {
+ if (mScrollListeners != null) {
+ mScrollListeners.clear();
+ }
+ }
+
+ /**
+ * Convenience method to scroll to a certain position.
+ *
+ * RecyclerView does not implement scrolling logic, rather forwards the call to
+ * {@link com.android.internal.widget.RecyclerView.LayoutManager#scrollToPosition(int)}
+ * @param position Scroll to this adapter position
+ * @see com.android.internal.widget.RecyclerView.LayoutManager#scrollToPosition(int)
+ */
+ public void scrollToPosition(int position) {
+ if (mLayoutFrozen) {
+ return;
+ }
+ stopScroll();
+ if (mLayout == null) {
+ Log.e(TAG, "Cannot scroll to position a LayoutManager set. "
+ + "Call setLayoutManager with a non-null argument.");
+ return;
+ }
+ mLayout.scrollToPosition(position);
+ awakenScrollBars();
+ }
+
+ void jumpToPositionForSmoothScroller(int position) {
+ if (mLayout == null) {
+ return;
+ }
+ mLayout.scrollToPosition(position);
+ awakenScrollBars();
+ }
+
+ /**
+ * Starts a smooth scroll to an adapter position.
+ * <p>
+ * To support smooth scrolling, you must override
+ * {@link LayoutManager#smoothScrollToPosition(RecyclerView, State, int)} and create a
+ * {@link SmoothScroller}.
+ * <p>
+ * {@link LayoutManager} is responsible for creating the actual scroll action. If you want to
+ * provide a custom smooth scroll logic, override
+ * {@link LayoutManager#smoothScrollToPosition(RecyclerView, State, int)} in your
+ * LayoutManager.
+ *
+ * @param position The adapter position to scroll to
+ * @see LayoutManager#smoothScrollToPosition(RecyclerView, State, int)
+ */
+ public void smoothScrollToPosition(int position) {
+ if (mLayoutFrozen) {
+ return;
+ }
+ if (mLayout == null) {
+ Log.e(TAG, "Cannot smooth scroll without a LayoutManager set. "
+ + "Call setLayoutManager with a non-null argument.");
+ return;
+ }
+ mLayout.smoothScrollToPosition(this, mState, position);
+ }
+
+ @Override
+ public void scrollTo(int x, int y) {
+ Log.w(TAG, "RecyclerView does not support scrolling to an absolute position. "
+ + "Use scrollToPosition instead");
+ }
+
+ @Override
+ public void scrollBy(int x, int y) {
+ if (mLayout == null) {
+ Log.e(TAG, "Cannot scroll without a LayoutManager set. "
+ + "Call setLayoutManager with a non-null argument.");
+ return;
+ }
+ if (mLayoutFrozen) {
+ return;
+ }
+ final boolean canScrollHorizontal = mLayout.canScrollHorizontally();
+ final boolean canScrollVertical = mLayout.canScrollVertically();
+ if (canScrollHorizontal || canScrollVertical) {
+ scrollByInternal(canScrollHorizontal ? x : 0, canScrollVertical ? y : 0, null);
+ }
+ }
+
+ /**
+ * Helper method reflect data changes to the state.
+ * <p>
+ * Adapter changes during a scroll may trigger a crash because scroll assumes no data change
+ * but data actually changed.
+ * <p>
+ * This method consumes all deferred changes to avoid that case.
+ */
+ void consumePendingUpdateOperations() {
+ if (!mFirstLayoutComplete || mDataSetHasChangedAfterLayout) {
+ Trace.beginSection(TRACE_ON_DATA_SET_CHANGE_LAYOUT_TAG);
+ dispatchLayout();
+ Trace.endSection();
+ return;
+ }
+ if (!mAdapterHelper.hasPendingUpdates()) {
+ return;
+ }
+
+ // if it is only an item change (no add-remove-notifyDataSetChanged) we can check if any
+ // of the visible items is affected and if not, just ignore the change.
+ if (mAdapterHelper.hasAnyUpdateTypes(AdapterHelper.UpdateOp.UPDATE) && !mAdapterHelper
+ .hasAnyUpdateTypes(AdapterHelper.UpdateOp.ADD | AdapterHelper.UpdateOp.REMOVE
+ | AdapterHelper.UpdateOp.MOVE)) {
+ Trace.beginSection(TRACE_HANDLE_ADAPTER_UPDATES_TAG);
+ eatRequestLayout();
+ onEnterLayoutOrScroll();
+ mAdapterHelper.preProcess();
+ if (!mLayoutRequestEaten) {
+ if (hasUpdatedView()) {
+ dispatchLayout();
+ } else {
+ // no need to layout, clean state
+ mAdapterHelper.consumePostponedUpdates();
+ }
+ }
+ resumeRequestLayout(true);
+ onExitLayoutOrScroll();
+ Trace.endSection();
+ } else if (mAdapterHelper.hasPendingUpdates()) {
+ Trace.beginSection(TRACE_ON_DATA_SET_CHANGE_LAYOUT_TAG);
+ dispatchLayout();
+ Trace.endSection();
+ }
+ }
+
+ /**
+ * @return True if an existing view holder needs to be updated
+ */
+ private boolean hasUpdatedView() {
+ final int childCount = mChildHelper.getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getChildAt(i));
+ if (holder == null || holder.shouldIgnore()) {
+ continue;
+ }
+ if (holder.isUpdated()) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Does not perform bounds checking. Used by internal methods that have already validated input.
+ * <p>
+ * It also reports any unused scroll request to the related EdgeEffect.
+ *
+ * @param x The amount of horizontal scroll request
+ * @param y The amount of vertical scroll request
+ * @param ev The originating MotionEvent, or null if not from a touch event.
+ *
+ * @return Whether any scroll was consumed in either direction.
+ */
+ boolean scrollByInternal(int x, int y, MotionEvent ev) {
+ int unconsumedX = 0, unconsumedY = 0;
+ int consumedX = 0, consumedY = 0;
+
+ consumePendingUpdateOperations();
+ if (mAdapter != null) {
+ eatRequestLayout();
+ onEnterLayoutOrScroll();
+ Trace.beginSection(TRACE_SCROLL_TAG);
+ if (x != 0) {
+ consumedX = mLayout.scrollHorizontallyBy(x, mRecycler, mState);
+ unconsumedX = x - consumedX;
+ }
+ if (y != 0) {
+ consumedY = mLayout.scrollVerticallyBy(y, mRecycler, mState);
+ unconsumedY = y - consumedY;
+ }
+ Trace.endSection();
+ repositionShadowingViews();
+ onExitLayoutOrScroll();
+ resumeRequestLayout(false);
+ }
+ if (!mItemDecorations.isEmpty()) {
+ invalidate();
+ }
+
+ if (dispatchNestedScroll(consumedX, consumedY, unconsumedX, unconsumedY, mScrollOffset)) {
+ // Update the last touch co-ords, taking any scroll offset into account
+ mLastTouchX -= mScrollOffset[0];
+ mLastTouchY -= mScrollOffset[1];
+ if (ev != null) {
+ ev.offsetLocation(mScrollOffset[0], mScrollOffset[1]);
+ }
+ mNestedOffsets[0] += mScrollOffset[0];
+ mNestedOffsets[1] += mScrollOffset[1];
+ } else if (getOverScrollMode() != View.OVER_SCROLL_NEVER) {
+ if (ev != null) {
+ pullGlows(ev.getX(), unconsumedX, ev.getY(), unconsumedY);
+ }
+ considerReleasingGlowsOnScroll(x, y);
+ }
+ if (consumedX != 0 || consumedY != 0) {
+ dispatchOnScrolled(consumedX, consumedY);
+ }
+ if (!awakenScrollBars()) {
+ invalidate();
+ }
+ return consumedX != 0 || consumedY != 0;
+ }
+
+ /**
+ * <p>Compute the horizontal offset of the horizontal scrollbar's thumb within the horizontal
+ * range. This value is used to compute the length of the thumb within the scrollbar's track.
+ * </p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the units used by
+ * {@link #computeHorizontalScrollRange()} and {@link #computeHorizontalScrollExtent()}.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * <p>If you want to support scroll bars, override
+ * {@link RecyclerView.LayoutManager#computeHorizontalScrollOffset(RecyclerView.State)} in your
+ * LayoutManager. </p>
+ *
+ * @return The horizontal offset of the scrollbar's thumb
+ * @see com.android.internal.widget.RecyclerView.LayoutManager#computeHorizontalScrollOffset
+ * (RecyclerView.State)
+ */
+ @Override
+ public int computeHorizontalScrollOffset() {
+ if (mLayout == null) {
+ return 0;
+ }
+ return mLayout.canScrollHorizontally() ? mLayout.computeHorizontalScrollOffset(mState) : 0;
+ }
+
+ /**
+ * <p>Compute the horizontal extent of the horizontal scrollbar's thumb within the
+ * horizontal range. This value is used to compute the length of the thumb within the
+ * scrollbar's track.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the units used by
+ * {@link #computeHorizontalScrollRange()} and {@link #computeHorizontalScrollOffset()}.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * <p>If you want to support scroll bars, override
+ * {@link RecyclerView.LayoutManager#computeHorizontalScrollExtent(RecyclerView.State)} in your
+ * LayoutManager.</p>
+ *
+ * @return The horizontal extent of the scrollbar's thumb
+ * @see RecyclerView.LayoutManager#computeHorizontalScrollExtent(RecyclerView.State)
+ */
+ @Override
+ public int computeHorizontalScrollExtent() {
+ if (mLayout == null) {
+ return 0;
+ }
+ return mLayout.canScrollHorizontally() ? mLayout.computeHorizontalScrollExtent(mState) : 0;
+ }
+
+ /**
+ * <p>Compute the horizontal range that the horizontal scrollbar represents.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the units used by
+ * {@link #computeHorizontalScrollExtent()} and {@link #computeHorizontalScrollOffset()}.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * <p>If you want to support scroll bars, override
+ * {@link RecyclerView.LayoutManager#computeHorizontalScrollRange(RecyclerView.State)} in your
+ * LayoutManager.</p>
+ *
+ * @return The total horizontal range represented by the vertical scrollbar
+ * @see RecyclerView.LayoutManager#computeHorizontalScrollRange(RecyclerView.State)
+ */
+ @Override
+ public int computeHorizontalScrollRange() {
+ if (mLayout == null) {
+ return 0;
+ }
+ return mLayout.canScrollHorizontally() ? mLayout.computeHorizontalScrollRange(mState) : 0;
+ }
+
+ /**
+ * <p>Compute the vertical offset of the vertical scrollbar's thumb within the vertical range.
+ * This value is used to compute the length of the thumb within the scrollbar's track. </p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the units used by
+ * {@link #computeVerticalScrollRange()} and {@link #computeVerticalScrollExtent()}.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * <p>If you want to support scroll bars, override
+ * {@link RecyclerView.LayoutManager#computeVerticalScrollOffset(RecyclerView.State)} in your
+ * LayoutManager.</p>
+ *
+ * @return The vertical offset of the scrollbar's thumb
+ * @see com.android.internal.widget.RecyclerView.LayoutManager#computeVerticalScrollOffset
+ * (RecyclerView.State)
+ */
+ @Override
+ public int computeVerticalScrollOffset() {
+ if (mLayout == null) {
+ return 0;
+ }
+ return mLayout.canScrollVertically() ? mLayout.computeVerticalScrollOffset(mState) : 0;
+ }
+
+ /**
+ * <p>Compute the vertical extent of the vertical scrollbar's thumb within the vertical range.
+ * This value is used to compute the length of the thumb within the scrollbar's track.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the units used by
+ * {@link #computeVerticalScrollRange()} and {@link #computeVerticalScrollOffset()}.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * <p>If you want to support scroll bars, override
+ * {@link RecyclerView.LayoutManager#computeVerticalScrollExtent(RecyclerView.State)} in your
+ * LayoutManager.</p>
+ *
+ * @return The vertical extent of the scrollbar's thumb
+ * @see RecyclerView.LayoutManager#computeVerticalScrollExtent(RecyclerView.State)
+ */
+ @Override
+ public int computeVerticalScrollExtent() {
+ if (mLayout == null) {
+ return 0;
+ }
+ return mLayout.canScrollVertically() ? mLayout.computeVerticalScrollExtent(mState) : 0;
+ }
+
+ /**
+ * <p>Compute the vertical range that the vertical scrollbar represents.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the units used by
+ * {@link #computeVerticalScrollExtent()} and {@link #computeVerticalScrollOffset()}.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * <p>If you want to support scroll bars, override
+ * {@link RecyclerView.LayoutManager#computeVerticalScrollRange(RecyclerView.State)} in your
+ * LayoutManager.</p>
+ *
+ * @return The total vertical range represented by the vertical scrollbar
+ * @see RecyclerView.LayoutManager#computeVerticalScrollRange(RecyclerView.State)
+ */
+ @Override
+ public int computeVerticalScrollRange() {
+ if (mLayout == null) {
+ return 0;
+ }
+ return mLayout.canScrollVertically() ? mLayout.computeVerticalScrollRange(mState) : 0;
+ }
+
+
+ void eatRequestLayout() {
+ mEatRequestLayout++;
+ if (mEatRequestLayout == 1 && !mLayoutFrozen) {
+ mLayoutRequestEaten = false;
+ }
+ }
+
+ void resumeRequestLayout(boolean performLayoutChildren) {
+ if (mEatRequestLayout < 1) {
+ //noinspection PointlessBooleanExpression
+ if (DEBUG) {
+ throw new IllegalStateException("invalid eat request layout count");
+ }
+ mEatRequestLayout = 1;
+ }
+ if (!performLayoutChildren) {
+ // Reset the layout request eaten counter.
+ // This is necessary since eatRequest calls can be nested in which case the other
+ // call will override the inner one.
+ // for instance:
+ // eat layout for process adapter updates
+ // eat layout for dispatchLayout
+ // a bunch of req layout calls arrive
+
+ mLayoutRequestEaten = false;
+ }
+ if (mEatRequestLayout == 1) {
+ // when layout is frozen we should delay dispatchLayout()
+ if (performLayoutChildren && mLayoutRequestEaten && !mLayoutFrozen
+ && mLayout != null && mAdapter != null) {
+ dispatchLayout();
+ }
+ if (!mLayoutFrozen) {
+ mLayoutRequestEaten = false;
+ }
+ }
+ mEatRequestLayout--;
+ }
+
+ /**
+ * Enable or disable layout and scroll. After <code>setLayoutFrozen(true)</code> is called,
+ * Layout requests will be postponed until <code>setLayoutFrozen(false)</code> is called;
+ * child views are not updated when RecyclerView is frozen, {@link #smoothScrollBy(int, int)},
+ * {@link #scrollBy(int, int)}, {@link #scrollToPosition(int)} and
+ * {@link #smoothScrollToPosition(int)} are dropped; TouchEvents and GenericMotionEvents are
+ * dropped; {@link LayoutManager#onFocusSearchFailed(View, int, Recycler, State)} will not be
+ * called.
+ *
+ * <p>
+ * <code>setLayoutFrozen(true)</code> does not prevent app from directly calling {@link
+ * LayoutManager#scrollToPosition(int)}, {@link LayoutManager#smoothScrollToPosition(
+ * RecyclerView, State, int)}.
+ * <p>
+ * {@link #setAdapter(Adapter)} and {@link #swapAdapter(Adapter, boolean)} will automatically
+ * stop frozen.
+ * <p>
+ * Note: Running ItemAnimator is not stopped automatically, it's caller's
+ * responsibility to call ItemAnimator.end().
+ *
+ * @param frozen true to freeze layout and scroll, false to re-enable.
+ */
+ public void setLayoutFrozen(boolean frozen) {
+ if (frozen != mLayoutFrozen) {
+ assertNotInLayoutOrScroll("Do not setLayoutFrozen in layout or scroll");
+ if (!frozen) {
+ mLayoutFrozen = false;
+ if (mLayoutRequestEaten && mLayout != null && mAdapter != null) {
+ requestLayout();
+ }
+ mLayoutRequestEaten = false;
+ } else {
+ final long now = SystemClock.uptimeMillis();
+ MotionEvent cancelEvent = MotionEvent.obtain(now, now,
+ MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0);
+ onTouchEvent(cancelEvent);
+ mLayoutFrozen = true;
+ mIgnoreMotionEventTillDown = true;
+ stopScroll();
+ }
+ }
+ }
+
+ /**
+ * Returns true if layout and scroll are frozen.
+ *
+ * @return true if layout and scroll are frozen
+ * @see #setLayoutFrozen(boolean)
+ */
+ public boolean isLayoutFrozen() {
+ return mLayoutFrozen;
+ }
+
+ /**
+ * Animate a scroll by the given amount of pixels along either axis.
+ *
+ * @param dx Pixels to scroll horizontally
+ * @param dy Pixels to scroll vertically
+ */
+ public void smoothScrollBy(int dx, int dy) {
+ smoothScrollBy(dx, dy, null);
+ }
+
+ /**
+ * Animate a scroll by the given amount of pixels along either axis.
+ *
+ * @param dx Pixels to scroll horizontally
+ * @param dy Pixels to scroll vertically
+ * @param interpolator {@link Interpolator} to be used for scrolling. If it is
+ * {@code null}, RecyclerView is going to use the default interpolator.
+ */
+ public void smoothScrollBy(int dx, int dy, Interpolator interpolator) {
+ if (mLayout == null) {
+ Log.e(TAG, "Cannot smooth scroll without a LayoutManager set. "
+ + "Call setLayoutManager with a non-null argument.");
+ return;
+ }
+ if (mLayoutFrozen) {
+ return;
+ }
+ if (!mLayout.canScrollHorizontally()) {
+ dx = 0;
+ }
+ if (!mLayout.canScrollVertically()) {
+ dy = 0;
+ }
+ if (dx != 0 || dy != 0) {
+ mViewFlinger.smoothScrollBy(dx, dy, interpolator);
+ }
+ }
+
+ /**
+ * Begin a standard fling with an initial velocity along each axis in pixels per second.
+ * If the velocity given is below the system-defined minimum this method will return false
+ * and no fling will occur.
+ *
+ * @param velocityX Initial horizontal velocity in pixels per second
+ * @param velocityY Initial vertical velocity in pixels per second
+ * @return true if the fling was started, false if the velocity was too low to fling or
+ * LayoutManager does not support scrolling in the axis fling is issued.
+ *
+ * @see LayoutManager#canScrollVertically()
+ * @see LayoutManager#canScrollHorizontally()
+ */
+ public boolean fling(int velocityX, int velocityY) {
+ if (mLayout == null) {
+ Log.e(TAG, "Cannot fling without a LayoutManager set. "
+ + "Call setLayoutManager with a non-null argument.");
+ return false;
+ }
+ if (mLayoutFrozen) {
+ return false;
+ }
+
+ final boolean canScrollHorizontal = mLayout.canScrollHorizontally();
+ final boolean canScrollVertical = mLayout.canScrollVertically();
+
+ if (!canScrollHorizontal || Math.abs(velocityX) < mMinFlingVelocity) {
+ velocityX = 0;
+ }
+ if (!canScrollVertical || Math.abs(velocityY) < mMinFlingVelocity) {
+ velocityY = 0;
+ }
+ if (velocityX == 0 && velocityY == 0) {
+ // If we don't have any velocity, return false
+ return false;
+ }
+
+ if (!dispatchNestedPreFling(velocityX, velocityY)) {
+ final boolean canScroll = canScrollHorizontal || canScrollVertical;
+ dispatchNestedFling(velocityX, velocityY, canScroll);
+
+ if (mOnFlingListener != null && mOnFlingListener.onFling(velocityX, velocityY)) {
+ return true;
+ }
+
+ if (canScroll) {
+ velocityX = Math.max(-mMaxFlingVelocity, Math.min(velocityX, mMaxFlingVelocity));
+ velocityY = Math.max(-mMaxFlingVelocity, Math.min(velocityY, mMaxFlingVelocity));
+ mViewFlinger.fling(velocityX, velocityY);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Stop any current scroll in progress, such as one started by
+ * {@link #smoothScrollBy(int, int)}, {@link #fling(int, int)} or a touch-initiated fling.
+ */
+ public void stopScroll() {
+ setScrollState(SCROLL_STATE_IDLE);
+ stopScrollersInternal();
+ }
+
+ /**
+ * Similar to {@link #stopScroll()} but does not set the state.
+ */
+ private void stopScrollersInternal() {
+ mViewFlinger.stop();
+ if (mLayout != null) {
+ mLayout.stopSmoothScroller();
+ }
+ }
+
+ /**
+ * Returns the minimum velocity to start a fling.
+ *
+ * @return The minimum velocity to start a fling
+ */
+ public int getMinFlingVelocity() {
+ return mMinFlingVelocity;
+ }
+
+
+ /**
+ * Returns the maximum fling velocity used by this RecyclerView.
+ *
+ * @return The maximum fling velocity used by this RecyclerView.
+ */
+ public int getMaxFlingVelocity() {
+ return mMaxFlingVelocity;
+ }
+
+ /**
+ * Apply a pull to relevant overscroll glow effects
+ */
+ private void pullGlows(float x, float overscrollX, float y, float overscrollY) {
+ boolean invalidate = false;
+ if (overscrollX < 0) {
+ ensureLeftGlow();
+ mLeftGlow.onPull(-overscrollX / getWidth(), 1f - y / getHeight());
+ invalidate = true;
+ } else if (overscrollX > 0) {
+ ensureRightGlow();
+ mRightGlow.onPull(overscrollX / getWidth(), y / getHeight());
+ invalidate = true;
+ }
+
+ if (overscrollY < 0) {
+ ensureTopGlow();
+ mTopGlow.onPull(-overscrollY / getHeight(), x / getWidth());
+ invalidate = true;
+ } else if (overscrollY > 0) {
+ ensureBottomGlow();
+ mBottomGlow.onPull(overscrollY / getHeight(), 1f - x / getWidth());
+ invalidate = true;
+ }
+
+ if (invalidate || overscrollX != 0 || overscrollY != 0) {
+ postInvalidateOnAnimation();
+ }
+ }
+
+ private void releaseGlows() {
+ boolean needsInvalidate = false;
+ if (mLeftGlow != null) {
+ mLeftGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (mTopGlow != null) {
+ mTopGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (mRightGlow != null) {
+ mRightGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (mBottomGlow != null) {
+ mBottomGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (needsInvalidate) {
+ postInvalidateOnAnimation();
+ }
+ }
+
+ void considerReleasingGlowsOnScroll(int dx, int dy) {
+ boolean needsInvalidate = false;
+ if (mLeftGlow != null && !mLeftGlow.isFinished() && dx > 0) {
+ mLeftGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (mRightGlow != null && !mRightGlow.isFinished() && dx < 0) {
+ mRightGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (mTopGlow != null && !mTopGlow.isFinished() && dy > 0) {
+ mTopGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (mBottomGlow != null && !mBottomGlow.isFinished() && dy < 0) {
+ mBottomGlow.onRelease();
+ needsInvalidate = true;
+ }
+ if (needsInvalidate) {
+ postInvalidateOnAnimation();
+ }
+ }
+
+ void absorbGlows(int velocityX, int velocityY) {
+ if (velocityX < 0) {
+ ensureLeftGlow();
+ mLeftGlow.onAbsorb(-velocityX);
+ } else if (velocityX > 0) {
+ ensureRightGlow();
+ mRightGlow.onAbsorb(velocityX);
+ }
+
+ if (velocityY < 0) {
+ ensureTopGlow();
+ mTopGlow.onAbsorb(-velocityY);
+ } else if (velocityY > 0) {
+ ensureBottomGlow();
+ mBottomGlow.onAbsorb(velocityY);
+ }
+
+ if (velocityX != 0 || velocityY != 0) {
+ postInvalidateOnAnimation();
+ }
+ }
+
+ void ensureLeftGlow() {
+ if (mLeftGlow != null) {
+ return;
+ }
+ mLeftGlow = new EdgeEffect(getContext());
+ if (mClipToPadding) {
+ mLeftGlow.setSize(getMeasuredHeight() - getPaddingTop() - getPaddingBottom(),
+ getMeasuredWidth() - getPaddingLeft() - getPaddingRight());
+ } else {
+ mLeftGlow.setSize(getMeasuredHeight(), getMeasuredWidth());
+ }
+ }
+
+ void ensureRightGlow() {
+ if (mRightGlow != null) {
+ return;
+ }
+ mRightGlow = new EdgeEffect(getContext());
+ if (mClipToPadding) {
+ mRightGlow.setSize(getMeasuredHeight() - getPaddingTop() - getPaddingBottom(),
+ getMeasuredWidth() - getPaddingLeft() - getPaddingRight());
+ } else {
+ mRightGlow.setSize(getMeasuredHeight(), getMeasuredWidth());
+ }
+ }
+
+ void ensureTopGlow() {
+ if (mTopGlow != null) {
+ return;
+ }
+ mTopGlow = new EdgeEffect(getContext());
+ if (mClipToPadding) {
+ mTopGlow.setSize(getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),
+ getMeasuredHeight() - getPaddingTop() - getPaddingBottom());
+ } else {
+ mTopGlow.setSize(getMeasuredWidth(), getMeasuredHeight());
+ }
+
+ }
+
+ void ensureBottomGlow() {
+ if (mBottomGlow != null) {
+ return;
+ }
+ mBottomGlow = new EdgeEffect(getContext());
+ if (mClipToPadding) {
+ mBottomGlow.setSize(getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),
+ getMeasuredHeight() - getPaddingTop() - getPaddingBottom());
+ } else {
+ mBottomGlow.setSize(getMeasuredWidth(), getMeasuredHeight());
+ }
+ }
+
+ void invalidateGlows() {
+ mLeftGlow = mRightGlow = mTopGlow = mBottomGlow = null;
+ }
+
+ /**
+ * Since RecyclerView is a collection ViewGroup that includes virtual children (items that are
+ * in the Adapter but not visible in the UI), it employs a more involved focus search strategy
+ * that differs from other ViewGroups.
+ * <p>
+ * It first does a focus search within the RecyclerView. If this search finds a View that is in
+ * the focus direction with respect to the currently focused View, RecyclerView returns that
+ * child as the next focus target. When it cannot find such child, it calls
+ * {@link LayoutManager#onFocusSearchFailed(View, int, Recycler, State)} to layout more Views
+ * in the focus search direction. If LayoutManager adds a View that matches the
+ * focus search criteria, it will be returned as the focus search result. Otherwise,
+ * RecyclerView will call parent to handle the focus search like a regular ViewGroup.
+ * <p>
+ * When the direction is {@link View#FOCUS_FORWARD} or {@link View#FOCUS_BACKWARD}, a View that
+ * is not in the focus direction is still valid focus target which may not be the desired
+ * behavior if the Adapter has more children in the focus direction. To handle this case,
+ * RecyclerView converts the focus direction to an absolute direction and makes a preliminary
+ * focus search in that direction. If there are no Views to gain focus, it will call
+ * {@link LayoutManager#onFocusSearchFailed(View, int, Recycler, State)} before running a
+ * focus search with the original (relative) direction. This allows RecyclerView to provide
+ * better candidates to the focus search while still allowing the view system to take focus from
+ * the RecyclerView and give it to a more suitable child if such child exists.
+ *
+ * @param focused The view that currently has focus
+ * @param direction One of {@link View#FOCUS_UP}, {@link View#FOCUS_DOWN},
+ * {@link View#FOCUS_LEFT}, {@link View#FOCUS_RIGHT}, {@link View#FOCUS_FORWARD},
+ * {@link View#FOCUS_BACKWARD} or 0 for not applicable.
+ *
+ * @return A new View that can be the next focus after the focused View
+ */
+ @Override
+ public View focusSearch(View focused, int direction) {
+ View result = mLayout.onInterceptFocusSearch(focused, direction);
+ if (result != null) {
+ return result;
+ }
+ final boolean canRunFocusFailure = mAdapter != null && mLayout != null
+ && !isComputingLayout() && !mLayoutFrozen;
+
+ final FocusFinder ff = FocusFinder.getInstance();
+ if (canRunFocusFailure
+ && (direction == View.FOCUS_FORWARD || direction == View.FOCUS_BACKWARD)) {
+ // convert direction to absolute direction and see if we have a view there and if not
+ // tell LayoutManager to add if it can.
+ boolean needsFocusFailureLayout = false;
+ if (mLayout.canScrollVertically()) {
+ final int absDir =
+ direction == View.FOCUS_FORWARD ? View.FOCUS_DOWN : View.FOCUS_UP;
+ final View found = ff.findNextFocus(this, focused, absDir);
+ needsFocusFailureLayout = found == null;
+ if (FORCE_ABS_FOCUS_SEARCH_DIRECTION) {
+ // Workaround for broken FOCUS_BACKWARD in API 15 and older devices.
+ direction = absDir;
+ }
+ }
+ if (!needsFocusFailureLayout && mLayout.canScrollHorizontally()) {
+ boolean rtl = mLayout.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL;
+ final int absDir = (direction == View.FOCUS_FORWARD) ^ rtl
+ ? View.FOCUS_RIGHT : View.FOCUS_LEFT;
+ final View found = ff.findNextFocus(this, focused, absDir);
+ needsFocusFailureLayout = found == null;
+ if (FORCE_ABS_FOCUS_SEARCH_DIRECTION) {
+ // Workaround for broken FOCUS_BACKWARD in API 15 and older devices.
+ direction = absDir;
+ }
+ }
+ if (needsFocusFailureLayout) {
+ consumePendingUpdateOperations();
+ final View focusedItemView = findContainingItemView(focused);
+ if (focusedItemView == null) {
+ // panic, focused view is not a child anymore, cannot call super.
+ return null;
+ }
+ eatRequestLayout();
+ mLayout.onFocusSearchFailed(focused, direction, mRecycler, mState);
+ resumeRequestLayout(false);
+ }
+ result = ff.findNextFocus(this, focused, direction);
+ } else {
+ result = ff.findNextFocus(this, focused, direction);
+ if (result == null && canRunFocusFailure) {
+ consumePendingUpdateOperations();
+ final View focusedItemView = findContainingItemView(focused);
+ if (focusedItemView == null) {
+ // panic, focused view is not a child anymore, cannot call super.
+ return null;
+ }
+ eatRequestLayout();
+ result = mLayout.onFocusSearchFailed(focused, direction, mRecycler, mState);
+ resumeRequestLayout(false);
+ }
+ }
+ return isPreferredNextFocus(focused, result, direction)
+ ? result : super.focusSearch(focused, direction);
+ }
+
+ /**
+ * Checks if the new focus candidate is a good enough candidate such that RecyclerView will
+ * assign it as the next focus View instead of letting view hierarchy decide.
+ * A good candidate means a View that is aligned in the focus direction wrt the focused View
+ * and is not the RecyclerView itself.
+ * When this method returns false, RecyclerView will let the parent make the decision so the
+ * same View may still get the focus as a result of that search.
+ */
+ private boolean isPreferredNextFocus(View focused, View next, int direction) {
+ if (next == null || next == this) {
+ return false;
+ }
+ if (focused == null) {
+ return true;
+ }
+
+ if (direction == View.FOCUS_FORWARD || direction == View.FOCUS_BACKWARD) {
+ final boolean rtl = mLayout.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL;
+ final int absHorizontal = (direction == View.FOCUS_FORWARD) ^ rtl
+ ? View.FOCUS_RIGHT : View.FOCUS_LEFT;
+ if (isPreferredNextFocusAbsolute(focused, next, absHorizontal)) {
+ return true;
+ }
+ if (direction == View.FOCUS_FORWARD) {
+ return isPreferredNextFocusAbsolute(focused, next, View.FOCUS_DOWN);
+ } else {
+ return isPreferredNextFocusAbsolute(focused, next, View.FOCUS_UP);
+ }
+ } else {
+ return isPreferredNextFocusAbsolute(focused, next, direction);
+ }
+
+ }
+
+ /**
+ * Logic taken from FocusSearch#isCandidate
+ */
+ private boolean isPreferredNextFocusAbsolute(View focused, View next, int direction) {
+ mTempRect.set(0, 0, focused.getWidth(), focused.getHeight());
+ mTempRect2.set(0, 0, next.getWidth(), next.getHeight());
+ offsetDescendantRectToMyCoords(focused, mTempRect);
+ offsetDescendantRectToMyCoords(next, mTempRect2);
+ switch (direction) {
+ case View.FOCUS_LEFT:
+ return (mTempRect.right > mTempRect2.right
+ || mTempRect.left >= mTempRect2.right)
+ && mTempRect.left > mTempRect2.left;
+ case View.FOCUS_RIGHT:
+ return (mTempRect.left < mTempRect2.left
+ || mTempRect.right <= mTempRect2.left)
+ && mTempRect.right < mTempRect2.right;
+ case View.FOCUS_UP:
+ return (mTempRect.bottom > mTempRect2.bottom
+ || mTempRect.top >= mTempRect2.bottom)
+ && mTempRect.top > mTempRect2.top;
+ case View.FOCUS_DOWN:
+ return (mTempRect.top < mTempRect2.top
+ || mTempRect.bottom <= mTempRect2.top)
+ && mTempRect.bottom < mTempRect2.bottom;
+ }
+ throw new IllegalArgumentException("direction must be absolute. received:" + direction);
+ }
+
+ @Override
+ public void requestChildFocus(View child, View focused) {
+ if (!mLayout.onRequestChildFocus(this, mState, child, focused) && focused != null) {
+ mTempRect.set(0, 0, focused.getWidth(), focused.getHeight());
+
+ // get item decor offsets w/o refreshing. If they are invalid, there will be another
+ // layout pass to fix them, then it is LayoutManager's responsibility to keep focused
+ // View in viewport.
+ final ViewGroup.LayoutParams focusedLayoutParams = focused.getLayoutParams();
+ if (focusedLayoutParams instanceof LayoutParams) {
+ // if focused child has item decors, use them. Otherwise, ignore.
+ final LayoutParams lp = (LayoutParams) focusedLayoutParams;
+ if (!lp.mInsetsDirty) {
+ final Rect insets = lp.mDecorInsets;
+ mTempRect.left -= insets.left;
+ mTempRect.right += insets.right;
+ mTempRect.top -= insets.top;
+ mTempRect.bottom += insets.bottom;
+ }
+ }
+
+ offsetDescendantRectToMyCoords(focused, mTempRect);
+ offsetRectIntoDescendantCoords(child, mTempRect);
+ requestChildRectangleOnScreen(child, mTempRect, !mFirstLayoutComplete);
+ }
+ super.requestChildFocus(child, focused);
+ }
+
+ @Override
+ public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) {
+ return mLayout.requestChildRectangleOnScreen(this, child, rect, immediate);
+ }
+
+ @Override
+ public void addFocusables(ArrayList<View> views, int direction, int focusableMode) {
+ if (mLayout == null || !mLayout.onAddFocusables(this, views, direction, focusableMode)) {
+ super.addFocusables(views, direction, focusableMode);
+ }
+ }
+
+ @Override
+ protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
+ if (isComputingLayout()) {
+ // if we are in the middle of a layout calculation, don't let any child take focus.
+ // RV will handle it after layout calculation is finished.
+ return false;
+ }
+ return super.onRequestFocusInDescendants(direction, previouslyFocusedRect);
+ }
+
+ @Override
+ protected void onAttachedToWindow() {
+ super.onAttachedToWindow();
+ mLayoutOrScrollCounter = 0;
+ mIsAttached = true;
+ mFirstLayoutComplete = mFirstLayoutComplete && !isLayoutRequested();
+ if (mLayout != null) {
+ mLayout.dispatchAttachedToWindow(this);
+ }
+ mPostedAnimatorRunner = false;
+
+ if (ALLOW_THREAD_GAP_WORK) {
+ // Register with gap worker
+ mGapWorker = GapWorker.sGapWorker.get();
+ if (mGapWorker == null) {
+ mGapWorker = new GapWorker();
+
+ // break 60 fps assumption if data from display appears valid
+ // NOTE: we only do this query once, statically, because it's very expensive (> 1ms)
+ Display display = getDisplay();
+ float refreshRate = 60.0f;
+ if (!isInEditMode() && display != null) {
+ float displayRefreshRate = display.getRefreshRate();
+ if (displayRefreshRate >= 30.0f) {
+ refreshRate = displayRefreshRate;
+ }
+ }
+ mGapWorker.mFrameIntervalNs = (long) (1000000000 / refreshRate);
+ GapWorker.sGapWorker.set(mGapWorker);
+ }
+ mGapWorker.add(this);
+ }
+ }
+
+ @Override
+ protected void onDetachedFromWindow() {
+ super.onDetachedFromWindow();
+ if (mItemAnimator != null) {
+ mItemAnimator.endAnimations();
+ }
+ stopScroll();
+ mIsAttached = false;
+ if (mLayout != null) {
+ mLayout.dispatchDetachedFromWindow(this, mRecycler);
+ }
+ mPendingAccessibilityImportanceChange.clear();
+ removeCallbacks(mItemAnimatorRunner);
+ mViewInfoStore.onDetach();
+
+ if (ALLOW_THREAD_GAP_WORK) {
+ // Unregister with gap worker
+ mGapWorker.remove(this);
+ mGapWorker = null;
+ }
+ }
+
+ /**
+ * Returns true if RecyclerView is attached to window.
+ */
+ // @override
+ public boolean isAttachedToWindow() {
+ return mIsAttached;
+ }
+
+ /**
+ * Checks if RecyclerView is in the middle of a layout or scroll and throws an
+ * {@link IllegalStateException} if it <b>is not</b>.
+ *
+ * @param message The message for the exception. Can be null.
+ * @see #assertNotInLayoutOrScroll(String)
+ */
+ void assertInLayoutOrScroll(String message) {
+ if (!isComputingLayout()) {
+ if (message == null) {
+ throw new IllegalStateException("Cannot call this method unless RecyclerView is "
+ + "computing a layout or scrolling");
+ }
+ throw new IllegalStateException(message);
+
+ }
+ }
+
+ /**
+ * Checks if RecyclerView is in the middle of a layout or scroll and throws an
+ * {@link IllegalStateException} if it <b>is</b>.
+ *
+ * @param message The message for the exception. Can be null.
+ * @see #assertInLayoutOrScroll(String)
+ */
+ void assertNotInLayoutOrScroll(String message) {
+ if (isComputingLayout()) {
+ if (message == null) {
+ throw new IllegalStateException("Cannot call this method while RecyclerView is "
+ + "computing a layout or scrolling");
+ }
+ throw new IllegalStateException(message);
+ }
+ if (mDispatchScrollCounter > 0) {
+ Log.w(TAG, "Cannot call this method in a scroll callback. Scroll callbacks might be run"
+ + " during a measure & layout pass where you cannot change the RecyclerView"
+ + " data. Any method call that might change the structure of the RecyclerView"
+ + " or the adapter contents should be postponed to the next frame.",
+ new IllegalStateException(""));
+ }
+ }
+
+ /**
+ * Add an {@link OnItemTouchListener} to intercept touch events before they are dispatched
+ * to child views or this view's standard scrolling behavior.
+ *
+ * <p>Client code may use listeners to implement item manipulation behavior. Once a listener
+ * returns true from
+ * {@link OnItemTouchListener#onInterceptTouchEvent(RecyclerView, MotionEvent)} its
+ * {@link OnItemTouchListener#onTouchEvent(RecyclerView, MotionEvent)} method will be called
+ * for each incoming MotionEvent until the end of the gesture.</p>
+ *
+ * @param listener Listener to add
+ * @see SimpleOnItemTouchListener
+ */
+ public void addOnItemTouchListener(OnItemTouchListener listener) {
+ mOnItemTouchListeners.add(listener);
+ }
+
+ /**
+ * Remove an {@link OnItemTouchListener}. It will no longer be able to intercept touch events.
+ *
+ * @param listener Listener to remove
+ */
+ public void removeOnItemTouchListener(OnItemTouchListener listener) {
+ mOnItemTouchListeners.remove(listener);
+ if (mActiveOnItemTouchListener == listener) {
+ mActiveOnItemTouchListener = null;
+ }
+ }
+
+ private boolean dispatchOnItemTouchIntercept(MotionEvent e) {
+ final int action = e.getAction();
+ if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_DOWN) {
+ mActiveOnItemTouchListener = null;
+ }
+
+ final int listenerCount = mOnItemTouchListeners.size();
+ for (int i = 0; i < listenerCount; i++) {
+ final OnItemTouchListener listener = mOnItemTouchListeners.get(i);
+ if (listener.onInterceptTouchEvent(this, e) && action != MotionEvent.ACTION_CANCEL) {
+ mActiveOnItemTouchListener = listener;
+ return true;
+ }
+ }
+ return false;
+ }
+
+ private boolean dispatchOnItemTouch(MotionEvent e) {
+ final int action = e.getAction();
+ if (mActiveOnItemTouchListener != null) {
+ if (action == MotionEvent.ACTION_DOWN) {
+ // Stale state from a previous gesture, we're starting a new one. Clear it.
+ mActiveOnItemTouchListener = null;
+ } else {
+ mActiveOnItemTouchListener.onTouchEvent(this, e);
+ if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
+ // Clean up for the next gesture.
+ mActiveOnItemTouchListener = null;
+ }
+ return true;
+ }
+ }
+
+ // Listeners will have already received the ACTION_DOWN via dispatchOnItemTouchIntercept
+ // as called from onInterceptTouchEvent; skip it.
+ if (action != MotionEvent.ACTION_DOWN) {
+ final int listenerCount = mOnItemTouchListeners.size();
+ for (int i = 0; i < listenerCount; i++) {
+ final OnItemTouchListener listener = mOnItemTouchListeners.get(i);
+ if (listener.onInterceptTouchEvent(this, e)) {
+ mActiveOnItemTouchListener = listener;
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+
+ @Override
+ public boolean onInterceptTouchEvent(MotionEvent e) {
+ if (mLayoutFrozen) {
+ // When layout is frozen, RV does not intercept the motion event.
+ // A child view e.g. a button may still get the click.
+ return false;
+ }
+ if (dispatchOnItemTouchIntercept(e)) {
+ cancelTouch();
+ return true;
+ }
+
+ if (mLayout == null) {
+ return false;
+ }
+
+ final boolean canScrollHorizontally = mLayout.canScrollHorizontally();
+ final boolean canScrollVertically = mLayout.canScrollVertically();
+
+ if (mVelocityTracker == null) {
+ mVelocityTracker = VelocityTracker.obtain();
+ }
+ mVelocityTracker.addMovement(e);
+
+ final int action = e.getActionMasked();
+ final int actionIndex = e.getActionIndex();
+
+ switch (action) {
+ case MotionEvent.ACTION_DOWN:
+ if (mIgnoreMotionEventTillDown) {
+ mIgnoreMotionEventTillDown = false;
+ }
+ mScrollPointerId = e.getPointerId(0);
+ mInitialTouchX = mLastTouchX = (int) (e.getX() + 0.5f);
+ mInitialTouchY = mLastTouchY = (int) (e.getY() + 0.5f);
+
+ if (mScrollState == SCROLL_STATE_SETTLING) {
+ getParent().requestDisallowInterceptTouchEvent(true);
+ setScrollState(SCROLL_STATE_DRAGGING);
+ }
+
+ // Clear the nested offsets
+ mNestedOffsets[0] = mNestedOffsets[1] = 0;
+
+ int nestedScrollAxis = View.SCROLL_AXIS_NONE;
+ if (canScrollHorizontally) {
+ nestedScrollAxis |= View.SCROLL_AXIS_HORIZONTAL;
+ }
+ if (canScrollVertically) {
+ nestedScrollAxis |= View.SCROLL_AXIS_VERTICAL;
+ }
+ startNestedScroll(nestedScrollAxis);
+ break;
+
+ case MotionEvent.ACTION_POINTER_DOWN:
+ mScrollPointerId = e.getPointerId(actionIndex);
+ mInitialTouchX = mLastTouchX = (int) (e.getX(actionIndex) + 0.5f);
+ mInitialTouchY = mLastTouchY = (int) (e.getY(actionIndex) + 0.5f);
+ break;
+
+ case MotionEvent.ACTION_MOVE: {
+ final int index = e.findPointerIndex(mScrollPointerId);
+ if (index < 0) {
+ Log.e(TAG, "Error processing scroll; pointer index for id "
+ + mScrollPointerId + " not found. Did any MotionEvents get skipped?");
+ return false;
+ }
+
+ final int x = (int) (e.getX(index) + 0.5f);
+ final int y = (int) (e.getY(index) + 0.5f);
+ if (mScrollState != SCROLL_STATE_DRAGGING) {
+ final int dx = x - mInitialTouchX;
+ final int dy = y - mInitialTouchY;
+ boolean startScroll = false;
+ if (canScrollHorizontally && Math.abs(dx) > mTouchSlop) {
+ mLastTouchX = mInitialTouchX + mTouchSlop * (dx < 0 ? -1 : 1);
+ startScroll = true;
+ }
+ if (canScrollVertically && Math.abs(dy) > mTouchSlop) {
+ mLastTouchY = mInitialTouchY + mTouchSlop * (dy < 0 ? -1 : 1);
+ startScroll = true;
+ }
+ if (startScroll) {
+ setScrollState(SCROLL_STATE_DRAGGING);
+ }
+ }
+ } break;
+
+ case MotionEvent.ACTION_POINTER_UP: {
+ onPointerUp(e);
+ } break;
+
+ case MotionEvent.ACTION_UP: {
+ mVelocityTracker.clear();
+ stopNestedScroll();
+ } break;
+
+ case MotionEvent.ACTION_CANCEL: {
+ cancelTouch();
+ }
+ }
+ return mScrollState == SCROLL_STATE_DRAGGING;
+ }
+
+ @Override
+ public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
+ final int listenerCount = mOnItemTouchListeners.size();
+ for (int i = 0; i < listenerCount; i++) {
+ final OnItemTouchListener listener = mOnItemTouchListeners.get(i);
+ listener.onRequestDisallowInterceptTouchEvent(disallowIntercept);
+ }
+ super.requestDisallowInterceptTouchEvent(disallowIntercept);
+ }
+
+ @Override
+ public boolean onTouchEvent(MotionEvent e) {
+ if (mLayoutFrozen || mIgnoreMotionEventTillDown) {
+ return false;
+ }
+ if (dispatchOnItemTouch(e)) {
+ cancelTouch();
+ return true;
+ }
+
+ if (mLayout == null) {
+ return false;
+ }
+
+ final boolean canScrollHorizontally = mLayout.canScrollHorizontally();
+ final boolean canScrollVertically = mLayout.canScrollVertically();
+
+ if (mVelocityTracker == null) {
+ mVelocityTracker = VelocityTracker.obtain();
+ }
+ boolean eventAddedToVelocityTracker = false;
+
+ final MotionEvent vtev = MotionEvent.obtain(e);
+ final int action = e.getActionMasked();
+ final int actionIndex = e.getActionIndex();
+
+ if (action == MotionEvent.ACTION_DOWN) {
+ mNestedOffsets[0] = mNestedOffsets[1] = 0;
+ }
+ vtev.offsetLocation(mNestedOffsets[0], mNestedOffsets[1]);
+
+ switch (action) {
+ case MotionEvent.ACTION_DOWN: {
+ mScrollPointerId = e.getPointerId(0);
+ mInitialTouchX = mLastTouchX = (int) (e.getX() + 0.5f);
+ mInitialTouchY = mLastTouchY = (int) (e.getY() + 0.5f);
+
+ int nestedScrollAxis = View.SCROLL_AXIS_NONE;
+ if (canScrollHorizontally) {
+ nestedScrollAxis |= View.SCROLL_AXIS_HORIZONTAL;
+ }
+ if (canScrollVertically) {
+ nestedScrollAxis |= View.SCROLL_AXIS_VERTICAL;
+ }
+ startNestedScroll(nestedScrollAxis);
+ } break;
+
+ case MotionEvent.ACTION_POINTER_DOWN: {
+ mScrollPointerId = e.getPointerId(actionIndex);
+ mInitialTouchX = mLastTouchX = (int) (e.getX(actionIndex) + 0.5f);
+ mInitialTouchY = mLastTouchY = (int) (e.getY(actionIndex) + 0.5f);
+ } break;
+
+ case MotionEvent.ACTION_MOVE: {
+ final int index = e.findPointerIndex(mScrollPointerId);
+ if (index < 0) {
+ Log.e(TAG, "Error processing scroll; pointer index for id "
+ + mScrollPointerId + " not found. Did any MotionEvents get skipped?");
+ return false;
+ }
+
+ final int x = (int) (e.getX(index) + 0.5f);
+ final int y = (int) (e.getY(index) + 0.5f);
+ int dx = mLastTouchX - x;
+ int dy = mLastTouchY - y;
+
+ if (dispatchNestedPreScroll(dx, dy, mScrollConsumed, mScrollOffset)) {
+ dx -= mScrollConsumed[0];
+ dy -= mScrollConsumed[1];
+ vtev.offsetLocation(mScrollOffset[0], mScrollOffset[1]);
+ // Updated the nested offsets
+ mNestedOffsets[0] += mScrollOffset[0];
+ mNestedOffsets[1] += mScrollOffset[1];
+ }
+
+ if (mScrollState != SCROLL_STATE_DRAGGING) {
+ boolean startScroll = false;
+ if (canScrollHorizontally && Math.abs(dx) > mTouchSlop) {
+ if (dx > 0) {
+ dx -= mTouchSlop;
+ } else {
+ dx += mTouchSlop;
+ }
+ startScroll = true;
+ }
+ if (canScrollVertically && Math.abs(dy) > mTouchSlop) {
+ if (dy > 0) {
+ dy -= mTouchSlop;
+ } else {
+ dy += mTouchSlop;
+ }
+ startScroll = true;
+ }
+ if (startScroll) {
+ setScrollState(SCROLL_STATE_DRAGGING);
+ }
+ }
+
+ if (mScrollState == SCROLL_STATE_DRAGGING) {
+ mLastTouchX = x - mScrollOffset[0];
+ mLastTouchY = y - mScrollOffset[1];
+
+ if (scrollByInternal(
+ canScrollHorizontally ? dx : 0,
+ canScrollVertically ? dy : 0,
+ vtev)) {
+ getParent().requestDisallowInterceptTouchEvent(true);
+ }
+ if (mGapWorker != null && (dx != 0 || dy != 0)) {
+ mGapWorker.postFromTraversal(this, dx, dy);
+ }
+ }
+ } break;
+
+ case MotionEvent.ACTION_POINTER_UP: {
+ onPointerUp(e);
+ } break;
+
+ case MotionEvent.ACTION_UP: {
+ mVelocityTracker.addMovement(vtev);
+ eventAddedToVelocityTracker = true;
+ mVelocityTracker.computeCurrentVelocity(1000, mMaxFlingVelocity);
+ final float xvel = canScrollHorizontally
+ ? -mVelocityTracker.getXVelocity(mScrollPointerId) : 0;
+ final float yvel = canScrollVertically
+ ? -mVelocityTracker.getYVelocity(mScrollPointerId) : 0;
+ if (!((xvel != 0 || yvel != 0) && fling((int) xvel, (int) yvel))) {
+ setScrollState(SCROLL_STATE_IDLE);
+ }
+ resetTouch();
+ } break;
+
+ case MotionEvent.ACTION_CANCEL: {
+ cancelTouch();
+ } break;
+ }
+
+ if (!eventAddedToVelocityTracker) {
+ mVelocityTracker.addMovement(vtev);
+ }
+ vtev.recycle();
+
+ return true;
+ }
+
+ private void resetTouch() {
+ if (mVelocityTracker != null) {
+ mVelocityTracker.clear();
+ }
+ stopNestedScroll();
+ releaseGlows();
+ }
+
+ private void cancelTouch() {
+ resetTouch();
+ setScrollState(SCROLL_STATE_IDLE);
+ }
+
+ private void onPointerUp(MotionEvent e) {
+ final int actionIndex = e.getActionIndex();
+ if (e.getPointerId(actionIndex) == mScrollPointerId) {
+ // Pick a new pointer to pick up the slack.
+ final int newIndex = actionIndex == 0 ? 1 : 0;
+ mScrollPointerId = e.getPointerId(newIndex);
+ mInitialTouchX = mLastTouchX = (int) (e.getX(newIndex) + 0.5f);
+ mInitialTouchY = mLastTouchY = (int) (e.getY(newIndex) + 0.5f);
+ }
+ }
+
+ // @Override
+ public boolean onGenericMotionEvent(MotionEvent event) {
+ if (mLayout == null) {
+ return false;
+ }
+ if (mLayoutFrozen) {
+ return false;
+ }
+ if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
+ if (event.getAction() == MotionEvent.ACTION_SCROLL) {
+ final float vScroll, hScroll;
+ if (mLayout.canScrollVertically()) {
+ // Inverse the sign of the vertical scroll to align the scroll orientation
+ // with AbsListView.
+ vScroll = -event.getAxisValue(MotionEvent.AXIS_VSCROLL);
+ } else {
+ vScroll = 0f;
+ }
+ if (mLayout.canScrollHorizontally()) {
+ hScroll = event.getAxisValue(MotionEvent.AXIS_HSCROLL);
+ } else {
+ hScroll = 0f;
+ }
+
+ if (vScroll != 0 || hScroll != 0) {
+ final float scrollFactor = getScrollFactor();
+ scrollByInternal((int) (hScroll * scrollFactor),
+ (int) (vScroll * scrollFactor), event);
+ }
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Ported from View.getVerticalScrollFactor.
+ */
+ private float getScrollFactor() {
+ if (mScrollFactor == Float.MIN_VALUE) {
+ TypedValue outValue = new TypedValue();
+ if (getContext().getTheme().resolveAttribute(
+ android.R.attr.listPreferredItemHeight, outValue, true)) {
+ mScrollFactor = outValue.getDimension(
+ getContext().getResources().getDisplayMetrics());
+ } else {
+ return 0; //listPreferredItemHeight is not defined, no generic scrolling
+ }
+ }
+ return mScrollFactor;
+ }
+
+ @Override
+ protected void onMeasure(int widthSpec, int heightSpec) {
+ if (mLayout == null) {
+ defaultOnMeasure(widthSpec, heightSpec);
+ return;
+ }
+ if (mLayout.mAutoMeasure) {
+ final int widthMode = MeasureSpec.getMode(widthSpec);
+ final int heightMode = MeasureSpec.getMode(heightSpec);
+ final boolean skipMeasure = widthMode == MeasureSpec.EXACTLY
+ && heightMode == MeasureSpec.EXACTLY;
+ mLayout.onMeasure(mRecycler, mState, widthSpec, heightSpec);
+ if (skipMeasure || mAdapter == null) {
+ return;
+ }
+ if (mState.mLayoutStep == State.STEP_START) {
+ dispatchLayoutStep1();
+ }
+ // set dimensions in 2nd step. Pre-layout should happen with old dimensions for
+ // consistency
+ mLayout.setMeasureSpecs(widthSpec, heightSpec);
+ mState.mIsMeasuring = true;
+ dispatchLayoutStep2();
+
+ // now we can get the width and height from the children.
+ mLayout.setMeasuredDimensionFromChildren(widthSpec, heightSpec);
+
+ // if RecyclerView has non-exact width and height and if there is at least one child
+ // which also has non-exact width & height, we have to re-measure.
+ if (mLayout.shouldMeasureTwice()) {
+ mLayout.setMeasureSpecs(
+ MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.EXACTLY),
+ MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY));
+ mState.mIsMeasuring = true;
+ dispatchLayoutStep2();
+ // now we can get the width and height from the children.
+ mLayout.setMeasuredDimensionFromChildren(widthSpec, heightSpec);
+ }
+ } else {
+ if (mHasFixedSize) {
+ mLayout.onMeasure(mRecycler, mState, widthSpec, heightSpec);
+ return;
+ }
+ // custom onMeasure
+ if (mAdapterUpdateDuringMeasure) {
+ eatRequestLayout();
+ onEnterLayoutOrScroll();
+ processAdapterUpdatesAndSetAnimationFlags();
+ onExitLayoutOrScroll();
+
+ if (mState.mRunPredictiveAnimations) {
+ mState.mInPreLayout = true;
+ } else {
+ // consume remaining updates to provide a consistent state with the layout pass.
+ mAdapterHelper.consumeUpdatesInOnePass();
+ mState.mInPreLayout = false;
+ }
+ mAdapterUpdateDuringMeasure = false;
+ resumeRequestLayout(false);
+ }
+
+ if (mAdapter != null) {
+ mState.mItemCount = mAdapter.getItemCount();
+ } else {
+ mState.mItemCount = 0;
+ }
+ eatRequestLayout();
+ mLayout.onMeasure(mRecycler, mState, widthSpec, heightSpec);
+ resumeRequestLayout(false);
+ mState.mInPreLayout = false; // clear
+ }
+ }
+
+ /**
+ * Used when onMeasure is called before layout manager is set
+ */
+ void defaultOnMeasure(int widthSpec, int heightSpec) {
+ // calling LayoutManager here is not pretty but that API is already public and it is better
+ // than creating another method since this is internal.
+ final int width = LayoutManager.chooseSize(widthSpec,
+ getPaddingLeft() + getPaddingRight(),
+ getMinimumWidth());
+ final int height = LayoutManager.chooseSize(heightSpec,
+ getPaddingTop() + getPaddingBottom(),
+ getMinimumHeight());
+
+ setMeasuredDimension(width, height);
+ }
+
+ @Override
+ protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+ super.onSizeChanged(w, h, oldw, oldh);
+ if (w != oldw || h != oldh) {
+ invalidateGlows();
+ // layout's w/h are updated during measure/layout steps.
+ }
+ }
+
+ /**
+ * Sets the {@link ItemAnimator} that will handle animations involving changes
+ * to the items in this RecyclerView. By default, RecyclerView instantiates and
+ * uses an instance of {@link DefaultItemAnimator}. Whether item animations are
+ * enabled for the RecyclerView depends on the ItemAnimator and whether
+ * the LayoutManager {@link LayoutManager#supportsPredictiveItemAnimations()
+ * supports item animations}.
+ *
+ * @param animator The ItemAnimator being set. If null, no animations will occur
+ * when changes occur to the items in this RecyclerView.
+ */
+ public void setItemAnimator(ItemAnimator animator) {
+ if (mItemAnimator != null) {
+ mItemAnimator.endAnimations();
+ mItemAnimator.setListener(null);
+ }
+ mItemAnimator = animator;
+ if (mItemAnimator != null) {
+ mItemAnimator.setListener(mItemAnimatorListener);
+ }
+ }
+
+ void onEnterLayoutOrScroll() {
+ mLayoutOrScrollCounter++;
+ }
+
+ void onExitLayoutOrScroll() {
+ mLayoutOrScrollCounter--;
+ if (mLayoutOrScrollCounter < 1) {
+ if (DEBUG && mLayoutOrScrollCounter < 0) {
+ throw new IllegalStateException("layout or scroll counter cannot go below zero."
+ + "Some calls are not matching");
+ }
+ mLayoutOrScrollCounter = 0;
+ dispatchContentChangedIfNecessary();
+ dispatchPendingImportantForAccessibilityChanges();
+ }
+ }
+
+ boolean isAccessibilityEnabled() {
+ return mAccessibilityManager != null && mAccessibilityManager.isEnabled();
+ }
+
+ private void dispatchContentChangedIfNecessary() {
+ final int flags = mEatenAccessibilityChangeFlags;
+ mEatenAccessibilityChangeFlags = 0;
+ if (flags != 0 && isAccessibilityEnabled()) {
+ final AccessibilityEvent event = AccessibilityEvent.obtain();
+ event.setEventType(AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
+ event.setContentChangeTypes(flags);
+ sendAccessibilityEventUnchecked(event);
+ }
+ }
+
+ /**
+ * Returns whether RecyclerView is currently computing a layout.
+ * <p>
+ * If this method returns true, it means that RecyclerView is in a lockdown state and any
+ * attempt to update adapter contents will result in an exception because adapter contents
+ * cannot be changed while RecyclerView is trying to compute the layout.
+ * <p>
+ * It is very unlikely that your code will be running during this state as it is
+ * called by the framework when a layout traversal happens or RecyclerView starts to scroll
+ * in response to system events (touch, accessibility etc).
+ * <p>
+ * This case may happen if you have some custom logic to change adapter contents in
+ * response to a View callback (e.g. focus change callback) which might be triggered during a
+ * layout calculation. In these cases, you should just postpone the change using a Handler or a
+ * similar mechanism.
+ *
+ * @return <code>true</code> if RecyclerView is currently computing a layout, <code>false</code>
+ * otherwise
+ */
+ public boolean isComputingLayout() {
+ return mLayoutOrScrollCounter > 0;
+ }
+
+ /**
+ * Returns true if an accessibility event should not be dispatched now. This happens when an
+ * accessibility request arrives while RecyclerView does not have a stable state which is very
+ * hard to handle for a LayoutManager. Instead, this method records necessary information about
+ * the event and dispatches a window change event after the critical section is finished.
+ *
+ * @return True if the accessibility event should be postponed.
+ */
+ boolean shouldDeferAccessibilityEvent(AccessibilityEvent event) {
+ if (isComputingLayout()) {
+ int type = 0;
+ if (event != null) {
+ type = event.getContentChangeTypes();
+ }
+ if (type == 0) {
+ type = AccessibilityEvent.CONTENT_CHANGE_TYPE_UNDEFINED;
+ }
+ mEatenAccessibilityChangeFlags |= type;
+ return true;
+ }
+ return false;
+ }
+
+ @Override
+ public void sendAccessibilityEventUnchecked(AccessibilityEvent event) {
+ if (shouldDeferAccessibilityEvent(event)) {
+ return;
+ }
+ super.sendAccessibilityEventUnchecked(event);
+ }
+
+ /**
+ * Gets the current ItemAnimator for this RecyclerView. A null return value
+ * indicates that there is no animator and that item changes will happen without
+ * any animations. By default, RecyclerView instantiates and
+ * uses an instance of {@link DefaultItemAnimator}.
+ *
+ * @return ItemAnimator The current ItemAnimator. If null, no animations will occur
+ * when changes occur to the items in this RecyclerView.
+ */
+ public ItemAnimator getItemAnimator() {
+ return mItemAnimator;
+ }
+
+ /**
+ * Post a runnable to the next frame to run pending item animations. Only the first such
+ * request will be posted, governed by the mPostedAnimatorRunner flag.
+ */
+ void postAnimationRunner() {
+ if (!mPostedAnimatorRunner && mIsAttached) {
+ postOnAnimation(mItemAnimatorRunner);
+ mPostedAnimatorRunner = true;
+ }
+ }
+
+ private boolean predictiveItemAnimationsEnabled() {
+ return (mItemAnimator != null && mLayout.supportsPredictiveItemAnimations());
+ }
+
+ /**
+ * Consumes adapter updates and calculates which type of animations we want to run.
+ * Called in onMeasure and dispatchLayout.
+ * <p>
+ * This method may process only the pre-layout state of updates or all of them.
+ */
+ private void processAdapterUpdatesAndSetAnimationFlags() {
+ if (mDataSetHasChangedAfterLayout) {
+ // Processing these items have no value since data set changed unexpectedly.
+ // Instead, we just reset it.
+ mAdapterHelper.reset();
+ mLayout.onItemsChanged(this);
+ }
+ // simple animations are a subset of advanced animations (which will cause a
+ // pre-layout step)
+ // If layout supports predictive animations, pre-process to decide if we want to run them
+ if (predictiveItemAnimationsEnabled()) {
+ mAdapterHelper.preProcess();
+ } else {
+ mAdapterHelper.consumeUpdatesInOnePass();
+ }
+ boolean animationTypeSupported = mItemsAddedOrRemoved || mItemsChanged;
+ mState.mRunSimpleAnimations = mFirstLayoutComplete
+ && mItemAnimator != null
+ && (mDataSetHasChangedAfterLayout
+ || animationTypeSupported
+ || mLayout.mRequestedSimpleAnimations)
+ && (!mDataSetHasChangedAfterLayout
+ || mAdapter.hasStableIds());
+ mState.mRunPredictiveAnimations = mState.mRunSimpleAnimations
+ && animationTypeSupported
+ && !mDataSetHasChangedAfterLayout
+ && predictiveItemAnimationsEnabled();
+ }
+
+ /**
+ * Wrapper around layoutChildren() that handles animating changes caused by layout.
+ * Animations work on the assumption that there are five different kinds of items
+ * in play:
+ * PERSISTENT: items are visible before and after layout
+ * REMOVED: items were visible before layout and were removed by the app
+ * ADDED: items did not exist before layout and were added by the app
+ * DISAPPEARING: items exist in the data set before/after, but changed from
+ * visible to non-visible in the process of layout (they were moved off
+ * screen as a side-effect of other changes)
+ * APPEARING: items exist in the data set before/after, but changed from
+ * non-visible to visible in the process of layout (they were moved on
+ * screen as a side-effect of other changes)
+ * The overall approach figures out what items exist before/after layout and
+ * infers one of the five above states for each of the items. Then the animations
+ * are set up accordingly:
+ * PERSISTENT views are animated via
+ * {@link ItemAnimator#animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo)}
+ * DISAPPEARING views are animated via
+ * {@link ItemAnimator#animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)}
+ * APPEARING views are animated via
+ * {@link ItemAnimator#animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)}
+ * and changed views are animated via
+ * {@link ItemAnimator#animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)}.
+ */
+ void dispatchLayout() {
+ if (mAdapter == null) {
+ Log.e(TAG, "No adapter attached; skipping layout");
+ // leave the state in START
+ return;
+ }
+ if (mLayout == null) {
+ Log.e(TAG, "No layout manager attached; skipping layout");
+ // leave the state in START
+ return;
+ }
+ mState.mIsMeasuring = false;
+ if (mState.mLayoutStep == State.STEP_START) {
+ dispatchLayoutStep1();
+ mLayout.setExactMeasureSpecsFrom(this);
+ dispatchLayoutStep2();
+ } else if (mAdapterHelper.hasUpdates() || mLayout.getWidth() != getWidth()
+ || mLayout.getHeight() != getHeight()) {
+ // First 2 steps are done in onMeasure but looks like we have to run again due to
+ // changed size.
+ mLayout.setExactMeasureSpecsFrom(this);
+ dispatchLayoutStep2();
+ } else {
+ // always make sure we sync them (to ensure mode is exact)
+ mLayout.setExactMeasureSpecsFrom(this);
+ }
+ dispatchLayoutStep3();
+ }
+
+ private void saveFocusInfo() {
+ View child = null;
+ if (mPreserveFocusAfterLayout && hasFocus() && mAdapter != null) {
+ child = getFocusedChild();
+ }
+
+ final ViewHolder focusedVh = child == null ? null : findContainingViewHolder(child);
+ if (focusedVh == null) {
+ resetFocusInfo();
+ } else {
+ mState.mFocusedItemId = mAdapter.hasStableIds() ? focusedVh.getItemId() : NO_ID;
+ // mFocusedItemPosition should hold the current adapter position of the previously
+ // focused item. If the item is removed, we store the previous adapter position of the
+ // removed item.
+ mState.mFocusedItemPosition = mDataSetHasChangedAfterLayout ? NO_POSITION
+ : (focusedVh.isRemoved() ? focusedVh.mOldPosition
+ : focusedVh.getAdapterPosition());
+ mState.mFocusedSubChildId = getDeepestFocusedViewWithId(focusedVh.itemView);
+ }
+ }
+
+ private void resetFocusInfo() {
+ mState.mFocusedItemId = NO_ID;
+ mState.mFocusedItemPosition = NO_POSITION;
+ mState.mFocusedSubChildId = View.NO_ID;
+ }
+
+ /**
+ * Finds the best view candidate to request focus on using mFocusedItemPosition index of the
+ * previously focused item. It first traverses the adapter forward to find a focusable candidate
+ * and if no such candidate is found, it reverses the focus search direction for the items
+ * before the mFocusedItemPosition'th index;
+ * @return The best candidate to request focus on, or null if no such candidate exists. Null
+ * indicates all the existing adapter items are unfocusable.
+ */
+ @Nullable
+ private View findNextViewToFocus() {
+ int startFocusSearchIndex = mState.mFocusedItemPosition != -1 ? mState.mFocusedItemPosition
+ : 0;
+ ViewHolder nextFocus;
+ final int itemCount = mState.getItemCount();
+ for (int i = startFocusSearchIndex; i < itemCount; i++) {
+ nextFocus = findViewHolderForAdapterPosition(i);
+ if (nextFocus == null) {
+ break;
+ }
+ if (nextFocus.itemView.hasFocusable()) {
+ return nextFocus.itemView;
+ }
+ }
+ final int limit = Math.min(itemCount, startFocusSearchIndex);
+ for (int i = limit - 1; i >= 0; i--) {
+ nextFocus = findViewHolderForAdapterPosition(i);
+ if (nextFocus == null) {
+ return null;
+ }
+ if (nextFocus.itemView.hasFocusable()) {
+ return nextFocus.itemView;
+ }
+ }
+ return null;
+ }
+
+ private void recoverFocusFromState() {
+ if (!mPreserveFocusAfterLayout || mAdapter == null || !hasFocus()
+ || getDescendantFocusability() == FOCUS_BLOCK_DESCENDANTS
+ || (getDescendantFocusability() == FOCUS_BEFORE_DESCENDANTS && isFocused())) {
+ // No-op if either of these cases happens:
+ // 1. RV has no focus, or 2. RV blocks focus to its children, or 3. RV takes focus
+ // before its children and is focused (i.e. it already stole the focus away from its
+ // descendants).
+ return;
+ }
+ // only recover focus if RV itself has the focus or the focused view is hidden
+ if (!isFocused()) {
+ final View focusedChild = getFocusedChild();
+ if (IGNORE_DETACHED_FOCUSED_CHILD
+ && (focusedChild.getParent() == null || !focusedChild.hasFocus())) {
+ // Special handling of API 15-. A focused child can be invalid because mFocus is not
+ // cleared when the child is detached (mParent = null),
+ // This happens because clearFocus on API 15- does not invalidate mFocus of its
+ // parent when this child is detached.
+ // For API 16+, this is not an issue because requestFocus takes care of clearing the
+ // prior detached focused child. For API 15- the problem happens in 2 cases because
+ // clearChild does not call clearChildFocus on RV: 1. setFocusable(false) is called
+ // for the current focused item which calls clearChild or 2. when the prior focused
+ // child is removed, removeDetachedView called in layout step 3 which calls
+ // clearChild. We should ignore this invalid focused child in all our calculations
+ // for the next view to receive focus, and apply the focus recovery logic instead.
+ if (mChildHelper.getChildCount() == 0) {
+ // No children left. Request focus on the RV itself since one of its children
+ // was holding focus previously.
+ requestFocus();
+ return;
+ }
+ } else if (!mChildHelper.isHidden(focusedChild)) {
+ // If the currently focused child is hidden, apply the focus recovery logic.
+ // Otherwise return, i.e. the currently (unhidden) focused child is good enough :/.
+ return;
+ }
+ }
+ ViewHolder focusTarget = null;
+ // RV first attempts to locate the previously focused item to request focus on using
+ // mFocusedItemId. If such an item no longer exists, it then makes a best-effort attempt to
+ // find the next best candidate to request focus on based on mFocusedItemPosition.
+ if (mState.mFocusedItemId != NO_ID && mAdapter.hasStableIds()) {
+ focusTarget = findViewHolderForItemId(mState.mFocusedItemId);
+ }
+ View viewToFocus = null;
+ if (focusTarget == null || mChildHelper.isHidden(focusTarget.itemView)
+ || !focusTarget.itemView.hasFocusable()) {
+ if (mChildHelper.getChildCount() > 0) {
+ // At this point, RV has focus and either of these conditions are true:
+ // 1. There's no previously focused item either because RV received focused before
+ // layout, or the previously focused item was removed, or RV doesn't have stable IDs
+ // 2. Previous focus child is hidden, or 3. Previous focused child is no longer
+ // focusable. In either of these cases, we make sure that RV still passes down the
+ // focus to one of its focusable children using a best-effort algorithm.
+ viewToFocus = findNextViewToFocus();
+ }
+ } else {
+ // looks like the focused item has been replaced with another view that represents the
+ // same item in the adapter. Request focus on that.
+ viewToFocus = focusTarget.itemView;
+ }
+
+ if (viewToFocus != null) {
+ if (mState.mFocusedSubChildId != NO_ID) {
+ View child = viewToFocus.findViewById(mState.mFocusedSubChildId);
+ if (child != null && child.isFocusable()) {
+ viewToFocus = child;
+ }
+ }
+ viewToFocus.requestFocus();
+ }
+ }
+
+ private int getDeepestFocusedViewWithId(View view) {
+ int lastKnownId = view.getId();
+ while (!view.isFocused() && view instanceof ViewGroup && view.hasFocus()) {
+ view = ((ViewGroup) view).getFocusedChild();
+ final int id = view.getId();
+ if (id != View.NO_ID) {
+ lastKnownId = view.getId();
+ }
+ }
+ return lastKnownId;
+ }
+
+ /**
+ * The first step of a layout where we;
+ * - process adapter updates
+ * - decide which animation should run
+ * - save information about current views
+ * - If necessary, run predictive layout and save its information
+ */
+ private void dispatchLayoutStep1() {
+ mState.assertLayoutStep(State.STEP_START);
+ mState.mIsMeasuring = false;
+ eatRequestLayout();
+ mViewInfoStore.clear();
+ onEnterLayoutOrScroll();
+ processAdapterUpdatesAndSetAnimationFlags();
+ saveFocusInfo();
+ mState.mTrackOldChangeHolders = mState.mRunSimpleAnimations && mItemsChanged;
+ mItemsAddedOrRemoved = mItemsChanged = false;
+ mState.mInPreLayout = mState.mRunPredictiveAnimations;
+ mState.mItemCount = mAdapter.getItemCount();
+ findMinMaxChildLayoutPositions(mMinMaxLayoutPositions);
+
+ if (mState.mRunSimpleAnimations) {
+ // Step 0: Find out where all non-removed items are, pre-layout
+ int count = mChildHelper.getChildCount();
+ for (int i = 0; i < count; ++i) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getChildAt(i));
+ if (holder.shouldIgnore() || (holder.isInvalid() && !mAdapter.hasStableIds())) {
+ continue;
+ }
+ final ItemHolderInfo animationInfo = mItemAnimator
+ .recordPreLayoutInformation(mState, holder,
+ ItemAnimator.buildAdapterChangeFlagsForAnimations(holder),
+ holder.getUnmodifiedPayloads());
+ mViewInfoStore.addToPreLayout(holder, animationInfo);
+ if (mState.mTrackOldChangeHolders && holder.isUpdated() && !holder.isRemoved()
+ && !holder.shouldIgnore() && !holder.isInvalid()) {
+ long key = getChangedHolderKey(holder);
+ // This is NOT the only place where a ViewHolder is added to old change holders
+ // list. There is another case where:
+ // * A VH is currently hidden but not deleted
+ // * The hidden item is changed in the adapter
+ // * Layout manager decides to layout the item in the pre-Layout pass (step1)
+ // When this case is detected, RV will un-hide that view and add to the old
+ // change holders list.
+ mViewInfoStore.addToOldChangeHolders(key, holder);
+ }
+ }
+ }
+ if (mState.mRunPredictiveAnimations) {
+ // Step 1: run prelayout: This will use the old positions of items. The layout manager
+ // is expected to layout everything, even removed items (though not to add removed
+ // items back to the container). This gives the pre-layout position of APPEARING views
+ // which come into existence as part of the real layout.
+
+ // Save old positions so that LayoutManager can run its mapping logic.
+ saveOldPositions();
+ final boolean didStructureChange = mState.mStructureChanged;
+ mState.mStructureChanged = false;
+ // temporarily disable flag because we are asking for previous layout
+ mLayout.onLayoutChildren(mRecycler, mState);
+ mState.mStructureChanged = didStructureChange;
+
+ for (int i = 0; i < mChildHelper.getChildCount(); ++i) {
+ final View child = mChildHelper.getChildAt(i);
+ final ViewHolder viewHolder = getChildViewHolderInt(child);
+ if (viewHolder.shouldIgnore()) {
+ continue;
+ }
+ if (!mViewInfoStore.isInPreLayout(viewHolder)) {
+ int flags = ItemAnimator.buildAdapterChangeFlagsForAnimations(viewHolder);
+ boolean wasHidden = viewHolder
+ .hasAnyOfTheFlags(ViewHolder.FLAG_BOUNCED_FROM_HIDDEN_LIST);
+ if (!wasHidden) {
+ flags |= ItemAnimator.FLAG_APPEARED_IN_PRE_LAYOUT;
+ }
+ final ItemHolderInfo animationInfo = mItemAnimator.recordPreLayoutInformation(
+ mState, viewHolder, flags, viewHolder.getUnmodifiedPayloads());
+ if (wasHidden) {
+ recordAnimationInfoIfBouncedHiddenView(viewHolder, animationInfo);
+ } else {
+ mViewInfoStore.addToAppearedInPreLayoutHolders(viewHolder, animationInfo);
+ }
+ }
+ }
+ // we don't process disappearing list because they may re-appear in post layout pass.
+ clearOldPositions();
+ } else {
+ clearOldPositions();
+ }
+ onExitLayoutOrScroll();
+ resumeRequestLayout(false);
+ mState.mLayoutStep = State.STEP_LAYOUT;
+ }
+
+ /**
+ * The second layout step where we do the actual layout of the views for the final state.
+ * This step might be run multiple times if necessary (e.g. measure).
+ */
+ private void dispatchLayoutStep2() {
+ eatRequestLayout();
+ onEnterLayoutOrScroll();
+ mState.assertLayoutStep(State.STEP_LAYOUT | State.STEP_ANIMATIONS);
+ mAdapterHelper.consumeUpdatesInOnePass();
+ mState.mItemCount = mAdapter.getItemCount();
+ mState.mDeletedInvisibleItemCountSincePreviousLayout = 0;
+
+ // Step 2: Run layout
+ mState.mInPreLayout = false;
+ mLayout.onLayoutChildren(mRecycler, mState);
+
+ mState.mStructureChanged = false;
+ mPendingSavedState = null;
+
+ // onLayoutChildren may have caused client code to disable item animations; re-check
+ mState.mRunSimpleAnimations = mState.mRunSimpleAnimations && mItemAnimator != null;
+ mState.mLayoutStep = State.STEP_ANIMATIONS;
+ onExitLayoutOrScroll();
+ resumeRequestLayout(false);
+ }
+
+ /**
+ * The final step of the layout where we save the information about views for animations,
+ * trigger animations and do any necessary cleanup.
+ */
+ private void dispatchLayoutStep3() {
+ mState.assertLayoutStep(State.STEP_ANIMATIONS);
+ eatRequestLayout();
+ onEnterLayoutOrScroll();
+ mState.mLayoutStep = State.STEP_START;
+ if (mState.mRunSimpleAnimations) {
+ // Step 3: Find out where things are now, and process change animations.
+ // traverse list in reverse because we may call animateChange in the loop which may
+ // remove the target view holder.
+ for (int i = mChildHelper.getChildCount() - 1; i >= 0; i--) {
+ ViewHolder holder = getChildViewHolderInt(mChildHelper.getChildAt(i));
+ if (holder.shouldIgnore()) {
+ continue;
+ }
+ long key = getChangedHolderKey(holder);
+ final ItemHolderInfo animationInfo = mItemAnimator
+ .recordPostLayoutInformation(mState, holder);
+ ViewHolder oldChangeViewHolder = mViewInfoStore.getFromOldChangeHolders(key);
+ if (oldChangeViewHolder != null && !oldChangeViewHolder.shouldIgnore()) {
+ // run a change animation
+
+ // If an Item is CHANGED but the updated version is disappearing, it creates
+ // a conflicting case.
+ // Since a view that is marked as disappearing is likely to be going out of
+ // bounds, we run a change animation. Both views will be cleaned automatically
+ // once their animations finish.
+ // On the other hand, if it is the same view holder instance, we run a
+ // disappearing animation instead because we are not going to rebind the updated
+ // VH unless it is enforced by the layout manager.
+ final boolean oldDisappearing = mViewInfoStore.isDisappearing(
+ oldChangeViewHolder);
+ final boolean newDisappearing = mViewInfoStore.isDisappearing(holder);
+ if (oldDisappearing && oldChangeViewHolder == holder) {
+ // run disappear animation instead of change
+ mViewInfoStore.addToPostLayout(holder, animationInfo);
+ } else {
+ final ItemHolderInfo preInfo = mViewInfoStore.popFromPreLayout(
+ oldChangeViewHolder);
+ // we add and remove so that any post info is merged.
+ mViewInfoStore.addToPostLayout(holder, animationInfo);
+ ItemHolderInfo postInfo = mViewInfoStore.popFromPostLayout(holder);
+ if (preInfo == null) {
+ handleMissingPreInfoForChangeError(key, holder, oldChangeViewHolder);
+ } else {
+ animateChange(oldChangeViewHolder, holder, preInfo, postInfo,
+ oldDisappearing, newDisappearing);
+ }
+ }
+ } else {
+ mViewInfoStore.addToPostLayout(holder, animationInfo);
+ }
+ }
+
+ // Step 4: Process view info lists and trigger animations
+ mViewInfoStore.process(mViewInfoProcessCallback);
+ }
+
+ mLayout.removeAndRecycleScrapInt(mRecycler);
+ mState.mPreviousLayoutItemCount = mState.mItemCount;
+ mDataSetHasChangedAfterLayout = false;
+ mState.mRunSimpleAnimations = false;
+
+ mState.mRunPredictiveAnimations = false;
+ mLayout.mRequestedSimpleAnimations = false;
+ if (mRecycler.mChangedScrap != null) {
+ mRecycler.mChangedScrap.clear();
+ }
+ if (mLayout.mPrefetchMaxObservedInInitialPrefetch) {
+ // Initial prefetch has expanded cache, so reset until next prefetch.
+ // This prevents initial prefetches from expanding the cache permanently.
+ mLayout.mPrefetchMaxCountObserved = 0;
+ mLayout.mPrefetchMaxObservedInInitialPrefetch = false;
+ mRecycler.updateViewCacheSize();
+ }
+
+ mLayout.onLayoutCompleted(mState);
+ onExitLayoutOrScroll();
+ resumeRequestLayout(false);
+ mViewInfoStore.clear();
+ if (didChildRangeChange(mMinMaxLayoutPositions[0], mMinMaxLayoutPositions[1])) {
+ dispatchOnScrolled(0, 0);
+ }
+ recoverFocusFromState();
+ resetFocusInfo();
+ }
+
+ /**
+ * This handles the case where there is an unexpected VH missing in the pre-layout map.
+ * <p>
+ * We might be able to detect the error in the application which will help the developer to
+ * resolve the issue.
+ * <p>
+ * If it is not an expected error, we at least print an error to notify the developer and ignore
+ * the animation.
+ *
+ * https://code.google.com/p/android/issues/detail?id=193958
+ *
+ * @param key The change key
+ * @param holder Current ViewHolder
+ * @param oldChangeViewHolder Changed ViewHolder
+ */
+ private void handleMissingPreInfoForChangeError(long key,
+ ViewHolder holder, ViewHolder oldChangeViewHolder) {
+ // check if two VH have the same key, if so, print that as an error
+ final int childCount = mChildHelper.getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ View view = mChildHelper.getChildAt(i);
+ ViewHolder other = getChildViewHolderInt(view);
+ if (other == holder) {
+ continue;
+ }
+ final long otherKey = getChangedHolderKey(other);
+ if (otherKey == key) {
+ if (mAdapter != null && mAdapter.hasStableIds()) {
+ throw new IllegalStateException("Two different ViewHolders have the same stable"
+ + " ID. Stable IDs in your adapter MUST BE unique and SHOULD NOT"
+ + " change.\n ViewHolder 1:" + other + " \n View Holder 2:" + holder);
+ } else {
+ throw new IllegalStateException("Two different ViewHolders have the same change"
+ + " ID. This might happen due to inconsistent Adapter update events or"
+ + " if the LayoutManager lays out the same View multiple times."
+ + "\n ViewHolder 1:" + other + " \n View Holder 2:" + holder);
+ }
+ }
+ }
+ // Very unlikely to happen but if it does, notify the developer.
+ Log.e(TAG, "Problem while matching changed view holders with the new"
+ + "ones. The pre-layout information for the change holder " + oldChangeViewHolder
+ + " cannot be found but it is necessary for " + holder);
+ }
+
+ /**
+ * Records the animation information for a view holder that was bounced from hidden list. It
+ * also clears the bounce back flag.
+ */
+ void recordAnimationInfoIfBouncedHiddenView(ViewHolder viewHolder,
+ ItemHolderInfo animationInfo) {
+ // looks like this view bounced back from hidden list!
+ viewHolder.setFlags(0, ViewHolder.FLAG_BOUNCED_FROM_HIDDEN_LIST);
+ if (mState.mTrackOldChangeHolders && viewHolder.isUpdated()
+ && !viewHolder.isRemoved() && !viewHolder.shouldIgnore()) {
+ long key = getChangedHolderKey(viewHolder);
+ mViewInfoStore.addToOldChangeHolders(key, viewHolder);
+ }
+ mViewInfoStore.addToPreLayout(viewHolder, animationInfo);
+ }
+
+ private void findMinMaxChildLayoutPositions(int[] into) {
+ final int count = mChildHelper.getChildCount();
+ if (count == 0) {
+ into[0] = NO_POSITION;
+ into[1] = NO_POSITION;
+ return;
+ }
+ int minPositionPreLayout = Integer.MAX_VALUE;
+ int maxPositionPreLayout = Integer.MIN_VALUE;
+ for (int i = 0; i < count; ++i) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getChildAt(i));
+ if (holder.shouldIgnore()) {
+ continue;
+ }
+ final int pos = holder.getLayoutPosition();
+ if (pos < minPositionPreLayout) {
+ minPositionPreLayout = pos;
+ }
+ if (pos > maxPositionPreLayout) {
+ maxPositionPreLayout = pos;
+ }
+ }
+ into[0] = minPositionPreLayout;
+ into[1] = maxPositionPreLayout;
+ }
+
+ private boolean didChildRangeChange(int minPositionPreLayout, int maxPositionPreLayout) {
+ findMinMaxChildLayoutPositions(mMinMaxLayoutPositions);
+ return mMinMaxLayoutPositions[0] != minPositionPreLayout
+ || mMinMaxLayoutPositions[1] != maxPositionPreLayout;
+ }
+
+ @Override
+ protected void removeDetachedView(View child, boolean animate) {
+ ViewHolder vh = getChildViewHolderInt(child);
+ if (vh != null) {
+ if (vh.isTmpDetached()) {
+ vh.clearTmpDetachFlag();
+ } else if (!vh.shouldIgnore()) {
+ throw new IllegalArgumentException("Called removeDetachedView with a view which"
+ + " is not flagged as tmp detached." + vh);
+ }
+ }
+ dispatchChildDetached(child);
+ super.removeDetachedView(child, animate);
+ }
+
+ /**
+ * Returns a unique key to be used while handling change animations.
+ * It might be child's position or stable id depending on the adapter type.
+ */
+ long getChangedHolderKey(ViewHolder holder) {
+ return mAdapter.hasStableIds() ? holder.getItemId() : holder.mPosition;
+ }
+
+ void animateAppearance(@NonNull ViewHolder itemHolder,
+ @Nullable ItemHolderInfo preLayoutInfo, @NonNull ItemHolderInfo postLayoutInfo) {
+ itemHolder.setIsRecyclable(false);
+ if (mItemAnimator.animateAppearance(itemHolder, preLayoutInfo, postLayoutInfo)) {
+ postAnimationRunner();
+ }
+ }
+
+ void animateDisappearance(@NonNull ViewHolder holder,
+ @NonNull ItemHolderInfo preLayoutInfo, @Nullable ItemHolderInfo postLayoutInfo) {
+ addAnimatingView(holder);
+ holder.setIsRecyclable(false);
+ if (mItemAnimator.animateDisappearance(holder, preLayoutInfo, postLayoutInfo)) {
+ postAnimationRunner();
+ }
+ }
+
+ private void animateChange(@NonNull ViewHolder oldHolder, @NonNull ViewHolder newHolder,
+ @NonNull ItemHolderInfo preInfo, @NonNull ItemHolderInfo postInfo,
+ boolean oldHolderDisappearing, boolean newHolderDisappearing) {
+ oldHolder.setIsRecyclable(false);
+ if (oldHolderDisappearing) {
+ addAnimatingView(oldHolder);
+ }
+ if (oldHolder != newHolder) {
+ if (newHolderDisappearing) {
+ addAnimatingView(newHolder);
+ }
+ oldHolder.mShadowedHolder = newHolder;
+ // old holder should disappear after animation ends
+ addAnimatingView(oldHolder);
+ mRecycler.unscrapView(oldHolder);
+ newHolder.setIsRecyclable(false);
+ newHolder.mShadowingHolder = oldHolder;
+ }
+ if (mItemAnimator.animateChange(oldHolder, newHolder, preInfo, postInfo)) {
+ postAnimationRunner();
+ }
+ }
+
+ @Override
+ protected void onLayout(boolean changed, int l, int t, int r, int b) {
+ Trace.beginSection(TRACE_ON_LAYOUT_TAG);
+ dispatchLayout();
+ Trace.endSection();
+ mFirstLayoutComplete = true;
+ }
+
+ @Override
+ public void requestLayout() {
+ if (mEatRequestLayout == 0 && !mLayoutFrozen) {
+ super.requestLayout();
+ } else {
+ mLayoutRequestEaten = true;
+ }
+ }
+
+ void markItemDecorInsetsDirty() {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final View child = mChildHelper.getUnfilteredChildAt(i);
+ ((LayoutParams) child.getLayoutParams()).mInsetsDirty = true;
+ }
+ mRecycler.markItemDecorInsetsDirty();
+ }
+
+ @Override
+ public void draw(Canvas c) {
+ super.draw(c);
+
+ final int count = mItemDecorations.size();
+ for (int i = 0; i < count; i++) {
+ mItemDecorations.get(i).onDrawOver(c, this, mState);
+ }
+ // TODO If padding is not 0 and clipChildrenToPadding is false, to draw glows properly, we
+ // need find children closest to edges. Not sure if it is worth the effort.
+ boolean needsInvalidate = false;
+ if (mLeftGlow != null && !mLeftGlow.isFinished()) {
+ final int restore = c.save();
+ final int padding = mClipToPadding ? getPaddingBottom() : 0;
+ c.rotate(270);
+ c.translate(-getHeight() + padding, 0);
+ needsInvalidate = mLeftGlow != null && mLeftGlow.draw(c);
+ c.restoreToCount(restore);
+ }
+ if (mTopGlow != null && !mTopGlow.isFinished()) {
+ final int restore = c.save();
+ if (mClipToPadding) {
+ c.translate(getPaddingLeft(), getPaddingTop());
+ }
+ needsInvalidate |= mTopGlow != null && mTopGlow.draw(c);
+ c.restoreToCount(restore);
+ }
+ if (mRightGlow != null && !mRightGlow.isFinished()) {
+ final int restore = c.save();
+ final int width = getWidth();
+ final int padding = mClipToPadding ? getPaddingTop() : 0;
+ c.rotate(90);
+ c.translate(-padding, -width);
+ needsInvalidate |= mRightGlow != null && mRightGlow.draw(c);
+ c.restoreToCount(restore);
+ }
+ if (mBottomGlow != null && !mBottomGlow.isFinished()) {
+ final int restore = c.save();
+ c.rotate(180);
+ if (mClipToPadding) {
+ c.translate(-getWidth() + getPaddingRight(), -getHeight() + getPaddingBottom());
+ } else {
+ c.translate(-getWidth(), -getHeight());
+ }
+ needsInvalidate |= mBottomGlow != null && mBottomGlow.draw(c);
+ c.restoreToCount(restore);
+ }
+
+ // If some views are animating, ItemDecorators are likely to move/change with them.
+ // Invalidate RecyclerView to re-draw decorators. This is still efficient because children's
+ // display lists are not invalidated.
+ if (!needsInvalidate && mItemAnimator != null && mItemDecorations.size() > 0
+ && mItemAnimator.isRunning()) {
+ needsInvalidate = true;
+ }
+
+ if (needsInvalidate) {
+ postInvalidateOnAnimation();
+ }
+ }
+
+ @Override
+ public void onDraw(Canvas c) {
+ super.onDraw(c);
+
+ final int count = mItemDecorations.size();
+ for (int i = 0; i < count; i++) {
+ mItemDecorations.get(i).onDraw(c, this, mState);
+ }
+ }
+
+ @Override
+ protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
+ return p instanceof LayoutParams && mLayout.checkLayoutParams((LayoutParams) p);
+ }
+
+ @Override
+ protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
+ if (mLayout == null) {
+ throw new IllegalStateException("RecyclerView has no LayoutManager");
+ }
+ return mLayout.generateDefaultLayoutParams();
+ }
+
+ @Override
+ public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
+ if (mLayout == null) {
+ throw new IllegalStateException("RecyclerView has no LayoutManager");
+ }
+ return mLayout.generateLayoutParams(getContext(), attrs);
+ }
+
+ @Override
+ protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
+ if (mLayout == null) {
+ throw new IllegalStateException("RecyclerView has no LayoutManager");
+ }
+ return mLayout.generateLayoutParams(p);
+ }
+
+ /**
+ * Returns true if RecyclerView is currently running some animations.
+ * <p>
+ * If you want to be notified when animations are finished, use
+ * {@link ItemAnimator#isRunning(ItemAnimator.ItemAnimatorFinishedListener)}.
+ *
+ * @return True if there are some item animations currently running or waiting to be started.
+ */
+ public boolean isAnimating() {
+ return mItemAnimator != null && mItemAnimator.isRunning();
+ }
+
+ void saveOldPositions() {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (DEBUG && holder.mPosition == -1 && !holder.isRemoved()) {
+ throw new IllegalStateException("view holder cannot have position -1 unless it"
+ + " is removed");
+ }
+ if (!holder.shouldIgnore()) {
+ holder.saveOldPosition();
+ }
+ }
+ }
+
+ void clearOldPositions() {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (!holder.shouldIgnore()) {
+ holder.clearOldPosition();
+ }
+ }
+ mRecycler.clearOldPositions();
+ }
+
+ void offsetPositionRecordsForMove(int from, int to) {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ final int start, end, inBetweenOffset;
+ if (from < to) {
+ start = from;
+ end = to;
+ inBetweenOffset = -1;
+ } else {
+ start = to;
+ end = from;
+ inBetweenOffset = 1;
+ }
+
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder == null || holder.mPosition < start || holder.mPosition > end) {
+ continue;
+ }
+ if (DEBUG) {
+ Log.d(TAG, "offsetPositionRecordsForMove attached child " + i + " holder "
+ + holder);
+ }
+ if (holder.mPosition == from) {
+ holder.offsetPosition(to - from, false);
+ } else {
+ holder.offsetPosition(inBetweenOffset, false);
+ }
+
+ mState.mStructureChanged = true;
+ }
+ mRecycler.offsetPositionRecordsForMove(from, to);
+ requestLayout();
+ }
+
+ void offsetPositionRecordsForInsert(int positionStart, int itemCount) {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder != null && !holder.shouldIgnore() && holder.mPosition >= positionStart) {
+ if (DEBUG) {
+ Log.d(TAG, "offsetPositionRecordsForInsert attached child " + i + " holder "
+ + holder + " now at position " + (holder.mPosition + itemCount));
+ }
+ holder.offsetPosition(itemCount, false);
+ mState.mStructureChanged = true;
+ }
+ }
+ mRecycler.offsetPositionRecordsForInsert(positionStart, itemCount);
+ requestLayout();
+ }
+
+ void offsetPositionRecordsForRemove(int positionStart, int itemCount,
+ boolean applyToPreLayout) {
+ final int positionEnd = positionStart + itemCount;
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder != null && !holder.shouldIgnore()) {
+ if (holder.mPosition >= positionEnd) {
+ if (DEBUG) {
+ Log.d(TAG, "offsetPositionRecordsForRemove attached child " + i
+ + " holder " + holder + " now at position "
+ + (holder.mPosition - itemCount));
+ }
+ holder.offsetPosition(-itemCount, applyToPreLayout);
+ mState.mStructureChanged = true;
+ } else if (holder.mPosition >= positionStart) {
+ if (DEBUG) {
+ Log.d(TAG, "offsetPositionRecordsForRemove attached child " + i
+ + " holder " + holder + " now REMOVED");
+ }
+ holder.flagRemovedAndOffsetPosition(positionStart - 1, -itemCount,
+ applyToPreLayout);
+ mState.mStructureChanged = true;
+ }
+ }
+ }
+ mRecycler.offsetPositionRecordsForRemove(positionStart, itemCount, applyToPreLayout);
+ requestLayout();
+ }
+
+ /**
+ * Rebind existing views for the given range, or create as needed.
+ *
+ * @param positionStart Adapter position to start at
+ * @param itemCount Number of views that must explicitly be rebound
+ */
+ void viewRangeUpdate(int positionStart, int itemCount, Object payload) {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ final int positionEnd = positionStart + itemCount;
+
+ for (int i = 0; i < childCount; i++) {
+ final View child = mChildHelper.getUnfilteredChildAt(i);
+ final ViewHolder holder = getChildViewHolderInt(child);
+ if (holder == null || holder.shouldIgnore()) {
+ continue;
+ }
+ if (holder.mPosition >= positionStart && holder.mPosition < positionEnd) {
+ // We re-bind these view holders after pre-processing is complete so that
+ // ViewHolders have their final positions assigned.
+ holder.addFlags(ViewHolder.FLAG_UPDATE);
+ holder.addChangePayload(payload);
+ // lp cannot be null since we get ViewHolder from it.
+ ((LayoutParams) child.getLayoutParams()).mInsetsDirty = true;
+ }
+ }
+ mRecycler.viewRangeUpdate(positionStart, itemCount);
+ }
+
+ boolean canReuseUpdatedViewHolder(ViewHolder viewHolder) {
+ return mItemAnimator == null || mItemAnimator.canReuseUpdatedViewHolder(viewHolder,
+ viewHolder.getUnmodifiedPayloads());
+ }
+
+
+ /**
+ * Call this method to signal that *all* adapter content has changed (generally, because of
+ * swapAdapter, or notifyDataSetChanged), and that once layout occurs, all attached items should
+ * be discarded or animated. Note that this work is deferred because RecyclerView requires a
+ * layout to resolve non-incremental changes to the data set.
+ *
+ * Attached items are labeled as position unknown, and may no longer be cached.
+ *
+ * It is still possible for items to be prefetched while mDataSetHasChangedAfterLayout == true,
+ * so calling this method *must* be associated with marking the cache invalid, so that the
+ * only valid items that remain in the cache, once layout occurs, are prefetched items.
+ */
+ void setDataSetChangedAfterLayout() {
+ if (mDataSetHasChangedAfterLayout) {
+ return;
+ }
+ mDataSetHasChangedAfterLayout = true;
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder != null && !holder.shouldIgnore()) {
+ holder.addFlags(ViewHolder.FLAG_ADAPTER_POSITION_UNKNOWN);
+ }
+ }
+ mRecycler.setAdapterPositionsAsUnknown();
+
+ // immediately mark all views as invalid, so prefetched views can be
+ // differentiated from views bound to previous data set - both in children, and cache
+ markKnownViewsInvalid();
+ }
+
+ /**
+ * Mark all known views as invalid. Used in response to a, "the whole world might have changed"
+ * data change event.
+ */
+ void markKnownViewsInvalid() {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder != null && !holder.shouldIgnore()) {
+ holder.addFlags(ViewHolder.FLAG_UPDATE | ViewHolder.FLAG_INVALID);
+ }
+ }
+ markItemDecorInsetsDirty();
+ mRecycler.markKnownViewsInvalid();
+ }
+
+ /**
+ * Invalidates all ItemDecorations. If RecyclerView has item decorations, calling this method
+ * will trigger a {@link #requestLayout()} call.
+ */
+ public void invalidateItemDecorations() {
+ if (mItemDecorations.size() == 0) {
+ return;
+ }
+ if (mLayout != null) {
+ mLayout.assertNotInLayoutOrScroll("Cannot invalidate item decorations during a scroll"
+ + " or layout");
+ }
+ markItemDecorInsetsDirty();
+ requestLayout();
+ }
+
+ /**
+ * Returns true if the RecyclerView should attempt to preserve currently focused Adapter Item's
+ * focus even if the View representing the Item is replaced during a layout calculation.
+ * <p>
+ * By default, this value is {@code true}.
+ *
+ * @return True if the RecyclerView will try to preserve focused Item after a layout if it loses
+ * focus.
+ *
+ * @see #setPreserveFocusAfterLayout(boolean)
+ */
+ public boolean getPreserveFocusAfterLayout() {
+ return mPreserveFocusAfterLayout;
+ }
+
+ /**
+ * Set whether the RecyclerView should try to keep the same Item focused after a layout
+ * calculation or not.
+ * <p>
+ * Usually, LayoutManagers keep focused views visible before and after layout but sometimes,
+ * views may lose focus during a layout calculation as their state changes or they are replaced
+ * with another view due to type change or animation. In these cases, RecyclerView can request
+ * focus on the new view automatically.
+ *
+ * @param preserveFocusAfterLayout Whether RecyclerView should preserve focused Item during a
+ * layout calculations. Defaults to true.
+ *
+ * @see #getPreserveFocusAfterLayout()
+ */
+ public void setPreserveFocusAfterLayout(boolean preserveFocusAfterLayout) {
+ mPreserveFocusAfterLayout = preserveFocusAfterLayout;
+ }
+
+ /**
+ * Retrieve the {@link ViewHolder} for the given child view.
+ *
+ * @param child Child of this RecyclerView to query for its ViewHolder
+ * @return The child view's ViewHolder
+ */
+ public ViewHolder getChildViewHolder(View child) {
+ final ViewParent parent = child.getParent();
+ if (parent != null && parent != this) {
+ throw new IllegalArgumentException("View " + child + " is not a direct child of "
+ + this);
+ }
+ return getChildViewHolderInt(child);
+ }
+
+ /**
+ * Traverses the ancestors of the given view and returns the item view that contains it and
+ * also a direct child of the RecyclerView. This returned view can be used to get the
+ * ViewHolder by calling {@link #getChildViewHolder(View)}.
+ *
+ * @param view The view that is a descendant of the RecyclerView.
+ *
+ * @return The direct child of the RecyclerView which contains the given view or null if the
+ * provided view is not a descendant of this RecyclerView.
+ *
+ * @see #getChildViewHolder(View)
+ * @see #findContainingViewHolder(View)
+ */
+ @Nullable
+ public View findContainingItemView(View view) {
+ ViewParent parent = view.getParent();
+ while (parent != null && parent != this && parent instanceof View) {
+ view = (View) parent;
+ parent = view.getParent();
+ }
+ return parent == this ? view : null;
+ }
+
+ /**
+ * Returns the ViewHolder that contains the given view.
+ *
+ * @param view The view that is a descendant of the RecyclerView.
+ *
+ * @return The ViewHolder that contains the given view or null if the provided view is not a
+ * descendant of this RecyclerView.
+ */
+ @Nullable
+ public ViewHolder findContainingViewHolder(View view) {
+ View itemView = findContainingItemView(view);
+ return itemView == null ? null : getChildViewHolder(itemView);
+ }
+
+
+ static ViewHolder getChildViewHolderInt(View child) {
+ if (child == null) {
+ return null;
+ }
+ return ((LayoutParams) child.getLayoutParams()).mViewHolder;
+ }
+
+ /**
+ * @deprecated use {@link #getChildAdapterPosition(View)} or
+ * {@link #getChildLayoutPosition(View)}.
+ */
+ @Deprecated
+ public int getChildPosition(View child) {
+ return getChildAdapterPosition(child);
+ }
+
+ /**
+ * Return the adapter position that the given child view corresponds to.
+ *
+ * @param child Child View to query
+ * @return Adapter position corresponding to the given view or {@link #NO_POSITION}
+ */
+ public int getChildAdapterPosition(View child) {
+ final ViewHolder holder = getChildViewHolderInt(child);
+ return holder != null ? holder.getAdapterPosition() : NO_POSITION;
+ }
+
+ /**
+ * Return the adapter position of the given child view as of the latest completed layout pass.
+ * <p>
+ * This position may not be equal to Item's adapter position if there are pending changes
+ * in the adapter which have not been reflected to the layout yet.
+ *
+ * @param child Child View to query
+ * @return Adapter position of the given View as of last layout pass or {@link #NO_POSITION} if
+ * the View is representing a removed item.
+ */
+ public int getChildLayoutPosition(View child) {
+ final ViewHolder holder = getChildViewHolderInt(child);
+ return holder != null ? holder.getLayoutPosition() : NO_POSITION;
+ }
+
+ /**
+ * Return the stable item id that the given child view corresponds to.
+ *
+ * @param child Child View to query
+ * @return Item id corresponding to the given view or {@link #NO_ID}
+ */
+ public long getChildItemId(View child) {
+ if (mAdapter == null || !mAdapter.hasStableIds()) {
+ return NO_ID;
+ }
+ final ViewHolder holder = getChildViewHolderInt(child);
+ return holder != null ? holder.getItemId() : NO_ID;
+ }
+
+ /**
+ * @deprecated use {@link #findViewHolderForLayoutPosition(int)} or
+ * {@link #findViewHolderForAdapterPosition(int)}
+ */
+ @Deprecated
+ public ViewHolder findViewHolderForPosition(int position) {
+ return findViewHolderForPosition(position, false);
+ }
+
+ /**
+ * Return the ViewHolder for the item in the given position of the data set as of the latest
+ * layout pass.
+ * <p>
+ * This method checks only the children of RecyclerView. If the item at the given
+ * <code>position</code> is not laid out, it <em>will not</em> create a new one.
+ * <p>
+ * Note that when Adapter contents change, ViewHolder positions are not updated until the
+ * next layout calculation. If there are pending adapter updates, the return value of this
+ * method may not match your adapter contents. You can use
+ * #{@link ViewHolder#getAdapterPosition()} to get the current adapter position of a ViewHolder.
+ * <p>
+ * When the ItemAnimator is running a change animation, there might be 2 ViewHolders
+ * with the same layout position representing the same Item. In this case, the updated
+ * ViewHolder will be returned.
+ *
+ * @param position The position of the item in the data set of the adapter
+ * @return The ViewHolder at <code>position</code> or null if there is no such item
+ */
+ public ViewHolder findViewHolderForLayoutPosition(int position) {
+ return findViewHolderForPosition(position, false);
+ }
+
+ /**
+ * Return the ViewHolder for the item in the given position of the data set. Unlike
+ * {@link #findViewHolderForLayoutPosition(int)} this method takes into account any pending
+ * adapter changes that may not be reflected to the layout yet. On the other hand, if
+ * {@link Adapter#notifyDataSetChanged()} has been called but the new layout has not been
+ * calculated yet, this method will return <code>null</code> since the new positions of views
+ * are unknown until the layout is calculated.
+ * <p>
+ * This method checks only the children of RecyclerView. If the item at the given
+ * <code>position</code> is not laid out, it <em>will not</em> create a new one.
+ * <p>
+ * When the ItemAnimator is running a change animation, there might be 2 ViewHolders
+ * representing the same Item. In this case, the updated ViewHolder will be returned.
+ *
+ * @param position The position of the item in the data set of the adapter
+ * @return The ViewHolder at <code>position</code> or null if there is no such item
+ */
+ public ViewHolder findViewHolderForAdapterPosition(int position) {
+ if (mDataSetHasChangedAfterLayout) {
+ return null;
+ }
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ // hidden VHs are not preferred but if that is the only one we find, we rather return it
+ ViewHolder hidden = null;
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder != null && !holder.isRemoved()
+ && getAdapterPositionFor(holder) == position) {
+ if (mChildHelper.isHidden(holder.itemView)) {
+ hidden = holder;
+ } else {
+ return holder;
+ }
+ }
+ }
+ return hidden;
+ }
+
+ ViewHolder findViewHolderForPosition(int position, boolean checkNewPosition) {
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ ViewHolder hidden = null;
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder != null && !holder.isRemoved()) {
+ if (checkNewPosition) {
+ if (holder.mPosition != position) {
+ continue;
+ }
+ } else if (holder.getLayoutPosition() != position) {
+ continue;
+ }
+ if (mChildHelper.isHidden(holder.itemView)) {
+ hidden = holder;
+ } else {
+ return holder;
+ }
+ }
+ }
+ // This method should not query cached views. It creates a problem during adapter updates
+ // when we are dealing with already laid out views. Also, for the public method, it is more
+ // reasonable to return null if position is not laid out.
+ return hidden;
+ }
+
+ /**
+ * Return the ViewHolder for the item with the given id. The RecyclerView must
+ * use an Adapter with {@link Adapter#setHasStableIds(boolean) stableIds} to
+ * return a non-null value.
+ * <p>
+ * This method checks only the children of RecyclerView. If the item with the given
+ * <code>id</code> is not laid out, it <em>will not</em> create a new one.
+ *
+ * When the ItemAnimator is running a change animation, there might be 2 ViewHolders with the
+ * same id. In this case, the updated ViewHolder will be returned.
+ *
+ * @param id The id for the requested item
+ * @return The ViewHolder with the given <code>id</code> or null if there is no such item
+ */
+ public ViewHolder findViewHolderForItemId(long id) {
+ if (mAdapter == null || !mAdapter.hasStableIds()) {
+ return null;
+ }
+ final int childCount = mChildHelper.getUnfilteredChildCount();
+ ViewHolder hidden = null;
+ for (int i = 0; i < childCount; i++) {
+ final ViewHolder holder = getChildViewHolderInt(mChildHelper.getUnfilteredChildAt(i));
+ if (holder != null && !holder.isRemoved() && holder.getItemId() == id) {
+ if (mChildHelper.isHidden(holder.itemView)) {
+ hidden = holder;
+ } else {
+ return holder;
+ }
+ }
+ }
+ return hidden;
+ }
+
+ /**
+ * Find the topmost view under the given point.
+ *
+ * @param x Horizontal position in pixels to search
+ * @param y Vertical position in pixels to search
+ * @return The child view under (x, y) or null if no matching child is found
+ */
+ public View findChildViewUnder(float x, float y) {
+ final int count = mChildHelper.getChildCount();
+ for (int i = count - 1; i >= 0; i--) {
+ final View child = mChildHelper.getChildAt(i);
+ final float translationX = child.getTranslationX();
+ final float translationY = child.getTranslationY();
+ if (x >= child.getLeft() + translationX
+ && x <= child.getRight() + translationX
+ && y >= child.getTop() + translationY
+ && y <= child.getBottom() + translationY) {
+ return child;
+ }
+ }
+ return null;
+ }
+
+ @Override
+ public boolean drawChild(Canvas canvas, View child, long drawingTime) {
+ return super.drawChild(canvas, child, drawingTime);
+ }
+
+ /**
+ * Offset the bounds of all child views by <code>dy</code> pixels.
+ * Useful for implementing simple scrolling in {@link LayoutManager LayoutManagers}.
+ *
+ * @param dy Vertical pixel offset to apply to the bounds of all child views
+ */
+ public void offsetChildrenVertical(int dy) {
+ final int childCount = mChildHelper.getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ mChildHelper.getChildAt(i).offsetTopAndBottom(dy);
+ }
+ }
+
+ /**
+ * Called when an item view is attached to this RecyclerView.
+ *
+ * <p>Subclasses of RecyclerView may want to perform extra bookkeeping or modifications
+ * of child views as they become attached. This will be called before a
+ * {@link LayoutManager} measures or lays out the view and is a good time to perform these
+ * changes.</p>
+ *
+ * @param child Child view that is now attached to this RecyclerView and its associated window
+ */
+ public void onChildAttachedToWindow(View child) {
+ }
+
+ /**
+ * Called when an item view is detached from this RecyclerView.
+ *
+ * <p>Subclasses of RecyclerView may want to perform extra bookkeeping or modifications
+ * of child views as they become detached. This will be called as a
+ * {@link LayoutManager} fully detaches the child view from the parent and its window.</p>
+ *
+ * @param child Child view that is now detached from this RecyclerView and its associated window
+ */
+ public void onChildDetachedFromWindow(View child) {
+ }
+
+ /**
+ * Offset the bounds of all child views by <code>dx</code> pixels.
+ * Useful for implementing simple scrolling in {@link LayoutManager LayoutManagers}.
+ *
+ * @param dx Horizontal pixel offset to apply to the bounds of all child views
+ */
+ public void offsetChildrenHorizontal(int dx) {
+ final int childCount = mChildHelper.getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ mChildHelper.getChildAt(i).offsetLeftAndRight(dx);
+ }
+ }
+
+ /**
+ * Returns the bounds of the view including its decoration and margins.
+ *
+ * @param view The view element to check
+ * @param outBounds A rect that will receive the bounds of the element including its
+ * decoration and margins.
+ */
+ public void getDecoratedBoundsWithMargins(View view, Rect outBounds) {
+ getDecoratedBoundsWithMarginsInt(view, outBounds);
+ }
+
+ static void getDecoratedBoundsWithMarginsInt(View view, Rect outBounds) {
+ final LayoutParams lp = (LayoutParams) view.getLayoutParams();
+ final Rect insets = lp.mDecorInsets;
+ outBounds.set(view.getLeft() - insets.left - lp.leftMargin,
+ view.getTop() - insets.top - lp.topMargin,
+ view.getRight() + insets.right + lp.rightMargin,
+ view.getBottom() + insets.bottom + lp.bottomMargin);
+ }
+
+ Rect getItemDecorInsetsForChild(View child) {
+ final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+ if (!lp.mInsetsDirty) {
+ return lp.mDecorInsets;
+ }
+
+ if (mState.isPreLayout() && (lp.isItemChanged() || lp.isViewInvalid())) {
+ // changed/invalid items should not be updated until they are rebound.
+ return lp.mDecorInsets;
+ }
+ final Rect insets = lp.mDecorInsets;
+ insets.set(0, 0, 0, 0);
+ final int decorCount = mItemDecorations.size();
+ for (int i = 0; i < decorCount; i++) {
+ mTempRect.set(0, 0, 0, 0);
+ mItemDecorations.get(i).getItemOffsets(mTempRect, child, this, mState);
+ insets.left += mTempRect.left;
+ insets.top += mTempRect.top;
+ insets.right += mTempRect.right;
+ insets.bottom += mTempRect.bottom;
+ }
+ lp.mInsetsDirty = false;
+ return insets;
+ }
+
+ /**
+ * Called when the scroll position of this RecyclerView changes. Subclasses should use
+ * this method to respond to scrolling within the adapter's data set instead of an explicit
+ * listener.
+ *
+ * <p>This method will always be invoked before listeners. If a subclass needs to perform
+ * any additional upkeep or bookkeeping after scrolling but before listeners run,
+ * this is a good place to do so.</p>
+ *
+ * <p>This differs from {@link View#onScrollChanged(int, int, int, int)} in that it receives
+ * the distance scrolled in either direction within the adapter's data set instead of absolute
+ * scroll coordinates. Since RecyclerView cannot compute the absolute scroll position from
+ * any arbitrary point in the data set, <code>onScrollChanged</code> will always receive
+ * the current {@link View#getScrollX()} and {@link View#getScrollY()} values which
+ * do not correspond to the data set scroll position. However, some subclasses may choose
+ * to use these fields as special offsets.</p>
+ *
+ * @param dx horizontal distance scrolled in pixels
+ * @param dy vertical distance scrolled in pixels
+ */
+ public void onScrolled(int dx, int dy) {
+ // Do nothing
+ }
+
+ void dispatchOnScrolled(int hresult, int vresult) {
+ mDispatchScrollCounter++;
+ // Pass the current scrollX/scrollY values; no actual change in these properties occurred
+ // but some general-purpose code may choose to respond to changes this way.
+ final int scrollX = getScrollX();
+ final int scrollY = getScrollY();
+ onScrollChanged(scrollX, scrollY, scrollX, scrollY);
+
+ // Pass the real deltas to onScrolled, the RecyclerView-specific method.
+ onScrolled(hresult, vresult);
+
+ // Invoke listeners last. Subclassed view methods always handle the event first.
+ // All internal state is consistent by the time listeners are invoked.
+ if (mScrollListener != null) {
+ mScrollListener.onScrolled(this, hresult, vresult);
+ }
+ if (mScrollListeners != null) {
+ for (int i = mScrollListeners.size() - 1; i >= 0; i--) {
+ mScrollListeners.get(i).onScrolled(this, hresult, vresult);
+ }
+ }
+ mDispatchScrollCounter--;
+ }
+
+ /**
+ * Called when the scroll state of this RecyclerView changes. Subclasses should use this
+ * method to respond to state changes instead of an explicit listener.
+ *
+ * <p>This method will always be invoked before listeners, but after the LayoutManager
+ * responds to the scroll state change.</p>
+ *
+ * @param state the new scroll state, one of {@link #SCROLL_STATE_IDLE},
+ * {@link #SCROLL_STATE_DRAGGING} or {@link #SCROLL_STATE_SETTLING}
+ */
+ public void onScrollStateChanged(int state) {
+ // Do nothing
+ }
+
+ void dispatchOnScrollStateChanged(int state) {
+ // Let the LayoutManager go first; this allows it to bring any properties into
+ // a consistent state before the RecyclerView subclass responds.
+ if (mLayout != null) {
+ mLayout.onScrollStateChanged(state);
+ }
+
+ // Let the RecyclerView subclass handle this event next; any LayoutManager property
+ // changes will be reflected by this time.
+ onScrollStateChanged(state);
+
+ // Listeners go last. All other internal state is consistent by this point.
+ if (mScrollListener != null) {
+ mScrollListener.onScrollStateChanged(this, state);
+ }
+ if (mScrollListeners != null) {
+ for (int i = mScrollListeners.size() - 1; i >= 0; i--) {
+ mScrollListeners.get(i).onScrollStateChanged(this, state);
+ }
+ }
+ }
+
+ /**
+ * Returns whether there are pending adapter updates which are not yet applied to the layout.
+ * <p>
+ * If this method returns <code>true</code>, it means that what user is currently seeing may not
+ * reflect them adapter contents (depending on what has changed).
+ * You may use this information to defer or cancel some operations.
+ * <p>
+ * This method returns true if RecyclerView has not yet calculated the first layout after it is
+ * attached to the Window or the Adapter has been replaced.
+ *
+ * @return True if there are some adapter updates which are not yet reflected to layout or false
+ * if layout is up to date.
+ */
+ public boolean hasPendingAdapterUpdates() {
+ return !mFirstLayoutComplete || mDataSetHasChangedAfterLayout
+ || mAdapterHelper.hasPendingUpdates();
+ }
+
+ class ViewFlinger implements Runnable {
+ private int mLastFlingX;
+ private int mLastFlingY;
+ private OverScroller mScroller;
+ Interpolator mInterpolator = sQuinticInterpolator;
+
+
+ // When set to true, postOnAnimation callbacks are delayed until the run method completes
+ private boolean mEatRunOnAnimationRequest = false;
+
+ // Tracks if postAnimationCallback should be re-attached when it is done
+ private boolean mReSchedulePostAnimationCallback = false;
+
+ ViewFlinger() {
+ mScroller = new OverScroller(getContext(), sQuinticInterpolator);
+ }
+
+ @Override
+ public void run() {
+ if (mLayout == null) {
+ stop();
+ return; // no layout, cannot scroll.
+ }
+ disableRunOnAnimationRequests();
+ consumePendingUpdateOperations();
+ // keep a local reference so that if it is changed during onAnimation method, it won't
+ // cause unexpected behaviors
+ final OverScroller scroller = mScroller;
+ final SmoothScroller smoothScroller = mLayout.mSmoothScroller;
+ if (scroller.computeScrollOffset()) {
+ final int x = scroller.getCurrX();
+ final int y = scroller.getCurrY();
+ final int dx = x - mLastFlingX;
+ final int dy = y - mLastFlingY;
+ int hresult = 0;
+ int vresult = 0;
+ mLastFlingX = x;
+ mLastFlingY = y;
+ int overscrollX = 0, overscrollY = 0;
+ if (mAdapter != null) {
+ eatRequestLayout();
+ onEnterLayoutOrScroll();
+ Trace.beginSection(TRACE_SCROLL_TAG);
+ if (dx != 0) {
+ hresult = mLayout.scrollHorizontallyBy(dx, mRecycler, mState);
+ overscrollX = dx - hresult;
+ }
+ if (dy != 0) {
+ vresult = mLayout.scrollVerticallyBy(dy, mRecycler, mState);
+ overscrollY = dy - vresult;
+ }
+ Trace.endSection();
+ repositionShadowingViews();
+
+ onExitLayoutOrScroll();
+ resumeRequestLayout(false);
+
+ if (smoothScroller != null && !smoothScroller.isPendingInitialRun()
+ && smoothScroller.isRunning()) {
+ final int adapterSize = mState.getItemCount();
+ if (adapterSize == 0) {
+ smoothScroller.stop();
+ } else if (smoothScroller.getTargetPosition() >= adapterSize) {
+ smoothScroller.setTargetPosition(adapterSize - 1);
+ smoothScroller.onAnimation(dx - overscrollX, dy - overscrollY);
+ } else {
+ smoothScroller.onAnimation(dx - overscrollX, dy - overscrollY);
+ }
+ }
+ }
+ if (!mItemDecorations.isEmpty()) {
+ invalidate();
+ }
+ if (getOverScrollMode() != View.OVER_SCROLL_NEVER) {
+ considerReleasingGlowsOnScroll(dx, dy);
+ }
+ if (overscrollX != 0 || overscrollY != 0) {
+ final int vel = (int) scroller.getCurrVelocity();
+
+ int velX = 0;
+ if (overscrollX != x) {
+ velX = overscrollX < 0 ? -vel : overscrollX > 0 ? vel : 0;
+ }
+
+ int velY = 0;
+ if (overscrollY != y) {
+ velY = overscrollY < 0 ? -vel : overscrollY > 0 ? vel : 0;
+ }
+
+ if (getOverScrollMode() != View.OVER_SCROLL_NEVER) {
+ absorbGlows(velX, velY);
+ }
+ if ((velX != 0 || overscrollX == x || scroller.getFinalX() == 0)
+ && (velY != 0 || overscrollY == y || scroller.getFinalY() == 0)) {
+ scroller.abortAnimation();
+ }
+ }
+ if (hresult != 0 || vresult != 0) {
+ dispatchOnScrolled(hresult, vresult);
+ }
+
+ if (!awakenScrollBars()) {
+ invalidate();
+ }
+
+ final boolean fullyConsumedVertical = dy != 0 && mLayout.canScrollVertically()
+ && vresult == dy;
+ final boolean fullyConsumedHorizontal = dx != 0 && mLayout.canScrollHorizontally()
+ && hresult == dx;
+ final boolean fullyConsumedAny = (dx == 0 && dy == 0) || fullyConsumedHorizontal
+ || fullyConsumedVertical;
+
+ if (scroller.isFinished() || !fullyConsumedAny) {
+ setScrollState(SCROLL_STATE_IDLE); // setting state to idle will stop this.
+ if (ALLOW_THREAD_GAP_WORK) {
+ mPrefetchRegistry.clearPrefetchPositions();
+ }
+ } else {
+ postOnAnimation();
+ if (mGapWorker != null) {
+ mGapWorker.postFromTraversal(RecyclerView.this, dx, dy);
+ }
+ }
+ }
+ // call this after the onAnimation is complete not to have inconsistent callbacks etc.
+ if (smoothScroller != null) {
+ if (smoothScroller.isPendingInitialRun()) {
+ smoothScroller.onAnimation(0, 0);
+ }
+ if (!mReSchedulePostAnimationCallback) {
+ smoothScroller.stop(); //stop if it does not trigger any scroll
+ }
+ }
+ enableRunOnAnimationRequests();
+ }
+
+ private void disableRunOnAnimationRequests() {
+ mReSchedulePostAnimationCallback = false;
+ mEatRunOnAnimationRequest = true;
+ }
+
+ private void enableRunOnAnimationRequests() {
+ mEatRunOnAnimationRequest = false;
+ if (mReSchedulePostAnimationCallback) {
+ postOnAnimation();
+ }
+ }
+
+ void postOnAnimation() {
+ if (mEatRunOnAnimationRequest) {
+ mReSchedulePostAnimationCallback = true;
+ } else {
+ removeCallbacks(this);
+ RecyclerView.this.postOnAnimation(this);
+ }
+ }
+
+ public void fling(int velocityX, int velocityY) {
+ setScrollState(SCROLL_STATE_SETTLING);
+ mLastFlingX = mLastFlingY = 0;
+ mScroller.fling(0, 0, velocityX, velocityY,
+ Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MIN_VALUE, Integer.MAX_VALUE);
+ postOnAnimation();
+ }
+
+ public void smoothScrollBy(int dx, int dy) {
+ smoothScrollBy(dx, dy, 0, 0);
+ }
+
+ public void smoothScrollBy(int dx, int dy, int vx, int vy) {
+ smoothScrollBy(dx, dy, computeScrollDuration(dx, dy, vx, vy));
+ }
+
+ private float distanceInfluenceForSnapDuration(float f) {
+ f -= 0.5f; // center the values about 0.
+ f *= 0.3f * Math.PI / 2.0f;
+ return (float) Math.sin(f);
+ }
+
+ private int computeScrollDuration(int dx, int dy, int vx, int vy) {
+ final int absDx = Math.abs(dx);
+ final int absDy = Math.abs(dy);
+ final boolean horizontal = absDx > absDy;
+ final int velocity = (int) Math.sqrt(vx * vx + vy * vy);
+ final int delta = (int) Math.sqrt(dx * dx + dy * dy);
+ final int containerSize = horizontal ? getWidth() : getHeight();
+ final int halfContainerSize = containerSize / 2;
+ final float distanceRatio = Math.min(1.f, 1.f * delta / containerSize);
+ final float distance = halfContainerSize + halfContainerSize
+ * distanceInfluenceForSnapDuration(distanceRatio);
+
+ final int duration;
+ if (velocity > 0) {
+ duration = 4 * Math.round(1000 * Math.abs(distance / velocity));
+ } else {
+ float absDelta = (float) (horizontal ? absDx : absDy);
+ duration = (int) (((absDelta / containerSize) + 1) * 300);
+ }
+ return Math.min(duration, MAX_SCROLL_DURATION);
+ }
+
+ public void smoothScrollBy(int dx, int dy, int duration) {
+ smoothScrollBy(dx, dy, duration, sQuinticInterpolator);
+ }
+
+ public void smoothScrollBy(int dx, int dy, Interpolator interpolator) {
+ smoothScrollBy(dx, dy, computeScrollDuration(dx, dy, 0, 0),
+ interpolator == null ? sQuinticInterpolator : interpolator);
+ }
+
+ public void smoothScrollBy(int dx, int dy, int duration, Interpolator interpolator) {
+ if (mInterpolator != interpolator) {
+ mInterpolator = interpolator;
+ mScroller = new OverScroller(getContext(), interpolator);
+ }
+ setScrollState(SCROLL_STATE_SETTLING);
+ mLastFlingX = mLastFlingY = 0;
+ mScroller.startScroll(0, 0, dx, dy, duration);
+ postOnAnimation();
+ }
+
+ public void stop() {
+ removeCallbacks(this);
+ mScroller.abortAnimation();
+ }
+
+ }
+
+ void repositionShadowingViews() {
+ // Fix up shadow views used by change animations
+ int count = mChildHelper.getChildCount();
+ for (int i = 0; i < count; i++) {
+ View view = mChildHelper.getChildAt(i);
+ ViewHolder holder = getChildViewHolder(view);
+ if (holder != null && holder.mShadowingHolder != null) {
+ View shadowingView = holder.mShadowingHolder.itemView;
+ int left = view.getLeft();
+ int top = view.getTop();
+ if (left != shadowingView.getLeft() || top != shadowingView.getTop()) {
+ shadowingView.layout(left, top,
+ left + shadowingView.getWidth(),
+ top + shadowingView.getHeight());
+ }
+ }
+ }
+ }
+
+ private class RecyclerViewDataObserver extends AdapterDataObserver {
+ RecyclerViewDataObserver() {
+ }
+
+ @Override
+ public void onChanged() {
+ assertNotInLayoutOrScroll(null);
+ mState.mStructureChanged = true;
+
+ setDataSetChangedAfterLayout();
+ if (!mAdapterHelper.hasPendingUpdates()) {
+ requestLayout();
+ }
+ }
+
+ @Override
+ public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {
+ assertNotInLayoutOrScroll(null);
+ if (mAdapterHelper.onItemRangeChanged(positionStart, itemCount, payload)) {
+ triggerUpdateProcessor();
+ }
+ }
+
+ @Override
+ public void onItemRangeInserted(int positionStart, int itemCount) {
+ assertNotInLayoutOrScroll(null);
+ if (mAdapterHelper.onItemRangeInserted(positionStart, itemCount)) {
+ triggerUpdateProcessor();
+ }
+ }
+
+ @Override
+ public void onItemRangeRemoved(int positionStart, int itemCount) {
+ assertNotInLayoutOrScroll(null);
+ if (mAdapterHelper.onItemRangeRemoved(positionStart, itemCount)) {
+ triggerUpdateProcessor();
+ }
+ }
+
+ @Override
+ public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
+ assertNotInLayoutOrScroll(null);
+ if (mAdapterHelper.onItemRangeMoved(fromPosition, toPosition, itemCount)) {
+ triggerUpdateProcessor();
+ }
+ }
+
+ void triggerUpdateProcessor() {
+ if (POST_UPDATES_ON_ANIMATION && mHasFixedSize && mIsAttached) {
+ RecyclerView.this.postOnAnimation(mUpdateChildViewsRunnable);
+ } else {
+ mAdapterUpdateDuringMeasure = true;
+ requestLayout();
+ }
+ }
+ }
+
+ /**
+ * RecycledViewPool lets you share Views between multiple RecyclerViews.
+ * <p>
+ * If you want to recycle views across RecyclerViews, create an instance of RecycledViewPool
+ * and use {@link RecyclerView#setRecycledViewPool(RecycledViewPool)}.
+ * <p>
+ * RecyclerView automatically creates a pool for itself if you don't provide one.
+ *
+ */
+ public static class RecycledViewPool {
+ private static final int DEFAULT_MAX_SCRAP = 5;
+
+ /**
+ * Tracks both pooled holders, as well as create/bind timing metadata for the given type.
+ *
+ * Note that this tracks running averages of create/bind time across all RecyclerViews
+ * (and, indirectly, Adapters) that use this pool.
+ *
+ * 1) This enables us to track average create and bind times across multiple adapters. Even
+ * though create (and especially bind) may behave differently for different Adapter
+ * subclasses, sharing the pool is a strong signal that they'll perform similarly, per type.
+ *
+ * 2) If {@link #willBindInTime(int, long, long)} returns false for one view, it will return
+ * false for all other views of its type for the same deadline. This prevents items
+ * constructed by {@link GapWorker} prefetch from being bound to a lower priority prefetch.
+ */
+ static class ScrapData {
+ ArrayList<ViewHolder> mScrapHeap = new ArrayList<>();
+ int mMaxScrap = DEFAULT_MAX_SCRAP;
+ long mCreateRunningAverageNs = 0;
+ long mBindRunningAverageNs = 0;
+ }
+ SparseArray<ScrapData> mScrap = new SparseArray<>();
+
+ private int mAttachCount = 0;
+
+ public void clear() {
+ for (int i = 0; i < mScrap.size(); i++) {
+ ScrapData data = mScrap.valueAt(i);
+ data.mScrapHeap.clear();
+ }
+ }
+
+ public void setMaxRecycledViews(int viewType, int max) {
+ ScrapData scrapData = getScrapDataForType(viewType);
+ scrapData.mMaxScrap = max;
+ final ArrayList<ViewHolder> scrapHeap = scrapData.mScrapHeap;
+ if (scrapHeap != null) {
+ while (scrapHeap.size() > max) {
+ scrapHeap.remove(scrapHeap.size() - 1);
+ }
+ }
+ }
+
+ /**
+ * Returns the current number of Views held by the RecycledViewPool of the given view type.
+ */
+ public int getRecycledViewCount(int viewType) {
+ return getScrapDataForType(viewType).mScrapHeap.size();
+ }
+
+ public ViewHolder getRecycledView(int viewType) {
+ final ScrapData scrapData = mScrap.get(viewType);
+ if (scrapData != null && !scrapData.mScrapHeap.isEmpty()) {
+ final ArrayList<ViewHolder> scrapHeap = scrapData.mScrapHeap;
+ return scrapHeap.remove(scrapHeap.size() - 1);
+ }
+ return null;
+ }
+
+ int size() {
+ int count = 0;
+ for (int i = 0; i < mScrap.size(); i++) {
+ ArrayList<ViewHolder> viewHolders = mScrap.valueAt(i).mScrapHeap;
+ if (viewHolders != null) {
+ count += viewHolders.size();
+ }
+ }
+ return count;
+ }
+
+ public void putRecycledView(ViewHolder scrap) {
+ final int viewType = scrap.getItemViewType();
+ final ArrayList scrapHeap = getScrapDataForType(viewType).mScrapHeap;
+ if (mScrap.get(viewType).mMaxScrap <= scrapHeap.size()) {
+ return;
+ }
+ if (DEBUG && scrapHeap.contains(scrap)) {
+ throw new IllegalArgumentException("this scrap item already exists");
+ }
+ scrap.resetInternal();
+ scrapHeap.add(scrap);
+ }
+
+ long runningAverage(long oldAverage, long newValue) {
+ if (oldAverage == 0) {
+ return newValue;
+ }
+ return (oldAverage / 4 * 3) + (newValue / 4);
+ }
+
+ void factorInCreateTime(int viewType, long createTimeNs) {
+ ScrapData scrapData = getScrapDataForType(viewType);
+ scrapData.mCreateRunningAverageNs = runningAverage(
+ scrapData.mCreateRunningAverageNs, createTimeNs);
+ }
+
+ void factorInBindTime(int viewType, long bindTimeNs) {
+ ScrapData scrapData = getScrapDataForType(viewType);
+ scrapData.mBindRunningAverageNs = runningAverage(
+ scrapData.mBindRunningAverageNs, bindTimeNs);
+ }
+
+ boolean willCreateInTime(int viewType, long approxCurrentNs, long deadlineNs) {
+ long expectedDurationNs = getScrapDataForType(viewType).mCreateRunningAverageNs;
+ return expectedDurationNs == 0 || (approxCurrentNs + expectedDurationNs < deadlineNs);
+ }
+
+ boolean willBindInTime(int viewType, long approxCurrentNs, long deadlineNs) {
+ long expectedDurationNs = getScrapDataForType(viewType).mBindRunningAverageNs;
+ return expectedDurationNs == 0 || (approxCurrentNs + expectedDurationNs < deadlineNs);
+ }
+
+ void attach(Adapter adapter) {
+ mAttachCount++;
+ }
+
+ void detach() {
+ mAttachCount--;
+ }
+
+
+ /**
+ * Detaches the old adapter and attaches the new one.
+ * <p>
+ * RecycledViewPool will clear its cache if it has only one adapter attached and the new
+ * adapter uses a different ViewHolder than the oldAdapter.
+ *
+ * @param oldAdapter The previous adapter instance. Will be detached.
+ * @param newAdapter The new adapter instance. Will be attached.
+ * @param compatibleWithPrevious True if both oldAdapter and newAdapter are using the same
+ * ViewHolder and view types.
+ */
+ void onAdapterChanged(Adapter oldAdapter, Adapter newAdapter,
+ boolean compatibleWithPrevious) {
+ if (oldAdapter != null) {
+ detach();
+ }
+ if (!compatibleWithPrevious && mAttachCount == 0) {
+ clear();
+ }
+ if (newAdapter != null) {
+ attach(newAdapter);
+ }
+ }
+
+ private ScrapData getScrapDataForType(int viewType) {
+ ScrapData scrapData = mScrap.get(viewType);
+ if (scrapData == null) {
+ scrapData = new ScrapData();
+ mScrap.put(viewType, scrapData);
+ }
+ return scrapData;
+ }
+ }
+
+ /**
+ * Utility method for finding an internal RecyclerView, if present
+ */
+ @Nullable
+ static RecyclerView findNestedRecyclerView(@NonNull View view) {
+ if (!(view instanceof ViewGroup)) {
+ return null;
+ }
+ if (view instanceof RecyclerView) {
+ return (RecyclerView) view;
+ }
+ final ViewGroup parent = (ViewGroup) view;
+ final int count = parent.getChildCount();
+ for (int i = 0; i < count; i++) {
+ final View child = parent.getChildAt(i);
+ final RecyclerView descendant = findNestedRecyclerView(child);
+ if (descendant != null) {
+ return descendant;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Utility method for clearing holder's internal RecyclerView, if present
+ */
+ static void clearNestedRecyclerViewIfNotNested(@NonNull ViewHolder holder) {
+ if (holder.mNestedRecyclerView != null) {
+ View item = holder.mNestedRecyclerView.get();
+ while (item != null) {
+ if (item == holder.itemView) {
+ return; // match found, don't need to clear
+ }
+
+ ViewParent parent = item.getParent();
+ if (parent instanceof View) {
+ item = (View) parent;
+ } else {
+ item = null;
+ }
+ }
+ holder.mNestedRecyclerView = null; // not nested
+ }
+ }
+
+ /**
+ * Time base for deadline-aware work scheduling. Overridable for testing.
+ *
+ * Will return 0 to avoid cost of System.nanoTime where deadline-aware work scheduling
+ * isn't relevant.
+ */
+ long getNanoTime() {
+ if (ALLOW_THREAD_GAP_WORK) {
+ return System.nanoTime();
+ } else {
+ return 0;
+ }
+ }
+
+ /**
+ * A Recycler is responsible for managing scrapped or detached item views for reuse.
+ *
+ * <p>A "scrapped" view is a view that is still attached to its parent RecyclerView but
+ * that has been marked for removal or reuse.</p>
+ *
+ * <p>Typical use of a Recycler by a {@link LayoutManager} will be to obtain views for
+ * an adapter's data set representing the data at a given position or item ID.
+ * If the view to be reused is considered "dirty" the adapter will be asked to rebind it.
+ * If not, the view can be quickly reused by the LayoutManager with no further work.
+ * Clean views that have not {@link android.view.View#isLayoutRequested() requested layout}
+ * may be repositioned by a LayoutManager without remeasurement.</p>
+ */
+ public final class Recycler {
+ final ArrayList<ViewHolder> mAttachedScrap = new ArrayList<>();
+ ArrayList<ViewHolder> mChangedScrap = null;
+
+ final ArrayList<ViewHolder> mCachedViews = new ArrayList<ViewHolder>();
+
+ private final List<ViewHolder>
+ mUnmodifiableAttachedScrap = Collections.unmodifiableList(mAttachedScrap);
+
+ private int mRequestedCacheMax = DEFAULT_CACHE_SIZE;
+ int mViewCacheMax = DEFAULT_CACHE_SIZE;
+
+ RecycledViewPool mRecyclerPool;
+
+ private ViewCacheExtension mViewCacheExtension;
+
+ static final int DEFAULT_CACHE_SIZE = 2;
+
+ /**
+ * Clear scrap views out of this recycler. Detached views contained within a
+ * recycled view pool will remain.
+ */
+ public void clear() {
+ mAttachedScrap.clear();
+ recycleAndClearCachedViews();
+ }
+
+ /**
+ * Set the maximum number of detached, valid views we should retain for later use.
+ *
+ * @param viewCount Number of views to keep before sending views to the shared pool
+ */
+ public void setViewCacheSize(int viewCount) {
+ mRequestedCacheMax = viewCount;
+ updateViewCacheSize();
+ }
+
+ void updateViewCacheSize() {
+ int extraCache = mLayout != null ? mLayout.mPrefetchMaxCountObserved : 0;
+ mViewCacheMax = mRequestedCacheMax + extraCache;
+
+ // first, try the views that can be recycled
+ for (int i = mCachedViews.size() - 1;
+ i >= 0 && mCachedViews.size() > mViewCacheMax; i--) {
+ recycleCachedViewAt(i);
+ }
+ }
+
+ /**
+ * Returns an unmodifiable list of ViewHolders that are currently in the scrap list.
+ *
+ * @return List of ViewHolders in the scrap list.
+ */
+ public List<ViewHolder> getScrapList() {
+ return mUnmodifiableAttachedScrap;
+ }
+
+ /**
+ * Helper method for getViewForPosition.
+ * <p>
+ * Checks whether a given view holder can be used for the provided position.
+ *
+ * @param holder ViewHolder
+ * @return true if ViewHolder matches the provided position, false otherwise
+ */
+ boolean validateViewHolderForOffsetPosition(ViewHolder holder) {
+ // if it is a removed holder, nothing to verify since we cannot ask adapter anymore
+ // if it is not removed, verify the type and id.
+ if (holder.isRemoved()) {
+ if (DEBUG && !mState.isPreLayout()) {
+ throw new IllegalStateException("should not receive a removed view unless it"
+ + " is pre layout");
+ }
+ return mState.isPreLayout();
+ }
+ if (holder.mPosition < 0 || holder.mPosition >= mAdapter.getItemCount()) {
+ throw new IndexOutOfBoundsException("Inconsistency detected. Invalid view holder "
+ + "adapter position" + holder);
+ }
+ if (!mState.isPreLayout()) {
+ // don't check type if it is pre-layout.
+ final int type = mAdapter.getItemViewType(holder.mPosition);
+ if (type != holder.getItemViewType()) {
+ return false;
+ }
+ }
+ if (mAdapter.hasStableIds()) {
+ return holder.getItemId() == mAdapter.getItemId(holder.mPosition);
+ }
+ return true;
+ }
+
+ /**
+ * Attempts to bind view, and account for relevant timing information. If
+ * deadlineNs != FOREVER_NS, this method may fail to bind, and return false.
+ *
+ * @param holder Holder to be bound.
+ * @param offsetPosition Position of item to be bound.
+ * @param position Pre-layout position of item to be bound.
+ * @param deadlineNs Time, relative to getNanoTime(), by which bind/create work should
+ * complete. If FOREVER_NS is passed, this method will not fail to
+ * bind the holder.
+ * @return
+ */
+ private boolean tryBindViewHolderByDeadline(ViewHolder holder, int offsetPosition,
+ int position, long deadlineNs) {
+ holder.mOwnerRecyclerView = RecyclerView.this;
+ final int viewType = holder.getItemViewType();
+ long startBindNs = getNanoTime();
+ if (deadlineNs != FOREVER_NS
+ && !mRecyclerPool.willBindInTime(viewType, startBindNs, deadlineNs)) {
+ // abort - we have a deadline we can't meet
+ return false;
+ }
+ mAdapter.bindViewHolder(holder, offsetPosition);
+ long endBindNs = getNanoTime();
+ mRecyclerPool.factorInBindTime(holder.getItemViewType(), endBindNs - startBindNs);
+ attachAccessibilityDelegate(holder.itemView);
+ if (mState.isPreLayout()) {
+ holder.mPreLayoutPosition = position;
+ }
+ return true;
+ }
+
+ /**
+ * Binds the given View to the position. The View can be a View previously retrieved via
+ * {@link #getViewForPosition(int)} or created by
+ * {@link Adapter#onCreateViewHolder(ViewGroup, int)}.
+ * <p>
+ * Generally, a LayoutManager should acquire its views via {@link #getViewForPosition(int)}
+ * and let the RecyclerView handle caching. This is a helper method for LayoutManager who
+ * wants to handle its own recycling logic.
+ * <p>
+ * Note that, {@link #getViewForPosition(int)} already binds the View to the position so
+ * you don't need to call this method unless you want to bind this View to another position.
+ *
+ * @param view The view to update.
+ * @param position The position of the item to bind to this View.
+ */
+ public void bindViewToPosition(View view, int position) {
+ ViewHolder holder = getChildViewHolderInt(view);
+ if (holder == null) {
+ throw new IllegalArgumentException("The view does not have a ViewHolder. You cannot"
+ + " pass arbitrary views to this method, they should be created by the "
+ + "Adapter");
+ }
+ final int offsetPosition = mAdapterHelper.findPositionOffset(position);
+ if (offsetPosition < 0 || offsetPosition >= mAdapter.getItemCount()) {
+ throw new IndexOutOfBoundsException("Inconsistency detected. Invalid item "
+ + "position " + position + "(offset:" + offsetPosition + ")."
+ + "state:" + mState.getItemCount());
+ }
+ tryBindViewHolderByDeadline(holder, offsetPosition, position, FOREVER_NS);
+
+ final ViewGroup.LayoutParams lp = holder.itemView.getLayoutParams();
+ final LayoutParams rvLayoutParams;
+ if (lp == null) {
+ rvLayoutParams = (LayoutParams) generateDefaultLayoutParams();
+ holder.itemView.setLayoutParams(rvLayoutParams);
+ } else if (!checkLayoutParams(lp)) {
+ rvLayoutParams = (LayoutParams) generateLayoutParams(lp);
+ holder.itemView.setLayoutParams(rvLayoutParams);
+ } else {
+ rvLayoutParams = (LayoutParams) lp;
+ }
+
+ rvLayoutParams.mInsetsDirty = true;
+ rvLayoutParams.mViewHolder = holder;
+ rvLayoutParams.mPendingInvalidate = holder.itemView.getParent() == null;
+ }
+
+ /**
+ * RecyclerView provides artificial position range (item count) in pre-layout state and
+ * automatically maps these positions to {@link Adapter} positions when
+ * {@link #getViewForPosition(int)} or {@link #bindViewToPosition(View, int)} is called.
+ * <p>
+ * Usually, LayoutManager does not need to worry about this. However, in some cases, your
+ * LayoutManager may need to call some custom component with item positions in which
+ * case you need the actual adapter position instead of the pre layout position. You
+ * can use this method to convert a pre-layout position to adapter (post layout) position.
+ * <p>
+ * Note that if the provided position belongs to a deleted ViewHolder, this method will
+ * return -1.
+ * <p>
+ * Calling this method in post-layout state returns the same value back.
+ *
+ * @param position The pre-layout position to convert. Must be greater or equal to 0 and
+ * less than {@link State#getItemCount()}.
+ */
+ public int convertPreLayoutPositionToPostLayout(int position) {
+ if (position < 0 || position >= mState.getItemCount()) {
+ throw new IndexOutOfBoundsException("invalid position " + position + ". State "
+ + "item count is " + mState.getItemCount());
+ }
+ if (!mState.isPreLayout()) {
+ return position;
+ }
+ return mAdapterHelper.findPositionOffset(position);
+ }
+
+ /**
+ * Obtain a view initialized for the given position.
+ *
+ * This method should be used by {@link LayoutManager} implementations to obtain
+ * views to represent data from an {@link Adapter}.
+ * <p>
+ * The Recycler may reuse a scrap or detached view from a shared pool if one is
+ * available for the correct view type. If the adapter has not indicated that the
+ * data at the given position has changed, the Recycler will attempt to hand back
+ * a scrap view that was previously initialized for that data without rebinding.
+ *
+ * @param position Position to obtain a view for
+ * @return A view representing the data at <code>position</code> from <code>adapter</code>
+ */
+ public View getViewForPosition(int position) {
+ return getViewForPosition(position, false);
+ }
+
+ View getViewForPosition(int position, boolean dryRun) {
+ return tryGetViewHolderForPositionByDeadline(position, dryRun, FOREVER_NS).itemView;
+ }
+
+ /**
+ * Attempts to get the ViewHolder for the given position, either from the Recycler scrap,
+ * cache, the RecycledViewPool, or creating it directly.
+ * <p>
+ * If a deadlineNs other than {@link #FOREVER_NS} is passed, this method early return
+ * rather than constructing or binding a ViewHolder if it doesn't think it has time.
+ * If a ViewHolder must be constructed and not enough time remains, null is returned. If a
+ * ViewHolder is aquired and must be bound but not enough time remains, an unbound holder is
+ * returned. Use {@link ViewHolder#isBound()} on the returned object to check for this.
+ *
+ * @param position Position of ViewHolder to be returned.
+ * @param dryRun True if the ViewHolder should not be removed from scrap/cache/
+ * @param deadlineNs Time, relative to getNanoTime(), by which bind/create work should
+ * complete. If FOREVER_NS is passed, this method will not fail to
+ * create/bind the holder if needed.
+ *
+ * @return ViewHolder for requested position
+ */
+ @Nullable
+ ViewHolder tryGetViewHolderForPositionByDeadline(int position,
+ boolean dryRun, long deadlineNs) {
+ if (position < 0 || position >= mState.getItemCount()) {
+ throw new IndexOutOfBoundsException("Invalid item position " + position
+ + "(" + position + "). Item count:" + mState.getItemCount());
+ }
+ boolean fromScrapOrHiddenOrCache = false;
+ ViewHolder holder = null;
+ // 0) If there is a changed scrap, try to find from there
+ if (mState.isPreLayout()) {
+ holder = getChangedScrapViewForPosition(position);
+ fromScrapOrHiddenOrCache = holder != null;
+ }
+ // 1) Find by position from scrap/hidden list/cache
+ if (holder == null) {
+ holder = getScrapOrHiddenOrCachedHolderForPosition(position, dryRun);
+ if (holder != null) {
+ if (!validateViewHolderForOffsetPosition(holder)) {
+ // recycle holder (and unscrap if relevant) since it can't be used
+ if (!dryRun) {
+ // we would like to recycle this but need to make sure it is not used by
+ // animation logic etc.
+ holder.addFlags(ViewHolder.FLAG_INVALID);
+ if (holder.isScrap()) {
+ removeDetachedView(holder.itemView, false);
+ holder.unScrap();
+ } else if (holder.wasReturnedFromScrap()) {
+ holder.clearReturnedFromScrapFlag();
+ }
+ recycleViewHolderInternal(holder);
+ }
+ holder = null;
+ } else {
+ fromScrapOrHiddenOrCache = true;
+ }
+ }
+ }
+ if (holder == null) {
+ final int offsetPosition = mAdapterHelper.findPositionOffset(position);
+ if (offsetPosition < 0 || offsetPosition >= mAdapter.getItemCount()) {
+ throw new IndexOutOfBoundsException("Inconsistency detected. Invalid item "
+ + "position " + position + "(offset:" + offsetPosition + ")."
+ + "state:" + mState.getItemCount());
+ }
+
+ final int type = mAdapter.getItemViewType(offsetPosition);
+ // 2) Find from scrap/cache via stable ids, if exists
+ if (mAdapter.hasStableIds()) {
+ holder = getScrapOrCachedViewForId(mAdapter.getItemId(offsetPosition),
+ type, dryRun);
+ if (holder != null) {
+ // update position
+ holder.mPosition = offsetPosition;
+ fromScrapOrHiddenOrCache = true;
+ }
+ }
+ if (holder == null && mViewCacheExtension != null) {
+ // We are NOT sending the offsetPosition because LayoutManager does not
+ // know it.
+ final View view = mViewCacheExtension
+ .getViewForPositionAndType(this, position, type);
+ if (view != null) {
+ holder = getChildViewHolder(view);
+ if (holder == null) {
+ throw new IllegalArgumentException("getViewForPositionAndType returned"
+ + " a view which does not have a ViewHolder");
+ } else if (holder.shouldIgnore()) {
+ throw new IllegalArgumentException("getViewForPositionAndType returned"
+ + " a view that is ignored. You must call stopIgnoring before"
+ + " returning this view.");
+ }
+ }
+ }
+ if (holder == null) { // fallback to pool
+ if (DEBUG) {
+ Log.d(TAG, "tryGetViewHolderForPositionByDeadline("
+ + position + ") fetching from shared pool");
+ }
+ holder = getRecycledViewPool().getRecycledView(type);
+ if (holder != null) {
+ holder.resetInternal();
+ if (FORCE_INVALIDATE_DISPLAY_LIST) {
+ invalidateDisplayListInt(holder);
+ }
+ }
+ }
+ if (holder == null) {
+ long start = getNanoTime();
+ if (deadlineNs != FOREVER_NS
+ && !mRecyclerPool.willCreateInTime(type, start, deadlineNs)) {
+ // abort - we have a deadline we can't meet
+ return null;
+ }
+ holder = mAdapter.createViewHolder(RecyclerView.this, type);
+ if (ALLOW_THREAD_GAP_WORK) {
+ // only bother finding nested RV if prefetching
+ RecyclerView innerView = findNestedRecyclerView(holder.itemView);
+ if (innerView != null) {
+ holder.mNestedRecyclerView = new WeakReference<>(innerView);
+ }
+ }
+
+ long end = getNanoTime();
+ mRecyclerPool.factorInCreateTime(type, end - start);
+ if (DEBUG) {
+ Log.d(TAG, "tryGetViewHolderForPositionByDeadline created new ViewHolder");
+ }
+ }
+ }
+
+ // This is very ugly but the only place we can grab this information
+ // before the View is rebound and returned to the LayoutManager for post layout ops.
+ // We don't need this in pre-layout since the VH is not updated by the LM.
+ if (fromScrapOrHiddenOrCache && !mState.isPreLayout() && holder
+ .hasAnyOfTheFlags(ViewHolder.FLAG_BOUNCED_FROM_HIDDEN_LIST)) {
+ holder.setFlags(0, ViewHolder.FLAG_BOUNCED_FROM_HIDDEN_LIST);
+ if (mState.mRunSimpleAnimations) {
+ int changeFlags = ItemAnimator
+ .buildAdapterChangeFlagsForAnimations(holder);
+ changeFlags |= ItemAnimator.FLAG_APPEARED_IN_PRE_LAYOUT;
+ final ItemHolderInfo info = mItemAnimator.recordPreLayoutInformation(mState,
+ holder, changeFlags, holder.getUnmodifiedPayloads());
+ recordAnimationInfoIfBouncedHiddenView(holder, info);
+ }
+ }
+
+ boolean bound = false;
+ if (mState.isPreLayout() && holder.isBound()) {
+ // do not update unless we absolutely have to.
+ holder.mPreLayoutPosition = position;
+ } else if (!holder.isBound() || holder.needsUpdate() || holder.isInvalid()) {
+ if (DEBUG && holder.isRemoved()) {
+ throw new IllegalStateException("Removed holder should be bound and it should"
+ + " come here only in pre-layout. Holder: " + holder);
+ }
+ final int offsetPosition = mAdapterHelper.findPositionOffset(position);
+ bound = tryBindViewHolderByDeadline(holder, offsetPosition, position, deadlineNs);
+ }
+
+ final ViewGroup.LayoutParams lp = holder.itemView.getLayoutParams();
+ final LayoutParams rvLayoutParams;
+ if (lp == null) {
+ rvLayoutParams = (LayoutParams) generateDefaultLayoutParams();
+ holder.itemView.setLayoutParams(rvLayoutParams);
+ } else if (!checkLayoutParams(lp)) {
+ rvLayoutParams = (LayoutParams) generateLayoutParams(lp);
+ holder.itemView.setLayoutParams(rvLayoutParams);
+ } else {
+ rvLayoutParams = (LayoutParams) lp;
+ }
+ rvLayoutParams.mViewHolder = holder;
+ rvLayoutParams.mPendingInvalidate = fromScrapOrHiddenOrCache && bound;
+ return holder;
+ }
+
+ private void attachAccessibilityDelegate(View itemView) {
+ if (isAccessibilityEnabled()) {
+ if (itemView.getImportantForAccessibility()
+ == View.IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
+ itemView.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
+ }
+
+ if (itemView.getAccessibilityDelegate() == null) {
+ itemView.setAccessibilityDelegate(mAccessibilityDelegate.getItemDelegate());
+ }
+ }
+ }
+
+ private void invalidateDisplayListInt(ViewHolder holder) {
+ if (holder.itemView instanceof ViewGroup) {
+ invalidateDisplayListInt((ViewGroup) holder.itemView, false);
+ }
+ }
+
+ private void invalidateDisplayListInt(ViewGroup viewGroup, boolean invalidateThis) {
+ for (int i = viewGroup.getChildCount() - 1; i >= 0; i--) {
+ final View view = viewGroup.getChildAt(i);
+ if (view instanceof ViewGroup) {
+ invalidateDisplayListInt((ViewGroup) view, true);
+ }
+ }
+ if (!invalidateThis) {
+ return;
+ }
+ // we need to force it to become invisible
+ if (viewGroup.getVisibility() == View.INVISIBLE) {
+ viewGroup.setVisibility(View.VISIBLE);
+ viewGroup.setVisibility(View.INVISIBLE);
+ } else {
+ final int visibility = viewGroup.getVisibility();
+ viewGroup.setVisibility(View.INVISIBLE);
+ viewGroup.setVisibility(visibility);
+ }
+ }
+
+ /**
+ * Recycle a detached view. The specified view will be added to a pool of views
+ * for later rebinding and reuse.
+ *
+ * <p>A view must be fully detached (removed from parent) before it may be recycled. If the
+ * View is scrapped, it will be removed from scrap list.</p>
+ *
+ * @param view Removed view for recycling
+ * @see LayoutManager#removeAndRecycleView(View, Recycler)
+ */
+ public void recycleView(View view) {
+ // This public recycle method tries to make view recycle-able since layout manager
+ // intended to recycle this view (e.g. even if it is in scrap or change cache)
+ ViewHolder holder = getChildViewHolderInt(view);
+ if (holder.isTmpDetached()) {
+ removeDetachedView(view, false);
+ }
+ if (holder.isScrap()) {
+ holder.unScrap();
+ } else if (holder.wasReturnedFromScrap()) {
+ holder.clearReturnedFromScrapFlag();
+ }
+ recycleViewHolderInternal(holder);
+ }
+
+ /**
+ * Internally, use this method instead of {@link #recycleView(android.view.View)} to
+ * catch potential bugs.
+ * @param view
+ */
+ void recycleViewInternal(View view) {
+ recycleViewHolderInternal(getChildViewHolderInt(view));
+ }
+
+ void recycleAndClearCachedViews() {
+ final int count = mCachedViews.size();
+ for (int i = count - 1; i >= 0; i--) {
+ recycleCachedViewAt(i);
+ }
+ mCachedViews.clear();
+ if (ALLOW_THREAD_GAP_WORK) {
+ mPrefetchRegistry.clearPrefetchPositions();
+ }
+ }
+
+ /**
+ * Recycles a cached view and removes the view from the list. Views are added to cache
+ * if and only if they are recyclable, so this method does not check it again.
+ * <p>
+ * A small exception to this rule is when the view does not have an animator reference
+ * but transient state is true (due to animations created outside ItemAnimator). In that
+ * case, adapter may choose to recycle it. From RecyclerView's perspective, the view is
+ * still recyclable since Adapter wants to do so.
+ *
+ * @param cachedViewIndex The index of the view in cached views list
+ */
+ void recycleCachedViewAt(int cachedViewIndex) {
+ if (DEBUG) {
+ Log.d(TAG, "Recycling cached view at index " + cachedViewIndex);
+ }
+ ViewHolder viewHolder = mCachedViews.get(cachedViewIndex);
+ if (DEBUG) {
+ Log.d(TAG, "CachedViewHolder to be recycled: " + viewHolder);
+ }
+ addViewHolderToRecycledViewPool(viewHolder, true);
+ mCachedViews.remove(cachedViewIndex);
+ }
+
+ /**
+ * internal implementation checks if view is scrapped or attached and throws an exception
+ * if so.
+ * Public version un-scraps before calling recycle.
+ */
+ void recycleViewHolderInternal(ViewHolder holder) {
+ if (holder.isScrap() || holder.itemView.getParent() != null) {
+ throw new IllegalArgumentException(
+ "Scrapped or attached views may not be recycled. isScrap:"
+ + holder.isScrap() + " isAttached:"
+ + (holder.itemView.getParent() != null));
+ }
+
+ if (holder.isTmpDetached()) {
+ throw new IllegalArgumentException("Tmp detached view should be removed "
+ + "from RecyclerView before it can be recycled: " + holder);
+ }
+
+ if (holder.shouldIgnore()) {
+ throw new IllegalArgumentException("Trying to recycle an ignored view holder. You"
+ + " should first call stopIgnoringView(view) before calling recycle.");
+ }
+ //noinspection unchecked
+ final boolean transientStatePreventsRecycling = holder
+ .doesTransientStatePreventRecycling();
+ final boolean forceRecycle = mAdapter != null
+ && transientStatePreventsRecycling
+ && mAdapter.onFailedToRecycleView(holder);
+ boolean cached = false;
+ boolean recycled = false;
+ if (DEBUG && mCachedViews.contains(holder)) {
+ throw new IllegalArgumentException("cached view received recycle internal? "
+ + holder);
+ }
+ if (forceRecycle || holder.isRecyclable()) {
+ if (mViewCacheMax > 0
+ && !holder.hasAnyOfTheFlags(ViewHolder.FLAG_INVALID
+ | ViewHolder.FLAG_REMOVED
+ | ViewHolder.FLAG_UPDATE
+ | ViewHolder.FLAG_ADAPTER_POSITION_UNKNOWN)) {
+ // Retire oldest cached view
+ int cachedViewSize = mCachedViews.size();
+ if (cachedViewSize >= mViewCacheMax && cachedViewSize > 0) {
+ recycleCachedViewAt(0);
+ cachedViewSize--;
+ }
+
+ int targetCacheIndex = cachedViewSize;
+ if (ALLOW_THREAD_GAP_WORK
+ && cachedViewSize > 0
+ && !mPrefetchRegistry.lastPrefetchIncludedPosition(holder.mPosition)) {
+ // when adding the view, skip past most recently prefetched views
+ int cacheIndex = cachedViewSize - 1;
+ while (cacheIndex >= 0) {
+ int cachedPos = mCachedViews.get(cacheIndex).mPosition;
+ if (!mPrefetchRegistry.lastPrefetchIncludedPosition(cachedPos)) {
+ break;
+ }
+ cacheIndex--;
+ }
+ targetCacheIndex = cacheIndex + 1;
+ }
+ mCachedViews.add(targetCacheIndex, holder);
+ cached = true;
+ }
+ if (!cached) {
+ addViewHolderToRecycledViewPool(holder, true);
+ recycled = true;
+ }
+ } else {
+ // NOTE: A view can fail to be recycled when it is scrolled off while an animation
+ // runs. In this case, the item is eventually recycled by
+ // ItemAnimatorRestoreListener#onAnimationFinished.
+
+ // TODO: consider cancelling an animation when an item is removed scrollBy,
+ // to return it to the pool faster
+ if (DEBUG) {
+ Log.d(TAG, "trying to recycle a non-recycleable holder. Hopefully, it will "
+ + "re-visit here. We are still removing it from animation lists");
+ }
+ }
+ // even if the holder is not removed, we still call this method so that it is removed
+ // from view holder lists.
+ mViewInfoStore.removeViewHolder(holder);
+ if (!cached && !recycled && transientStatePreventsRecycling) {
+ holder.mOwnerRecyclerView = null;
+ }
+ }
+
+ /**
+ * Prepares the ViewHolder to be removed/recycled, and inserts it into the RecycledViewPool.
+ *
+ * Pass false to dispatchRecycled for views that have not been bound.
+ *
+ * @param holder Holder to be added to the pool.
+ * @param dispatchRecycled True to dispatch View recycled callbacks.
+ */
+ void addViewHolderToRecycledViewPool(ViewHolder holder, boolean dispatchRecycled) {
+ clearNestedRecyclerViewIfNotNested(holder);
+ holder.itemView.setAccessibilityDelegate(null);
+ if (dispatchRecycled) {
+ dispatchViewRecycled(holder);
+ }
+ holder.mOwnerRecyclerView = null;
+ getRecycledViewPool().putRecycledView(holder);
+ }
+
+ /**
+ * Used as a fast path for unscrapping and recycling a view during a bulk operation.
+ * The caller must call {@link #clearScrap()} when it's done to update the recycler's
+ * internal bookkeeping.
+ */
+ void quickRecycleScrapView(View view) {
+ final ViewHolder holder = getChildViewHolderInt(view);
+ holder.mScrapContainer = null;
+ holder.mInChangeScrap = false;
+ holder.clearReturnedFromScrapFlag();
+ recycleViewHolderInternal(holder);
+ }
+
+ /**
+ * Mark an attached view as scrap.
+ *
+ * <p>"Scrap" views are still attached to their parent RecyclerView but are eligible
+ * for rebinding and reuse. Requests for a view for a given position may return a
+ * reused or rebound scrap view instance.</p>
+ *
+ * @param view View to scrap
+ */
+ void scrapView(View view) {
+ final ViewHolder holder = getChildViewHolderInt(view);
+ if (holder.hasAnyOfTheFlags(ViewHolder.FLAG_REMOVED | ViewHolder.FLAG_INVALID)
+ || !holder.isUpdated() || canReuseUpdatedViewHolder(holder)) {
+ if (holder.isInvalid() && !holder.isRemoved() && !mAdapter.hasStableIds()) {
+ throw new IllegalArgumentException("Called scrap view with an invalid view."
+ + " Invalid views cannot be reused from scrap, they should rebound from"
+ + " recycler pool.");
+ }
+ holder.setScrapContainer(this, false);
+ mAttachedScrap.add(holder);
+ } else {
+ if (mChangedScrap == null) {
+ mChangedScrap = new ArrayList<ViewHolder>();
+ }
+ holder.setScrapContainer(this, true);
+ mChangedScrap.add(holder);
+ }
+ }
+
+ /**
+ * Remove a previously scrapped view from the pool of eligible scrap.
+ *
+ * <p>This view will no longer be eligible for reuse until re-scrapped or
+ * until it is explicitly removed and recycled.</p>
+ */
+ void unscrapView(ViewHolder holder) {
+ if (holder.mInChangeScrap) {
+ mChangedScrap.remove(holder);
+ } else {
+ mAttachedScrap.remove(holder);
+ }
+ holder.mScrapContainer = null;
+ holder.mInChangeScrap = false;
+ holder.clearReturnedFromScrapFlag();
+ }
+
+ int getScrapCount() {
+ return mAttachedScrap.size();
+ }
+
+ View getScrapViewAt(int index) {
+ return mAttachedScrap.get(index).itemView;
+ }
+
+ void clearScrap() {
+ mAttachedScrap.clear();
+ if (mChangedScrap != null) {
+ mChangedScrap.clear();
+ }
+ }
+
+ ViewHolder getChangedScrapViewForPosition(int position) {
+ // If pre-layout, check the changed scrap for an exact match.
+ final int changedScrapSize;
+ if (mChangedScrap == null || (changedScrapSize = mChangedScrap.size()) == 0) {
+ return null;
+ }
+ // find by position
+ for (int i = 0; i < changedScrapSize; i++) {
+ final ViewHolder holder = mChangedScrap.get(i);
+ if (!holder.wasReturnedFromScrap() && holder.getLayoutPosition() == position) {
+ holder.addFlags(ViewHolder.FLAG_RETURNED_FROM_SCRAP);
+ return holder;
+ }
+ }
+ // find by id
+ if (mAdapter.hasStableIds()) {
+ final int offsetPosition = mAdapterHelper.findPositionOffset(position);
+ if (offsetPosition > 0 && offsetPosition < mAdapter.getItemCount()) {
+ final long id = mAdapter.getItemId(offsetPosition);
+ for (int i = 0; i < changedScrapSize; i++) {
+ final ViewHolder holder = mChangedScrap.get(i);
+ if (!holder.wasReturnedFromScrap() && holder.getItemId() == id) {
+ holder.addFlags(ViewHolder.FLAG_RETURNED_FROM_SCRAP);
+ return holder;
+ }
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns a view for the position either from attach scrap, hidden children, or cache.
+ *
+ * @param position Item position
+ * @param dryRun Does a dry run, finds the ViewHolder but does not remove
+ * @return a ViewHolder that can be re-used for this position.
+ */
+ ViewHolder getScrapOrHiddenOrCachedHolderForPosition(int position, boolean dryRun) {
+ final int scrapCount = mAttachedScrap.size();
+
+ // Try first for an exact, non-invalid match from scrap.
+ for (int i = 0; i < scrapCount; i++) {
+ final ViewHolder holder = mAttachedScrap.get(i);
+ if (!holder.wasReturnedFromScrap() && holder.getLayoutPosition() == position
+ && !holder.isInvalid() && (mState.mInPreLayout || !holder.isRemoved())) {
+ holder.addFlags(ViewHolder.FLAG_RETURNED_FROM_SCRAP);
+ return holder;
+ }
+ }
+
+ if (!dryRun) {
+ View view = mChildHelper.findHiddenNonRemovedView(position);
+ if (view != null) {
+ // This View is good to be used. We just need to unhide, detach and move to the
+ // scrap list.
+ final ViewHolder vh = getChildViewHolderInt(view);
+ mChildHelper.unhide(view);
+ int layoutIndex = mChildHelper.indexOfChild(view);
+ if (layoutIndex == RecyclerView.NO_POSITION) {
+ throw new IllegalStateException("layout index should not be -1 after "
+ + "unhiding a view:" + vh);
+ }
+ mChildHelper.detachViewFromParent(layoutIndex);
+ scrapView(view);
+ vh.addFlags(ViewHolder.FLAG_RETURNED_FROM_SCRAP
+ | ViewHolder.FLAG_BOUNCED_FROM_HIDDEN_LIST);
+ return vh;
+ }
+ }
+
+ // Search in our first-level recycled view cache.
+ final int cacheSize = mCachedViews.size();
+ for (int i = 0; i < cacheSize; i++) {
+ final ViewHolder holder = mCachedViews.get(i);
+ // invalid view holders may be in cache if adapter has stable ids as they can be
+ // retrieved via getScrapOrCachedViewForId
+ if (!holder.isInvalid() && holder.getLayoutPosition() == position) {
+ if (!dryRun) {
+ mCachedViews.remove(i);
+ }
+ if (DEBUG) {
+ Log.d(TAG, "getScrapOrHiddenOrCachedHolderForPosition(" + position
+ + ") found match in cache: " + holder);
+ }
+ return holder;
+ }
+ }
+ return null;
+ }
+
+ ViewHolder getScrapOrCachedViewForId(long id, int type, boolean dryRun) {
+ // Look in our attached views first
+ final int count = mAttachedScrap.size();
+ for (int i = count - 1; i >= 0; i--) {
+ final ViewHolder holder = mAttachedScrap.get(i);
+ if (holder.getItemId() == id && !holder.wasReturnedFromScrap()) {
+ if (type == holder.getItemViewType()) {
+ holder.addFlags(ViewHolder.FLAG_RETURNED_FROM_SCRAP);
+ if (holder.isRemoved()) {
+ // this might be valid in two cases:
+ // > item is removed but we are in pre-layout pass
+ // >> do nothing. return as is. make sure we don't rebind
+ // > item is removed then added to another position and we are in
+ // post layout.
+ // >> remove removed and invalid flags, add update flag to rebind
+ // because item was invisible to us and we don't know what happened in
+ // between.
+ if (!mState.isPreLayout()) {
+ holder.setFlags(ViewHolder.FLAG_UPDATE, ViewHolder.FLAG_UPDATE
+ | ViewHolder.FLAG_INVALID | ViewHolder.FLAG_REMOVED);
+ }
+ }
+ return holder;
+ } else if (!dryRun) {
+ // if we are running animations, it is actually better to keep it in scrap
+ // but this would force layout manager to lay it out which would be bad.
+ // Recycle this scrap. Type mismatch.
+ mAttachedScrap.remove(i);
+ removeDetachedView(holder.itemView, false);
+ quickRecycleScrapView(holder.itemView);
+ }
+ }
+ }
+
+ // Search the first-level cache
+ final int cacheSize = mCachedViews.size();
+ for (int i = cacheSize - 1; i >= 0; i--) {
+ final ViewHolder holder = mCachedViews.get(i);
+ if (holder.getItemId() == id) {
+ if (type == holder.getItemViewType()) {
+ if (!dryRun) {
+ mCachedViews.remove(i);
+ }
+ return holder;
+ } else if (!dryRun) {
+ recycleCachedViewAt(i);
+ return null;
+ }
+ }
+ }
+ return null;
+ }
+
+ void dispatchViewRecycled(ViewHolder holder) {
+ if (mRecyclerListener != null) {
+ mRecyclerListener.onViewRecycled(holder);
+ }
+ if (mAdapter != null) {
+ mAdapter.onViewRecycled(holder);
+ }
+ if (mState != null) {
+ mViewInfoStore.removeViewHolder(holder);
+ }
+ if (DEBUG) Log.d(TAG, "dispatchViewRecycled: " + holder);
+ }
+
+ void onAdapterChanged(Adapter oldAdapter, Adapter newAdapter,
+ boolean compatibleWithPrevious) {
+ clear();
+ getRecycledViewPool().onAdapterChanged(oldAdapter, newAdapter, compatibleWithPrevious);
+ }
+
+ void offsetPositionRecordsForMove(int from, int to) {
+ final int start, end, inBetweenOffset;
+ if (from < to) {
+ start = from;
+ end = to;
+ inBetweenOffset = -1;
+ } else {
+ start = to;
+ end = from;
+ inBetweenOffset = 1;
+ }
+ final int cachedCount = mCachedViews.size();
+ for (int i = 0; i < cachedCount; i++) {
+ final ViewHolder holder = mCachedViews.get(i);
+ if (holder == null || holder.mPosition < start || holder.mPosition > end) {
+ continue;
+ }
+ if (holder.mPosition == from) {
+ holder.offsetPosition(to - from, false);
+ } else {
+ holder.offsetPosition(inBetweenOffset, false);
+ }
+ if (DEBUG) {
+ Log.d(TAG, "offsetPositionRecordsForMove cached child " + i + " holder "
+ + holder);
+ }
+ }
+ }
+
+ void offsetPositionRecordsForInsert(int insertedAt, int count) {
+ final int cachedCount = mCachedViews.size();
+ for (int i = 0; i < cachedCount; i++) {
+ final ViewHolder holder = mCachedViews.get(i);
+ if (holder != null && holder.mPosition >= insertedAt) {
+ if (DEBUG) {
+ Log.d(TAG, "offsetPositionRecordsForInsert cached " + i + " holder "
+ + holder + " now at position " + (holder.mPosition + count));
+ }
+ holder.offsetPosition(count, true);
+ }
+ }
+ }
+
+ /**
+ * @param removedFrom Remove start index
+ * @param count Remove count
+ * @param applyToPreLayout If true, changes will affect ViewHolder's pre-layout position, if
+ * false, they'll be applied before the second layout pass
+ */
+ void offsetPositionRecordsForRemove(int removedFrom, int count, boolean applyToPreLayout) {
+ final int removedEnd = removedFrom + count;
+ final int cachedCount = mCachedViews.size();
+ for (int i = cachedCount - 1; i >= 0; i--) {
+ final ViewHolder holder = mCachedViews.get(i);
+ if (holder != null) {
+ if (holder.mPosition >= removedEnd) {
+ if (DEBUG) {
+ Log.d(TAG, "offsetPositionRecordsForRemove cached " + i
+ + " holder " + holder + " now at position "
+ + (holder.mPosition - count));
+ }
+ holder.offsetPosition(-count, applyToPreLayout);
+ } else if (holder.mPosition >= removedFrom) {
+ // Item for this view was removed. Dump it from the cache.
+ holder.addFlags(ViewHolder.FLAG_REMOVED);
+ recycleCachedViewAt(i);
+ }
+ }
+ }
+ }
+
+ void setViewCacheExtension(ViewCacheExtension extension) {
+ mViewCacheExtension = extension;
+ }
+
+ void setRecycledViewPool(RecycledViewPool pool) {
+ if (mRecyclerPool != null) {
+ mRecyclerPool.detach();
+ }
+ mRecyclerPool = pool;
+ if (pool != null) {
+ mRecyclerPool.attach(getAdapter());
+ }
+ }
+
+ RecycledViewPool getRecycledViewPool() {
+ if (mRecyclerPool == null) {
+ mRecyclerPool = new RecycledViewPool();
+ }
+ return mRecyclerPool;
+ }
+
+ void viewRangeUpdate(int positionStart, int itemCount) {
+ final int positionEnd = positionStart + itemCount;
+ final int cachedCount = mCachedViews.size();
+ for (int i = cachedCount - 1; i >= 0; i--) {
+ final ViewHolder holder = mCachedViews.get(i);
+ if (holder == null) {
+ continue;
+ }
+
+ final int pos = holder.getLayoutPosition();
+ if (pos >= positionStart && pos < positionEnd) {
+ holder.addFlags(ViewHolder.FLAG_UPDATE);
+ recycleCachedViewAt(i);
+ // cached views should not be flagged as changed because this will cause them
+ // to animate when they are returned from cache.
+ }
+ }
+ }
+
+ void setAdapterPositionsAsUnknown() {
+ final int cachedCount = mCachedViews.size();
+ for (int i = 0; i < cachedCount; i++) {
+ final ViewHolder holder = mCachedViews.get(i);
+ if (holder != null) {
+ holder.addFlags(ViewHolder.FLAG_ADAPTER_POSITION_UNKNOWN);
+ }
+ }
+ }
+
+ void markKnownViewsInvalid() {
+ if (mAdapter != null && mAdapter.hasStableIds()) {
+ final int cachedCount = mCachedViews.size();
+ for (int i = 0; i < cachedCount; i++) {
+ final ViewHolder holder = mCachedViews.get(i);
+ if (holder != null) {
+ holder.addFlags(ViewHolder.FLAG_UPDATE | ViewHolder.FLAG_INVALID);
+ holder.addChangePayload(null);
+ }
+ }
+ } else {
+ // we cannot re-use cached views in this case. Recycle them all
+ recycleAndClearCachedViews();
+ }
+ }
+
+ void clearOldPositions() {
+ final int cachedCount = mCachedViews.size();
+ for (int i = 0; i < cachedCount; i++) {
+ final ViewHolder holder = mCachedViews.get(i);
+ holder.clearOldPosition();
+ }
+ final int scrapCount = mAttachedScrap.size();
+ for (int i = 0; i < scrapCount; i++) {
+ mAttachedScrap.get(i).clearOldPosition();
+ }
+ if (mChangedScrap != null) {
+ final int changedScrapCount = mChangedScrap.size();
+ for (int i = 0; i < changedScrapCount; i++) {
+ mChangedScrap.get(i).clearOldPosition();
+ }
+ }
+ }
+
+ void markItemDecorInsetsDirty() {
+ final int cachedCount = mCachedViews.size();
+ for (int i = 0; i < cachedCount; i++) {
+ final ViewHolder holder = mCachedViews.get(i);
+ LayoutParams layoutParams = (LayoutParams) holder.itemView.getLayoutParams();
+ if (layoutParams != null) {
+ layoutParams.mInsetsDirty = true;
+ }
+ }
+ }
+ }
+
+ /**
+ * ViewCacheExtension is a helper class to provide an additional layer of view caching that can
+ * be controlled by the developer.
+ * <p>
+ * When {@link Recycler#getViewForPosition(int)} is called, Recycler checks attached scrap and
+ * first level cache to find a matching View. If it cannot find a suitable View, Recycler will
+ * call the {@link #getViewForPositionAndType(Recycler, int, int)} before checking
+ * {@link RecycledViewPool}.
+ * <p>
+ * Note that, Recycler never sends Views to this method to be cached. It is developers
+ * responsibility to decide whether they want to keep their Views in this custom cache or let
+ * the default recycling policy handle it.
+ */
+ public abstract static class ViewCacheExtension {
+
+ /**
+ * Returns a View that can be binded to the given Adapter position.
+ * <p>
+ * This method should <b>not</b> create a new View. Instead, it is expected to return
+ * an already created View that can be re-used for the given type and position.
+ * If the View is marked as ignored, it should first call
+ * {@link LayoutManager#stopIgnoringView(View)} before returning the View.
+ * <p>
+ * RecyclerView will re-bind the returned View to the position if necessary.
+ *
+ * @param recycler The Recycler that can be used to bind the View
+ * @param position The adapter position
+ * @param type The type of the View, defined by adapter
+ * @return A View that is bound to the given position or NULL if there is no View to re-use
+ * @see LayoutManager#ignoreView(View)
+ */
+ public abstract View getViewForPositionAndType(Recycler recycler, int position, int type);
+ }
+
+ /**
+ * Base class for an Adapter
+ *
+ * <p>Adapters provide a binding from an app-specific data set to views that are displayed
+ * within a {@link RecyclerView}.</p>
+ *
+ * @param <VH> A class that extends ViewHolder that will be used by the adapter.
+ */
+ public abstract static class Adapter<VH extends ViewHolder> {
+ private final AdapterDataObservable mObservable = new AdapterDataObservable();
+ private boolean mHasStableIds = false;
+
+ /**
+ * Called when RecyclerView needs a new {@link ViewHolder} of the given type to represent
+ * an item.
+ * <p>
+ * This new ViewHolder should be constructed with a new View that can represent the items
+ * of the given type. You can either create a new View manually or inflate it from an XML
+ * layout file.
+ * <p>
+ * The new ViewHolder will be used to display items of the adapter using
+ * {@link #onBindViewHolder(ViewHolder, int, List)}. Since it will be re-used to display
+ * different items in the data set, it is a good idea to cache references to sub views of
+ * the View to avoid unnecessary {@link View#findViewById(int)} calls.
+ *
+ * @param parent The ViewGroup into which the new View will be added after it is bound to
+ * an adapter position.
+ * @param viewType The view type of the new View.
+ *
+ * @return A new ViewHolder that holds a View of the given view type.
+ * @see #getItemViewType(int)
+ * @see #onBindViewHolder(ViewHolder, int)
+ */
+ public abstract VH onCreateViewHolder(ViewGroup parent, int viewType);
+
+ /**
+ * Called by RecyclerView to display the data at the specified position. This method should
+ * update the contents of the {@link ViewHolder#itemView} to reflect the item at the given
+ * position.
+ * <p>
+ * Note that unlike {@link android.widget.ListView}, RecyclerView will not call this method
+ * again if the position of the item changes in the data set unless the item itself is
+ * invalidated or the new position cannot be determined. For this reason, you should only
+ * use the <code>position</code> parameter while acquiring the related data item inside
+ * this method and should not keep a copy of it. If you need the position of an item later
+ * on (e.g. in a click listener), use {@link ViewHolder#getAdapterPosition()} which will
+ * have the updated adapter position.
+ *
+ * Override {@link #onBindViewHolder(ViewHolder, int, List)} instead if Adapter can
+ * handle efficient partial bind.
+ *
+ * @param holder The ViewHolder which should be updated to represent the contents of the
+ * item at the given position in the data set.
+ * @param position The position of the item within the adapter's data set.
+ */
+ public abstract void onBindViewHolder(VH holder, int position);
+
+ /**
+ * Called by RecyclerView to display the data at the specified position. This method
+ * should update the contents of the {@link ViewHolder#itemView} to reflect the item at
+ * the given position.
+ * <p>
+ * Note that unlike {@link android.widget.ListView}, RecyclerView will not call this method
+ * again if the position of the item changes in the data set unless the item itself is
+ * invalidated or the new position cannot be determined. For this reason, you should only
+ * use the <code>position</code> parameter while acquiring the related data item inside
+ * this method and should not keep a copy of it. If you need the position of an item later
+ * on (e.g. in a click listener), use {@link ViewHolder#getAdapterPosition()} which will
+ * have the updated adapter position.
+ * <p>
+ * Partial bind vs full bind:
+ * <p>
+ * The payloads parameter is a merge list from {@link #notifyItemChanged(int, Object)} or
+ * {@link #notifyItemRangeChanged(int, int, Object)}. If the payloads list is not empty,
+ * the ViewHolder is currently bound to old data and Adapter may run an efficient partial
+ * update using the payload info. If the payload is empty, Adapter must run a full bind.
+ * Adapter should not assume that the payload passed in notify methods will be received by
+ * onBindViewHolder(). For example when the view is not attached to the screen, the
+ * payload in notifyItemChange() will be simply dropped.
+ *
+ * @param holder The ViewHolder which should be updated to represent the contents of the
+ * item at the given position in the data set.
+ * @param position The position of the item within the adapter's data set.
+ * @param payloads A non-null list of merged payloads. Can be empty list if requires full
+ * update.
+ */
+ public void onBindViewHolder(VH holder, int position, List<Object> payloads) {
+ onBindViewHolder(holder, position);
+ }
+
+ /**
+ * This method calls {@link #onCreateViewHolder(ViewGroup, int)} to create a new
+ * {@link ViewHolder} and initializes some private fields to be used by RecyclerView.
+ *
+ * @see #onCreateViewHolder(ViewGroup, int)
+ */
+ public final VH createViewHolder(ViewGroup parent, int viewType) {
+ Trace.beginSection(TRACE_CREATE_VIEW_TAG);
+ final VH holder = onCreateViewHolder(parent, viewType);
+ holder.mItemViewType = viewType;
+ Trace.endSection();
+ return holder;
+ }
+
+ /**
+ * This method internally calls {@link #onBindViewHolder(ViewHolder, int)} to update the
+ * {@link ViewHolder} contents with the item at the given position and also sets up some
+ * private fields to be used by RecyclerView.
+ *
+ * @see #onBindViewHolder(ViewHolder, int)
+ */
+ public final void bindViewHolder(VH holder, int position) {
+ holder.mPosition = position;
+ if (hasStableIds()) {
+ holder.mItemId = getItemId(position);
+ }
+ holder.setFlags(ViewHolder.FLAG_BOUND,
+ ViewHolder.FLAG_BOUND | ViewHolder.FLAG_UPDATE | ViewHolder.FLAG_INVALID
+ | ViewHolder.FLAG_ADAPTER_POSITION_UNKNOWN);
+ Trace.beginSection(TRACE_BIND_VIEW_TAG);
+ onBindViewHolder(holder, position, holder.getUnmodifiedPayloads());
+ holder.clearPayload();
+ final ViewGroup.LayoutParams layoutParams = holder.itemView.getLayoutParams();
+ if (layoutParams instanceof RecyclerView.LayoutParams) {
+ ((LayoutParams) layoutParams).mInsetsDirty = true;
+ }
+ Trace.endSection();
+ }
+
+ /**
+ * Return the view type of the item at <code>position</code> for the purposes
+ * of view recycling.
+ *
+ * <p>The default implementation of this method returns 0, making the assumption of
+ * a single view type for the adapter. Unlike ListView adapters, types need not
+ * be contiguous. Consider using id resources to uniquely identify item view types.
+ *
+ * @param position position to query
+ * @return integer value identifying the type of the view needed to represent the item at
+ * <code>position</code>. Type codes need not be contiguous.
+ */
+ public int getItemViewType(int position) {
+ return 0;
+ }
+
+ /**
+ * Indicates whether each item in the data set can be represented with a unique identifier
+ * of type {@link java.lang.Long}.
+ *
+ * @param hasStableIds Whether items in data set have unique identifiers or not.
+ * @see #hasStableIds()
+ * @see #getItemId(int)
+ */
+ public void setHasStableIds(boolean hasStableIds) {
+ if (hasObservers()) {
+ throw new IllegalStateException("Cannot change whether this adapter has "
+ + "stable IDs while the adapter has registered observers.");
+ }
+ mHasStableIds = hasStableIds;
+ }
+
+ /**
+ * Return the stable ID for the item at <code>position</code>. If {@link #hasStableIds()}
+ * would return false this method should return {@link #NO_ID}. The default implementation
+ * of this method returns {@link #NO_ID}.
+ *
+ * @param position Adapter position to query
+ * @return the stable ID of the item at position
+ */
+ public long getItemId(int position) {
+ return NO_ID;
+ }
+
+ /**
+ * Returns the total number of items in the data set held by the adapter.
+ *
+ * @return The total number of items in this adapter.
+ */
+ public abstract int getItemCount();
+
+ /**
+ * Returns true if this adapter publishes a unique <code>long</code> value that can
+ * act as a key for the item at a given position in the data set. If that item is relocated
+ * in the data set, the ID returned for that item should be the same.
+ *
+ * @return true if this adapter's items have stable IDs
+ */
+ public final boolean hasStableIds() {
+ return mHasStableIds;
+ }
+
+ /**
+ * Called when a view created by this adapter has been recycled.
+ *
+ * <p>A view is recycled when a {@link LayoutManager} decides that it no longer
+ * needs to be attached to its parent {@link RecyclerView}. This can be because it has
+ * fallen out of visibility or a set of cached views represented by views still
+ * attached to the parent RecyclerView. If an item view has large or expensive data
+ * bound to it such as large bitmaps, this may be a good place to release those
+ * resources.</p>
+ * <p>
+ * RecyclerView calls this method right before clearing ViewHolder's internal data and
+ * sending it to RecycledViewPool. This way, if ViewHolder was holding valid information
+ * before being recycled, you can call {@link ViewHolder#getAdapterPosition()} to get
+ * its adapter position.
+ *
+ * @param holder The ViewHolder for the view being recycled
+ */
+ public void onViewRecycled(VH holder) {
+ }
+
+ /**
+ * Called by the RecyclerView if a ViewHolder created by this Adapter cannot be recycled
+ * due to its transient state. Upon receiving this callback, Adapter can clear the
+ * animation(s) that effect the View's transient state and return <code>true</code> so that
+ * the View can be recycled. Keep in mind that the View in question is already removed from
+ * the RecyclerView.
+ * <p>
+ * In some cases, it is acceptable to recycle a View although it has transient state. Most
+ * of the time, this is a case where the transient state will be cleared in
+ * {@link #onBindViewHolder(ViewHolder, int)} call when View is rebound to a new position.
+ * For this reason, RecyclerView leaves the decision to the Adapter and uses the return
+ * value of this method to decide whether the View should be recycled or not.
+ * <p>
+ * Note that when all animations are created by {@link RecyclerView.ItemAnimator}, you
+ * should never receive this callback because RecyclerView keeps those Views as children
+ * until their animations are complete. This callback is useful when children of the item
+ * views create animations which may not be easy to implement using an {@link ItemAnimator}.
+ * <p>
+ * You should <em>never</em> fix this issue by calling
+ * <code>holder.itemView.setHasTransientState(false);</code> unless you've previously called
+ * <code>holder.itemView.setHasTransientState(true);</code>. Each
+ * <code>View.setHasTransientState(true)</code> call must be matched by a
+ * <code>View.setHasTransientState(false)</code> call, otherwise, the state of the View
+ * may become inconsistent. You should always prefer to end or cancel animations that are
+ * triggering the transient state instead of handling it manually.
+ *
+ * @param holder The ViewHolder containing the View that could not be recycled due to its
+ * transient state.
+ * @return True if the View should be recycled, false otherwise. Note that if this method
+ * returns <code>true</code>, RecyclerView <em>will ignore</em> the transient state of
+ * the View and recycle it regardless. If this method returns <code>false</code>,
+ * RecyclerView will check the View's transient state again before giving a final decision.
+ * Default implementation returns false.
+ */
+ public boolean onFailedToRecycleView(VH holder) {
+ return false;
+ }
+
+ /**
+ * Called when a view created by this adapter has been attached to a window.
+ *
+ * <p>This can be used as a reasonable signal that the view is about to be seen
+ * by the user. If the adapter previously freed any resources in
+ * {@link #onViewDetachedFromWindow(RecyclerView.ViewHolder) onViewDetachedFromWindow}
+ * those resources should be restored here.</p>
+ *
+ * @param holder Holder of the view being attached
+ */
+ public void onViewAttachedToWindow(VH holder) {
+ }
+
+ /**
+ * Called when a view created by this adapter has been detached from its window.
+ *
+ * <p>Becoming detached from the window is not necessarily a permanent condition;
+ * the consumer of an Adapter's views may choose to cache views offscreen while they
+ * are not visible, attaching and detaching them as appropriate.</p>
+ *
+ * @param holder Holder of the view being detached
+ */
+ public void onViewDetachedFromWindow(VH holder) {
+ }
+
+ /**
+ * Returns true if one or more observers are attached to this adapter.
+ *
+ * @return true if this adapter has observers
+ */
+ public final boolean hasObservers() {
+ return mObservable.hasObservers();
+ }
+
+ /**
+ * Register a new observer to listen for data changes.
+ *
+ * <p>The adapter may publish a variety of events describing specific changes.
+ * Not all adapters may support all change types and some may fall back to a generic
+ * {@link com.android.internal.widget.RecyclerView.AdapterDataObserver#onChanged()
+ * "something changed"} event if more specific data is not available.</p>
+ *
+ * <p>Components registering observers with an adapter are responsible for
+ * {@link #unregisterAdapterDataObserver(RecyclerView.AdapterDataObserver)
+ * unregistering} those observers when finished.</p>
+ *
+ * @param observer Observer to register
+ *
+ * @see #unregisterAdapterDataObserver(RecyclerView.AdapterDataObserver)
+ */
+ public void registerAdapterDataObserver(AdapterDataObserver observer) {
+ mObservable.registerObserver(observer);
+ }
+
+ /**
+ * Unregister an observer currently listening for data changes.
+ *
+ * <p>The unregistered observer will no longer receive events about changes
+ * to the adapter.</p>
+ *
+ * @param observer Observer to unregister
+ *
+ * @see #registerAdapterDataObserver(RecyclerView.AdapterDataObserver)
+ */
+ public void unregisterAdapterDataObserver(AdapterDataObserver observer) {
+ mObservable.unregisterObserver(observer);
+ }
+
+ /**
+ * Called by RecyclerView when it starts observing this Adapter.
+ * <p>
+ * Keep in mind that same adapter may be observed by multiple RecyclerViews.
+ *
+ * @param recyclerView The RecyclerView instance which started observing this adapter.
+ * @see #onDetachedFromRecyclerView(RecyclerView)
+ */
+ public void onAttachedToRecyclerView(RecyclerView recyclerView) {
+ }
+
+ /**
+ * Called by RecyclerView when it stops observing this Adapter.
+ *
+ * @param recyclerView The RecyclerView instance which stopped observing this adapter.
+ * @see #onAttachedToRecyclerView(RecyclerView)
+ */
+ public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
+ }
+
+ /**
+ * Notify any registered observers that the data set has changed.
+ *
+ * <p>There are two different classes of data change events, item changes and structural
+ * changes. Item changes are when a single item has its data updated but no positional
+ * changes have occurred. Structural changes are when items are inserted, removed or moved
+ * within the data set.</p>
+ *
+ * <p>This event does not specify what about the data set has changed, forcing
+ * any observers to assume that all existing items and structure may no longer be valid.
+ * LayoutManagers will be forced to fully rebind and relayout all visible views.</p>
+ *
+ * <p><code>RecyclerView</code> will attempt to synthesize visible structural change events
+ * for adapters that report that they have {@link #hasStableIds() stable IDs} when
+ * this method is used. This can help for the purposes of animation and visual
+ * object persistence but individual item views will still need to be rebound
+ * and relaid out.</p>
+ *
+ * <p>If you are writing an adapter it will always be more efficient to use the more
+ * specific change events if you can. Rely on <code>notifyDataSetChanged()</code>
+ * as a last resort.</p>
+ *
+ * @see #notifyItemChanged(int)
+ * @see #notifyItemInserted(int)
+ * @see #notifyItemRemoved(int)
+ * @see #notifyItemRangeChanged(int, int)
+ * @see #notifyItemRangeInserted(int, int)
+ * @see #notifyItemRangeRemoved(int, int)
+ */
+ public final void notifyDataSetChanged() {
+ mObservable.notifyChanged();
+ }
+
+ /**
+ * Notify any registered observers that the item at <code>position</code> has changed.
+ * Equivalent to calling <code>notifyItemChanged(position, null);</code>.
+ *
+ * <p>This is an item change event, not a structural change event. It indicates that any
+ * reflection of the data at <code>position</code> is out of date and should be updated.
+ * The item at <code>position</code> retains the same identity.</p>
+ *
+ * @param position Position of the item that has changed
+ *
+ * @see #notifyItemRangeChanged(int, int)
+ */
+ public final void notifyItemChanged(int position) {
+ mObservable.notifyItemRangeChanged(position, 1);
+ }
+
+ /**
+ * Notify any registered observers that the item at <code>position</code> has changed with
+ * an optional payload object.
+ *
+ * <p>This is an item change event, not a structural change event. It indicates that any
+ * reflection of the data at <code>position</code> is out of date and should be updated.
+ * The item at <code>position</code> retains the same identity.
+ * </p>
+ *
+ * <p>
+ * Client can optionally pass a payload for partial change. These payloads will be merged
+ * and may be passed to adapter's {@link #onBindViewHolder(ViewHolder, int, List)} if the
+ * item is already represented by a ViewHolder and it will be rebound to the same
+ * ViewHolder. A notifyItemRangeChanged() with null payload will clear all existing
+ * payloads on that item and prevent future payload until
+ * {@link #onBindViewHolder(ViewHolder, int, List)} is called. Adapter should not assume
+ * that the payload will always be passed to onBindViewHolder(), e.g. when the view is not
+ * attached, the payload will be simply dropped.
+ *
+ * @param position Position of the item that has changed
+ * @param payload Optional parameter, use null to identify a "full" update
+ *
+ * @see #notifyItemRangeChanged(int, int)
+ */
+ public final void notifyItemChanged(int position, Object payload) {
+ mObservable.notifyItemRangeChanged(position, 1, payload);
+ }
+
+ /**
+ * Notify any registered observers that the <code>itemCount</code> items starting at
+ * position <code>positionStart</code> have changed.
+ * Equivalent to calling <code>notifyItemRangeChanged(position, itemCount, null);</code>.
+ *
+ * <p>This is an item change event, not a structural change event. It indicates that
+ * any reflection of the data in the given position range is out of date and should
+ * be updated. The items in the given range retain the same identity.</p>
+ *
+ * @param positionStart Position of the first item that has changed
+ * @param itemCount Number of items that have changed
+ *
+ * @see #notifyItemChanged(int)
+ */
+ public final void notifyItemRangeChanged(int positionStart, int itemCount) {
+ mObservable.notifyItemRangeChanged(positionStart, itemCount);
+ }
+
+ /**
+ * Notify any registered observers that the <code>itemCount</code> items starting at
+ * position <code>positionStart</code> have changed. An optional payload can be
+ * passed to each changed item.
+ *
+ * <p>This is an item change event, not a structural change event. It indicates that any
+ * reflection of the data in the given position range is out of date and should be updated.
+ * The items in the given range retain the same identity.
+ * </p>
+ *
+ * <p>
+ * Client can optionally pass a payload for partial change. These payloads will be merged
+ * and may be passed to adapter's {@link #onBindViewHolder(ViewHolder, int, List)} if the
+ * item is already represented by a ViewHolder and it will be rebound to the same
+ * ViewHolder. A notifyItemRangeChanged() with null payload will clear all existing
+ * payloads on that item and prevent future payload until
+ * {@link #onBindViewHolder(ViewHolder, int, List)} is called. Adapter should not assume
+ * that the payload will always be passed to onBindViewHolder(), e.g. when the view is not
+ * attached, the payload will be simply dropped.
+ *
+ * @param positionStart Position of the first item that has changed
+ * @param itemCount Number of items that have changed
+ * @param payload Optional parameter, use null to identify a "full" update
+ *
+ * @see #notifyItemChanged(int)
+ */
+ public final void notifyItemRangeChanged(int positionStart, int itemCount, Object payload) {
+ mObservable.notifyItemRangeChanged(positionStart, itemCount, payload);
+ }
+
+ /**
+ * Notify any registered observers that the item reflected at <code>position</code>
+ * has been newly inserted. The item previously at <code>position</code> is now at
+ * position <code>position + 1</code>.
+ *
+ * <p>This is a structural change event. Representations of other existing items in the
+ * data set are still considered up to date and will not be rebound, though their
+ * positions may be altered.</p>
+ *
+ * @param position Position of the newly inserted item in the data set
+ *
+ * @see #notifyItemRangeInserted(int, int)
+ */
+ public final void notifyItemInserted(int position) {
+ mObservable.notifyItemRangeInserted(position, 1);
+ }
+
+ /**
+ * Notify any registered observers that the item reflected at <code>fromPosition</code>
+ * has been moved to <code>toPosition</code>.
+ *
+ * <p>This is a structural change event. Representations of other existing items in the
+ * data set are still considered up to date and will not be rebound, though their
+ * positions may be altered.</p>
+ *
+ * @param fromPosition Previous position of the item.
+ * @param toPosition New position of the item.
+ */
+ public final void notifyItemMoved(int fromPosition, int toPosition) {
+ mObservable.notifyItemMoved(fromPosition, toPosition);
+ }
+
+ /**
+ * Notify any registered observers that the currently reflected <code>itemCount</code>
+ * items starting at <code>positionStart</code> have been newly inserted. The items
+ * previously located at <code>positionStart</code> and beyond can now be found starting
+ * at position <code>positionStart + itemCount</code>.
+ *
+ * <p>This is a structural change event. Representations of other existing items in the
+ * data set are still considered up to date and will not be rebound, though their positions
+ * may be altered.</p>
+ *
+ * @param positionStart Position of the first item that was inserted
+ * @param itemCount Number of items inserted
+ *
+ * @see #notifyItemInserted(int)
+ */
+ public final void notifyItemRangeInserted(int positionStart, int itemCount) {
+ mObservable.notifyItemRangeInserted(positionStart, itemCount);
+ }
+
+ /**
+ * Notify any registered observers that the item previously located at <code>position</code>
+ * has been removed from the data set. The items previously located at and after
+ * <code>position</code> may now be found at <code>oldPosition - 1</code>.
+ *
+ * <p>This is a structural change event. Representations of other existing items in the
+ * data set are still considered up to date and will not be rebound, though their positions
+ * may be altered.</p>
+ *
+ * @param position Position of the item that has now been removed
+ *
+ * @see #notifyItemRangeRemoved(int, int)
+ */
+ public final void notifyItemRemoved(int position) {
+ mObservable.notifyItemRangeRemoved(position, 1);
+ }
+
+ /**
+ * Notify any registered observers that the <code>itemCount</code> items previously
+ * located at <code>positionStart</code> have been removed from the data set. The items
+ * previously located at and after <code>positionStart + itemCount</code> may now be found
+ * at <code>oldPosition - itemCount</code>.
+ *
+ * <p>This is a structural change event. Representations of other existing items in the data
+ * set are still considered up to date and will not be rebound, though their positions
+ * may be altered.</p>
+ *
+ * @param positionStart Previous position of the first item that was removed
+ * @param itemCount Number of items removed from the data set
+ */
+ public final void notifyItemRangeRemoved(int positionStart, int itemCount) {
+ mObservable.notifyItemRangeRemoved(positionStart, itemCount);
+ }
+ }
+
+ void dispatchChildDetached(View child) {
+ final ViewHolder viewHolder = getChildViewHolderInt(child);
+ onChildDetachedFromWindow(child);
+ if (mAdapter != null && viewHolder != null) {
+ mAdapter.onViewDetachedFromWindow(viewHolder);
+ }
+ if (mOnChildAttachStateListeners != null) {
+ final int cnt = mOnChildAttachStateListeners.size();
+ for (int i = cnt - 1; i >= 0; i--) {
+ mOnChildAttachStateListeners.get(i).onChildViewDetachedFromWindow(child);
+ }
+ }
+ }
+
+ void dispatchChildAttached(View child) {
+ final ViewHolder viewHolder = getChildViewHolderInt(child);
+ onChildAttachedToWindow(child);
+ if (mAdapter != null && viewHolder != null) {
+ mAdapter.onViewAttachedToWindow(viewHolder);
+ }
+ if (mOnChildAttachStateListeners != null) {
+ final int cnt = mOnChildAttachStateListeners.size();
+ for (int i = cnt - 1; i >= 0; i--) {
+ mOnChildAttachStateListeners.get(i).onChildViewAttachedToWindow(child);
+ }
+ }
+ }
+
+ /**
+ * A <code>LayoutManager</code> is responsible for measuring and positioning item views
+ * within a <code>RecyclerView</code> as well as determining the policy for when to recycle
+ * item views that are no longer visible to the user. By changing the <code>LayoutManager</code>
+ * a <code>RecyclerView</code> can be used to implement a standard vertically scrolling list,
+ * a uniform grid, staggered grids, horizontally scrolling collections and more. Several stock
+ * layout managers are provided for general use.
+ * <p/>
+ * If the LayoutManager specifies a default constructor or one with the signature
+ * ({@link Context}, {@link AttributeSet}, {@code int}, {@code int}), RecyclerView will
+ * instantiate and set the LayoutManager when being inflated. Most used properties can
+ * be then obtained from {@link #getProperties(Context, AttributeSet, int, int)}. In case
+ * a LayoutManager specifies both constructors, the non-default constructor will take
+ * precedence.
+ *
+ */
+ public abstract static class LayoutManager {
+ ChildHelper mChildHelper;
+ RecyclerView mRecyclerView;
+
+ @Nullable
+ SmoothScroller mSmoothScroller;
+
+ boolean mRequestedSimpleAnimations = false;
+
+ boolean mIsAttachedToWindow = false;
+
+ boolean mAutoMeasure = false;
+
+ /**
+ * LayoutManager has its own more strict measurement cache to avoid re-measuring a child
+ * if the space that will be given to it is already larger than what it has measured before.
+ */
+ private boolean mMeasurementCacheEnabled = true;
+
+ private boolean mItemPrefetchEnabled = true;
+
+ /**
+ * Written by {@link GapWorker} when prefetches occur to track largest number of view ever
+ * requested by a {@link #collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)} or
+ * {@link #collectAdjacentPrefetchPositions(int, int, State, LayoutPrefetchRegistry)} call.
+ *
+ * If expanded by a {@link #collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)},
+ * will be reset upon layout to prevent initial prefetches (often large, since they're
+ * proportional to expected child count) from expanding cache permanently.
+ */
+ int mPrefetchMaxCountObserved;
+
+ /**
+ * If true, mPrefetchMaxCountObserved is only valid until next layout, and should be reset.
+ */
+ boolean mPrefetchMaxObservedInInitialPrefetch;
+
+ /**
+ * These measure specs might be the measure specs that were passed into RecyclerView's
+ * onMeasure method OR fake measure specs created by the RecyclerView.
+ * For example, when a layout is run, RecyclerView always sets these specs to be
+ * EXACTLY because a LayoutManager cannot resize RecyclerView during a layout pass.
+ * <p>
+ * Also, to be able to use the hint in unspecified measure specs, RecyclerView checks the
+ * API level and sets the size to 0 pre-M to avoid any issue that might be caused by
+ * corrupt values. Older platforms have no responsibility to provide a size if they set
+ * mode to unspecified.
+ */
+ private int mWidthMode, mHeightMode;
+ private int mWidth, mHeight;
+
+
+ /**
+ * Interface for LayoutManagers to request items to be prefetched, based on position, with
+ * specified distance from viewport, which indicates priority.
+ *
+ * @see LayoutManager#collectAdjacentPrefetchPositions(int, int, State, LayoutPrefetchRegistry)
+ * @see LayoutManager#collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)
+ */
+ public interface LayoutPrefetchRegistry {
+ /**
+ * Requests an an item to be prefetched, based on position, with a specified distance,
+ * indicating priority.
+ *
+ * @param layoutPosition Position of the item to prefetch.
+ * @param pixelDistance Distance from the current viewport to the bounds of the item,
+ * must be non-negative.
+ */
+ void addPosition(int layoutPosition, int pixelDistance);
+ }
+
+ void setRecyclerView(RecyclerView recyclerView) {
+ if (recyclerView == null) {
+ mRecyclerView = null;
+ mChildHelper = null;
+ mWidth = 0;
+ mHeight = 0;
+ } else {
+ mRecyclerView = recyclerView;
+ mChildHelper = recyclerView.mChildHelper;
+ mWidth = recyclerView.getWidth();
+ mHeight = recyclerView.getHeight();
+ }
+ mWidthMode = MeasureSpec.EXACTLY;
+ mHeightMode = MeasureSpec.EXACTLY;
+ }
+
+ void setMeasureSpecs(int wSpec, int hSpec) {
+ mWidth = MeasureSpec.getSize(wSpec);
+ mWidthMode = MeasureSpec.getMode(wSpec);
+ if (mWidthMode == MeasureSpec.UNSPECIFIED && !ALLOW_SIZE_IN_UNSPECIFIED_SPEC) {
+ mWidth = 0;
+ }
+
+ mHeight = MeasureSpec.getSize(hSpec);
+ mHeightMode = MeasureSpec.getMode(hSpec);
+ if (mHeightMode == MeasureSpec.UNSPECIFIED && !ALLOW_SIZE_IN_UNSPECIFIED_SPEC) {
+ mHeight = 0;
+ }
+ }
+
+ /**
+ * Called after a layout is calculated during a measure pass when using auto-measure.
+ * <p>
+ * It simply traverses all children to calculate a bounding box then calls
+ * {@link #setMeasuredDimension(Rect, int, int)}. LayoutManagers can override that method
+ * if they need to handle the bounding box differently.
+ * <p>
+ * For example, GridLayoutManager override that method to ensure that even if a column is
+ * empty, the GridLayoutManager still measures wide enough to include it.
+ *
+ * @param widthSpec The widthSpec that was passing into RecyclerView's onMeasure
+ * @param heightSpec The heightSpec that was passing into RecyclerView's onMeasure
+ */
+ void setMeasuredDimensionFromChildren(int widthSpec, int heightSpec) {
+ final int count = getChildCount();
+ if (count == 0) {
+ mRecyclerView.defaultOnMeasure(widthSpec, heightSpec);
+ return;
+ }
+ int minX = Integer.MAX_VALUE;
+ int minY = Integer.MAX_VALUE;
+ int maxX = Integer.MIN_VALUE;
+ int maxY = Integer.MIN_VALUE;
+
+ for (int i = 0; i < count; i++) {
+ View child = getChildAt(i);
+ final Rect bounds = mRecyclerView.mTempRect;
+ getDecoratedBoundsWithMargins(child, bounds);
+ if (bounds.left < minX) {
+ minX = bounds.left;
+ }
+ if (bounds.right > maxX) {
+ maxX = bounds.right;
+ }
+ if (bounds.top < minY) {
+ minY = bounds.top;
+ }
+ if (bounds.bottom > maxY) {
+ maxY = bounds.bottom;
+ }
+ }
+ mRecyclerView.mTempRect.set(minX, minY, maxX, maxY);
+ setMeasuredDimension(mRecyclerView.mTempRect, widthSpec, heightSpec);
+ }
+
+ /**
+ * Sets the measured dimensions from the given bounding box of the children and the
+ * measurement specs that were passed into {@link RecyclerView#onMeasure(int, int)}. It is
+ * called after the RecyclerView calls
+ * {@link LayoutManager#onLayoutChildren(Recycler, State)} during a measurement pass.
+ * <p>
+ * This method should call {@link #setMeasuredDimension(int, int)}.
+ * <p>
+ * The default implementation adds the RecyclerView's padding to the given bounding box
+ * then caps the value to be within the given measurement specs.
+ * <p>
+ * This method is only called if the LayoutManager opted into the auto measurement API.
+ *
+ * @param childrenBounds The bounding box of all children
+ * @param wSpec The widthMeasureSpec that was passed into the RecyclerView.
+ * @param hSpec The heightMeasureSpec that was passed into the RecyclerView.
+ *
+ * @see #setAutoMeasureEnabled(boolean)
+ */
+ public void setMeasuredDimension(Rect childrenBounds, int wSpec, int hSpec) {
+ int usedWidth = childrenBounds.width() + getPaddingLeft() + getPaddingRight();
+ int usedHeight = childrenBounds.height() + getPaddingTop() + getPaddingBottom();
+ int width = chooseSize(wSpec, usedWidth, getMinimumWidth());
+ int height = chooseSize(hSpec, usedHeight, getMinimumHeight());
+ setMeasuredDimension(width, height);
+ }
+
+ /**
+ * Calls {@code RecyclerView#requestLayout} on the underlying RecyclerView
+ */
+ public void requestLayout() {
+ if (mRecyclerView != null) {
+ mRecyclerView.requestLayout();
+ }
+ }
+
+ /**
+ * Checks if RecyclerView is in the middle of a layout or scroll and throws an
+ * {@link IllegalStateException} if it <b>is not</b>.
+ *
+ * @param message The message for the exception. Can be null.
+ * @see #assertNotInLayoutOrScroll(String)
+ */
+ public void assertInLayoutOrScroll(String message) {
+ if (mRecyclerView != null) {
+ mRecyclerView.assertInLayoutOrScroll(message);
+ }
+ }
+
+ /**
+ * Chooses a size from the given specs and parameters that is closest to the desired size
+ * and also complies with the spec.
+ *
+ * @param spec The measureSpec
+ * @param desired The preferred measurement
+ * @param min The minimum value
+ *
+ * @return A size that fits to the given specs
+ */
+ public static int chooseSize(int spec, int desired, int min) {
+ final int mode = View.MeasureSpec.getMode(spec);
+ final int size = View.MeasureSpec.getSize(spec);
+ switch (mode) {
+ case View.MeasureSpec.EXACTLY:
+ return size;
+ case View.MeasureSpec.AT_MOST:
+ return Math.min(size, Math.max(desired, min));
+ case View.MeasureSpec.UNSPECIFIED:
+ default:
+ return Math.max(desired, min);
+ }
+ }
+
+ /**
+ * Checks if RecyclerView is in the middle of a layout or scroll and throws an
+ * {@link IllegalStateException} if it <b>is</b>.
+ *
+ * @param message The message for the exception. Can be null.
+ * @see #assertInLayoutOrScroll(String)
+ */
+ public void assertNotInLayoutOrScroll(String message) {
+ if (mRecyclerView != null) {
+ mRecyclerView.assertNotInLayoutOrScroll(message);
+ }
+ }
+
+ /**
+ * Defines whether the layout should be measured by the RecyclerView or the LayoutManager
+ * wants to handle the layout measurements itself.
+ * <p>
+ * This method is usually called by the LayoutManager with value {@code true} if it wants
+ * to support WRAP_CONTENT. If you are using a public LayoutManager but want to customize
+ * the measurement logic, you can call this method with {@code false} and override
+ * {@link LayoutManager#onMeasure(int, int)} to implement your custom measurement logic.
+ * <p>
+ * AutoMeasure is a convenience mechanism for LayoutManagers to easily wrap their content or
+ * handle various specs provided by the RecyclerView's parent.
+ * It works by calling {@link LayoutManager#onLayoutChildren(Recycler, State)} during an
+ * {@link RecyclerView#onMeasure(int, int)} call, then calculating desired dimensions based
+ * on children's positions. It does this while supporting all existing animation
+ * capabilities of the RecyclerView.
+ * <p>
+ * AutoMeasure works as follows:
+ * <ol>
+ * <li>LayoutManager should call {@code setAutoMeasureEnabled(true)} to enable it. All of
+ * the framework LayoutManagers use {@code auto-measure}.</li>
+ * <li>When {@link RecyclerView#onMeasure(int, int)} is called, if the provided specs are
+ * exact, RecyclerView will only call LayoutManager's {@code onMeasure} and return without
+ * doing any layout calculation.</li>
+ * <li>If one of the layout specs is not {@code EXACT}, the RecyclerView will start the
+ * layout process in {@code onMeasure} call. It will process all pending Adapter updates and
+ * decide whether to run a predictive layout or not. If it decides to do so, it will first
+ * call {@link #onLayoutChildren(Recycler, State)} with {@link State#isPreLayout()} set to
+ * {@code true}. At this stage, {@link #getWidth()} and {@link #getHeight()} will still
+ * return the width and height of the RecyclerView as of the last layout calculation.
+ * <p>
+ * After handling the predictive case, RecyclerView will call
+ * {@link #onLayoutChildren(Recycler, State)} with {@link State#isMeasuring()} set to
+ * {@code true} and {@link State#isPreLayout()} set to {@code false}. The LayoutManager can
+ * access the measurement specs via {@link #getHeight()}, {@link #getHeightMode()},
+ * {@link #getWidth()} and {@link #getWidthMode()}.</li>
+ * <li>After the layout calculation, RecyclerView sets the measured width & height by
+ * calculating the bounding box for the children (+ RecyclerView's padding). The
+ * LayoutManagers can override {@link #setMeasuredDimension(Rect, int, int)} to choose
+ * different values. For instance, GridLayoutManager overrides this value to handle the case
+ * where if it is vertical and has 3 columns but only 2 items, it should still measure its
+ * width to fit 3 items, not 2.</li>
+ * <li>Any following on measure call to the RecyclerView will run
+ * {@link #onLayoutChildren(Recycler, State)} with {@link State#isMeasuring()} set to
+ * {@code true} and {@link State#isPreLayout()} set to {@code false}. RecyclerView will
+ * take care of which views are actually added / removed / moved / changed for animations so
+ * that the LayoutManager should not worry about them and handle each
+ * {@link #onLayoutChildren(Recycler, State)} call as if it is the last one.
+ * </li>
+ * <li>When measure is complete and RecyclerView's
+ * {@link #onLayout(boolean, int, int, int, int)} method is called, RecyclerView checks
+ * whether it already did layout calculations during the measure pass and if so, it re-uses
+ * that information. It may still decide to call {@link #onLayoutChildren(Recycler, State)}
+ * if the last measure spec was different from the final dimensions or adapter contents
+ * have changed between the measure call and the layout call.</li>
+ * <li>Finally, animations are calculated and run as usual.</li>
+ * </ol>
+ *
+ * @param enabled <code>True</code> if the Layout should be measured by the
+ * RecyclerView, <code>false</code> if the LayoutManager wants
+ * to measure itself.
+ *
+ * @see #setMeasuredDimension(Rect, int, int)
+ * @see #isAutoMeasureEnabled()
+ */
+ public void setAutoMeasureEnabled(boolean enabled) {
+ mAutoMeasure = enabled;
+ }
+
+ /**
+ * Returns whether the LayoutManager uses the automatic measurement API or not.
+ *
+ * @return <code>True</code> if the LayoutManager is measured by the RecyclerView or
+ * <code>false</code> if it measures itself.
+ *
+ * @see #setAutoMeasureEnabled(boolean)
+ */
+ public boolean isAutoMeasureEnabled() {
+ return mAutoMeasure;
+ }
+
+ /**
+ * Returns whether this LayoutManager supports automatic item animations.
+ * A LayoutManager wishing to support item animations should obey certain
+ * rules as outlined in {@link #onLayoutChildren(Recycler, State)}.
+ * The default return value is <code>false</code>, so subclasses of LayoutManager
+ * will not get predictive item animations by default.
+ *
+ * <p>Whether item animations are enabled in a RecyclerView is determined both
+ * by the return value from this method and the
+ * {@link RecyclerView#setItemAnimator(ItemAnimator) ItemAnimator} set on the
+ * RecyclerView itself. If the RecyclerView has a non-null ItemAnimator but this
+ * method returns false, then simple item animations will be enabled, in which
+ * views that are moving onto or off of the screen are simply faded in/out. If
+ * the RecyclerView has a non-null ItemAnimator and this method returns true,
+ * then there will be two calls to {@link #onLayoutChildren(Recycler, State)} to
+ * setup up the information needed to more intelligently predict where appearing
+ * and disappearing views should be animated from/to.</p>
+ *
+ * @return true if predictive item animations should be enabled, false otherwise
+ */
+ public boolean supportsPredictiveItemAnimations() {
+ return false;
+ }
+
+ /**
+ * Sets whether the LayoutManager should be queried for views outside of
+ * its viewport while the UI thread is idle between frames.
+ *
+ * <p>If enabled, the LayoutManager will be queried for items to inflate/bind in between
+ * view system traversals on devices running API 21 or greater. Default value is true.</p>
+ *
+ * <p>On platforms API level 21 and higher, the UI thread is idle between passing a frame
+ * to RenderThread and the starting up its next frame at the next VSync pulse. By
+ * prefetching out of window views in this time period, delays from inflation and view
+ * binding are much less likely to cause jank and stuttering during scrolls and flings.</p>
+ *
+ * <p>While prefetch is enabled, it will have the side effect of expanding the effective
+ * size of the View cache to hold prefetched views.</p>
+ *
+ * @param enabled <code>True</code> if items should be prefetched in between traversals.
+ *
+ * @see #isItemPrefetchEnabled()
+ */
+ public final void setItemPrefetchEnabled(boolean enabled) {
+ if (enabled != mItemPrefetchEnabled) {
+ mItemPrefetchEnabled = enabled;
+ mPrefetchMaxCountObserved = 0;
+ if (mRecyclerView != null) {
+ mRecyclerView.mRecycler.updateViewCacheSize();
+ }
+ }
+ }
+
+ /**
+ * Sets whether the LayoutManager should be queried for views outside of
+ * its viewport while the UI thread is idle between frames.
+ *
+ * @see #setItemPrefetchEnabled(boolean)
+ *
+ * @return true if item prefetch is enabled, false otherwise
+ */
+ public final boolean isItemPrefetchEnabled() {
+ return mItemPrefetchEnabled;
+ }
+
+ /**
+ * Gather all positions from the LayoutManager to be prefetched, given specified momentum.
+ *
+ * <p>If item prefetch is enabled, this method is called in between traversals to gather
+ * which positions the LayoutManager will soon need, given upcoming movement in subsequent
+ * traversals.</p>
+ *
+ * <p>The LayoutManager should call {@link LayoutPrefetchRegistry#addPosition(int, int)} for
+ * each item to be prepared, and these positions will have their ViewHolders created and
+ * bound, if there is sufficient time available, in advance of being needed by a
+ * scroll or layout.</p>
+ *
+ * @param dx X movement component.
+ * @param dy Y movement component.
+ * @param state State of RecyclerView
+ * @param layoutPrefetchRegistry PrefetchRegistry to add prefetch entries into.
+ *
+ * @see #isItemPrefetchEnabled()
+ * @see #collectInitialPrefetchPositions(int, LayoutPrefetchRegistry)
+ */
+ public void collectAdjacentPrefetchPositions(int dx, int dy, State state,
+ LayoutPrefetchRegistry layoutPrefetchRegistry) {}
+
+ /**
+ * Gather all positions from the LayoutManager to be prefetched in preperation for its
+ * RecyclerView to come on screen, due to the movement of another, containing RecyclerView.
+ *
+ * <p>This method is only called when a RecyclerView is nested in another RecyclerView.</p>
+ *
+ * <p>If item prefetch is enabled for this LayoutManager, as well in another containing
+ * LayoutManager, this method is called in between draw traversals to gather
+ * which positions this LayoutManager will first need, once it appears on the screen.</p>
+ *
+ * <p>For example, if this LayoutManager represents a horizontally scrolling list within a
+ * vertically scrolling LayoutManager, this method would be called when the horizontal list
+ * is about to come onscreen.</p>
+ *
+ * <p>The LayoutManager should call {@link LayoutPrefetchRegistry#addPosition(int, int)} for
+ * each item to be prepared, and these positions will have their ViewHolders created and
+ * bound, if there is sufficient time available, in advance of being needed by a
+ * scroll or layout.</p>
+ *
+ * @param adapterItemCount number of items in the associated adapter.
+ * @param layoutPrefetchRegistry PrefetchRegistry to add prefetch entries into.
+ *
+ * @see #isItemPrefetchEnabled()
+ * @see #collectAdjacentPrefetchPositions(int, int, State, LayoutPrefetchRegistry)
+ */
+ public void collectInitialPrefetchPositions(int adapterItemCount,
+ LayoutPrefetchRegistry layoutPrefetchRegistry) {}
+
+ void dispatchAttachedToWindow(RecyclerView view) {
+ mIsAttachedToWindow = true;
+ onAttachedToWindow(view);
+ }
+
+ void dispatchDetachedFromWindow(RecyclerView view, Recycler recycler) {
+ mIsAttachedToWindow = false;
+ onDetachedFromWindow(view, recycler);
+ }
+
+ /**
+ * Returns whether LayoutManager is currently attached to a RecyclerView which is attached
+ * to a window.
+ *
+ * @return True if this LayoutManager is controlling a RecyclerView and the RecyclerView
+ * is attached to window.
+ */
+ public boolean isAttachedToWindow() {
+ return mIsAttachedToWindow;
+ }
+
+ /**
+ * Causes the Runnable to execute on the next animation time step.
+ * The runnable will be run on the user interface thread.
+ * <p>
+ * Calling this method when LayoutManager is not attached to a RecyclerView has no effect.
+ *
+ * @param action The Runnable that will be executed.
+ *
+ * @see #removeCallbacks
+ */
+ public void postOnAnimation(Runnable action) {
+ if (mRecyclerView != null) {
+ mRecyclerView.postOnAnimation(action);
+ }
+ }
+
+ /**
+ * Removes the specified Runnable from the message queue.
+ * <p>
+ * Calling this method when LayoutManager is not attached to a RecyclerView has no effect.
+ *
+ * @param action The Runnable to remove from the message handling queue
+ *
+ * @return true if RecyclerView could ask the Handler to remove the Runnable,
+ * false otherwise. When the returned value is true, the Runnable
+ * may or may not have been actually removed from the message queue
+ * (for instance, if the Runnable was not in the queue already.)
+ *
+ * @see #postOnAnimation
+ */
+ public boolean removeCallbacks(Runnable action) {
+ if (mRecyclerView != null) {
+ return mRecyclerView.removeCallbacks(action);
+ }
+ return false;
+ }
+ /**
+ * Called when this LayoutManager is both attached to a RecyclerView and that RecyclerView
+ * is attached to a window.
+ * <p>
+ * If the RecyclerView is re-attached with the same LayoutManager and Adapter, it may not
+ * call {@link #onLayoutChildren(Recycler, State)} if nothing has changed and a layout was
+ * not requested on the RecyclerView while it was detached.
+ * <p>
+ * Subclass implementations should always call through to the superclass implementation.
+ *
+ * @param view The RecyclerView this LayoutManager is bound to
+ *
+ * @see #onDetachedFromWindow(RecyclerView, Recycler)
+ */
+ @CallSuper
+ public void onAttachedToWindow(RecyclerView view) {
+ }
+
+ /**
+ * @deprecated
+ * override {@link #onDetachedFromWindow(RecyclerView, Recycler)}
+ */
+ @Deprecated
+ public void onDetachedFromWindow(RecyclerView view) {
+
+ }
+
+ /**
+ * Called when this LayoutManager is detached from its parent RecyclerView or when
+ * its parent RecyclerView is detached from its window.
+ * <p>
+ * LayoutManager should clear all of its View references as another LayoutManager might be
+ * assigned to the RecyclerView.
+ * <p>
+ * If the RecyclerView is re-attached with the same LayoutManager and Adapter, it may not
+ * call {@link #onLayoutChildren(Recycler, State)} if nothing has changed and a layout was
+ * not requested on the RecyclerView while it was detached.
+ * <p>
+ * If your LayoutManager has View references that it cleans in on-detach, it should also
+ * call {@link RecyclerView#requestLayout()} to ensure that it is re-laid out when
+ * RecyclerView is re-attached.
+ * <p>
+ * Subclass implementations should always call through to the superclass implementation.
+ *
+ * @param view The RecyclerView this LayoutManager is bound to
+ * @param recycler The recycler to use if you prefer to recycle your children instead of
+ * keeping them around.
+ *
+ * @see #onAttachedToWindow(RecyclerView)
+ */
+ @CallSuper
+ public void onDetachedFromWindow(RecyclerView view, Recycler recycler) {
+ onDetachedFromWindow(view);
+ }
+
+ /**
+ * Check if the RecyclerView is configured to clip child views to its padding.
+ *
+ * @return true if this RecyclerView clips children to its padding, false otherwise
+ */
+ public boolean getClipToPadding() {
+ return mRecyclerView != null && mRecyclerView.mClipToPadding;
+ }
+
+ /**
+ * Lay out all relevant child views from the given adapter.
+ *
+ * The LayoutManager is in charge of the behavior of item animations. By default,
+ * RecyclerView has a non-null {@link #getItemAnimator() ItemAnimator}, and simple
+ * item animations are enabled. This means that add/remove operations on the
+ * adapter will result in animations to add new or appearing items, removed or
+ * disappearing items, and moved items. If a LayoutManager returns false from
+ * {@link #supportsPredictiveItemAnimations()}, which is the default, and runs a
+ * normal layout operation during {@link #onLayoutChildren(Recycler, State)}, the
+ * RecyclerView will have enough information to run those animations in a simple
+ * way. For example, the default ItemAnimator, {@link DefaultItemAnimator}, will
+ * simply fade views in and out, whether they are actually added/removed or whether
+ * they are moved on or off the screen due to other add/remove operations.
+ *
+ * <p>A LayoutManager wanting a better item animation experience, where items can be
+ * animated onto and off of the screen according to where the items exist when they
+ * are not on screen, then the LayoutManager should return true from
+ * {@link #supportsPredictiveItemAnimations()} and add additional logic to
+ * {@link #onLayoutChildren(Recycler, State)}. Supporting predictive animations
+ * means that {@link #onLayoutChildren(Recycler, State)} will be called twice;
+ * once as a "pre" layout step to determine where items would have been prior to
+ * a real layout, and again to do the "real" layout. In the pre-layout phase,
+ * items will remember their pre-layout positions to allow them to be laid out
+ * appropriately. Also, {@link LayoutParams#isItemRemoved() removed} items will
+ * be returned from the scrap to help determine correct placement of other items.
+ * These removed items should not be added to the child list, but should be used
+ * to help calculate correct positioning of other views, including views that
+ * were not previously onscreen (referred to as APPEARING views), but whose
+ * pre-layout offscreen position can be determined given the extra
+ * information about the pre-layout removed views.</p>
+ *
+ * <p>The second layout pass is the real layout in which only non-removed views
+ * will be used. The only additional requirement during this pass is, if
+ * {@link #supportsPredictiveItemAnimations()} returns true, to note which
+ * views exist in the child list prior to layout and which are not there after
+ * layout (referred to as DISAPPEARING views), and to position/layout those views
+ * appropriately, without regard to the actual bounds of the RecyclerView. This allows
+ * the animation system to know the location to which to animate these disappearing
+ * views.</p>
+ *
+ * <p>The default LayoutManager implementations for RecyclerView handle all of these
+ * requirements for animations already. Clients of RecyclerView can either use one
+ * of these layout managers directly or look at their implementations of
+ * onLayoutChildren() to see how they account for the APPEARING and
+ * DISAPPEARING views.</p>
+ *
+ * @param recycler Recycler to use for fetching potentially cached views for a
+ * position
+ * @param state Transient state of RecyclerView
+ */
+ public void onLayoutChildren(Recycler recycler, State state) {
+ Log.e(TAG, "You must override onLayoutChildren(Recycler recycler, State state) ");
+ }
+
+ /**
+ * Called after a full layout calculation is finished. The layout calculation may include
+ * multiple {@link #onLayoutChildren(Recycler, State)} calls due to animations or
+ * layout measurement but it will include only one {@link #onLayoutCompleted(State)} call.
+ * This method will be called at the end of {@link View#layout(int, int, int, int)} call.
+ * <p>
+ * This is a good place for the LayoutManager to do some cleanup like pending scroll
+ * position, saved state etc.
+ *
+ * @param state Transient state of RecyclerView
+ */
+ public void onLayoutCompleted(State state) {
+ }
+
+ /**
+ * Create a default <code>LayoutParams</code> object for a child of the RecyclerView.
+ *
+ * <p>LayoutManagers will often want to use a custom <code>LayoutParams</code> type
+ * to store extra information specific to the layout. Client code should subclass
+ * {@link RecyclerView.LayoutParams} for this purpose.</p>
+ *
+ * <p><em>Important:</em> if you use your own custom <code>LayoutParams</code> type
+ * you must also override
+ * {@link #checkLayoutParams(LayoutParams)},
+ * {@link #generateLayoutParams(android.view.ViewGroup.LayoutParams)} and
+ * {@link #generateLayoutParams(android.content.Context, android.util.AttributeSet)}.</p>
+ *
+ * @return A new LayoutParams for a child view
+ */
+ public abstract LayoutParams generateDefaultLayoutParams();
+
+ /**
+ * Determines the validity of the supplied LayoutParams object.
+ *
+ * <p>This should check to make sure that the object is of the correct type
+ * and all values are within acceptable ranges. The default implementation
+ * returns <code>true</code> for non-null params.</p>
+ *
+ * @param lp LayoutParams object to check
+ * @return true if this LayoutParams object is valid, false otherwise
+ */
+ public boolean checkLayoutParams(LayoutParams lp) {
+ return lp != null;
+ }
+
+ /**
+ * Create a LayoutParams object suitable for this LayoutManager, copying relevant
+ * values from the supplied LayoutParams object if possible.
+ *
+ * <p><em>Important:</em> if you use your own custom <code>LayoutParams</code> type
+ * you must also override
+ * {@link #checkLayoutParams(LayoutParams)},
+ * {@link #generateLayoutParams(android.view.ViewGroup.LayoutParams)} and
+ * {@link #generateLayoutParams(android.content.Context, android.util.AttributeSet)}.</p>
+ *
+ * @param lp Source LayoutParams object to copy values from
+ * @return a new LayoutParams object
+ */
+ public LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) {
+ if (lp instanceof LayoutParams) {
+ return new LayoutParams((LayoutParams) lp);
+ } else if (lp instanceof MarginLayoutParams) {
+ return new LayoutParams((MarginLayoutParams) lp);
+ } else {
+ return new LayoutParams(lp);
+ }
+ }
+
+ /**
+ * Create a LayoutParams object suitable for this LayoutManager from
+ * an inflated layout resource.
+ *
+ * <p><em>Important:</em> if you use your own custom <code>LayoutParams</code> type
+ * you must also override
+ * {@link #checkLayoutParams(LayoutParams)},
+ * {@link #generateLayoutParams(android.view.ViewGroup.LayoutParams)} and
+ * {@link #generateLayoutParams(android.content.Context, android.util.AttributeSet)}.</p>
+ *
+ * @param c Context for obtaining styled attributes
+ * @param attrs AttributeSet describing the supplied arguments
+ * @return a new LayoutParams object
+ */
+ public LayoutParams generateLayoutParams(Context c, AttributeSet attrs) {
+ return new LayoutParams(c, attrs);
+ }
+
+ /**
+ * Scroll horizontally by dx pixels in screen coordinates and return the distance traveled.
+ * The default implementation does nothing and returns 0.
+ *
+ * @param dx distance to scroll by in pixels. X increases as scroll position
+ * approaches the right.
+ * @param recycler Recycler to use for fetching potentially cached views for a
+ * position
+ * @param state Transient state of RecyclerView
+ * @return The actual distance scrolled. The return value will be negative if dx was
+ * negative and scrolling proceeeded in that direction.
+ * <code>Math.abs(result)</code> may be less than dx if a boundary was reached.
+ */
+ public int scrollHorizontallyBy(int dx, Recycler recycler, State state) {
+ return 0;
+ }
+
+ /**
+ * Scroll vertically by dy pixels in screen coordinates and return the distance traveled.
+ * The default implementation does nothing and returns 0.
+ *
+ * @param dy distance to scroll in pixels. Y increases as scroll position
+ * approaches the bottom.
+ * @param recycler Recycler to use for fetching potentially cached views for a
+ * position
+ * @param state Transient state of RecyclerView
+ * @return The actual distance scrolled. The return value will be negative if dy was
+ * negative and scrolling proceeeded in that direction.
+ * <code>Math.abs(result)</code> may be less than dy if a boundary was reached.
+ */
+ public int scrollVerticallyBy(int dy, Recycler recycler, State state) {
+ return 0;
+ }
+
+ /**
+ * Query if horizontal scrolling is currently supported. The default implementation
+ * returns false.
+ *
+ * @return True if this LayoutManager can scroll the current contents horizontally
+ */
+ public boolean canScrollHorizontally() {
+ return false;
+ }
+
+ /**
+ * Query if vertical scrolling is currently supported. The default implementation
+ * returns false.
+ *
+ * @return True if this LayoutManager can scroll the current contents vertically
+ */
+ public boolean canScrollVertically() {
+ return false;
+ }
+
+ /**
+ * Scroll to the specified adapter position.
+ *
+ * Actual position of the item on the screen depends on the LayoutManager implementation.
+ * @param position Scroll to this adapter position.
+ */
+ public void scrollToPosition(int position) {
+ if (DEBUG) {
+ Log.e(TAG, "You MUST implement scrollToPosition. It will soon become abstract");
+ }
+ }
+
+ /**
+ * <p>Smooth scroll to the specified adapter position.</p>
+ * <p>To support smooth scrolling, override this method, create your {@link SmoothScroller}
+ * instance and call {@link #startSmoothScroll(SmoothScroller)}.
+ * </p>
+ * @param recyclerView The RecyclerView to which this layout manager is attached
+ * @param state Current State of RecyclerView
+ * @param position Scroll to this adapter position.
+ */
+ public void smoothScrollToPosition(RecyclerView recyclerView, State state,
+ int position) {
+ Log.e(TAG, "You must override smoothScrollToPosition to support smooth scrolling");
+ }
+
+ /**
+ * <p>Starts a smooth scroll using the provided SmoothScroller.</p>
+ * <p>Calling this method will cancel any previous smooth scroll request.</p>
+ * @param smoothScroller Instance which defines how smooth scroll should be animated
+ */
+ public void startSmoothScroll(SmoothScroller smoothScroller) {
+ if (mSmoothScroller != null && smoothScroller != mSmoothScroller
+ && mSmoothScroller.isRunning()) {
+ mSmoothScroller.stop();
+ }
+ mSmoothScroller = smoothScroller;
+ mSmoothScroller.start(mRecyclerView, this);
+ }
+
+ /**
+ * @return true if RecycylerView is currently in the state of smooth scrolling.
+ */
+ public boolean isSmoothScrolling() {
+ return mSmoothScroller != null && mSmoothScroller.isRunning();
+ }
+
+
+ /**
+ * Returns the resolved layout direction for this RecyclerView.
+ *
+ * @return {@link android.view.View#LAYOUT_DIRECTION_RTL} if the layout
+ * direction is RTL or returns
+ * {@link android.view.View#LAYOUT_DIRECTION_LTR} if the layout direction
+ * is not RTL.
+ */
+ public int getLayoutDirection() {
+ return mRecyclerView.getLayoutDirection();
+ }
+
+ /**
+ * Ends all animations on the view created by the {@link ItemAnimator}.
+ *
+ * @param view The View for which the animations should be ended.
+ * @see RecyclerView.ItemAnimator#endAnimations()
+ */
+ public void endAnimation(View view) {
+ if (mRecyclerView.mItemAnimator != null) {
+ mRecyclerView.mItemAnimator.endAnimation(getChildViewHolderInt(view));
+ }
+ }
+
+ /**
+ * To be called only during {@link #onLayoutChildren(Recycler, State)} to add a view
+ * to the layout that is known to be going away, either because it has been
+ * {@link Adapter#notifyItemRemoved(int) removed} or because it is actually not in the
+ * visible portion of the container but is being laid out in order to inform RecyclerView
+ * in how to animate the item out of view.
+ * <p>
+ * Views added via this method are going to be invisible to LayoutManager after the
+ * dispatchLayout pass is complete. They cannot be retrieved via {@link #getChildAt(int)}
+ * or won't be included in {@link #getChildCount()} method.
+ *
+ * @param child View to add and then remove with animation.
+ */
+ public void addDisappearingView(View child) {
+ addDisappearingView(child, -1);
+ }
+
+ /**
+ * To be called only during {@link #onLayoutChildren(Recycler, State)} to add a view
+ * to the layout that is known to be going away, either because it has been
+ * {@link Adapter#notifyItemRemoved(int) removed} or because it is actually not in the
+ * visible portion of the container but is being laid out in order to inform RecyclerView
+ * in how to animate the item out of view.
+ * <p>
+ * Views added via this method are going to be invisible to LayoutManager after the
+ * dispatchLayout pass is complete. They cannot be retrieved via {@link #getChildAt(int)}
+ * or won't be included in {@link #getChildCount()} method.
+ *
+ * @param child View to add and then remove with animation.
+ * @param index Index of the view.
+ */
+ public void addDisappearingView(View child, int index) {
+ addViewInt(child, index, true);
+ }
+
+ /**
+ * Add a view to the currently attached RecyclerView if needed. LayoutManagers should
+ * use this method to add views obtained from a {@link Recycler} using
+ * {@link Recycler#getViewForPosition(int)}.
+ *
+ * @param child View to add
+ */
+ public void addView(View child) {
+ addView(child, -1);
+ }
+
+ /**
+ * Add a view to the currently attached RecyclerView if needed. LayoutManagers should
+ * use this method to add views obtained from a {@link Recycler} using
+ * {@link Recycler#getViewForPosition(int)}.
+ *
+ * @param child View to add
+ * @param index Index to add child at
+ */
+ public void addView(View child, int index) {
+ addViewInt(child, index, false);
+ }
+
+ private void addViewInt(View child, int index, boolean disappearing) {
+ final ViewHolder holder = getChildViewHolderInt(child);
+ if (disappearing || holder.isRemoved()) {
+ // these views will be hidden at the end of the layout pass.
+ mRecyclerView.mViewInfoStore.addToDisappearedInLayout(holder);
+ } else {
+ // This may look like unnecessary but may happen if layout manager supports
+ // predictive layouts and adapter removed then re-added the same item.
+ // In this case, added version will be visible in the post layout (because add is
+ // deferred) but RV will still bind it to the same View.
+ // So if a View re-appears in post layout pass, remove it from disappearing list.
+ mRecyclerView.mViewInfoStore.removeFromDisappearedInLayout(holder);
+ }
+ final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+ if (holder.wasReturnedFromScrap() || holder.isScrap()) {
+ if (holder.isScrap()) {
+ holder.unScrap();
+ } else {
+ holder.clearReturnedFromScrapFlag();
+ }
+ mChildHelper.attachViewToParent(child, index, child.getLayoutParams(), false);
+ if (DISPATCH_TEMP_DETACH) {
+ child.dispatchFinishTemporaryDetach();
+ }
+ } else if (child.getParent() == mRecyclerView) { // it was not a scrap but a valid child
+ // ensure in correct position
+ int currentIndex = mChildHelper.indexOfChild(child);
+ if (index == -1) {
+ index = mChildHelper.getChildCount();
+ }
+ if (currentIndex == -1) {
+ throw new IllegalStateException("Added View has RecyclerView as parent but"
+ + " view is not a real child. Unfiltered index:"
+ + mRecyclerView.indexOfChild(child));
+ }
+ if (currentIndex != index) {
+ mRecyclerView.mLayout.moveView(currentIndex, index);
+ }
+ } else {
+ mChildHelper.addView(child, index, false);
+ lp.mInsetsDirty = true;
+ if (mSmoothScroller != null && mSmoothScroller.isRunning()) {
+ mSmoothScroller.onChildAttachedToWindow(child);
+ }
+ }
+ if (lp.mPendingInvalidate) {
+ if (DEBUG) {
+ Log.d(TAG, "consuming pending invalidate on child " + lp.mViewHolder);
+ }
+ holder.itemView.invalidate();
+ lp.mPendingInvalidate = false;
+ }
+ }
+
+ /**
+ * Remove a view from the currently attached RecyclerView if needed. LayoutManagers should
+ * use this method to completely remove a child view that is no longer needed.
+ * LayoutManagers should strongly consider recycling removed views using
+ * {@link Recycler#recycleView(android.view.View)}.
+ *
+ * @param child View to remove
+ */
+ public void removeView(View child) {
+ mChildHelper.removeView(child);
+ }
+
+ /**
+ * Remove a view from the currently attached RecyclerView if needed. LayoutManagers should
+ * use this method to completely remove a child view that is no longer needed.
+ * LayoutManagers should strongly consider recycling removed views using
+ * {@link Recycler#recycleView(android.view.View)}.
+ *
+ * @param index Index of the child view to remove
+ */
+ public void removeViewAt(int index) {
+ final View child = getChildAt(index);
+ if (child != null) {
+ mChildHelper.removeViewAt(index);
+ }
+ }
+
+ /**
+ * Remove all views from the currently attached RecyclerView. This will not recycle
+ * any of the affected views; the LayoutManager is responsible for doing so if desired.
+ */
+ public void removeAllViews() {
+ // Only remove non-animating views
+ final int childCount = getChildCount();
+ for (int i = childCount - 1; i >= 0; i--) {
+ mChildHelper.removeViewAt(i);
+ }
+ }
+
+ /**
+ * Returns offset of the RecyclerView's text baseline from the its top boundary.
+ *
+ * @return The offset of the RecyclerView's text baseline from the its top boundary; -1 if
+ * there is no baseline.
+ */
+ public int getBaseline() {
+ return -1;
+ }
+
+ /**
+ * Returns the adapter position of the item represented by the given View. This does not
+ * contain any adapter changes that might have happened after the last layout.
+ *
+ * @param view The view to query
+ * @return The adapter position of the item which is rendered by this View.
+ */
+ public int getPosition(View view) {
+ return ((RecyclerView.LayoutParams) view.getLayoutParams()).getViewLayoutPosition();
+ }
+
+ /**
+ * Returns the View type defined by the adapter.
+ *
+ * @param view The view to query
+ * @return The type of the view assigned by the adapter.
+ */
+ public int getItemViewType(View view) {
+ return getChildViewHolderInt(view).getItemViewType();
+ }
+
+ /**
+ * Traverses the ancestors of the given view and returns the item view that contains it
+ * and also a direct child of the LayoutManager.
+ * <p>
+ * Note that this method may return null if the view is a child of the RecyclerView but
+ * not a child of the LayoutManager (e.g. running a disappear animation).
+ *
+ * @param view The view that is a descendant of the LayoutManager.
+ *
+ * @return The direct child of the LayoutManager which contains the given view or null if
+ * the provided view is not a descendant of this LayoutManager.
+ *
+ * @see RecyclerView#getChildViewHolder(View)
+ * @see RecyclerView#findContainingViewHolder(View)
+ */
+ @Nullable
+ public View findContainingItemView(View view) {
+ if (mRecyclerView == null) {
+ return null;
+ }
+ View found = mRecyclerView.findContainingItemView(view);
+ if (found == null) {
+ return null;
+ }
+ if (mChildHelper.isHidden(found)) {
+ return null;
+ }
+ return found;
+ }
+
+ /**
+ * Finds the view which represents the given adapter position.
+ * <p>
+ * This method traverses each child since it has no information about child order.
+ * Override this method to improve performance if your LayoutManager keeps data about
+ * child views.
+ * <p>
+ * If a view is ignored via {@link #ignoreView(View)}, it is also ignored by this method.
+ *
+ * @param position Position of the item in adapter
+ * @return The child view that represents the given position or null if the position is not
+ * laid out
+ */
+ public View findViewByPosition(int position) {
+ final int childCount = getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ View child = getChildAt(i);
+ ViewHolder vh = getChildViewHolderInt(child);
+ if (vh == null) {
+ continue;
+ }
+ if (vh.getLayoutPosition() == position && !vh.shouldIgnore()
+ && (mRecyclerView.mState.isPreLayout() || !vh.isRemoved())) {
+ return child;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Temporarily detach a child view.
+ *
+ * <p>LayoutManagers may want to perform a lightweight detach operation to rearrange
+ * views currently attached to the RecyclerView. Generally LayoutManager implementations
+ * will want to use {@link #detachAndScrapView(android.view.View, RecyclerView.Recycler)}
+ * so that the detached view may be rebound and reused.</p>
+ *
+ * <p>If a LayoutManager uses this method to detach a view, it <em>must</em>
+ * {@link #attachView(android.view.View, int, RecyclerView.LayoutParams) reattach}
+ * or {@link #removeDetachedView(android.view.View) fully remove} the detached view
+ * before the LayoutManager entry point method called by RecyclerView returns.</p>
+ *
+ * @param child Child to detach
+ */
+ public void detachView(View child) {
+ final int ind = mChildHelper.indexOfChild(child);
+ if (ind >= 0) {
+ detachViewInternal(ind, child);
+ }
+ }
+
+ /**
+ * Temporarily detach a child view.
+ *
+ * <p>LayoutManagers may want to perform a lightweight detach operation to rearrange
+ * views currently attached to the RecyclerView. Generally LayoutManager implementations
+ * will want to use {@link #detachAndScrapView(android.view.View, RecyclerView.Recycler)}
+ * so that the detached view may be rebound and reused.</p>
+ *
+ * <p>If a LayoutManager uses this method to detach a view, it <em>must</em>
+ * {@link #attachView(android.view.View, int, RecyclerView.LayoutParams) reattach}
+ * or {@link #removeDetachedView(android.view.View) fully remove} the detached view
+ * before the LayoutManager entry point method called by RecyclerView returns.</p>
+ *
+ * @param index Index of the child to detach
+ */
+ public void detachViewAt(int index) {
+ detachViewInternal(index, getChildAt(index));
+ }
+
+ private void detachViewInternal(int index, View view) {
+ if (DISPATCH_TEMP_DETACH) {
+ view.dispatchStartTemporaryDetach();
+ }
+ mChildHelper.detachViewFromParent(index);
+ }
+
+ /**
+ * Reattach a previously {@link #detachView(android.view.View) detached} view.
+ * This method should not be used to reattach views that were previously
+ * {@link #detachAndScrapView(android.view.View, RecyclerView.Recycler)} scrapped}.
+ *
+ * @param child Child to reattach
+ * @param index Intended child index for child
+ * @param lp LayoutParams for child
+ */
+ public void attachView(View child, int index, LayoutParams lp) {
+ ViewHolder vh = getChildViewHolderInt(child);
+ if (vh.isRemoved()) {
+ mRecyclerView.mViewInfoStore.addToDisappearedInLayout(vh);
+ } else {
+ mRecyclerView.mViewInfoStore.removeFromDisappearedInLayout(vh);
+ }
+ mChildHelper.attachViewToParent(child, index, lp, vh.isRemoved());
+ if (DISPATCH_TEMP_DETACH) {
+ child.dispatchFinishTemporaryDetach();
+ }
+ }
+
+ /**
+ * Reattach a previously {@link #detachView(android.view.View) detached} view.
+ * This method should not be used to reattach views that were previously
+ * {@link #detachAndScrapView(android.view.View, RecyclerView.Recycler)} scrapped}.
+ *
+ * @param child Child to reattach
+ * @param index Intended child index for child
+ */
+ public void attachView(View child, int index) {
+ attachView(child, index, (LayoutParams) child.getLayoutParams());
+ }
+
+ /**
+ * Reattach a previously {@link #detachView(android.view.View) detached} view.
+ * This method should not be used to reattach views that were previously
+ * {@link #detachAndScrapView(android.view.View, RecyclerView.Recycler)} scrapped}.
+ *
+ * @param child Child to reattach
+ */
+ public void attachView(View child) {
+ attachView(child, -1);
+ }
+
+ /**
+ * Finish removing a view that was previously temporarily
+ * {@link #detachView(android.view.View) detached}.
+ *
+ * @param child Detached child to remove
+ */
+ public void removeDetachedView(View child) {
+ mRecyclerView.removeDetachedView(child, false);
+ }
+
+ /**
+ * Moves a View from one position to another.
+ *
+ * @param fromIndex The View's initial index
+ * @param toIndex The View's target index
+ */
+ public void moveView(int fromIndex, int toIndex) {
+ View view = getChildAt(fromIndex);
+ if (view == null) {
+ throw new IllegalArgumentException("Cannot move a child from non-existing index:"
+ + fromIndex);
+ }
+ detachViewAt(fromIndex);
+ attachView(view, toIndex);
+ }
+
+ /**
+ * Detach a child view and add it to a {@link Recycler Recycler's} scrap heap.
+ *
+ * <p>Scrapping a view allows it to be rebound and reused to show updated or
+ * different data.</p>
+ *
+ * @param child Child to detach and scrap
+ * @param recycler Recycler to deposit the new scrap view into
+ */
+ public void detachAndScrapView(View child, Recycler recycler) {
+ int index = mChildHelper.indexOfChild(child);
+ scrapOrRecycleView(recycler, index, child);
+ }
+
+ /**
+ * Detach a child view and add it to a {@link Recycler Recycler's} scrap heap.
+ *
+ * <p>Scrapping a view allows it to be rebound and reused to show updated or
+ * different data.</p>
+ *
+ * @param index Index of child to detach and scrap
+ * @param recycler Recycler to deposit the new scrap view into
+ */
+ public void detachAndScrapViewAt(int index, Recycler recycler) {
+ final View child = getChildAt(index);
+ scrapOrRecycleView(recycler, index, child);
+ }
+
+ /**
+ * Remove a child view and recycle it using the given Recycler.
+ *
+ * @param child Child to remove and recycle
+ * @param recycler Recycler to use to recycle child
+ */
+ public void removeAndRecycleView(View child, Recycler recycler) {
+ removeView(child);
+ recycler.recycleView(child);
+ }
+
+ /**
+ * Remove a child view and recycle it using the given Recycler.
+ *
+ * @param index Index of child to remove and recycle
+ * @param recycler Recycler to use to recycle child
+ */
+ public void removeAndRecycleViewAt(int index, Recycler recycler) {
+ final View view = getChildAt(index);
+ removeViewAt(index);
+ recycler.recycleView(view);
+ }
+
+ /**
+ * Return the current number of child views attached to the parent RecyclerView.
+ * This does not include child views that were temporarily detached and/or scrapped.
+ *
+ * @return Number of attached children
+ */
+ public int getChildCount() {
+ return mChildHelper != null ? mChildHelper.getChildCount() : 0;
+ }
+
+ /**
+ * Return the child view at the given index
+ * @param index Index of child to return
+ * @return Child view at index
+ */
+ public View getChildAt(int index) {
+ return mChildHelper != null ? mChildHelper.getChildAt(index) : null;
+ }
+
+ /**
+ * Return the width measurement spec mode of the RecyclerView.
+ * <p>
+ * This value is set only if the LayoutManager opts into the auto measure api via
+ * {@link #setAutoMeasureEnabled(boolean)}.
+ * <p>
+ * When RecyclerView is running a layout, this value is always set to
+ * {@link View.MeasureSpec#EXACTLY} even if it was measured with a different spec mode.
+ *
+ * @return Width measure spec mode.
+ *
+ * @see View.MeasureSpec#getMode(int)
+ * @see View#onMeasure(int, int)
+ */
+ public int getWidthMode() {
+ return mWidthMode;
+ }
+
+ /**
+ * Return the height measurement spec mode of the RecyclerView.
+ * <p>
+ * This value is set only if the LayoutManager opts into the auto measure api via
+ * {@link #setAutoMeasureEnabled(boolean)}.
+ * <p>
+ * When RecyclerView is running a layout, this value is always set to
+ * {@link View.MeasureSpec#EXACTLY} even if it was measured with a different spec mode.
+ *
+ * @return Height measure spec mode.
+ *
+ * @see View.MeasureSpec#getMode(int)
+ * @see View#onMeasure(int, int)
+ */
+ public int getHeightMode() {
+ return mHeightMode;
+ }
+
+ /**
+ * Return the width of the parent RecyclerView
+ *
+ * @return Width in pixels
+ */
+ public int getWidth() {
+ return mWidth;
+ }
+
+ /**
+ * Return the height of the parent RecyclerView
+ *
+ * @return Height in pixels
+ */
+ public int getHeight() {
+ return mHeight;
+ }
+
+ /**
+ * Return the left padding of the parent RecyclerView
+ *
+ * @return Padding in pixels
+ */
+ public int getPaddingLeft() {
+ return mRecyclerView != null ? mRecyclerView.getPaddingLeft() : 0;
+ }
+
+ /**
+ * Return the top padding of the parent RecyclerView
+ *
+ * @return Padding in pixels
+ */
+ public int getPaddingTop() {
+ return mRecyclerView != null ? mRecyclerView.getPaddingTop() : 0;
+ }
+
+ /**
+ * Return the right padding of the parent RecyclerView
+ *
+ * @return Padding in pixels
+ */
+ public int getPaddingRight() {
+ return mRecyclerView != null ? mRecyclerView.getPaddingRight() : 0;
+ }
+
+ /**
+ * Return the bottom padding of the parent RecyclerView
+ *
+ * @return Padding in pixels
+ */
+ public int getPaddingBottom() {
+ return mRecyclerView != null ? mRecyclerView.getPaddingBottom() : 0;
+ }
+
+ /**
+ * Return the start padding of the parent RecyclerView
+ *
+ * @return Padding in pixels
+ */
+ public int getPaddingStart() {
+ return mRecyclerView != null ? mRecyclerView.getPaddingStart() : 0;
+ }
+
+ /**
+ * Return the end padding of the parent RecyclerView
+ *
+ * @return Padding in pixels
+ */
+ public int getPaddingEnd() {
+ return mRecyclerView != null ? mRecyclerView.getPaddingEnd() : 0;
+ }
+
+ /**
+ * Returns true if the RecyclerView this LayoutManager is bound to has focus.
+ *
+ * @return True if the RecyclerView has focus, false otherwise.
+ * @see View#isFocused()
+ */
+ public boolean isFocused() {
+ return mRecyclerView != null && mRecyclerView.isFocused();
+ }
+
+ /**
+ * Returns true if the RecyclerView this LayoutManager is bound to has or contains focus.
+ *
+ * @return true if the RecyclerView has or contains focus
+ * @see View#hasFocus()
+ */
+ public boolean hasFocus() {
+ return mRecyclerView != null && mRecyclerView.hasFocus();
+ }
+
+ /**
+ * Returns the item View which has or contains focus.
+ *
+ * @return A direct child of RecyclerView which has focus or contains the focused child.
+ */
+ public View getFocusedChild() {
+ if (mRecyclerView == null) {
+ return null;
+ }
+ final View focused = mRecyclerView.getFocusedChild();
+ if (focused == null || mChildHelper.isHidden(focused)) {
+ return null;
+ }
+ return focused;
+ }
+
+ /**
+ * Returns the number of items in the adapter bound to the parent RecyclerView.
+ * <p>
+ * Note that this number is not necessarily equal to
+ * {@link State#getItemCount() State#getItemCount()}. In methods where {@link State} is
+ * available, you should use {@link State#getItemCount() State#getItemCount()} instead.
+ * For more details, check the documentation for
+ * {@link State#getItemCount() State#getItemCount()}.
+ *
+ * @return The number of items in the bound adapter
+ * @see State#getItemCount()
+ */
+ public int getItemCount() {
+ final Adapter a = mRecyclerView != null ? mRecyclerView.getAdapter() : null;
+ return a != null ? a.getItemCount() : 0;
+ }
+
+ /**
+ * Offset all child views attached to the parent RecyclerView by dx pixels along
+ * the horizontal axis.
+ *
+ * @param dx Pixels to offset by
+ */
+ public void offsetChildrenHorizontal(int dx) {
+ if (mRecyclerView != null) {
+ mRecyclerView.offsetChildrenHorizontal(dx);
+ }
+ }
+
+ /**
+ * Offset all child views attached to the parent RecyclerView by dy pixels along
+ * the vertical axis.
+ *
+ * @param dy Pixels to offset by
+ */
+ public void offsetChildrenVertical(int dy) {
+ if (mRecyclerView != null) {
+ mRecyclerView.offsetChildrenVertical(dy);
+ }
+ }
+
+ /**
+ * Flags a view so that it will not be scrapped or recycled.
+ * <p>
+ * Scope of ignoring a child is strictly restricted to position tracking, scrapping and
+ * recyling. Methods like {@link #removeAndRecycleAllViews(Recycler)} will ignore the child
+ * whereas {@link #removeAllViews()} or {@link #offsetChildrenHorizontal(int)} will not
+ * ignore the child.
+ * <p>
+ * Before this child can be recycled again, you have to call
+ * {@link #stopIgnoringView(View)}.
+ * <p>
+ * You can call this method only if your LayoutManger is in onLayout or onScroll callback.
+ *
+ * @param view View to ignore.
+ * @see #stopIgnoringView(View)
+ */
+ public void ignoreView(View view) {
+ if (view.getParent() != mRecyclerView || mRecyclerView.indexOfChild(view) == -1) {
+ // checking this because calling this method on a recycled or detached view may
+ // cause loss of state.
+ throw new IllegalArgumentException("View should be fully attached to be ignored");
+ }
+ final ViewHolder vh = getChildViewHolderInt(view);
+ vh.addFlags(ViewHolder.FLAG_IGNORE);
+ mRecyclerView.mViewInfoStore.removeViewHolder(vh);
+ }
+
+ /**
+ * View can be scrapped and recycled again.
+ * <p>
+ * Note that calling this method removes all information in the view holder.
+ * <p>
+ * You can call this method only if your LayoutManger is in onLayout or onScroll callback.
+ *
+ * @param view View to ignore.
+ */
+ public void stopIgnoringView(View view) {
+ final ViewHolder vh = getChildViewHolderInt(view);
+ vh.stopIgnoring();
+ vh.resetInternal();
+ vh.addFlags(ViewHolder.FLAG_INVALID);
+ }
+
+ /**
+ * Temporarily detach and scrap all currently attached child views. Views will be scrapped
+ * into the given Recycler. The Recycler may prefer to reuse scrap views before
+ * other views that were previously recycled.
+ *
+ * @param recycler Recycler to scrap views into
+ */
+ public void detachAndScrapAttachedViews(Recycler recycler) {
+ final int childCount = getChildCount();
+ for (int i = childCount - 1; i >= 0; i--) {
+ final View v = getChildAt(i);
+ scrapOrRecycleView(recycler, i, v);
+ }
+ }
+
+ private void scrapOrRecycleView(Recycler recycler, int index, View view) {
+ final ViewHolder viewHolder = getChildViewHolderInt(view);
+ if (viewHolder.shouldIgnore()) {
+ if (DEBUG) {
+ Log.d(TAG, "ignoring view " + viewHolder);
+ }
+ return;
+ }
+ if (viewHolder.isInvalid() && !viewHolder.isRemoved()
+ && !mRecyclerView.mAdapter.hasStableIds()) {
+ removeViewAt(index);
+ recycler.recycleViewHolderInternal(viewHolder);
+ } else {
+ detachViewAt(index);
+ recycler.scrapView(view);
+ mRecyclerView.mViewInfoStore.onViewDetached(viewHolder);
+ }
+ }
+
+ /**
+ * Recycles the scrapped views.
+ * <p>
+ * When a view is detached and removed, it does not trigger a ViewGroup invalidate. This is
+ * the expected behavior if scrapped views are used for animations. Otherwise, we need to
+ * call remove and invalidate RecyclerView to ensure UI update.
+ *
+ * @param recycler Recycler
+ */
+ void removeAndRecycleScrapInt(Recycler recycler) {
+ final int scrapCount = recycler.getScrapCount();
+ // Loop backward, recycler might be changed by removeDetachedView()
+ for (int i = scrapCount - 1; i >= 0; i--) {
+ final View scrap = recycler.getScrapViewAt(i);
+ final ViewHolder vh = getChildViewHolderInt(scrap);
+ if (vh.shouldIgnore()) {
+ continue;
+ }
+ // If the scrap view is animating, we need to cancel them first. If we cancel it
+ // here, ItemAnimator callback may recycle it which will cause double recycling.
+ // To avoid this, we mark it as not recycleable before calling the item animator.
+ // Since removeDetachedView calls a user API, a common mistake (ending animations on
+ // the view) may recycle it too, so we guard it before we call user APIs.
+ vh.setIsRecyclable(false);
+ if (vh.isTmpDetached()) {
+ mRecyclerView.removeDetachedView(scrap, false);
+ }
+ if (mRecyclerView.mItemAnimator != null) {
+ mRecyclerView.mItemAnimator.endAnimation(vh);
+ }
+ vh.setIsRecyclable(true);
+ recycler.quickRecycleScrapView(scrap);
+ }
+ recycler.clearScrap();
+ if (scrapCount > 0) {
+ mRecyclerView.invalidate();
+ }
+ }
+
+
+ /**
+ * Measure a child view using standard measurement policy, taking the padding
+ * of the parent RecyclerView and any added item decorations into account.
+ *
+ * <p>If the RecyclerView can be scrolled in either dimension the caller may
+ * pass 0 as the widthUsed or heightUsed parameters as they will be irrelevant.</p>
+ *
+ * @param child Child view to measure
+ * @param widthUsed Width in pixels currently consumed by other views, if relevant
+ * @param heightUsed Height in pixels currently consumed by other views, if relevant
+ */
+ public void measureChild(View child, int widthUsed, int heightUsed) {
+ final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+
+ final Rect insets = mRecyclerView.getItemDecorInsetsForChild(child);
+ widthUsed += insets.left + insets.right;
+ heightUsed += insets.top + insets.bottom;
+ final int widthSpec = getChildMeasureSpec(getWidth(), getWidthMode(),
+ getPaddingLeft() + getPaddingRight() + widthUsed, lp.width,
+ canScrollHorizontally());
+ final int heightSpec = getChildMeasureSpec(getHeight(), getHeightMode(),
+ getPaddingTop() + getPaddingBottom() + heightUsed, lp.height,
+ canScrollVertically());
+ if (shouldMeasureChild(child, widthSpec, heightSpec, lp)) {
+ child.measure(widthSpec, heightSpec);
+ }
+ }
+
+ /**
+ * RecyclerView internally does its own View measurement caching which should help with
+ * WRAP_CONTENT.
+ * <p>
+ * Use this method if the View is already measured once in this layout pass.
+ */
+ boolean shouldReMeasureChild(View child, int widthSpec, int heightSpec, LayoutParams lp) {
+ return !mMeasurementCacheEnabled
+ || !isMeasurementUpToDate(child.getMeasuredWidth(), widthSpec, lp.width)
+ || !isMeasurementUpToDate(child.getMeasuredHeight(), heightSpec, lp.height);
+ }
+
+ // we may consider making this public
+ /**
+ * RecyclerView internally does its own View measurement caching which should help with
+ * WRAP_CONTENT.
+ * <p>
+ * Use this method if the View is not yet measured and you need to decide whether to
+ * measure this View or not.
+ */
+ boolean shouldMeasureChild(View child, int widthSpec, int heightSpec, LayoutParams lp) {
+ return child.isLayoutRequested()
+ || !mMeasurementCacheEnabled
+ || !isMeasurementUpToDate(child.getWidth(), widthSpec, lp.width)
+ || !isMeasurementUpToDate(child.getHeight(), heightSpec, lp.height);
+ }
+
+ /**
+ * In addition to the View Framework's measurement cache, RecyclerView uses its own
+ * additional measurement cache for its children to avoid re-measuring them when not
+ * necessary. It is on by default but it can be turned off via
+ * {@link #setMeasurementCacheEnabled(boolean)}.
+ *
+ * @return True if measurement cache is enabled, false otherwise.
+ *
+ * @see #setMeasurementCacheEnabled(boolean)
+ */
+ public boolean isMeasurementCacheEnabled() {
+ return mMeasurementCacheEnabled;
+ }
+
+ /**
+ * Sets whether RecyclerView should use its own measurement cache for the children. This is
+ * a more aggressive cache than the framework uses.
+ *
+ * @param measurementCacheEnabled True to enable the measurement cache, false otherwise.
+ *
+ * @see #isMeasurementCacheEnabled()
+ */
+ public void setMeasurementCacheEnabled(boolean measurementCacheEnabled) {
+ mMeasurementCacheEnabled = measurementCacheEnabled;
+ }
+
+ private static boolean isMeasurementUpToDate(int childSize, int spec, int dimension) {
+ final int specMode = MeasureSpec.getMode(spec);
+ final int specSize = MeasureSpec.getSize(spec);
+ if (dimension > 0 && childSize != dimension) {
+ return false;
+ }
+ switch (specMode) {
+ case MeasureSpec.UNSPECIFIED:
+ return true;
+ case MeasureSpec.AT_MOST:
+ return specSize >= childSize;
+ case MeasureSpec.EXACTLY:
+ return specSize == childSize;
+ }
+ return false;
+ }
+
+ /**
+ * Measure a child view using standard measurement policy, taking the padding
+ * of the parent RecyclerView, any added item decorations and the child margins
+ * into account.
+ *
+ * <p>If the RecyclerView can be scrolled in either dimension the caller may
+ * pass 0 as the widthUsed or heightUsed parameters as they will be irrelevant.</p>
+ *
+ * @param child Child view to measure
+ * @param widthUsed Width in pixels currently consumed by other views, if relevant
+ * @param heightUsed Height in pixels currently consumed by other views, if relevant
+ */
+ public void measureChildWithMargins(View child, int widthUsed, int heightUsed) {
+ final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+
+ final Rect insets = mRecyclerView.getItemDecorInsetsForChild(child);
+ widthUsed += insets.left + insets.right;
+ heightUsed += insets.top + insets.bottom;
+
+ final int widthSpec = getChildMeasureSpec(getWidth(), getWidthMode(),
+ getPaddingLeft() + getPaddingRight()
+ + lp.leftMargin + lp.rightMargin + widthUsed, lp.width,
+ canScrollHorizontally());
+ final int heightSpec = getChildMeasureSpec(getHeight(), getHeightMode(),
+ getPaddingTop() + getPaddingBottom()
+ + lp.topMargin + lp.bottomMargin + heightUsed, lp.height,
+ canScrollVertically());
+ if (shouldMeasureChild(child, widthSpec, heightSpec, lp)) {
+ child.measure(widthSpec, heightSpec);
+ }
+ }
+
+ /**
+ * Calculate a MeasureSpec value for measuring a child view in one dimension.
+ *
+ * @param parentSize Size of the parent view where the child will be placed
+ * @param padding Total space currently consumed by other elements of the parent
+ * @param childDimension Desired size of the child view, or MATCH_PARENT/WRAP_CONTENT.
+ * Generally obtained from the child view's LayoutParams
+ * @param canScroll true if the parent RecyclerView can scroll in this dimension
+ *
+ * @return a MeasureSpec value for the child view
+ * @deprecated use {@link #getChildMeasureSpec(int, int, int, int, boolean)}
+ */
+ @Deprecated
+ public static int getChildMeasureSpec(int parentSize, int padding, int childDimension,
+ boolean canScroll) {
+ int size = Math.max(0, parentSize - padding);
+ int resultSize = 0;
+ int resultMode = 0;
+ if (canScroll) {
+ if (childDimension >= 0) {
+ resultSize = childDimension;
+ resultMode = MeasureSpec.EXACTLY;
+ } else {
+ // MATCH_PARENT can't be applied since we can scroll in this dimension, wrap
+ // instead using UNSPECIFIED.
+ resultSize = 0;
+ resultMode = MeasureSpec.UNSPECIFIED;
+ }
+ } else {
+ if (childDimension >= 0) {
+ resultSize = childDimension;
+ resultMode = MeasureSpec.EXACTLY;
+ } else if (childDimension == LayoutParams.MATCH_PARENT) {
+ resultSize = size;
+ // TODO this should be my spec.
+ resultMode = MeasureSpec.EXACTLY;
+ } else if (childDimension == LayoutParams.WRAP_CONTENT) {
+ resultSize = size;
+ resultMode = MeasureSpec.AT_MOST;
+ }
+ }
+ return MeasureSpec.makeMeasureSpec(resultSize, resultMode);
+ }
+
+ /**
+ * Calculate a MeasureSpec value for measuring a child view in one dimension.
+ *
+ * @param parentSize Size of the parent view where the child will be placed
+ * @param parentMode The measurement spec mode of the parent
+ * @param padding Total space currently consumed by other elements of parent
+ * @param childDimension Desired size of the child view, or MATCH_PARENT/WRAP_CONTENT.
+ * Generally obtained from the child view's LayoutParams
+ * @param canScroll true if the parent RecyclerView can scroll in this dimension
+ *
+ * @return a MeasureSpec value for the child view
+ */
+ public static int getChildMeasureSpec(int parentSize, int parentMode, int padding,
+ int childDimension, boolean canScroll) {
+ int size = Math.max(0, parentSize - padding);
+ int resultSize = 0;
+ int resultMode = 0;
+ if (canScroll) {
+ if (childDimension >= 0) {
+ resultSize = childDimension;
+ resultMode = MeasureSpec.EXACTLY;
+ } else if (childDimension == LayoutParams.MATCH_PARENT) {
+ switch (parentMode) {
+ case MeasureSpec.AT_MOST:
+ case MeasureSpec.EXACTLY:
+ resultSize = size;
+ resultMode = parentMode;
+ break;
+ case MeasureSpec.UNSPECIFIED:
+ resultSize = 0;
+ resultMode = MeasureSpec.UNSPECIFIED;
+ break;
+ }
+ } else if (childDimension == LayoutParams.WRAP_CONTENT) {
+ resultSize = 0;
+ resultMode = MeasureSpec.UNSPECIFIED;
+ }
+ } else {
+ if (childDimension >= 0) {
+ resultSize = childDimension;
+ resultMode = MeasureSpec.EXACTLY;
+ } else if (childDimension == LayoutParams.MATCH_PARENT) {
+ resultSize = size;
+ resultMode = parentMode;
+ } else if (childDimension == LayoutParams.WRAP_CONTENT) {
+ resultSize = size;
+ if (parentMode == MeasureSpec.AT_MOST || parentMode == MeasureSpec.EXACTLY) {
+ resultMode = MeasureSpec.AT_MOST;
+ } else {
+ resultMode = MeasureSpec.UNSPECIFIED;
+ }
+
+ }
+ }
+ //noinspection WrongConstant
+ return MeasureSpec.makeMeasureSpec(resultSize, resultMode);
+ }
+
+ /**
+ * Returns the measured width of the given child, plus the additional size of
+ * any insets applied by {@link ItemDecoration ItemDecorations}.
+ *
+ * @param child Child view to query
+ * @return child's measured width plus <code>ItemDecoration</code> insets
+ *
+ * @see View#getMeasuredWidth()
+ */
+ public int getDecoratedMeasuredWidth(View child) {
+ final Rect insets = ((LayoutParams) child.getLayoutParams()).mDecorInsets;
+ return child.getMeasuredWidth() + insets.left + insets.right;
+ }
+
+ /**
+ * Returns the measured height of the given child, plus the additional size of
+ * any insets applied by {@link ItemDecoration ItemDecorations}.
+ *
+ * @param child Child view to query
+ * @return child's measured height plus <code>ItemDecoration</code> insets
+ *
+ * @see View#getMeasuredHeight()
+ */
+ public int getDecoratedMeasuredHeight(View child) {
+ final Rect insets = ((LayoutParams) child.getLayoutParams()).mDecorInsets;
+ return child.getMeasuredHeight() + insets.top + insets.bottom;
+ }
+
+ /**
+ * Lay out the given child view within the RecyclerView using coordinates that
+ * include any current {@link ItemDecoration ItemDecorations}.
+ *
+ * <p>LayoutManagers should prefer working in sizes and coordinates that include
+ * item decoration insets whenever possible. This allows the LayoutManager to effectively
+ * ignore decoration insets within measurement and layout code. See the following
+ * methods:</p>
+ * <ul>
+ * <li>{@link #layoutDecoratedWithMargins(View, int, int, int, int)}</li>
+ * <li>{@link #getDecoratedBoundsWithMargins(View, Rect)}</li>
+ * <li>{@link #measureChild(View, int, int)}</li>
+ * <li>{@link #measureChildWithMargins(View, int, int)}</li>
+ * <li>{@link #getDecoratedLeft(View)}</li>
+ * <li>{@link #getDecoratedTop(View)}</li>
+ * <li>{@link #getDecoratedRight(View)}</li>
+ * <li>{@link #getDecoratedBottom(View)}</li>
+ * <li>{@link #getDecoratedMeasuredWidth(View)}</li>
+ * <li>{@link #getDecoratedMeasuredHeight(View)}</li>
+ * </ul>
+ *
+ * @param child Child to lay out
+ * @param left Left edge, with item decoration insets included
+ * @param top Top edge, with item decoration insets included
+ * @param right Right edge, with item decoration insets included
+ * @param bottom Bottom edge, with item decoration insets included
+ *
+ * @see View#layout(int, int, int, int)
+ * @see #layoutDecoratedWithMargins(View, int, int, int, int)
+ */
+ public void layoutDecorated(View child, int left, int top, int right, int bottom) {
+ final Rect insets = ((LayoutParams) child.getLayoutParams()).mDecorInsets;
+ child.layout(left + insets.left, top + insets.top, right - insets.right,
+ bottom - insets.bottom);
+ }
+
+ /**
+ * Lay out the given child view within the RecyclerView using coordinates that
+ * include any current {@link ItemDecoration ItemDecorations} and margins.
+ *
+ * <p>LayoutManagers should prefer working in sizes and coordinates that include
+ * item decoration insets whenever possible. This allows the LayoutManager to effectively
+ * ignore decoration insets within measurement and layout code. See the following
+ * methods:</p>
+ * <ul>
+ * <li>{@link #layoutDecorated(View, int, int, int, int)}</li>
+ * <li>{@link #measureChild(View, int, int)}</li>
+ * <li>{@link #measureChildWithMargins(View, int, int)}</li>
+ * <li>{@link #getDecoratedLeft(View)}</li>
+ * <li>{@link #getDecoratedTop(View)}</li>
+ * <li>{@link #getDecoratedRight(View)}</li>
+ * <li>{@link #getDecoratedBottom(View)}</li>
+ * <li>{@link #getDecoratedMeasuredWidth(View)}</li>
+ * <li>{@link #getDecoratedMeasuredHeight(View)}</li>
+ * </ul>
+ *
+ * @param child Child to lay out
+ * @param left Left edge, with item decoration insets and left margin included
+ * @param top Top edge, with item decoration insets and top margin included
+ * @param right Right edge, with item decoration insets and right margin included
+ * @param bottom Bottom edge, with item decoration insets and bottom margin included
+ *
+ * @see View#layout(int, int, int, int)
+ * @see #layoutDecorated(View, int, int, int, int)
+ */
+ public void layoutDecoratedWithMargins(View child, int left, int top, int right,
+ int bottom) {
+ final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+ final Rect insets = lp.mDecorInsets;
+ child.layout(left + insets.left + lp.leftMargin, top + insets.top + lp.topMargin,
+ right - insets.right - lp.rightMargin,
+ bottom - insets.bottom - lp.bottomMargin);
+ }
+
+ /**
+ * Calculates the bounding box of the View while taking into account its matrix changes
+ * (translation, scale etc) with respect to the RecyclerView.
+ * <p>
+ * If {@code includeDecorInsets} is {@code true}, they are applied first before applying
+ * the View's matrix so that the decor offsets also go through the same transformation.
+ *
+ * @param child The ItemView whose bounding box should be calculated.
+ * @param includeDecorInsets True if the decor insets should be included in the bounding box
+ * @param out The rectangle into which the output will be written.
+ */
+ public void getTransformedBoundingBox(View child, boolean includeDecorInsets, Rect out) {
+ if (includeDecorInsets) {
+ Rect insets = ((LayoutParams) child.getLayoutParams()).mDecorInsets;
+ out.set(-insets.left, -insets.top,
+ child.getWidth() + insets.right, child.getHeight() + insets.bottom);
+ } else {
+ out.set(0, 0, child.getWidth(), child.getHeight());
+ }
+
+ if (mRecyclerView != null) {
+ final Matrix childMatrix = child.getMatrix();
+ if (childMatrix != null && !childMatrix.isIdentity()) {
+ final RectF tempRectF = mRecyclerView.mTempRectF;
+ tempRectF.set(out);
+ childMatrix.mapRect(tempRectF);
+ out.set(
+ (int) Math.floor(tempRectF.left),
+ (int) Math.floor(tempRectF.top),
+ (int) Math.ceil(tempRectF.right),
+ (int) Math.ceil(tempRectF.bottom)
+ );
+ }
+ }
+ out.offset(child.getLeft(), child.getTop());
+ }
+
+ /**
+ * Returns the bounds of the view including its decoration and margins.
+ *
+ * @param view The view element to check
+ * @param outBounds A rect that will receive the bounds of the element including its
+ * decoration and margins.
+ */
+ public void getDecoratedBoundsWithMargins(View view, Rect outBounds) {
+ RecyclerView.getDecoratedBoundsWithMarginsInt(view, outBounds);
+ }
+
+ /**
+ * Returns the left edge of the given child view within its parent, offset by any applied
+ * {@link ItemDecoration ItemDecorations}.
+ *
+ * @param child Child to query
+ * @return Child left edge with offsets applied
+ * @see #getLeftDecorationWidth(View)
+ */
+ public int getDecoratedLeft(View child) {
+ return child.getLeft() - getLeftDecorationWidth(child);
+ }
+
+ /**
+ * Returns the top edge of the given child view within its parent, offset by any applied
+ * {@link ItemDecoration ItemDecorations}.
+ *
+ * @param child Child to query
+ * @return Child top edge with offsets applied
+ * @see #getTopDecorationHeight(View)
+ */
+ public int getDecoratedTop(View child) {
+ return child.getTop() - getTopDecorationHeight(child);
+ }
+
+ /**
+ * Returns the right edge of the given child view within its parent, offset by any applied
+ * {@link ItemDecoration ItemDecorations}.
+ *
+ * @param child Child to query
+ * @return Child right edge with offsets applied
+ * @see #getRightDecorationWidth(View)
+ */
+ public int getDecoratedRight(View child) {
+ return child.getRight() + getRightDecorationWidth(child);
+ }
+
+ /**
+ * Returns the bottom edge of the given child view within its parent, offset by any applied
+ * {@link ItemDecoration ItemDecorations}.
+ *
+ * @param child Child to query
+ * @return Child bottom edge with offsets applied
+ * @see #getBottomDecorationHeight(View)
+ */
+ public int getDecoratedBottom(View child) {
+ return child.getBottom() + getBottomDecorationHeight(child);
+ }
+
+ /**
+ * Calculates the item decor insets applied to the given child and updates the provided
+ * Rect instance with the inset values.
+ * <ul>
+ * <li>The Rect's left is set to the total width of left decorations.</li>
+ * <li>The Rect's top is set to the total height of top decorations.</li>
+ * <li>The Rect's right is set to the total width of right decorations.</li>
+ * <li>The Rect's bottom is set to total height of bottom decorations.</li>
+ * </ul>
+ * <p>
+ * Note that item decorations are automatically calculated when one of the LayoutManager's
+ * measure child methods is called. If you need to measure the child with custom specs via
+ * {@link View#measure(int, int)}, you can use this method to get decorations.
+ *
+ * @param child The child view whose decorations should be calculated
+ * @param outRect The Rect to hold result values
+ */
+ public void calculateItemDecorationsForChild(View child, Rect outRect) {
+ if (mRecyclerView == null) {
+ outRect.set(0, 0, 0, 0);
+ return;
+ }
+ Rect insets = mRecyclerView.getItemDecorInsetsForChild(child);
+ outRect.set(insets);
+ }
+
+ /**
+ * Returns the total height of item decorations applied to child's top.
+ * <p>
+ * Note that this value is not updated until the View is measured or
+ * {@link #calculateItemDecorationsForChild(View, Rect)} is called.
+ *
+ * @param child Child to query
+ * @return The total height of item decorations applied to the child's top.
+ * @see #getDecoratedTop(View)
+ * @see #calculateItemDecorationsForChild(View, Rect)
+ */
+ public int getTopDecorationHeight(View child) {
+ return ((LayoutParams) child.getLayoutParams()).mDecorInsets.top;
+ }
+
+ /**
+ * Returns the total height of item decorations applied to child's bottom.
+ * <p>
+ * Note that this value is not updated until the View is measured or
+ * {@link #calculateItemDecorationsForChild(View, Rect)} is called.
+ *
+ * @param child Child to query
+ * @return The total height of item decorations applied to the child's bottom.
+ * @see #getDecoratedBottom(View)
+ * @see #calculateItemDecorationsForChild(View, Rect)
+ */
+ public int getBottomDecorationHeight(View child) {
+ return ((LayoutParams) child.getLayoutParams()).mDecorInsets.bottom;
+ }
+
+ /**
+ * Returns the total width of item decorations applied to child's left.
+ * <p>
+ * Note that this value is not updated until the View is measured or
+ * {@link #calculateItemDecorationsForChild(View, Rect)} is called.
+ *
+ * @param child Child to query
+ * @return The total width of item decorations applied to the child's left.
+ * @see #getDecoratedLeft(View)
+ * @see #calculateItemDecorationsForChild(View, Rect)
+ */
+ public int getLeftDecorationWidth(View child) {
+ return ((LayoutParams) child.getLayoutParams()).mDecorInsets.left;
+ }
+
+ /**
+ * Returns the total width of item decorations applied to child's right.
+ * <p>
+ * Note that this value is not updated until the View is measured or
+ * {@link #calculateItemDecorationsForChild(View, Rect)} is called.
+ *
+ * @param child Child to query
+ * @return The total width of item decorations applied to the child's right.
+ * @see #getDecoratedRight(View)
+ * @see #calculateItemDecorationsForChild(View, Rect)
+ */
+ public int getRightDecorationWidth(View child) {
+ return ((LayoutParams) child.getLayoutParams()).mDecorInsets.right;
+ }
+
+ /**
+ * Called when searching for a focusable view in the given direction has failed
+ * for the current content of the RecyclerView.
+ *
+ * <p>This is the LayoutManager's opportunity to populate views in the given direction
+ * to fulfill the request if it can. The LayoutManager should attach and return
+ * the view to be focused. The default implementation returns null.</p>
+ *
+ * @param focused The currently focused view
+ * @param direction One of {@link View#FOCUS_UP}, {@link View#FOCUS_DOWN},
+ * {@link View#FOCUS_LEFT}, {@link View#FOCUS_RIGHT},
+ * {@link View#FOCUS_BACKWARD}, {@link View#FOCUS_FORWARD}
+ * or 0 for not applicable
+ * @param recycler The recycler to use for obtaining views for currently offscreen items
+ * @param state Transient state of RecyclerView
+ * @return The chosen view to be focused
+ */
+ @Nullable
+ public View onFocusSearchFailed(View focused, int direction, Recycler recycler,
+ State state) {
+ return null;
+ }
+
+ /**
+ * This method gives a LayoutManager an opportunity to intercept the initial focus search
+ * before the default behavior of {@link FocusFinder} is used. If this method returns
+ * null FocusFinder will attempt to find a focusable child view. If it fails
+ * then {@link #onFocusSearchFailed(View, int, RecyclerView.Recycler, RecyclerView.State)}
+ * will be called to give the LayoutManager an opportunity to add new views for items
+ * that did not have attached views representing them. The LayoutManager should not add
+ * or remove views from this method.
+ *
+ * @param focused The currently focused view
+ * @param direction One of {@link View#FOCUS_UP}, {@link View#FOCUS_DOWN},
+ * {@link View#FOCUS_LEFT}, {@link View#FOCUS_RIGHT},
+ * {@link View#FOCUS_BACKWARD}, {@link View#FOCUS_FORWARD}
+ * @return A descendant view to focus or null to fall back to default behavior.
+ * The default implementation returns null.
+ */
+ public View onInterceptFocusSearch(View focused, int direction) {
+ return null;
+ }
+
+ /**
+ * Called when a child of the RecyclerView wants a particular rectangle to be positioned
+ * onto the screen. See {@link ViewParent#requestChildRectangleOnScreen(android.view.View,
+ * android.graphics.Rect, boolean)} for more details.
+ *
+ * <p>The base implementation will attempt to perform a standard programmatic scroll
+ * to bring the given rect into view, within the padded area of the RecyclerView.</p>
+ *
+ * @param child The direct child making the request.
+ * @param rect The rectangle in the child's coordinates the child
+ * wishes to be on the screen.
+ * @param immediate True to forbid animated or delayed scrolling,
+ * false otherwise
+ * @return Whether the group scrolled to handle the operation
+ */
+ public boolean requestChildRectangleOnScreen(RecyclerView parent, View child, Rect rect,
+ boolean immediate) {
+ final int parentLeft = getPaddingLeft();
+ final int parentTop = getPaddingTop();
+ final int parentRight = getWidth() - getPaddingRight();
+ final int parentBottom = getHeight() - getPaddingBottom();
+ final int childLeft = child.getLeft() + rect.left - child.getScrollX();
+ final int childTop = child.getTop() + rect.top - child.getScrollY();
+ final int childRight = childLeft + rect.width();
+ final int childBottom = childTop + rect.height();
+
+ final int offScreenLeft = Math.min(0, childLeft - parentLeft);
+ final int offScreenTop = Math.min(0, childTop - parentTop);
+ final int offScreenRight = Math.max(0, childRight - parentRight);
+ final int offScreenBottom = Math.max(0, childBottom - parentBottom);
+
+ // Favor the "start" layout direction over the end when bringing one side or the other
+ // of a large rect into view. If we decide to bring in end because start is already
+ // visible, limit the scroll such that start won't go out of bounds.
+ final int dx;
+ if (getLayoutDirection() == View.LAYOUT_DIRECTION_RTL) {
+ dx = offScreenRight != 0 ? offScreenRight
+ : Math.max(offScreenLeft, childRight - parentRight);
+ } else {
+ dx = offScreenLeft != 0 ? offScreenLeft
+ : Math.min(childLeft - parentLeft, offScreenRight);
+ }
+
+ // Favor bringing the top into view over the bottom. If top is already visible and
+ // we should scroll to make bottom visible, make sure top does not go out of bounds.
+ final int dy = offScreenTop != 0 ? offScreenTop
+ : Math.min(childTop - parentTop, offScreenBottom);
+
+ if (dx != 0 || dy != 0) {
+ if (immediate) {
+ parent.scrollBy(dx, dy);
+ } else {
+ parent.smoothScrollBy(dx, dy);
+ }
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * @deprecated Use {@link #onRequestChildFocus(RecyclerView, State, View, View)}
+ */
+ @Deprecated
+ public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) {
+ // eat the request if we are in the middle of a scroll or layout
+ return isSmoothScrolling() || parent.isComputingLayout();
+ }
+
+ /**
+ * Called when a descendant view of the RecyclerView requests focus.
+ *
+ * <p>A LayoutManager wishing to keep focused views aligned in a specific
+ * portion of the view may implement that behavior in an override of this method.</p>
+ *
+ * <p>If the LayoutManager executes different behavior that should override the default
+ * behavior of scrolling the focused child on screen instead of running alongside it,
+ * this method should return true.</p>
+ *
+ * @param parent The RecyclerView hosting this LayoutManager
+ * @param state Current state of RecyclerView
+ * @param child Direct child of the RecyclerView containing the newly focused view
+ * @param focused The newly focused view. This may be the same view as child or it may be
+ * null
+ * @return true if the default scroll behavior should be suppressed
+ */
+ public boolean onRequestChildFocus(RecyclerView parent, State state, View child,
+ View focused) {
+ return onRequestChildFocus(parent, child, focused);
+ }
+
+ /**
+ * Called if the RecyclerView this LayoutManager is bound to has a different adapter set.
+ * The LayoutManager may use this opportunity to clear caches and configure state such
+ * that it can relayout appropriately with the new data and potentially new view types.
+ *
+ * <p>The default implementation removes all currently attached views.</p>
+ *
+ * @param oldAdapter The previous adapter instance. Will be null if there was previously no
+ * adapter.
+ * @param newAdapter The new adapter instance. Might be null if
+ * {@link #setAdapter(RecyclerView.Adapter)} is called with {@code null}.
+ */
+ public void onAdapterChanged(Adapter oldAdapter, Adapter newAdapter) {
+ }
+
+ /**
+ * Called to populate focusable views within the RecyclerView.
+ *
+ * <p>The LayoutManager implementation should return <code>true</code> if the default
+ * behavior of {@link ViewGroup#addFocusables(java.util.ArrayList, int)} should be
+ * suppressed.</p>
+ *
+ * <p>The default implementation returns <code>false</code> to trigger RecyclerView
+ * to fall back to the default ViewGroup behavior.</p>
+ *
+ * @param recyclerView The RecyclerView hosting this LayoutManager
+ * @param views List of output views. This method should add valid focusable views
+ * to this list.
+ * @param direction One of {@link View#FOCUS_UP}, {@link View#FOCUS_DOWN},
+ * {@link View#FOCUS_LEFT}, {@link View#FOCUS_RIGHT},
+ * {@link View#FOCUS_BACKWARD}, {@link View#FOCUS_FORWARD}
+ * @param focusableMode The type of focusables to be added.
+ *
+ * @return true to suppress the default behavior, false to add default focusables after
+ * this method returns.
+ *
+ * @see #FOCUSABLES_ALL
+ * @see #FOCUSABLES_TOUCH_MODE
+ */
+ public boolean onAddFocusables(RecyclerView recyclerView, ArrayList<View> views,
+ int direction, int focusableMode) {
+ return false;
+ }
+
+ /**
+ * Called when {@link Adapter#notifyDataSetChanged()} is triggered instead of giving
+ * detailed information on what has actually changed.
+ *
+ * @param recyclerView
+ */
+ public void onItemsChanged(RecyclerView recyclerView) {
+ }
+
+ /**
+ * Called when items have been added to the adapter. The LayoutManager may choose to
+ * requestLayout if the inserted items would require refreshing the currently visible set
+ * of child views. (e.g. currently empty space would be filled by appended items, etc.)
+ *
+ * @param recyclerView
+ * @param positionStart
+ * @param itemCount
+ */
+ public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) {
+ }
+
+ /**
+ * Called when items have been removed from the adapter.
+ *
+ * @param recyclerView
+ * @param positionStart
+ * @param itemCount
+ */
+ public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) {
+ }
+
+ /**
+ * Called when items have been changed in the adapter.
+ * To receive payload, override {@link #onItemsUpdated(RecyclerView, int, int, Object)}
+ * instead, then this callback will not be invoked.
+ *
+ * @param recyclerView
+ * @param positionStart
+ * @param itemCount
+ */
+ public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) {
+ }
+
+ /**
+ * Called when items have been changed in the adapter and with optional payload.
+ * Default implementation calls {@link #onItemsUpdated(RecyclerView, int, int)}.
+ *
+ * @param recyclerView
+ * @param positionStart
+ * @param itemCount
+ * @param payload
+ */
+ public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount,
+ Object payload) {
+ onItemsUpdated(recyclerView, positionStart, itemCount);
+ }
+
+ /**
+ * Called when an item is moved withing the adapter.
+ * <p>
+ * Note that, an item may also change position in response to another ADD/REMOVE/MOVE
+ * operation. This callback is only called if and only if {@link Adapter#notifyItemMoved}
+ * is called.
+ *
+ * @param recyclerView
+ * @param from
+ * @param to
+ * @param itemCount
+ */
+ public void onItemsMoved(RecyclerView recyclerView, int from, int to, int itemCount) {
+
+ }
+
+
+ /**
+ * <p>Override this method if you want to support scroll bars.</p>
+ *
+ * <p>Read {@link RecyclerView#computeHorizontalScrollExtent()} for details.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * @param state Current state of RecyclerView
+ * @return The horizontal extent of the scrollbar's thumb
+ * @see RecyclerView#computeHorizontalScrollExtent()
+ */
+ public int computeHorizontalScrollExtent(State state) {
+ return 0;
+ }
+
+ /**
+ * <p>Override this method if you want to support scroll bars.</p>
+ *
+ * <p>Read {@link RecyclerView#computeHorizontalScrollOffset()} for details.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * @param state Current State of RecyclerView where you can find total item count
+ * @return The horizontal offset of the scrollbar's thumb
+ * @see RecyclerView#computeHorizontalScrollOffset()
+ */
+ public int computeHorizontalScrollOffset(State state) {
+ return 0;
+ }
+
+ /**
+ * <p>Override this method if you want to support scroll bars.</p>
+ *
+ * <p>Read {@link RecyclerView#computeHorizontalScrollRange()} for details.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * @param state Current State of RecyclerView where you can find total item count
+ * @return The total horizontal range represented by the vertical scrollbar
+ * @see RecyclerView#computeHorizontalScrollRange()
+ */
+ public int computeHorizontalScrollRange(State state) {
+ return 0;
+ }
+
+ /**
+ * <p>Override this method if you want to support scroll bars.</p>
+ *
+ * <p>Read {@link RecyclerView#computeVerticalScrollExtent()} for details.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * @param state Current state of RecyclerView
+ * @return The vertical extent of the scrollbar's thumb
+ * @see RecyclerView#computeVerticalScrollExtent()
+ */
+ public int computeVerticalScrollExtent(State state) {
+ return 0;
+ }
+
+ /**
+ * <p>Override this method if you want to support scroll bars.</p>
+ *
+ * <p>Read {@link RecyclerView#computeVerticalScrollOffset()} for details.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * @param state Current State of RecyclerView where you can find total item count
+ * @return The vertical offset of the scrollbar's thumb
+ * @see RecyclerView#computeVerticalScrollOffset()
+ */
+ public int computeVerticalScrollOffset(State state) {
+ return 0;
+ }
+
+ /**
+ * <p>Override this method if you want to support scroll bars.</p>
+ *
+ * <p>Read {@link RecyclerView#computeVerticalScrollRange()} for details.</p>
+ *
+ * <p>Default implementation returns 0.</p>
+ *
+ * @param state Current State of RecyclerView where you can find total item count
+ * @return The total vertical range represented by the vertical scrollbar
+ * @see RecyclerView#computeVerticalScrollRange()
+ */
+ public int computeVerticalScrollRange(State state) {
+ return 0;
+ }
+
+ /**
+ * Measure the attached RecyclerView. Implementations must call
+ * {@link #setMeasuredDimension(int, int)} before returning.
+ *
+ * <p>The default implementation will handle EXACTLY measurements and respect
+ * the minimum width and height properties of the host RecyclerView if measured
+ * as UNSPECIFIED. AT_MOST measurements will be treated as EXACTLY and the RecyclerView
+ * will consume all available space.</p>
+ *
+ * @param recycler Recycler
+ * @param state Transient state of RecyclerView
+ * @param widthSpec Width {@link android.view.View.MeasureSpec}
+ * @param heightSpec Height {@link android.view.View.MeasureSpec}
+ */
+ public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) {
+ mRecyclerView.defaultOnMeasure(widthSpec, heightSpec);
+ }
+
+ /**
+ * {@link View#setMeasuredDimension(int, int) Set the measured dimensions} of the
+ * host RecyclerView.
+ *
+ * @param widthSize Measured width
+ * @param heightSize Measured height
+ */
+ public void setMeasuredDimension(int widthSize, int heightSize) {
+ mRecyclerView.setMeasuredDimension(widthSize, heightSize);
+ }
+
+ /**
+ * @return The host RecyclerView's {@link View#getMinimumWidth()}
+ */
+ public int getMinimumWidth() {
+ return mRecyclerView.getMinimumWidth();
+ }
+
+ /**
+ * @return The host RecyclerView's {@link View#getMinimumHeight()}
+ */
+ public int getMinimumHeight() {
+ return mRecyclerView.getMinimumHeight();
+ }
+ /**
+ * <p>Called when the LayoutManager should save its state. This is a good time to save your
+ * scroll position, configuration and anything else that may be required to restore the same
+ * layout state if the LayoutManager is recreated.</p>
+ * <p>RecyclerView does NOT verify if the LayoutManager has changed between state save and
+ * restore. This will let you share information between your LayoutManagers but it is also
+ * your responsibility to make sure they use the same parcelable class.</p>
+ *
+ * @return Necessary information for LayoutManager to be able to restore its state
+ */
+ public Parcelable onSaveInstanceState() {
+ return null;
+ }
+
+
+ public void onRestoreInstanceState(Parcelable state) {
+
+ }
+
+ void stopSmoothScroller() {
+ if (mSmoothScroller != null) {
+ mSmoothScroller.stop();
+ }
+ }
+
+ private void onSmoothScrollerStopped(SmoothScroller smoothScroller) {
+ if (mSmoothScroller == smoothScroller) {
+ mSmoothScroller = null;
+ }
+ }
+
+ /**
+ * RecyclerView calls this method to notify LayoutManager that scroll state has changed.
+ *
+ * @param state The new scroll state for RecyclerView
+ */
+ public void onScrollStateChanged(int state) {
+ }
+
+ /**
+ * Removes all views and recycles them using the given recycler.
+ * <p>
+ * If you want to clean cached views as well, you should call {@link Recycler#clear()} too.
+ * <p>
+ * If a View is marked as "ignored", it is not removed nor recycled.
+ *
+ * @param recycler Recycler to use to recycle children
+ * @see #removeAndRecycleView(View, Recycler)
+ * @see #removeAndRecycleViewAt(int, Recycler)
+ * @see #ignoreView(View)
+ */
+ public void removeAndRecycleAllViews(Recycler recycler) {
+ for (int i = getChildCount() - 1; i >= 0; i--) {
+ final View view = getChildAt(i);
+ if (!getChildViewHolderInt(view).shouldIgnore()) {
+ removeAndRecycleViewAt(i, recycler);
+ }
+ }
+ }
+
+ // called by accessibility delegate
+ void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
+ onInitializeAccessibilityNodeInfo(mRecyclerView.mRecycler, mRecyclerView.mState, info);
+ }
+
+ /**
+ * Called by the AccessibilityDelegate when the information about the current layout should
+ * be populated.
+ * <p>
+ * Default implementation adds a {@link
+ * android.view.accessibility.AccessibilityNodeInfo.CollectionInfo}.
+ * <p>
+ * You should override
+ * {@link #getRowCountForAccessibility(RecyclerView.Recycler, RecyclerView.State)},
+ * {@link #getColumnCountForAccessibility(RecyclerView.Recycler, RecyclerView.State)},
+ * {@link #isLayoutHierarchical(RecyclerView.Recycler, RecyclerView.State)} and
+ * {@link #getSelectionModeForAccessibility(RecyclerView.Recycler, RecyclerView.State)} for
+ * more accurate accessibility information.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @param info The info that should be filled by the LayoutManager
+ * @see View#onInitializeAccessibilityNodeInfo(
+ *android.view.accessibility.AccessibilityNodeInfo)
+ * @see #getRowCountForAccessibility(RecyclerView.Recycler, RecyclerView.State)
+ * @see #getColumnCountForAccessibility(RecyclerView.Recycler, RecyclerView.State)
+ * @see #isLayoutHierarchical(RecyclerView.Recycler, RecyclerView.State)
+ * @see #getSelectionModeForAccessibility(RecyclerView.Recycler, RecyclerView.State)
+ */
+ public void onInitializeAccessibilityNodeInfo(Recycler recycler, State state,
+ AccessibilityNodeInfo info) {
+ if (mRecyclerView.canScrollVertically(-1)
+ || mRecyclerView.canScrollHorizontally(-1)) {
+ info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
+ info.setScrollable(true);
+ }
+ if (mRecyclerView.canScrollVertically(1)
+ || mRecyclerView.canScrollHorizontally(1)) {
+ info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
+ info.setScrollable(true);
+ }
+ final AccessibilityNodeInfo.CollectionInfo collectionInfo =
+ AccessibilityNodeInfo.CollectionInfo
+ .obtain(getRowCountForAccessibility(recycler, state),
+ getColumnCountForAccessibility(recycler, state),
+ isLayoutHierarchical(recycler, state),
+ getSelectionModeForAccessibility(recycler, state));
+ info.setCollectionInfo(collectionInfo);
+ }
+
+ // called by accessibility delegate
+ public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
+ onInitializeAccessibilityEvent(mRecyclerView.mRecycler, mRecyclerView.mState, event);
+ }
+
+ /**
+ * Called by the accessibility delegate to initialize an accessibility event.
+ * <p>
+ * Default implementation adds item count and scroll information to the event.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @param event The event instance to initialize
+ * @see View#onInitializeAccessibilityEvent(android.view.accessibility.AccessibilityEvent)
+ */
+ public void onInitializeAccessibilityEvent(Recycler recycler, State state,
+ AccessibilityEvent event) {
+ if (mRecyclerView == null || event == null) {
+ return;
+ }
+ event.setScrollable(mRecyclerView.canScrollVertically(1)
+ || mRecyclerView.canScrollVertically(-1)
+ || mRecyclerView.canScrollHorizontally(-1)
+ || mRecyclerView.canScrollHorizontally(1));
+
+ if (mRecyclerView.mAdapter != null) {
+ event.setItemCount(mRecyclerView.mAdapter.getItemCount());
+ }
+ }
+
+ // called by accessibility delegate
+ void onInitializeAccessibilityNodeInfoForItem(View host, AccessibilityNodeInfo info) {
+ final ViewHolder vh = getChildViewHolderInt(host);
+ // avoid trying to create accessibility node info for removed children
+ if (vh != null && !vh.isRemoved() && !mChildHelper.isHidden(vh.itemView)) {
+ onInitializeAccessibilityNodeInfoForItem(mRecyclerView.mRecycler,
+ mRecyclerView.mState, host, info);
+ }
+ }
+
+ /**
+ * Called by the AccessibilityDelegate when the accessibility information for a specific
+ * item should be populated.
+ * <p>
+ * Default implementation adds basic positioning information about the item.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @param host The child for which accessibility node info should be populated
+ * @param info The info to fill out about the item
+ * @see android.widget.AbsListView#onInitializeAccessibilityNodeInfoForItem(View, int,
+ * android.view.accessibility.AccessibilityNodeInfo)
+ */
+ public void onInitializeAccessibilityNodeInfoForItem(Recycler recycler, State state,
+ View host, AccessibilityNodeInfo info) {
+ int rowIndexGuess = canScrollVertically() ? getPosition(host) : 0;
+ int columnIndexGuess = canScrollHorizontally() ? getPosition(host) : 0;
+ final AccessibilityNodeInfo.CollectionItemInfo itemInfo =
+ AccessibilityNodeInfo.CollectionItemInfo.obtain(rowIndexGuess, 1,
+ columnIndexGuess, 1, false, false);
+ info.setCollectionItemInfo(itemInfo);
+ }
+
+ /**
+ * A LayoutManager can call this method to force RecyclerView to run simple animations in
+ * the next layout pass, even if there is not any trigger to do so. (e.g. adapter data
+ * change).
+ * <p>
+ * Note that, calling this method will not guarantee that RecyclerView will run animations
+ * at all. For example, if there is not any {@link ItemAnimator} set, RecyclerView will
+ * not run any animations but will still clear this flag after the layout is complete.
+ *
+ */
+ public void requestSimpleAnimationsInNextLayout() {
+ mRequestedSimpleAnimations = true;
+ }
+
+ /**
+ * Returns the selection mode for accessibility. Should be
+ * {@link AccessibilityNodeInfo.CollectionInfo#SELECTION_MODE_NONE},
+ * {@link AccessibilityNodeInfo.CollectionInfo#SELECTION_MODE_SINGLE} or
+ * {@link AccessibilityNodeInfo.CollectionInfo#SELECTION_MODE_MULTIPLE}.
+ * <p>
+ * Default implementation returns
+ * {@link AccessibilityNodeInfo.CollectionInfo#SELECTION_MODE_NONE}.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @return Selection mode for accessibility. Default implementation returns
+ * {@link AccessibilityNodeInfo.CollectionInfo#SELECTION_MODE_NONE}.
+ */
+ public int getSelectionModeForAccessibility(Recycler recycler, State state) {
+ return AccessibilityNodeInfo.CollectionInfo.SELECTION_MODE_NONE;
+ }
+
+ /**
+ * Returns the number of rows for accessibility.
+ * <p>
+ * Default implementation returns the number of items in the adapter if LayoutManager
+ * supports vertical scrolling or 1 if LayoutManager does not support vertical
+ * scrolling.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @return The number of rows in LayoutManager for accessibility.
+ */
+ public int getRowCountForAccessibility(Recycler recycler, State state) {
+ if (mRecyclerView == null || mRecyclerView.mAdapter == null) {
+ return 1;
+ }
+ return canScrollVertically() ? mRecyclerView.mAdapter.getItemCount() : 1;
+ }
+
+ /**
+ * Returns the number of columns for accessibility.
+ * <p>
+ * Default implementation returns the number of items in the adapter if LayoutManager
+ * supports horizontal scrolling or 1 if LayoutManager does not support horizontal
+ * scrolling.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @return The number of rows in LayoutManager for accessibility.
+ */
+ public int getColumnCountForAccessibility(Recycler recycler, State state) {
+ if (mRecyclerView == null || mRecyclerView.mAdapter == null) {
+ return 1;
+ }
+ return canScrollHorizontally() ? mRecyclerView.mAdapter.getItemCount() : 1;
+ }
+
+ /**
+ * Returns whether layout is hierarchical or not to be used for accessibility.
+ * <p>
+ * Default implementation returns false.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @return True if layout is hierarchical.
+ */
+ public boolean isLayoutHierarchical(Recycler recycler, State state) {
+ return false;
+ }
+
+ // called by accessibility delegate
+ boolean performAccessibilityAction(int action, Bundle args) {
+ return performAccessibilityAction(mRecyclerView.mRecycler, mRecyclerView.mState,
+ action, args);
+ }
+
+ /**
+ * Called by AccessibilityDelegate when an action is requested from the RecyclerView.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @param action The action to perform
+ * @param args Optional action arguments
+ * @see View#performAccessibilityAction(int, android.os.Bundle)
+ */
+ public boolean performAccessibilityAction(Recycler recycler, State state, int action,
+ Bundle args) {
+ if (mRecyclerView == null) {
+ return false;
+ }
+ int vScroll = 0, hScroll = 0;
+ switch (action) {
+ case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD:
+ if (mRecyclerView.canScrollVertically(-1)) {
+ vScroll = -(getHeight() - getPaddingTop() - getPaddingBottom());
+ }
+ if (mRecyclerView.canScrollHorizontally(-1)) {
+ hScroll = -(getWidth() - getPaddingLeft() - getPaddingRight());
+ }
+ break;
+ case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD:
+ if (mRecyclerView.canScrollVertically(1)) {
+ vScroll = getHeight() - getPaddingTop() - getPaddingBottom();
+ }
+ if (mRecyclerView.canScrollHorizontally(1)) {
+ hScroll = getWidth() - getPaddingLeft() - getPaddingRight();
+ }
+ break;
+ }
+ if (vScroll == 0 && hScroll == 0) {
+ return false;
+ }
+ mRecyclerView.scrollBy(hScroll, vScroll);
+ return true;
+ }
+
+ // called by accessibility delegate
+ boolean performAccessibilityActionForItem(View view, int action, Bundle args) {
+ return performAccessibilityActionForItem(mRecyclerView.mRecycler, mRecyclerView.mState,
+ view, action, args);
+ }
+
+ /**
+ * Called by AccessibilityDelegate when an accessibility action is requested on one of the
+ * children of LayoutManager.
+ * <p>
+ * Default implementation does not do anything.
+ *
+ * @param recycler The Recycler that can be used to convert view positions into adapter
+ * positions
+ * @param state The current state of RecyclerView
+ * @param view The child view on which the action is performed
+ * @param action The action to perform
+ * @param args Optional action arguments
+ * @return true if action is handled
+ * @see View#performAccessibilityAction(int, android.os.Bundle)
+ */
+ public boolean performAccessibilityActionForItem(Recycler recycler, State state, View view,
+ int action, Bundle args) {
+ return false;
+ }
+
+ /**
+ * Parse the xml attributes to get the most common properties used by layout managers.
+ *
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_android_orientation
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_spanCount
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_reverseLayout
+ * @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_stackFromEnd
+ *
+ * @return an object containing the properties as specified in the attrs.
+ */
+ public static Properties getProperties(Context context, AttributeSet attrs,
+ int defStyleAttr, int defStyleRes) {
+ Properties properties = new Properties();
+ TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RecyclerView,
+ defStyleAttr, defStyleRes);
+ properties.orientation = a.getInt(R.styleable.RecyclerView_orientation, VERTICAL);
+ properties.spanCount = a.getInt(R.styleable.RecyclerView_spanCount, 1);
+ properties.reverseLayout = a.getBoolean(R.styleable.RecyclerView_reverseLayout, false);
+ properties.stackFromEnd = a.getBoolean(R.styleable.RecyclerView_stackFromEnd, false);
+ a.recycle();
+ return properties;
+ }
+
+ void setExactMeasureSpecsFrom(RecyclerView recyclerView) {
+ setMeasureSpecs(
+ MeasureSpec.makeMeasureSpec(recyclerView.getWidth(), MeasureSpec.EXACTLY),
+ MeasureSpec.makeMeasureSpec(recyclerView.getHeight(), MeasureSpec.EXACTLY)
+ );
+ }
+
+ /**
+ * Internal API to allow LayoutManagers to be measured twice.
+ * <p>
+ * This is not public because LayoutManagers should be able to handle their layouts in one
+ * pass but it is very convenient to make existing LayoutManagers support wrapping content
+ * when both orientations are undefined.
+ * <p>
+ * This API will be removed after default LayoutManagers properly implement wrap content in
+ * non-scroll orientation.
+ */
+ boolean shouldMeasureTwice() {
+ return false;
+ }
+
+ boolean hasFlexibleChildInBothOrientations() {
+ final int childCount = getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final View child = getChildAt(i);
+ final ViewGroup.LayoutParams lp = child.getLayoutParams();
+ if (lp.width < 0 && lp.height < 0) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Some general properties that a LayoutManager may want to use.
+ */
+ public static class Properties {
+ /** @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_android_orientation */
+ public int orientation;
+ /** @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_spanCount */
+ public int spanCount;
+ /** @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_reverseLayout */
+ public boolean reverseLayout;
+ /** @attr ref android.support.v7.recyclerview.R.styleable#RecyclerView_stackFromEnd */
+ public boolean stackFromEnd;
+ }
+ }
+
+ /**
+ * An ItemDecoration allows the application to add a special drawing and layout offset
+ * to specific item views from the adapter's data set. This can be useful for drawing dividers
+ * between items, highlights, visual grouping boundaries and more.
+ *
+ * <p>All ItemDecorations are drawn in the order they were added, before the item
+ * views (in {@link ItemDecoration#onDraw(Canvas, RecyclerView, RecyclerView.State) onDraw()}
+ * and after the items (in {@link ItemDecoration#onDrawOver(Canvas, RecyclerView,
+ * RecyclerView.State)}.</p>
+ */
+ public abstract static class ItemDecoration {
+ /**
+ * Draw any appropriate decorations into the Canvas supplied to the RecyclerView.
+ * Any content drawn by this method will be drawn before the item views are drawn,
+ * and will thus appear underneath the views.
+ *
+ * @param c Canvas to draw into
+ * @param parent RecyclerView this ItemDecoration is drawing into
+ * @param state The current state of RecyclerView
+ */
+ public void onDraw(Canvas c, RecyclerView parent, State state) {
+ onDraw(c, parent);
+ }
+
+ /**
+ * @deprecated
+ * Override {@link #onDraw(Canvas, RecyclerView, RecyclerView.State)}
+ */
+ @Deprecated
+ public void onDraw(Canvas c, RecyclerView parent) {
+ }
+
+ /**
+ * Draw any appropriate decorations into the Canvas supplied to the RecyclerView.
+ * Any content drawn by this method will be drawn after the item views are drawn
+ * and will thus appear over the views.
+ *
+ * @param c Canvas to draw into
+ * @param parent RecyclerView this ItemDecoration is drawing into
+ * @param state The current state of RecyclerView.
+ */
+ public void onDrawOver(Canvas c, RecyclerView parent, State state) {
+ onDrawOver(c, parent);
+ }
+
+ /**
+ * @deprecated
+ * Override {@link #onDrawOver(Canvas, RecyclerView, RecyclerView.State)}
+ */
+ @Deprecated
+ public void onDrawOver(Canvas c, RecyclerView parent) {
+ }
+
+
+ /**
+ * @deprecated
+ * Use {@link #getItemOffsets(Rect, View, RecyclerView, State)}
+ */
+ @Deprecated
+ public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
+ outRect.set(0, 0, 0, 0);
+ }
+
+ /**
+ * Retrieve any offsets for the given item. Each field of <code>outRect</code> specifies
+ * the number of pixels that the item view should be inset by, similar to padding or margin.
+ * The default implementation sets the bounds of outRect to 0 and returns.
+ *
+ * <p>
+ * If this ItemDecoration does not affect the positioning of item views, it should set
+ * all four fields of <code>outRect</code> (left, top, right, bottom) to zero
+ * before returning.
+ *
+ * <p>
+ * If you need to access Adapter for additional data, you can call
+ * {@link RecyclerView#getChildAdapterPosition(View)} to get the adapter position of the
+ * View.
+ *
+ * @param outRect Rect to receive the output.
+ * @param view The child view to decorate
+ * @param parent RecyclerView this ItemDecoration is decorating
+ * @param state The current state of RecyclerView.
+ */
+ public void getItemOffsets(Rect outRect, View view, RecyclerView parent, State state) {
+ getItemOffsets(outRect, ((LayoutParams) view.getLayoutParams()).getViewLayoutPosition(),
+ parent);
+ }
+ }
+
+ /**
+ * An OnItemTouchListener allows the application to intercept touch events in progress at the
+ * view hierarchy level of the RecyclerView before those touch events are considered for
+ * RecyclerView's own scrolling behavior.
+ *
+ * <p>This can be useful for applications that wish to implement various forms of gestural
+ * manipulation of item views within the RecyclerView. OnItemTouchListeners may intercept
+ * a touch interaction already in progress even if the RecyclerView is already handling that
+ * gesture stream itself for the purposes of scrolling.</p>
+ *
+ * @see SimpleOnItemTouchListener
+ */
+ public interface OnItemTouchListener {
+ /**
+ * Silently observe and/or take over touch events sent to the RecyclerView
+ * before they are handled by either the RecyclerView itself or its child views.
+ *
+ * <p>The onInterceptTouchEvent methods of each attached OnItemTouchListener will be run
+ * in the order in which each listener was added, before any other touch processing
+ * by the RecyclerView itself or child views occurs.</p>
+ *
+ * @param e MotionEvent describing the touch event. All coordinates are in
+ * the RecyclerView's coordinate system.
+ * @return true if this OnItemTouchListener wishes to begin intercepting touch events, false
+ * to continue with the current behavior and continue observing future events in
+ * the gesture.
+ */
+ boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e);
+
+ /**
+ * Process a touch event as part of a gesture that was claimed by returning true from
+ * a previous call to {@link #onInterceptTouchEvent}.
+ *
+ * @param e MotionEvent describing the touch event. All coordinates are in
+ * the RecyclerView's coordinate system.
+ */
+ void onTouchEvent(RecyclerView rv, MotionEvent e);
+
+ /**
+ * Called when a child of RecyclerView does not want RecyclerView and its ancestors to
+ * intercept touch events with
+ * {@link ViewGroup#onInterceptTouchEvent(MotionEvent)}.
+ *
+ * @param disallowIntercept True if the child does not want the parent to
+ * intercept touch events.
+ * @see ViewParent#requestDisallowInterceptTouchEvent(boolean)
+ */
+ void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept);
+ }
+
+ /**
+ * An implementation of {@link RecyclerView.OnItemTouchListener} that has empty method bodies
+ * and default return values.
+ * <p>
+ * You may prefer to extend this class if you don't need to override all methods. Another
+ * benefit of using this class is future compatibility. As the interface may change, we'll
+ * always provide a default implementation on this class so that your code won't break when
+ * you update to a new version of the support library.
+ */
+ public static class SimpleOnItemTouchListener implements RecyclerView.OnItemTouchListener {
+ @Override
+ public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
+ return false;
+ }
+
+ @Override
+ public void onTouchEvent(RecyclerView rv, MotionEvent e) {
+ }
+
+ @Override
+ public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
+ }
+ }
+
+
+ /**
+ * An OnScrollListener can be added to a RecyclerView to receive messages when a scrolling event
+ * has occurred on that RecyclerView.
+ * <p>
+ * @see RecyclerView#addOnScrollListener(OnScrollListener)
+ * @see RecyclerView#clearOnChildAttachStateChangeListeners()
+ *
+ */
+ public abstract static class OnScrollListener {
+ /**
+ * Callback method to be invoked when RecyclerView's scroll state changes.
+ *
+ * @param recyclerView The RecyclerView whose scroll state has changed.
+ * @param newState The updated scroll state. One of {@link #SCROLL_STATE_IDLE},
+ * {@link #SCROLL_STATE_DRAGGING} or {@link #SCROLL_STATE_SETTLING}.
+ */
+ public void onScrollStateChanged(RecyclerView recyclerView, int newState){}
+
+ /**
+ * Callback method to be invoked when the RecyclerView has been scrolled. This will be
+ * called after the scroll has completed.
+ * <p>
+ * This callback will also be called if visible item range changes after a layout
+ * calculation. In that case, dx and dy will be 0.
+ *
+ * @param recyclerView The RecyclerView which scrolled.
+ * @param dx The amount of horizontal scroll.
+ * @param dy The amount of vertical scroll.
+ */
+ public void onScrolled(RecyclerView recyclerView, int dx, int dy){}
+ }
+
+ /**
+ * A RecyclerListener can be set on a RecyclerView to receive messages whenever
+ * a view is recycled.
+ *
+ * @see RecyclerView#setRecyclerListener(RecyclerListener)
+ */
+ public interface RecyclerListener {
+
+ /**
+ * This method is called whenever the view in the ViewHolder is recycled.
+ *
+ * RecyclerView calls this method right before clearing ViewHolder's internal data and
+ * sending it to RecycledViewPool. This way, if ViewHolder was holding valid information
+ * before being recycled, you can call {@link ViewHolder#getAdapterPosition()} to get
+ * its adapter position.
+ *
+ * @param holder The ViewHolder containing the view that was recycled
+ */
+ void onViewRecycled(ViewHolder holder);
+ }
+
+ /**
+ * A Listener interface that can be attached to a RecylcerView to get notified
+ * whenever a ViewHolder is attached to or detached from RecyclerView.
+ */
+ public interface OnChildAttachStateChangeListener {
+
+ /**
+ * Called when a view is attached to the RecyclerView.
+ *
+ * @param view The View which is attached to the RecyclerView
+ */
+ void onChildViewAttachedToWindow(View view);
+
+ /**
+ * Called when a view is detached from RecyclerView.
+ *
+ * @param view The View which is being detached from the RecyclerView
+ */
+ void onChildViewDetachedFromWindow(View view);
+ }
+
+ /**
+ * A ViewHolder describes an item view and metadata about its place within the RecyclerView.
+ *
+ * <p>{@link Adapter} implementations should subclass ViewHolder and add fields for caching
+ * potentially expensive {@link View#findViewById(int)} results.</p>
+ *
+ * <p>While {@link LayoutParams} belong to the {@link LayoutManager},
+ * {@link ViewHolder ViewHolders} belong to the adapter. Adapters should feel free to use
+ * their own custom ViewHolder implementations to store data that makes binding view contents
+ * easier. Implementations should assume that individual item views will hold strong references
+ * to <code>ViewHolder</code> objects and that <code>RecyclerView</code> instances may hold
+ * strong references to extra off-screen item views for caching purposes</p>
+ */
+ public abstract static class ViewHolder {
+ public final View itemView;
+ WeakReference<RecyclerView> mNestedRecyclerView;
+ int mPosition = NO_POSITION;
+ int mOldPosition = NO_POSITION;
+ long mItemId = NO_ID;
+ int mItemViewType = INVALID_TYPE;
+ int mPreLayoutPosition = NO_POSITION;
+
+ // The item that this holder is shadowing during an item change event/animation
+ ViewHolder mShadowedHolder = null;
+ // The item that is shadowing this holder during an item change event/animation
+ ViewHolder mShadowingHolder = null;
+
+ /**
+ * This ViewHolder has been bound to a position; mPosition, mItemId and mItemViewType
+ * are all valid.
+ */
+ static final int FLAG_BOUND = 1 << 0;
+
+ /**
+ * The data this ViewHolder's view reflects is stale and needs to be rebound
+ * by the adapter. mPosition and mItemId are consistent.
+ */
+ static final int FLAG_UPDATE = 1 << 1;
+
+ /**
+ * This ViewHolder's data is invalid. The identity implied by mPosition and mItemId
+ * are not to be trusted and may no longer match the item view type.
+ * This ViewHolder must be fully rebound to different data.
+ */
+ static final int FLAG_INVALID = 1 << 2;
+
+ /**
+ * This ViewHolder points at data that represents an item previously removed from the
+ * data set. Its view may still be used for things like outgoing animations.
+ */
+ static final int FLAG_REMOVED = 1 << 3;
+
+ /**
+ * This ViewHolder should not be recycled. This flag is set via setIsRecyclable()
+ * and is intended to keep views around during animations.
+ */
+ static final int FLAG_NOT_RECYCLABLE = 1 << 4;
+
+ /**
+ * This ViewHolder is returned from scrap which means we are expecting an addView call
+ * for this itemView. When returned from scrap, ViewHolder stays in the scrap list until
+ * the end of the layout pass and then recycled by RecyclerView if it is not added back to
+ * the RecyclerView.
+ */
+ static final int FLAG_RETURNED_FROM_SCRAP = 1 << 5;
+
+ /**
+ * This ViewHolder is fully managed by the LayoutManager. We do not scrap, recycle or remove
+ * it unless LayoutManager is replaced.
+ * It is still fully visible to the LayoutManager.
+ */
+ static final int FLAG_IGNORE = 1 << 7;
+
+ /**
+ * When the View is detached form the parent, we set this flag so that we can take correct
+ * action when we need to remove it or add it back.
+ */
+ static final int FLAG_TMP_DETACHED = 1 << 8;
+
+ /**
+ * Set when we can no longer determine the adapter position of this ViewHolder until it is
+ * rebound to a new position. It is different than FLAG_INVALID because FLAG_INVALID is
+ * set even when the type does not match. Also, FLAG_ADAPTER_POSITION_UNKNOWN is set as soon
+ * as adapter notification arrives vs FLAG_INVALID is set lazily before layout is
+ * re-calculated.
+ */
+ static final int FLAG_ADAPTER_POSITION_UNKNOWN = 1 << 9;
+
+ /**
+ * Set when a addChangePayload(null) is called
+ */
+ static final int FLAG_ADAPTER_FULLUPDATE = 1 << 10;
+
+ /**
+ * Used by ItemAnimator when a ViewHolder's position changes
+ */
+ static final int FLAG_MOVED = 1 << 11;
+
+ /**
+ * Used by ItemAnimator when a ViewHolder appears in pre-layout
+ */
+ static final int FLAG_APPEARED_IN_PRE_LAYOUT = 1 << 12;
+
+ static final int PENDING_ACCESSIBILITY_STATE_NOT_SET = -1;
+
+ /**
+ * Used when a ViewHolder starts the layout pass as a hidden ViewHolder but is re-used from
+ * hidden list (as if it was scrap) without being recycled in between.
+ *
+ * When a ViewHolder is hidden, there are 2 paths it can be re-used:
+ * a) Animation ends, view is recycled and used from the recycle pool.
+ * b) LayoutManager asks for the View for that position while the ViewHolder is hidden.
+ *
+ * This flag is used to represent "case b" where the ViewHolder is reused without being
+ * recycled (thus "bounced" from the hidden list). This state requires special handling
+ * because the ViewHolder must be added to pre layout maps for animations as if it was
+ * already there.
+ */
+ static final int FLAG_BOUNCED_FROM_HIDDEN_LIST = 1 << 13;
+
+ private int mFlags;
+
+ private static final List<Object> FULLUPDATE_PAYLOADS = Collections.EMPTY_LIST;
+
+ List<Object> mPayloads = null;
+ List<Object> mUnmodifiedPayloads = null;
+
+ private int mIsRecyclableCount = 0;
+
+ // If non-null, view is currently considered scrap and may be reused for other data by the
+ // scrap container.
+ private Recycler mScrapContainer = null;
+ // Keeps whether this ViewHolder lives in Change scrap or Attached scrap
+ private boolean mInChangeScrap = false;
+
+ // Saves isImportantForAccessibility value for the view item while it's in hidden state and
+ // marked as unimportant for accessibility.
+ private int mWasImportantForAccessibilityBeforeHidden =
+ View.IMPORTANT_FOR_ACCESSIBILITY_AUTO;
+ // set if we defer the accessibility state change of the view holder
+ @VisibleForTesting
+ int mPendingAccessibilityState = PENDING_ACCESSIBILITY_STATE_NOT_SET;
+
+ /**
+ * Is set when VH is bound from the adapter and cleaned right before it is sent to
+ * {@link RecycledViewPool}.
+ */
+ RecyclerView mOwnerRecyclerView;
+
+ public ViewHolder(View itemView) {
+ if (itemView == null) {
+ throw new IllegalArgumentException("itemView may not be null");
+ }
+ this.itemView = itemView;
+ }
+
+ void flagRemovedAndOffsetPosition(int mNewPosition, int offset, boolean applyToPreLayout) {
+ addFlags(ViewHolder.FLAG_REMOVED);
+ offsetPosition(offset, applyToPreLayout);
+ mPosition = mNewPosition;
+ }
+
+ void offsetPosition(int offset, boolean applyToPreLayout) {
+ if (mOldPosition == NO_POSITION) {
+ mOldPosition = mPosition;
+ }
+ if (mPreLayoutPosition == NO_POSITION) {
+ mPreLayoutPosition = mPosition;
+ }
+ if (applyToPreLayout) {
+ mPreLayoutPosition += offset;
+ }
+ mPosition += offset;
+ if (itemView.getLayoutParams() != null) {
+ ((LayoutParams) itemView.getLayoutParams()).mInsetsDirty = true;
+ }
+ }
+
+ void clearOldPosition() {
+ mOldPosition = NO_POSITION;
+ mPreLayoutPosition = NO_POSITION;
+ }
+
+ void saveOldPosition() {
+ if (mOldPosition == NO_POSITION) {
+ mOldPosition = mPosition;
+ }
+ }
+
+ boolean shouldIgnore() {
+ return (mFlags & FLAG_IGNORE) != 0;
+ }
+
+ /**
+ * @deprecated This method is deprecated because its meaning is ambiguous due to the async
+ * handling of adapter updates. Please use {@link #getLayoutPosition()} or
+ * {@link #getAdapterPosition()} depending on your use case.
+ *
+ * @see #getLayoutPosition()
+ * @see #getAdapterPosition()
+ */
+ @Deprecated
+ public final int getPosition() {
+ return mPreLayoutPosition == NO_POSITION ? mPosition : mPreLayoutPosition;
+ }
+
+ /**
+ * Returns the position of the ViewHolder in terms of the latest layout pass.
+ * <p>
+ * This position is mostly used by RecyclerView components to be consistent while
+ * RecyclerView lazily processes adapter updates.
+ * <p>
+ * For performance and animation reasons, RecyclerView batches all adapter updates until the
+ * next layout pass. This may cause mismatches between the Adapter position of the item and
+ * the position it had in the latest layout calculations.
+ * <p>
+ * LayoutManagers should always call this method while doing calculations based on item
+ * positions. All methods in {@link RecyclerView.LayoutManager}, {@link RecyclerView.State},
+ * {@link RecyclerView.Recycler} that receive a position expect it to be the layout position
+ * of the item.
+ * <p>
+ * If LayoutManager needs to call an external method that requires the adapter position of
+ * the item, it can use {@link #getAdapterPosition()} or
+ * {@link RecyclerView.Recycler#convertPreLayoutPositionToPostLayout(int)}.
+ *
+ * @return Returns the adapter position of the ViewHolder in the latest layout pass.
+ * @see #getAdapterPosition()
+ */
+ public final int getLayoutPosition() {
+ return mPreLayoutPosition == NO_POSITION ? mPosition : mPreLayoutPosition;
+ }
+
+ /**
+ * Returns the Adapter position of the item represented by this ViewHolder.
+ * <p>
+ * Note that this might be different than the {@link #getLayoutPosition()} if there are
+ * pending adapter updates but a new layout pass has not happened yet.
+ * <p>
+ * RecyclerView does not handle any adapter updates until the next layout traversal. This
+ * may create temporary inconsistencies between what user sees on the screen and what
+ * adapter contents have. This inconsistency is not important since it will be less than
+ * 16ms but it might be a problem if you want to use ViewHolder position to access the
+ * adapter. Sometimes, you may need to get the exact adapter position to do
+ * some actions in response to user events. In that case, you should use this method which
+ * will calculate the Adapter position of the ViewHolder.
+ * <p>
+ * Note that if you've called {@link RecyclerView.Adapter#notifyDataSetChanged()}, until the
+ * next layout pass, the return value of this method will be {@link #NO_POSITION}.
+ *
+ * @return The adapter position of the item if it still exists in the adapter.
+ * {@link RecyclerView#NO_POSITION} if item has been removed from the adapter,
+ * {@link RecyclerView.Adapter#notifyDataSetChanged()} has been called after the last
+ * layout pass or the ViewHolder has already been recycled.
+ */
+ public final int getAdapterPosition() {
+ if (mOwnerRecyclerView == null) {
+ return NO_POSITION;
+ }
+ return mOwnerRecyclerView.getAdapterPositionFor(this);
+ }
+
+ /**
+ * When LayoutManager supports animations, RecyclerView tracks 3 positions for ViewHolders
+ * to perform animations.
+ * <p>
+ * If a ViewHolder was laid out in the previous onLayout call, old position will keep its
+ * adapter index in the previous layout.
+ *
+ * @return The previous adapter index of the Item represented by this ViewHolder or
+ * {@link #NO_POSITION} if old position does not exists or cleared (pre-layout is
+ * complete).
+ */
+ public final int getOldPosition() {
+ return mOldPosition;
+ }
+
+ /**
+ * Returns The itemId represented by this ViewHolder.
+ *
+ * @return The item's id if adapter has stable ids, {@link RecyclerView#NO_ID}
+ * otherwise
+ */
+ public final long getItemId() {
+ return mItemId;
+ }
+
+ /**
+ * @return The view type of this ViewHolder.
+ */
+ public final int getItemViewType() {
+ return mItemViewType;
+ }
+
+ boolean isScrap() {
+ return mScrapContainer != null;
+ }
+
+ void unScrap() {
+ mScrapContainer.unscrapView(this);
+ }
+
+ boolean wasReturnedFromScrap() {
+ return (mFlags & FLAG_RETURNED_FROM_SCRAP) != 0;
+ }
+
+ void clearReturnedFromScrapFlag() {
+ mFlags = mFlags & ~FLAG_RETURNED_FROM_SCRAP;
+ }
+
+ void clearTmpDetachFlag() {
+ mFlags = mFlags & ~FLAG_TMP_DETACHED;
+ }
+
+ void stopIgnoring() {
+ mFlags = mFlags & ~FLAG_IGNORE;
+ }
+
+ void setScrapContainer(Recycler recycler, boolean isChangeScrap) {
+ mScrapContainer = recycler;
+ mInChangeScrap = isChangeScrap;
+ }
+
+ boolean isInvalid() {
+ return (mFlags & FLAG_INVALID) != 0;
+ }
+
+ boolean needsUpdate() {
+ return (mFlags & FLAG_UPDATE) != 0;
+ }
+
+ boolean isBound() {
+ return (mFlags & FLAG_BOUND) != 0;
+ }
+
+ boolean isRemoved() {
+ return (mFlags & FLAG_REMOVED) != 0;
+ }
+
+ boolean hasAnyOfTheFlags(int flags) {
+ return (mFlags & flags) != 0;
+ }
+
+ boolean isTmpDetached() {
+ return (mFlags & FLAG_TMP_DETACHED) != 0;
+ }
+
+ boolean isAdapterPositionUnknown() {
+ return (mFlags & FLAG_ADAPTER_POSITION_UNKNOWN) != 0 || isInvalid();
+ }
+
+ void setFlags(int flags, int mask) {
+ mFlags = (mFlags & ~mask) | (flags & mask);
+ }
+
+ void addFlags(int flags) {
+ mFlags |= flags;
+ }
+
+ void addChangePayload(Object payload) {
+ if (payload == null) {
+ addFlags(FLAG_ADAPTER_FULLUPDATE);
+ } else if ((mFlags & FLAG_ADAPTER_FULLUPDATE) == 0) {
+ createPayloadsIfNeeded();
+ mPayloads.add(payload);
+ }
+ }
+
+ private void createPayloadsIfNeeded() {
+ if (mPayloads == null) {
+ mPayloads = new ArrayList<Object>();
+ mUnmodifiedPayloads = Collections.unmodifiableList(mPayloads);
+ }
+ }
+
+ void clearPayload() {
+ if (mPayloads != null) {
+ mPayloads.clear();
+ }
+ mFlags = mFlags & ~FLAG_ADAPTER_FULLUPDATE;
+ }
+
+ List<Object> getUnmodifiedPayloads() {
+ if ((mFlags & FLAG_ADAPTER_FULLUPDATE) == 0) {
+ if (mPayloads == null || mPayloads.size() == 0) {
+ // Initial state, no update being called.
+ return FULLUPDATE_PAYLOADS;
+ }
+ // there are none-null payloads
+ return mUnmodifiedPayloads;
+ } else {
+ // a full update has been called.
+ return FULLUPDATE_PAYLOADS;
+ }
+ }
+
+ void resetInternal() {
+ mFlags = 0;
+ mPosition = NO_POSITION;
+ mOldPosition = NO_POSITION;
+ mItemId = NO_ID;
+ mPreLayoutPosition = NO_POSITION;
+ mIsRecyclableCount = 0;
+ mShadowedHolder = null;
+ mShadowingHolder = null;
+ clearPayload();
+ mWasImportantForAccessibilityBeforeHidden = View.IMPORTANT_FOR_ACCESSIBILITY_AUTO;
+ mPendingAccessibilityState = PENDING_ACCESSIBILITY_STATE_NOT_SET;
+ clearNestedRecyclerViewIfNotNested(this);
+ }
+
+ /**
+ * Called when the child view enters the hidden state
+ */
+ private void onEnteredHiddenState(RecyclerView parent) {
+ // While the view item is in hidden state, make it invisible for the accessibility.
+ mWasImportantForAccessibilityBeforeHidden =
+ itemView.getImportantForAccessibility();
+ parent.setChildImportantForAccessibilityInternal(this,
+ View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
+ }
+
+ /**
+ * Called when the child view leaves the hidden state
+ */
+ private void onLeftHiddenState(RecyclerView parent) {
+ parent.setChildImportantForAccessibilityInternal(this,
+ mWasImportantForAccessibilityBeforeHidden);
+ mWasImportantForAccessibilityBeforeHidden = View.IMPORTANT_FOR_ACCESSIBILITY_AUTO;
+ }
+
+ @Override
+ public String toString() {
+ final StringBuilder sb = new StringBuilder("ViewHolder{"
+ + Integer.toHexString(hashCode()) + " position=" + mPosition + " id=" + mItemId
+ + ", oldPos=" + mOldPosition + ", pLpos:" + mPreLayoutPosition);
+ if (isScrap()) {
+ sb.append(" scrap ")
+ .append(mInChangeScrap ? "[changeScrap]" : "[attachedScrap]");
+ }
+ if (isInvalid()) sb.append(" invalid");
+ if (!isBound()) sb.append(" unbound");
+ if (needsUpdate()) sb.append(" update");
+ if (isRemoved()) sb.append(" removed");
+ if (shouldIgnore()) sb.append(" ignored");
+ if (isTmpDetached()) sb.append(" tmpDetached");
+ if (!isRecyclable()) sb.append(" not recyclable(" + mIsRecyclableCount + ")");
+ if (isAdapterPositionUnknown()) sb.append(" undefined adapter position");
+
+ if (itemView.getParent() == null) sb.append(" no parent");
+ sb.append("}");
+ return sb.toString();
+ }
+
+ /**
+ * Informs the recycler whether this item can be recycled. Views which are not
+ * recyclable will not be reused for other items until setIsRecyclable() is
+ * later set to true. Calls to setIsRecyclable() should always be paired (one
+ * call to setIsRecyclabe(false) should always be matched with a later call to
+ * setIsRecyclable(true)). Pairs of calls may be nested, as the state is internally
+ * reference-counted.
+ *
+ * @param recyclable Whether this item is available to be recycled. Default value
+ * is true.
+ *
+ * @see #isRecyclable()
+ */
+ public final void setIsRecyclable(boolean recyclable) {
+ mIsRecyclableCount = recyclable ? mIsRecyclableCount - 1 : mIsRecyclableCount + 1;
+ if (mIsRecyclableCount < 0) {
+ mIsRecyclableCount = 0;
+ if (DEBUG) {
+ throw new RuntimeException("isRecyclable decremented below 0: "
+ + "unmatched pair of setIsRecyable() calls for " + this);
+ }
+ Log.e(VIEW_LOG_TAG, "isRecyclable decremented below 0: "
+ + "unmatched pair of setIsRecyable() calls for " + this);
+ } else if (!recyclable && mIsRecyclableCount == 1) {
+ mFlags |= FLAG_NOT_RECYCLABLE;
+ } else if (recyclable && mIsRecyclableCount == 0) {
+ mFlags &= ~FLAG_NOT_RECYCLABLE;
+ }
+ if (DEBUG) {
+ Log.d(TAG, "setIsRecyclable val:" + recyclable + ":" + this);
+ }
+ }
+
+ /**
+ * @return true if this item is available to be recycled, false otherwise.
+ *
+ * @see #setIsRecyclable(boolean)
+ */
+ public final boolean isRecyclable() {
+ return (mFlags & FLAG_NOT_RECYCLABLE) == 0
+ && !itemView.hasTransientState();
+ }
+
+ /**
+ * Returns whether we have animations referring to this view holder or not.
+ * This is similar to isRecyclable flag but does not check transient state.
+ */
+ private boolean shouldBeKeptAsChild() {
+ return (mFlags & FLAG_NOT_RECYCLABLE) != 0;
+ }
+
+ /**
+ * @return True if ViewHolder is not referenced by RecyclerView animations but has
+ * transient state which will prevent it from being recycled.
+ */
+ private boolean doesTransientStatePreventRecycling() {
+ return (mFlags & FLAG_NOT_RECYCLABLE) == 0 && itemView.hasTransientState();
+ }
+
+ boolean isUpdated() {
+ return (mFlags & FLAG_UPDATE) != 0;
+ }
+ }
+
+ /**
+ * This method is here so that we can control the important for a11y changes and test it.
+ */
+ @VisibleForTesting
+ boolean setChildImportantForAccessibilityInternal(ViewHolder viewHolder,
+ int importantForAccessibility) {
+ if (isComputingLayout()) {
+ viewHolder.mPendingAccessibilityState = importantForAccessibility;
+ mPendingAccessibilityImportanceChange.add(viewHolder);
+ return false;
+ }
+ viewHolder.itemView.setImportantForAccessibility(importantForAccessibility);
+ return true;
+ }
+
+ void dispatchPendingImportantForAccessibilityChanges() {
+ for (int i = mPendingAccessibilityImportanceChange.size() - 1; i >= 0; i--) {
+ ViewHolder viewHolder = mPendingAccessibilityImportanceChange.get(i);
+ if (viewHolder.itemView.getParent() != this || viewHolder.shouldIgnore()) {
+ continue;
+ }
+ int state = viewHolder.mPendingAccessibilityState;
+ if (state != ViewHolder.PENDING_ACCESSIBILITY_STATE_NOT_SET) {
+ //noinspection WrongConstant
+ viewHolder.itemView.setImportantForAccessibility(state);
+ viewHolder.mPendingAccessibilityState =
+ ViewHolder.PENDING_ACCESSIBILITY_STATE_NOT_SET;
+ }
+ }
+ mPendingAccessibilityImportanceChange.clear();
+ }
+
+ int getAdapterPositionFor(ViewHolder viewHolder) {
+ if (viewHolder.hasAnyOfTheFlags(ViewHolder.FLAG_INVALID
+ | ViewHolder.FLAG_REMOVED | ViewHolder.FLAG_ADAPTER_POSITION_UNKNOWN)
+ || !viewHolder.isBound()) {
+ return RecyclerView.NO_POSITION;
+ }
+ return mAdapterHelper.applyPendingUpdatesToPosition(viewHolder.mPosition);
+ }
+
+ /**
+ * {@link android.view.ViewGroup.MarginLayoutParams LayoutParams} subclass for children of
+ * {@link RecyclerView}. Custom {@link LayoutManager layout managers} are encouraged
+ * to create their own subclass of this <code>LayoutParams</code> class
+ * to store any additional required per-child view metadata about the layout.
+ */
+ public static class LayoutParams extends android.view.ViewGroup.MarginLayoutParams {
+ ViewHolder mViewHolder;
+ final Rect mDecorInsets = new Rect();
+ boolean mInsetsDirty = true;
+ // Flag is set to true if the view is bound while it is detached from RV.
+ // In this case, we need to manually call invalidate after view is added to guarantee that
+ // invalidation is populated through the View hierarchy
+ boolean mPendingInvalidate = false;
+
+ public LayoutParams(Context c, AttributeSet attrs) {
+ super(c, attrs);
+ }
+
+ public LayoutParams(int width, int height) {
+ super(width, height);
+ }
+
+ public LayoutParams(MarginLayoutParams source) {
+ super(source);
+ }
+
+ public LayoutParams(ViewGroup.LayoutParams source) {
+ super(source);
+ }
+
+ public LayoutParams(LayoutParams source) {
+ super((ViewGroup.LayoutParams) source);
+ }
+
+ /**
+ * Returns true if the view this LayoutParams is attached to needs to have its content
+ * updated from the corresponding adapter.
+ *
+ * @return true if the view should have its content updated
+ */
+ public boolean viewNeedsUpdate() {
+ return mViewHolder.needsUpdate();
+ }
+
+ /**
+ * Returns true if the view this LayoutParams is attached to is now representing
+ * potentially invalid data. A LayoutManager should scrap/recycle it.
+ *
+ * @return true if the view is invalid
+ */
+ public boolean isViewInvalid() {
+ return mViewHolder.isInvalid();
+ }
+
+ /**
+ * Returns true if the adapter data item corresponding to the view this LayoutParams
+ * is attached to has been removed from the data set. A LayoutManager may choose to
+ * treat it differently in order to animate its outgoing or disappearing state.
+ *
+ * @return true if the item the view corresponds to was removed from the data set
+ */
+ public boolean isItemRemoved() {
+ return mViewHolder.isRemoved();
+ }
+
+ /**
+ * Returns true if the adapter data item corresponding to the view this LayoutParams
+ * is attached to has been changed in the data set. A LayoutManager may choose to
+ * treat it differently in order to animate its changing state.
+ *
+ * @return true if the item the view corresponds to was changed in the data set
+ */
+ public boolean isItemChanged() {
+ return mViewHolder.isUpdated();
+ }
+
+ /**
+ * @deprecated use {@link #getViewLayoutPosition()} or {@link #getViewAdapterPosition()}
+ */
+ @Deprecated
+ public int getViewPosition() {
+ return mViewHolder.getPosition();
+ }
+
+ /**
+ * Returns the adapter position that the view this LayoutParams is attached to corresponds
+ * to as of latest layout calculation.
+ *
+ * @return the adapter position this view as of latest layout pass
+ */
+ public int getViewLayoutPosition() {
+ return mViewHolder.getLayoutPosition();
+ }
+
+ /**
+ * Returns the up-to-date adapter position that the view this LayoutParams is attached to
+ * corresponds to.
+ *
+ * @return the up-to-date adapter position this view. It may return
+ * {@link RecyclerView#NO_POSITION} if item represented by this View has been removed or
+ * its up-to-date position cannot be calculated.
+ */
+ public int getViewAdapterPosition() {
+ return mViewHolder.getAdapterPosition();
+ }
+ }
+
+ /**
+ * Observer base class for watching changes to an {@link Adapter}.
+ * See {@link Adapter#registerAdapterDataObserver(AdapterDataObserver)}.
+ */
+ public abstract static class AdapterDataObserver {
+ public void onChanged() {
+ // Do nothing
+ }
+
+ public void onItemRangeChanged(int positionStart, int itemCount) {
+ // do nothing
+ }
+
+ public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {
+ // fallback to onItemRangeChanged(positionStart, itemCount) if app
+ // does not override this method.
+ onItemRangeChanged(positionStart, itemCount);
+ }
+
+ public void onItemRangeInserted(int positionStart, int itemCount) {
+ // do nothing
+ }
+
+ public void onItemRangeRemoved(int positionStart, int itemCount) {
+ // do nothing
+ }
+
+ public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
+ // do nothing
+ }
+ }
+
+ /**
+ * <p>Base class for smooth scrolling. Handles basic tracking of the target view position and
+ * provides methods to trigger a programmatic scroll.</p>
+ *
+ * @see LinearSmoothScroller
+ */
+ public abstract static class SmoothScroller {
+
+ private int mTargetPosition = RecyclerView.NO_POSITION;
+
+ private RecyclerView mRecyclerView;
+
+ private LayoutManager mLayoutManager;
+
+ private boolean mPendingInitialRun;
+
+ private boolean mRunning;
+
+ private View mTargetView;
+
+ private final Action mRecyclingAction;
+
+ public SmoothScroller() {
+ mRecyclingAction = new Action(0, 0);
+ }
+
+ /**
+ * Starts a smooth scroll for the given target position.
+ * <p>In each animation step, {@link RecyclerView} will check
+ * for the target view and call either
+ * {@link #onTargetFound(android.view.View, RecyclerView.State, SmoothScroller.Action)} or
+ * {@link #onSeekTargetStep(int, int, RecyclerView.State, SmoothScroller.Action)} until
+ * SmoothScroller is stopped.</p>
+ *
+ * <p>Note that if RecyclerView finds the target view, it will automatically stop the
+ * SmoothScroller. This <b>does not</b> mean that scroll will stop, it only means it will
+ * stop calling SmoothScroller in each animation step.</p>
+ */
+ void start(RecyclerView recyclerView, LayoutManager layoutManager) {
+ mRecyclerView = recyclerView;
+ mLayoutManager = layoutManager;
+ if (mTargetPosition == RecyclerView.NO_POSITION) {
+ throw new IllegalArgumentException("Invalid target position");
+ }
+ mRecyclerView.mState.mTargetPosition = mTargetPosition;
+ mRunning = true;
+ mPendingInitialRun = true;
+ mTargetView = findViewByPosition(getTargetPosition());
+ onStart();
+ mRecyclerView.mViewFlinger.postOnAnimation();
+ }
+
+ public void setTargetPosition(int targetPosition) {
+ mTargetPosition = targetPosition;
+ }
+
+ /**
+ * @return The LayoutManager to which this SmoothScroller is attached. Will return
+ * <code>null</code> after the SmoothScroller is stopped.
+ */
+ @Nullable
+ public LayoutManager getLayoutManager() {
+ return mLayoutManager;
+ }
+
+ /**
+ * Stops running the SmoothScroller in each animation callback. Note that this does not
+ * cancel any existing {@link Action} updated by
+ * {@link #onTargetFound(android.view.View, RecyclerView.State, SmoothScroller.Action)} or
+ * {@link #onSeekTargetStep(int, int, RecyclerView.State, SmoothScroller.Action)}.
+ */
+ protected final void stop() {
+ if (!mRunning) {
+ return;
+ }
+ onStop();
+ mRecyclerView.mState.mTargetPosition = RecyclerView.NO_POSITION;
+ mTargetView = null;
+ mTargetPosition = RecyclerView.NO_POSITION;
+ mPendingInitialRun = false;
+ mRunning = false;
+ // trigger a cleanup
+ mLayoutManager.onSmoothScrollerStopped(this);
+ // clear references to avoid any potential leak by a custom smooth scroller
+ mLayoutManager = null;
+ mRecyclerView = null;
+ }
+
+ /**
+ * Returns true if SmoothScroller has been started but has not received the first
+ * animation
+ * callback yet.
+ *
+ * @return True if this SmoothScroller is waiting to start
+ */
+ public boolean isPendingInitialRun() {
+ return mPendingInitialRun;
+ }
+
+
+ /**
+ * @return True if SmoothScroller is currently active
+ */
+ public boolean isRunning() {
+ return mRunning;
+ }
+
+ /**
+ * Returns the adapter position of the target item
+ *
+ * @return Adapter position of the target item or
+ * {@link RecyclerView#NO_POSITION} if no target view is set.
+ */
+ public int getTargetPosition() {
+ return mTargetPosition;
+ }
+
+ private void onAnimation(int dx, int dy) {
+ final RecyclerView recyclerView = mRecyclerView;
+ if (!mRunning || mTargetPosition == RecyclerView.NO_POSITION || recyclerView == null) {
+ stop();
+ }
+ mPendingInitialRun = false;
+ if (mTargetView != null) {
+ // verify target position
+ if (getChildPosition(mTargetView) == mTargetPosition) {
+ onTargetFound(mTargetView, recyclerView.mState, mRecyclingAction);
+ mRecyclingAction.runIfNecessary(recyclerView);
+ stop();
+ } else {
+ Log.e(TAG, "Passed over target position while smooth scrolling.");
+ mTargetView = null;
+ }
+ }
+ if (mRunning) {
+ onSeekTargetStep(dx, dy, recyclerView.mState, mRecyclingAction);
+ boolean hadJumpTarget = mRecyclingAction.hasJumpTarget();
+ mRecyclingAction.runIfNecessary(recyclerView);
+ if (hadJumpTarget) {
+ // It is not stopped so needs to be restarted
+ if (mRunning) {
+ mPendingInitialRun = true;
+ recyclerView.mViewFlinger.postOnAnimation();
+ } else {
+ stop(); // done
+ }
+ }
+ }
+ }
+
+ /**
+ * @see RecyclerView#getChildLayoutPosition(android.view.View)
+ */
+ public int getChildPosition(View view) {
+ return mRecyclerView.getChildLayoutPosition(view);
+ }
+
+ /**
+ * @see RecyclerView.LayoutManager#getChildCount()
+ */
+ public int getChildCount() {
+ return mRecyclerView.mLayout.getChildCount();
+ }
+
+ /**
+ * @see RecyclerView.LayoutManager#findViewByPosition(int)
+ */
+ public View findViewByPosition(int position) {
+ return mRecyclerView.mLayout.findViewByPosition(position);
+ }
+
+ /**
+ * @see RecyclerView#scrollToPosition(int)
+ * @deprecated Use {@link Action#jumpTo(int)}.
+ */
+ @Deprecated
+ public void instantScrollToPosition(int position) {
+ mRecyclerView.scrollToPosition(position);
+ }
+
+ protected void onChildAttachedToWindow(View child) {
+ if (getChildPosition(child) == getTargetPosition()) {
+ mTargetView = child;
+ if (DEBUG) {
+ Log.d(TAG, "smooth scroll target view has been attached");
+ }
+ }
+ }
+
+ /**
+ * Normalizes the vector.
+ * @param scrollVector The vector that points to the target scroll position
+ */
+ protected void normalize(PointF scrollVector) {
+ final double magnitude = Math.sqrt(scrollVector.x * scrollVector.x + scrollVector.y
+ * scrollVector.y);
+ scrollVector.x /= magnitude;
+ scrollVector.y /= magnitude;
+ }
+
+ /**
+ * Called when smooth scroll is started. This might be a good time to do setup.
+ */
+ protected abstract void onStart();
+
+ /**
+ * Called when smooth scroller is stopped. This is a good place to cleanup your state etc.
+ * @see #stop()
+ */
+ protected abstract void onStop();
+
+ /**
+ * <p>RecyclerView will call this method each time it scrolls until it can find the target
+ * position in the layout.</p>
+ * <p>SmoothScroller should check dx, dy and if scroll should be changed, update the
+ * provided {@link Action} to define the next scroll.</p>
+ *
+ * @param dx Last scroll amount horizontally
+ * @param dy Last scroll amount vertically
+ * @param state Transient state of RecyclerView
+ * @param action If you want to trigger a new smooth scroll and cancel the previous one,
+ * update this object.
+ */
+ protected abstract void onSeekTargetStep(int dx, int dy, State state, Action action);
+
+ /**
+ * Called when the target position is laid out. This is the last callback SmoothScroller
+ * will receive and it should update the provided {@link Action} to define the scroll
+ * details towards the target view.
+ * @param targetView The view element which render the target position.
+ * @param state Transient state of RecyclerView
+ * @param action Action instance that you should update to define final scroll action
+ * towards the targetView
+ */
+ protected abstract void onTargetFound(View targetView, State state, Action action);
+
+ /**
+ * Holds information about a smooth scroll request by a {@link SmoothScroller}.
+ */
+ public static class Action {
+
+ public static final int UNDEFINED_DURATION = Integer.MIN_VALUE;
+
+ private int mDx;
+
+ private int mDy;
+
+ private int mDuration;
+
+ private int mJumpToPosition = NO_POSITION;
+
+ private Interpolator mInterpolator;
+
+ private boolean mChanged = false;
+
+ // we track this variable to inform custom implementer if they are updating the action
+ // in every animation callback
+ private int mConsecutiveUpdates = 0;
+
+ /**
+ * @param dx Pixels to scroll horizontally
+ * @param dy Pixels to scroll vertically
+ */
+ public Action(int dx, int dy) {
+ this(dx, dy, UNDEFINED_DURATION, null);
+ }
+
+ /**
+ * @param dx Pixels to scroll horizontally
+ * @param dy Pixels to scroll vertically
+ * @param duration Duration of the animation in milliseconds
+ */
+ public Action(int dx, int dy, int duration) {
+ this(dx, dy, duration, null);
+ }
+
+ /**
+ * @param dx Pixels to scroll horizontally
+ * @param dy Pixels to scroll vertically
+ * @param duration Duration of the animation in milliseconds
+ * @param interpolator Interpolator to be used when calculating scroll position in each
+ * animation step
+ */
+ public Action(int dx, int dy, int duration, Interpolator interpolator) {
+ mDx = dx;
+ mDy = dy;
+ mDuration = duration;
+ mInterpolator = interpolator;
+ }
+
+ /**
+ * Instead of specifying pixels to scroll, use the target position to jump using
+ * {@link RecyclerView#scrollToPosition(int)}.
+ * <p>
+ * You may prefer using this method if scroll target is really far away and you prefer
+ * to jump to a location and smooth scroll afterwards.
+ * <p>
+ * Note that calling this method takes priority over other update methods such as
+ * {@link #update(int, int, int, Interpolator)}, {@link #setX(float)},
+ * {@link #setY(float)} and #{@link #setInterpolator(Interpolator)}. If you call
+ * {@link #jumpTo(int)}, the other changes will not be considered for this animation
+ * frame.
+ *
+ * @param targetPosition The target item position to scroll to using instant scrolling.
+ */
+ public void jumpTo(int targetPosition) {
+ mJumpToPosition = targetPosition;
+ }
+
+ boolean hasJumpTarget() {
+ return mJumpToPosition >= 0;
+ }
+
+ void runIfNecessary(RecyclerView recyclerView) {
+ if (mJumpToPosition >= 0) {
+ final int position = mJumpToPosition;
+ mJumpToPosition = NO_POSITION;
+ recyclerView.jumpToPositionForSmoothScroller(position);
+ mChanged = false;
+ return;
+ }
+ if (mChanged) {
+ validate();
+ if (mInterpolator == null) {
+ if (mDuration == UNDEFINED_DURATION) {
+ recyclerView.mViewFlinger.smoothScrollBy(mDx, mDy);
+ } else {
+ recyclerView.mViewFlinger.smoothScrollBy(mDx, mDy, mDuration);
+ }
+ } else {
+ recyclerView.mViewFlinger.smoothScrollBy(
+ mDx, mDy, mDuration, mInterpolator);
+ }
+ mConsecutiveUpdates++;
+ if (mConsecutiveUpdates > 10) {
+ // A new action is being set in every animation step. This looks like a bad
+ // implementation. Inform developer.
+ Log.e(TAG, "Smooth Scroll action is being updated too frequently. Make sure"
+ + " you are not changing it unless necessary");
+ }
+ mChanged = false;
+ } else {
+ mConsecutiveUpdates = 0;
+ }
+ }
+
+ private void validate() {
+ if (mInterpolator != null && mDuration < 1) {
+ throw new IllegalStateException("If you provide an interpolator, you must"
+ + " set a positive duration");
+ } else if (mDuration < 1) {
+ throw new IllegalStateException("Scroll duration must be a positive number");
+ }
+ }
+
+ public int getDx() {
+ return mDx;
+ }
+
+ public void setDx(int dx) {
+ mChanged = true;
+ mDx = dx;
+ }
+
+ public int getDy() {
+ return mDy;
+ }
+
+ public void setDy(int dy) {
+ mChanged = true;
+ mDy = dy;
+ }
+
+ public int getDuration() {
+ return mDuration;
+ }
+
+ public void setDuration(int duration) {
+ mChanged = true;
+ mDuration = duration;
+ }
+
+ public Interpolator getInterpolator() {
+ return mInterpolator;
+ }
+
+ /**
+ * Sets the interpolator to calculate scroll steps
+ * @param interpolator The interpolator to use. If you specify an interpolator, you must
+ * also set the duration.
+ * @see #setDuration(int)
+ */
+ public void setInterpolator(Interpolator interpolator) {
+ mChanged = true;
+ mInterpolator = interpolator;
+ }
+
+ /**
+ * Updates the action with given parameters.
+ * @param dx Pixels to scroll horizontally
+ * @param dy Pixels to scroll vertically
+ * @param duration Duration of the animation in milliseconds
+ * @param interpolator Interpolator to be used when calculating scroll position in each
+ * animation step
+ */
+ public void update(int dx, int dy, int duration, Interpolator interpolator) {
+ mDx = dx;
+ mDy = dy;
+ mDuration = duration;
+ mInterpolator = interpolator;
+ mChanged = true;
+ }
+ }
+
+ /**
+ * An interface which is optionally implemented by custom {@link RecyclerView.LayoutManager}
+ * to provide a hint to a {@link SmoothScroller} about the location of the target position.
+ */
+ public interface ScrollVectorProvider {
+ /**
+ * Should calculate the vector that points to the direction where the target position
+ * can be found.
+ * <p>
+ * This method is used by the {@link LinearSmoothScroller} to initiate a scroll towards
+ * the target position.
+ * <p>
+ * The magnitude of the vector is not important. It is always normalized before being
+ * used by the {@link LinearSmoothScroller}.
+ * <p>
+ * LayoutManager should not check whether the position exists in the adapter or not.
+ *
+ * @param targetPosition the target position to which the returned vector should point
+ *
+ * @return the scroll vector for a given position.
+ */
+ PointF computeScrollVectorForPosition(int targetPosition);
+ }
+ }
+
+ static class AdapterDataObservable extends Observable<AdapterDataObserver> {
+ public boolean hasObservers() {
+ return !mObservers.isEmpty();
+ }
+
+ public void notifyChanged() {
+ // since onChanged() is implemented by the app, it could do anything, including
+ // removing itself from {@link mObservers} - and that could cause problems if
+ // an iterator is used on the ArrayList {@link mObservers}.
+ // to avoid such problems, just march thru the list in the reverse order.
+ for (int i = mObservers.size() - 1; i >= 0; i--) {
+ mObservers.get(i).onChanged();
+ }
+ }
+
+ public void notifyItemRangeChanged(int positionStart, int itemCount) {
+ notifyItemRangeChanged(positionStart, itemCount, null);
+ }
+
+ public void notifyItemRangeChanged(int positionStart, int itemCount, Object payload) {
+ // since onItemRangeChanged() is implemented by the app, it could do anything, including
+ // removing itself from {@link mObservers} - and that could cause problems if
+ // an iterator is used on the ArrayList {@link mObservers}.
+ // to avoid such problems, just march thru the list in the reverse order.
+ for (int i = mObservers.size() - 1; i >= 0; i--) {
+ mObservers.get(i).onItemRangeChanged(positionStart, itemCount, payload);
+ }
+ }
+
+ public void notifyItemRangeInserted(int positionStart, int itemCount) {
+ // since onItemRangeInserted() is implemented by the app, it could do anything,
+ // including removing itself from {@link mObservers} - and that could cause problems if
+ // an iterator is used on the ArrayList {@link mObservers}.
+ // to avoid such problems, just march thru the list in the reverse order.
+ for (int i = mObservers.size() - 1; i >= 0; i--) {
+ mObservers.get(i).onItemRangeInserted(positionStart, itemCount);
+ }
+ }
+
+ public void notifyItemRangeRemoved(int positionStart, int itemCount) {
+ // since onItemRangeRemoved() is implemented by the app, it could do anything, including
+ // removing itself from {@link mObservers} - and that could cause problems if
+ // an iterator is used on the ArrayList {@link mObservers}.
+ // to avoid such problems, just march thru the list in the reverse order.
+ for (int i = mObservers.size() - 1; i >= 0; i--) {
+ mObservers.get(i).onItemRangeRemoved(positionStart, itemCount);
+ }
+ }
+
+ public void notifyItemMoved(int fromPosition, int toPosition) {
+ for (int i = mObservers.size() - 1; i >= 0; i--) {
+ mObservers.get(i).onItemRangeMoved(fromPosition, toPosition, 1);
+ }
+ }
+ }
+
+ /**
+ * This is public so that the CREATOR can be access on cold launch.
+ * @hide
+ */
+ public static class SavedState extends AbsSavedState {
+
+ Parcelable mLayoutState;
+
+ /**
+ * called by CREATOR
+ */
+ SavedState(Parcel in) {
+ super(in);
+ mLayoutState = in.readParcelable(LayoutManager.class.getClassLoader());
+ }
+
+ /**
+ * Called by onSaveInstanceState
+ */
+ SavedState(Parcelable superState) {
+ super(superState);
+ }
+
+ @Override
+ public void writeToParcel(Parcel dest, int flags) {
+ super.writeToParcel(dest, flags);
+ dest.writeParcelable(mLayoutState, 0);
+ }
+
+ void copyFrom(SavedState other) {
+ mLayoutState = other.mLayoutState;
+ }
+
+ public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
+ @Override
+ public SavedState createFromParcel(Parcel in) {
+ return new SavedState(in);
+ }
+
+ @Override
+ public SavedState[] newArray(int size) {
+ return new SavedState[size];
+ }
+ };
+ }
+ /**
+ * <p>Contains useful information about the current RecyclerView state like target scroll
+ * position or view focus. State object can also keep arbitrary data, identified by resource
+ * ids.</p>
+ * <p>Often times, RecyclerView components will need to pass information between each other.
+ * To provide a well defined data bus between components, RecyclerView passes the same State
+ * object to component callbacks and these components can use it to exchange data.</p>
+ * <p>If you implement custom components, you can use State's put/get/remove methods to pass
+ * data between your components without needing to manage their lifecycles.</p>
+ */
+ public static class State {
+ static final int STEP_START = 1;
+ static final int STEP_LAYOUT = 1 << 1;
+ static final int STEP_ANIMATIONS = 1 << 2;
+
+ void assertLayoutStep(int accepted) {
+ if ((accepted & mLayoutStep) == 0) {
+ throw new IllegalStateException("Layout state should be one of "
+ + Integer.toBinaryString(accepted) + " but it is "
+ + Integer.toBinaryString(mLayoutStep));
+ }
+ }
+
+
+ /** Owned by SmoothScroller */
+ private int mTargetPosition = RecyclerView.NO_POSITION;
+
+ private SparseArray<Object> mData;
+
+ ////////////////////////////////////////////////////////////////////////////////////////////
+ // Fields below are carried from one layout pass to the next
+ ////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Number of items adapter had in the previous layout.
+ */
+ int mPreviousLayoutItemCount = 0;
+
+ /**
+ * Number of items that were NOT laid out but has been deleted from the adapter after the
+ * previous layout.
+ */
+ int mDeletedInvisibleItemCountSincePreviousLayout = 0;
+
+ ////////////////////////////////////////////////////////////////////////////////////////////
+ // Fields below must be updated or cleared before they are used (generally before a pass)
+ ////////////////////////////////////////////////////////////////////////////////////////////
+
+ @IntDef(flag = true, value = {
+ STEP_START, STEP_LAYOUT, STEP_ANIMATIONS
+ })
+ @Retention(RetentionPolicy.SOURCE)
+ @interface LayoutState {}
+
+ @LayoutState
+ int mLayoutStep = STEP_START;
+
+ /**
+ * Number of items adapter has.
+ */
+ int mItemCount = 0;
+
+ boolean mStructureChanged = false;
+
+ boolean mInPreLayout = false;
+
+ boolean mTrackOldChangeHolders = false;
+
+ boolean mIsMeasuring = false;
+
+ ////////////////////////////////////////////////////////////////////////////////////////////
+ // Fields below are always reset outside of the pass (or passes) that use them
+ ////////////////////////////////////////////////////////////////////////////////////////////
+
+ boolean mRunSimpleAnimations = false;
+
+ boolean mRunPredictiveAnimations = false;
+
+ /**
+ * This data is saved before a layout calculation happens. After the layout is finished,
+ * if the previously focused view has been replaced with another view for the same item, we
+ * move the focus to the new item automatically.
+ */
+ int mFocusedItemPosition;
+ long mFocusedItemId;
+ // when a sub child has focus, record its id and see if we can directly request focus on
+ // that one instead
+ int mFocusedSubChildId;
+
+ ////////////////////////////////////////////////////////////////////////////////////////////
+
+ State reset() {
+ mTargetPosition = RecyclerView.NO_POSITION;
+ if (mData != null) {
+ mData.clear();
+ }
+ mItemCount = 0;
+ mStructureChanged = false;
+ mIsMeasuring = false;
+ return this;
+ }
+
+ /**
+ * Prepare for a prefetch occurring on the RecyclerView in between traversals, potentially
+ * prior to any layout passes.
+ *
+ * <p>Don't touch any state stored between layout passes, only reset per-layout state, so
+ * that Recycler#getViewForPosition() can function safely.</p>
+ */
+ void prepareForNestedPrefetch(Adapter adapter) {
+ mLayoutStep = STEP_START;
+ mItemCount = adapter.getItemCount();
+ mStructureChanged = false;
+ mInPreLayout = false;
+ mTrackOldChangeHolders = false;
+ mIsMeasuring = false;
+ }
+
+ /**
+ * Returns true if the RecyclerView is currently measuring the layout. This value is
+ * {@code true} only if the LayoutManager opted into the auto measure API and RecyclerView
+ * has non-exact measurement specs.
+ * <p>
+ * Note that if the LayoutManager supports predictive animations and it is calculating the
+ * pre-layout step, this value will be {@code false} even if the RecyclerView is in
+ * {@code onMeasure} call. This is because pre-layout means the previous state of the
+ * RecyclerView and measurements made for that state cannot change the RecyclerView's size.
+ * LayoutManager is always guaranteed to receive another call to
+ * {@link LayoutManager#onLayoutChildren(Recycler, State)} when this happens.
+ *
+ * @return True if the RecyclerView is currently calculating its bounds, false otherwise.
+ */
+ public boolean isMeasuring() {
+ return mIsMeasuring;
+ }
+
+ /**
+ * Returns true if
+ * @return
+ */
+ public boolean isPreLayout() {
+ return mInPreLayout;
+ }
+
+ /**
+ * Returns whether RecyclerView will run predictive animations in this layout pass
+ * or not.
+ *
+ * @return true if RecyclerView is calculating predictive animations to be run at the end
+ * of the layout pass.
+ */
+ public boolean willRunPredictiveAnimations() {
+ return mRunPredictiveAnimations;
+ }
+
+ /**
+ * Returns whether RecyclerView will run simple animations in this layout pass
+ * or not.
+ *
+ * @return true if RecyclerView is calculating simple animations to be run at the end of
+ * the layout pass.
+ */
+ public boolean willRunSimpleAnimations() {
+ return mRunSimpleAnimations;
+ }
+
+ /**
+ * Removes the mapping from the specified id, if there was any.
+ * @param resourceId Id of the resource you want to remove. It is suggested to use R.id.* to
+ * preserve cross functionality and avoid conflicts.
+ */
+ public void remove(int resourceId) {
+ if (mData == null) {
+ return;
+ }
+ mData.remove(resourceId);
+ }
+
+ /**
+ * Gets the Object mapped from the specified id, or <code>null</code>
+ * if no such data exists.
+ *
+ * @param resourceId Id of the resource you want to remove. It is suggested to use R.id.*
+ * to
+ * preserve cross functionality and avoid conflicts.
+ */
+ public <T> T get(int resourceId) {
+ if (mData == null) {
+ return null;
+ }
+ return (T) mData.get(resourceId);
+ }
+
+ /**
+ * Adds a mapping from the specified id to the specified value, replacing the previous
+ * mapping from the specified key if there was one.
+ *
+ * @param resourceId Id of the resource you want to add. It is suggested to use R.id.* to
+ * preserve cross functionality and avoid conflicts.
+ * @param data The data you want to associate with the resourceId.
+ */
+ public void put(int resourceId, Object data) {
+ if (mData == null) {
+ mData = new SparseArray<Object>();
+ }
+ mData.put(resourceId, data);
+ }
+
+ /**
+ * If scroll is triggered to make a certain item visible, this value will return the
+ * adapter index of that item.
+ * @return Adapter index of the target item or
+ * {@link RecyclerView#NO_POSITION} if there is no target
+ * position.
+ */
+ public int getTargetScrollPosition() {
+ return mTargetPosition;
+ }
+
+ /**
+ * Returns if current scroll has a target position.
+ * @return true if scroll is being triggered to make a certain position visible
+ * @see #getTargetScrollPosition()
+ */
+ public boolean hasTargetScrollPosition() {
+ return mTargetPosition != RecyclerView.NO_POSITION;
+ }
+
+ /**
+ * @return true if the structure of the data set has changed since the last call to
+ * onLayoutChildren, false otherwise
+ */
+ public boolean didStructureChange() {
+ return mStructureChanged;
+ }
+
+ /**
+ * Returns the total number of items that can be laid out. Note that this number is not
+ * necessarily equal to the number of items in the adapter, so you should always use this
+ * number for your position calculations and never access the adapter directly.
+ * <p>
+ * RecyclerView listens for Adapter's notify events and calculates the effects of adapter
+ * data changes on existing Views. These calculations are used to decide which animations
+ * should be run.
+ * <p>
+ * To support predictive animations, RecyclerView may rewrite or reorder Adapter changes to
+ * present the correct state to LayoutManager in pre-layout pass.
+ * <p>
+ * For example, a newly added item is not included in pre-layout item count because
+ * pre-layout reflects the contents of the adapter before the item is added. Behind the
+ * scenes, RecyclerView offsets {@link Recycler#getViewForPosition(int)} calls such that
+ * LayoutManager does not know about the new item's existence in pre-layout. The item will
+ * be available in second layout pass and will be included in the item count. Similar
+ * adjustments are made for moved and removed items as well.
+ * <p>
+ * You can get the adapter's item count via {@link LayoutManager#getItemCount()} method.
+ *
+ * @return The number of items currently available
+ * @see LayoutManager#getItemCount()
+ */
+ public int getItemCount() {
+ return mInPreLayout
+ ? (mPreviousLayoutItemCount - mDeletedInvisibleItemCountSincePreviousLayout)
+ : mItemCount;
+ }
+
+ @Override
+ public String toString() {
+ return "State{"
+ + "mTargetPosition=" + mTargetPosition
+ + ", mData=" + mData
+ + ", mItemCount=" + mItemCount
+ + ", mPreviousLayoutItemCount=" + mPreviousLayoutItemCount
+ + ", mDeletedInvisibleItemCountSincePreviousLayout="
+ + mDeletedInvisibleItemCountSincePreviousLayout
+ + ", mStructureChanged=" + mStructureChanged
+ + ", mInPreLayout=" + mInPreLayout
+ + ", mRunSimpleAnimations=" + mRunSimpleAnimations
+ + ", mRunPredictiveAnimations=" + mRunPredictiveAnimations
+ + '}';
+ }
+ }
+
+ /**
+ * This class defines the behavior of fling if the developer wishes to handle it.
+ * <p>
+ * Subclasses of {@link OnFlingListener} can be used to implement custom fling behavior.
+ *
+ * @see #setOnFlingListener(OnFlingListener)
+ */
+ public abstract static class OnFlingListener {
+
+ /**
+ * Override this to handle a fling given the velocities in both x and y directions.
+ * Note that this method will only be called if the associated {@link LayoutManager}
+ * supports scrolling and the fling is not handled by nested scrolls first.
+ *
+ * @param velocityX the fling velocity on the X axis
+ * @param velocityY the fling velocity on the Y axis
+ *
+ * @return true if the fling washandled, false otherwise.
+ */
+ public abstract boolean onFling(int velocityX, int velocityY);
+ }
+
+ /**
+ * Internal listener that manages items after animations finish. This is how items are
+ * retained (not recycled) during animations, but allowed to be recycled afterwards.
+ * It depends on the contract with the ItemAnimator to call the appropriate dispatch*Finished()
+ * method on the animator's listener when it is done animating any item.
+ */
+ private class ItemAnimatorRestoreListener implements ItemAnimator.ItemAnimatorListener {
+
+ ItemAnimatorRestoreListener() {
+ }
+
+ @Override
+ public void onAnimationFinished(ViewHolder item) {
+ item.setIsRecyclable(true);
+ if (item.mShadowedHolder != null && item.mShadowingHolder == null) { // old vh
+ item.mShadowedHolder = null;
+ }
+ // always null this because an OldViewHolder can never become NewViewHolder w/o being
+ // recycled.
+ item.mShadowingHolder = null;
+ if (!item.shouldBeKeptAsChild()) {
+ if (!removeAnimatingView(item.itemView) && item.isTmpDetached()) {
+ removeDetachedView(item.itemView, false);
+ }
+ }
+ }
+ }
+
+ /**
+ * This class defines the animations that take place on items as changes are made
+ * to the adapter.
+ *
+ * Subclasses of ItemAnimator can be used to implement custom animations for actions on
+ * ViewHolder items. The RecyclerView will manage retaining these items while they
+ * are being animated, but implementors must call {@link #dispatchAnimationFinished(ViewHolder)}
+ * when a ViewHolder's animation is finished. In other words, there must be a matching
+ * {@link #dispatchAnimationFinished(ViewHolder)} call for each
+ * {@link #animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo) animateAppearance()},
+ * {@link #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateChange()}
+ * {@link #animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo) animatePersistence()},
+ * and
+ * {@link #animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateDisappearance()} call.
+ *
+ * <p>By default, RecyclerView uses {@link DefaultItemAnimator}.</p>
+ *
+ * @see #setItemAnimator(ItemAnimator)
+ */
+ @SuppressWarnings("UnusedParameters")
+ public abstract static class ItemAnimator {
+
+ /**
+ * The Item represented by this ViewHolder is updated.
+ * <p>
+ * @see #recordPreLayoutInformation(State, ViewHolder, int, List)
+ */
+ public static final int FLAG_CHANGED = ViewHolder.FLAG_UPDATE;
+
+ /**
+ * The Item represented by this ViewHolder is removed from the adapter.
+ * <p>
+ * @see #recordPreLayoutInformation(State, ViewHolder, int, List)
+ */
+ public static final int FLAG_REMOVED = ViewHolder.FLAG_REMOVED;
+
+ /**
+ * Adapter {@link Adapter#notifyDataSetChanged()} has been called and the content
+ * represented by this ViewHolder is invalid.
+ * <p>
+ * @see #recordPreLayoutInformation(State, ViewHolder, int, List)
+ */
+ public static final int FLAG_INVALIDATED = ViewHolder.FLAG_INVALID;
+
+ /**
+ * The position of the Item represented by this ViewHolder has been changed. This flag is
+ * not bound to {@link Adapter#notifyItemMoved(int, int)}. It might be set in response to
+ * any adapter change that may have a side effect on this item. (e.g. The item before this
+ * one has been removed from the Adapter).
+ * <p>
+ * @see #recordPreLayoutInformation(State, ViewHolder, int, List)
+ */
+ public static final int FLAG_MOVED = ViewHolder.FLAG_MOVED;
+
+ /**
+ * This ViewHolder was not laid out but has been added to the layout in pre-layout state
+ * by the {@link LayoutManager}. This means that the item was already in the Adapter but
+ * invisible and it may become visible in the post layout phase. LayoutManagers may prefer
+ * to add new items in pre-layout to specify their virtual location when they are invisible
+ * (e.g. to specify the item should <i>animate in</i> from below the visible area).
+ * <p>
+ * @see #recordPreLayoutInformation(State, ViewHolder, int, List)
+ */
+ public static final int FLAG_APPEARED_IN_PRE_LAYOUT =
+ ViewHolder.FLAG_APPEARED_IN_PRE_LAYOUT;
+
+ /**
+ * The set of flags that might be passed to
+ * {@link #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ */
+ @IntDef(flag = true, value = {
+ FLAG_CHANGED, FLAG_REMOVED, FLAG_MOVED, FLAG_INVALIDATED,
+ FLAG_APPEARED_IN_PRE_LAYOUT
+ })
+ @Retention(RetentionPolicy.SOURCE)
+ public @interface AdapterChanges {}
+ private ItemAnimatorListener mListener = null;
+ private ArrayList<ItemAnimatorFinishedListener> mFinishedListeners =
+ new ArrayList<ItemAnimatorFinishedListener>();
+
+ private long mAddDuration = 120;
+ private long mRemoveDuration = 120;
+ private long mMoveDuration = 250;
+ private long mChangeDuration = 250;
+
+ /**
+ * Gets the current duration for which all move animations will run.
+ *
+ * @return The current move duration
+ */
+ public long getMoveDuration() {
+ return mMoveDuration;
+ }
+
+ /**
+ * Sets the duration for which all move animations will run.
+ *
+ * @param moveDuration The move duration
+ */
+ public void setMoveDuration(long moveDuration) {
+ mMoveDuration = moveDuration;
+ }
+
+ /**
+ * Gets the current duration for which all add animations will run.
+ *
+ * @return The current add duration
+ */
+ public long getAddDuration() {
+ return mAddDuration;
+ }
+
+ /**
+ * Sets the duration for which all add animations will run.
+ *
+ * @param addDuration The add duration
+ */
+ public void setAddDuration(long addDuration) {
+ mAddDuration = addDuration;
+ }
+
+ /**
+ * Gets the current duration for which all remove animations will run.
+ *
+ * @return The current remove duration
+ */
+ public long getRemoveDuration() {
+ return mRemoveDuration;
+ }
+
+ /**
+ * Sets the duration for which all remove animations will run.
+ *
+ * @param removeDuration The remove duration
+ */
+ public void setRemoveDuration(long removeDuration) {
+ mRemoveDuration = removeDuration;
+ }
+
+ /**
+ * Gets the current duration for which all change animations will run.
+ *
+ * @return The current change duration
+ */
+ public long getChangeDuration() {
+ return mChangeDuration;
+ }
+
+ /**
+ * Sets the duration for which all change animations will run.
+ *
+ * @param changeDuration The change duration
+ */
+ public void setChangeDuration(long changeDuration) {
+ mChangeDuration = changeDuration;
+ }
+
+ /**
+ * Internal only:
+ * Sets the listener that must be called when the animator is finished
+ * animating the item (or immediately if no animation happens). This is set
+ * internally and is not intended to be set by external code.
+ *
+ * @param listener The listener that must be called.
+ */
+ void setListener(ItemAnimatorListener listener) {
+ mListener = listener;
+ }
+
+ /**
+ * Called by the RecyclerView before the layout begins. Item animator should record
+ * necessary information about the View before it is potentially rebound, moved or removed.
+ * <p>
+ * The data returned from this method will be passed to the related <code>animate**</code>
+ * methods.
+ * <p>
+ * Note that this method may be called after pre-layout phase if LayoutManager adds new
+ * Views to the layout in pre-layout pass.
+ * <p>
+ * The default implementation returns an {@link ItemHolderInfo} which holds the bounds of
+ * the View and the adapter change flags.
+ *
+ * @param state The current State of RecyclerView which includes some useful data
+ * about the layout that will be calculated.
+ * @param viewHolder The ViewHolder whose information should be recorded.
+ * @param changeFlags Additional information about what changes happened in the Adapter
+ * about the Item represented by this ViewHolder. For instance, if
+ * item is deleted from the adapter, {@link #FLAG_REMOVED} will be set.
+ * @param payloads The payload list that was previously passed to
+ * {@link Adapter#notifyItemChanged(int, Object)} or
+ * {@link Adapter#notifyItemRangeChanged(int, int, Object)}.
+ *
+ * @return An ItemHolderInfo instance that preserves necessary information about the
+ * ViewHolder. This object will be passed back to related <code>animate**</code> methods
+ * after layout is complete.
+ *
+ * @see #recordPostLayoutInformation(State, ViewHolder)
+ * @see #animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * @see #animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * @see #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * @see #animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ */
+ public @NonNull ItemHolderInfo recordPreLayoutInformation(@NonNull State state,
+ @NonNull ViewHolder viewHolder, @AdapterChanges int changeFlags,
+ @NonNull List<Object> payloads) {
+ return obtainHolderInfo().setFrom(viewHolder);
+ }
+
+ /**
+ * Called by the RecyclerView after the layout is complete. Item animator should record
+ * necessary information about the View's final state.
+ * <p>
+ * The data returned from this method will be passed to the related <code>animate**</code>
+ * methods.
+ * <p>
+ * The default implementation returns an {@link ItemHolderInfo} which holds the bounds of
+ * the View.
+ *
+ * @param state The current State of RecyclerView which includes some useful data about
+ * the layout that will be calculated.
+ * @param viewHolder The ViewHolder whose information should be recorded.
+ *
+ * @return An ItemHolderInfo that preserves necessary information about the ViewHolder.
+ * This object will be passed back to related <code>animate**</code> methods when
+ * RecyclerView decides how items should be animated.
+ *
+ * @see #recordPreLayoutInformation(State, ViewHolder, int, List)
+ * @see #animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * @see #animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * @see #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * @see #animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ */
+ public @NonNull ItemHolderInfo recordPostLayoutInformation(@NonNull State state,
+ @NonNull ViewHolder viewHolder) {
+ return obtainHolderInfo().setFrom(viewHolder);
+ }
+
+ /**
+ * Called by the RecyclerView when a ViewHolder has disappeared from the layout.
+ * <p>
+ * This means that the View was a child of the LayoutManager when layout started but has
+ * been removed by the LayoutManager. It might have been removed from the adapter or simply
+ * become invisible due to other factors. You can distinguish these two cases by checking
+ * the change flags that were passed to
+ * {@link #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ * <p>
+ * Note that when a ViewHolder both changes and disappears in the same layout pass, the
+ * animation callback method which will be called by the RecyclerView depends on the
+ * ItemAnimator's decision whether to re-use the same ViewHolder or not, and also the
+ * LayoutManager's decision whether to layout the changed version of a disappearing
+ * ViewHolder or not. RecyclerView will call
+ * {@link #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateChange} instead of {@code animateDisappearance} if and only if the ItemAnimator
+ * returns {@code false} from
+ * {@link #canReuseUpdatedViewHolder(ViewHolder) canReuseUpdatedViewHolder} and the
+ * LayoutManager lays out a new disappearing view that holds the updated information.
+ * Built-in LayoutManagers try to avoid laying out updated versions of disappearing views.
+ * <p>
+ * If LayoutManager supports predictive animations, it might provide a target disappear
+ * location for the View by laying it out in that location. When that happens,
+ * RecyclerView will call {@link #recordPostLayoutInformation(State, ViewHolder)} and the
+ * response of that call will be passed to this method as the <code>postLayoutInfo</code>.
+ * <p>
+ * ItemAnimator must call {@link #dispatchAnimationFinished(ViewHolder)} when the animation
+ * is complete (or instantly call {@link #dispatchAnimationFinished(ViewHolder)} if it
+ * decides not to animate the view).
+ *
+ * @param viewHolder The ViewHolder which should be animated
+ * @param preLayoutInfo The information that was returned from
+ * {@link #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ * @param postLayoutInfo The information that was returned from
+ * {@link #recordPostLayoutInformation(State, ViewHolder)}. Might be
+ * null if the LayoutManager did not layout the item.
+ *
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animateDisappearance(@NonNull ViewHolder viewHolder,
+ @NonNull ItemHolderInfo preLayoutInfo, @Nullable ItemHolderInfo postLayoutInfo);
+
+ /**
+ * Called by the RecyclerView when a ViewHolder is added to the layout.
+ * <p>
+ * In detail, this means that the ViewHolder was <b>not</b> a child when the layout started
+ * but has been added by the LayoutManager. It might be newly added to the adapter or
+ * simply become visible due to other factors.
+ * <p>
+ * ItemAnimator must call {@link #dispatchAnimationFinished(ViewHolder)} when the animation
+ * is complete (or instantly call {@link #dispatchAnimationFinished(ViewHolder)} if it
+ * decides not to animate the view).
+ *
+ * @param viewHolder The ViewHolder which should be animated
+ * @param preLayoutInfo The information that was returned from
+ * {@link #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ * Might be null if Item was just added to the adapter or
+ * LayoutManager does not support predictive animations or it could
+ * not predict that this ViewHolder will become visible.
+ * @param postLayoutInfo The information that was returned from {@link
+ * #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ *
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animateAppearance(@NonNull ViewHolder viewHolder,
+ @Nullable ItemHolderInfo preLayoutInfo, @NonNull ItemHolderInfo postLayoutInfo);
+
+ /**
+ * Called by the RecyclerView when a ViewHolder is present in both before and after the
+ * layout and RecyclerView has not received a {@link Adapter#notifyItemChanged(int)} call
+ * for it or a {@link Adapter#notifyDataSetChanged()} call.
+ * <p>
+ * This ViewHolder still represents the same data that it was representing when the layout
+ * started but its position / size may be changed by the LayoutManager.
+ * <p>
+ * If the Item's layout position didn't change, RecyclerView still calls this method because
+ * it does not track this information (or does not necessarily know that an animation is
+ * not required). Your ItemAnimator should handle this case and if there is nothing to
+ * animate, it should call {@link #dispatchAnimationFinished(ViewHolder)} and return
+ * <code>false</code>.
+ * <p>
+ * ItemAnimator must call {@link #dispatchAnimationFinished(ViewHolder)} when the animation
+ * is complete (or instantly call {@link #dispatchAnimationFinished(ViewHolder)} if it
+ * decides not to animate the view).
+ *
+ * @param viewHolder The ViewHolder which should be animated
+ * @param preLayoutInfo The information that was returned from
+ * {@link #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ * @param postLayoutInfo The information that was returned from {@link
+ * #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ *
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animatePersistence(@NonNull ViewHolder viewHolder,
+ @NonNull ItemHolderInfo preLayoutInfo, @NonNull ItemHolderInfo postLayoutInfo);
+
+ /**
+ * Called by the RecyclerView when an adapter item is present both before and after the
+ * layout and RecyclerView has received a {@link Adapter#notifyItemChanged(int)} call
+ * for it. This method may also be called when
+ * {@link Adapter#notifyDataSetChanged()} is called and adapter has stable ids so that
+ * RecyclerView could still rebind views to the same ViewHolders. If viewType changes when
+ * {@link Adapter#notifyDataSetChanged()} is called, this method <b>will not</b> be called,
+ * instead, {@link #animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)} will be
+ * called for the new ViewHolder and the old one will be recycled.
+ * <p>
+ * If this method is called due to a {@link Adapter#notifyDataSetChanged()} call, there is
+ * a good possibility that item contents didn't really change but it is rebound from the
+ * adapter. {@link DefaultItemAnimator} will skip animating the View if its location on the
+ * screen didn't change and your animator should handle this case as well and avoid creating
+ * unnecessary animations.
+ * <p>
+ * When an item is updated, ItemAnimator has a chance to ask RecyclerView to keep the
+ * previous presentation of the item as-is and supply a new ViewHolder for the updated
+ * presentation (see: {@link #canReuseUpdatedViewHolder(ViewHolder, List)}.
+ * This is useful if you don't know the contents of the Item and would like
+ * to cross-fade the old and the new one ({@link DefaultItemAnimator} uses this technique).
+ * <p>
+ * When you are writing a custom item animator for your layout, it might be more performant
+ * and elegant to re-use the same ViewHolder and animate the content changes manually.
+ * <p>
+ * When {@link Adapter#notifyItemChanged(int)} is called, the Item's view type may change.
+ * If the Item's view type has changed or ItemAnimator returned <code>false</code> for
+ * this ViewHolder when {@link #canReuseUpdatedViewHolder(ViewHolder, List)} was called, the
+ * <code>oldHolder</code> and <code>newHolder</code> will be different ViewHolder instances
+ * which represent the same Item. In that case, only the new ViewHolder is visible
+ * to the LayoutManager but RecyclerView keeps old ViewHolder attached for animations.
+ * <p>
+ * ItemAnimator must call {@link #dispatchAnimationFinished(ViewHolder)} for each distinct
+ * ViewHolder when their animation is complete
+ * (or instantly call {@link #dispatchAnimationFinished(ViewHolder)} if it decides not to
+ * animate the view).
+ * <p>
+ * If oldHolder and newHolder are the same instance, you should call
+ * {@link #dispatchAnimationFinished(ViewHolder)} <b>only once</b>.
+ * <p>
+ * Note that when a ViewHolder both changes and disappears in the same layout pass, the
+ * animation callback method which will be called by the RecyclerView depends on the
+ * ItemAnimator's decision whether to re-use the same ViewHolder or not, and also the
+ * LayoutManager's decision whether to layout the changed version of a disappearing
+ * ViewHolder or not. RecyclerView will call
+ * {@code animateChange} instead of
+ * {@link #animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateDisappearance} if and only if the ItemAnimator returns {@code false} from
+ * {@link #canReuseUpdatedViewHolder(ViewHolder) canReuseUpdatedViewHolder} and the
+ * LayoutManager lays out a new disappearing view that holds the updated information.
+ * Built-in LayoutManagers try to avoid laying out updated versions of disappearing views.
+ *
+ * @param oldHolder The ViewHolder before the layout is started, might be the same
+ * instance with newHolder.
+ * @param newHolder The ViewHolder after the layout is finished, might be the same
+ * instance with oldHolder.
+ * @param preLayoutInfo The information that was returned from
+ * {@link #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ * @param postLayoutInfo The information that was returned from {@link
+ * #recordPreLayoutInformation(State, ViewHolder, int, List)}.
+ *
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animateChange(@NonNull ViewHolder oldHolder,
+ @NonNull ViewHolder newHolder,
+ @NonNull ItemHolderInfo preLayoutInfo, @NonNull ItemHolderInfo postLayoutInfo);
+
+ @AdapterChanges static int buildAdapterChangeFlagsForAnimations(ViewHolder viewHolder) {
+ int flags = viewHolder.mFlags & (FLAG_INVALIDATED | FLAG_REMOVED | FLAG_CHANGED);
+ if (viewHolder.isInvalid()) {
+ return FLAG_INVALIDATED;
+ }
+ if ((flags & FLAG_INVALIDATED) == 0) {
+ final int oldPos = viewHolder.getOldPosition();
+ final int pos = viewHolder.getAdapterPosition();
+ if (oldPos != NO_POSITION && pos != NO_POSITION && oldPos != pos) {
+ flags |= FLAG_MOVED;
+ }
+ }
+ return flags;
+ }
+
+ /**
+ * Called when there are pending animations waiting to be started. This state
+ * is governed by the return values from
+ * {@link #animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateAppearance()},
+ * {@link #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateChange()}
+ * {@link #animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animatePersistence()}, and
+ * {@link #animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateDisappearance()}, which inform the RecyclerView that the ItemAnimator wants to be
+ * called later to start the associated animations. runPendingAnimations() will be scheduled
+ * to be run on the next frame.
+ */
+ public abstract void runPendingAnimations();
+
+ /**
+ * Method called when an animation on a view should be ended immediately.
+ * This could happen when other events, like scrolling, occur, so that
+ * animating views can be quickly put into their proper end locations.
+ * Implementations should ensure that any animations running on the item
+ * are canceled and affected properties are set to their end values.
+ * Also, {@link #dispatchAnimationFinished(ViewHolder)} should be called for each finished
+ * animation since the animations are effectively done when this method is called.
+ *
+ * @param item The item for which an animation should be stopped.
+ */
+ public abstract void endAnimation(ViewHolder item);
+
+ /**
+ * Method called when all item animations should be ended immediately.
+ * This could happen when other events, like scrolling, occur, so that
+ * animating views can be quickly put into their proper end locations.
+ * Implementations should ensure that any animations running on any items
+ * are canceled and affected properties are set to their end values.
+ * Also, {@link #dispatchAnimationFinished(ViewHolder)} should be called for each finished
+ * animation since the animations are effectively done when this method is called.
+ */
+ public abstract void endAnimations();
+
+ /**
+ * Method which returns whether there are any item animations currently running.
+ * This method can be used to determine whether to delay other actions until
+ * animations end.
+ *
+ * @return true if there are any item animations currently running, false otherwise.
+ */
+ public abstract boolean isRunning();
+
+ /**
+ * Method to be called by subclasses when an animation is finished.
+ * <p>
+ * For each call RecyclerView makes to
+ * {@link #animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateAppearance()},
+ * {@link #animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animatePersistence()}, or
+ * {@link #animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateDisappearance()}, there
+ * should
+ * be a matching {@link #dispatchAnimationFinished(ViewHolder)} call by the subclass.
+ * <p>
+ * For {@link #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateChange()}, subclass should call this method for both the <code>oldHolder</code>
+ * and <code>newHolder</code> (if they are not the same instance).
+ *
+ * @param viewHolder The ViewHolder whose animation is finished.
+ * @see #onAnimationFinished(ViewHolder)
+ */
+ public final void dispatchAnimationFinished(ViewHolder viewHolder) {
+ onAnimationFinished(viewHolder);
+ if (mListener != null) {
+ mListener.onAnimationFinished(viewHolder);
+ }
+ }
+
+ /**
+ * Called after {@link #dispatchAnimationFinished(ViewHolder)} is called by the
+ * ItemAnimator.
+ *
+ * @param viewHolder The ViewHolder whose animation is finished. There might still be other
+ * animations running on this ViewHolder.
+ * @see #dispatchAnimationFinished(ViewHolder)
+ */
+ public void onAnimationFinished(ViewHolder viewHolder) {
+ }
+
+ /**
+ * Method to be called by subclasses when an animation is started.
+ * <p>
+ * For each call RecyclerView makes to
+ * {@link #animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateAppearance()},
+ * {@link #animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animatePersistence()}, or
+ * {@link #animateDisappearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateDisappearance()}, there should be a matching
+ * {@link #dispatchAnimationStarted(ViewHolder)} call by the subclass.
+ * <p>
+ * For {@link #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * animateChange()}, subclass should call this method for both the <code>oldHolder</code>
+ * and <code>newHolder</code> (if they are not the same instance).
+ * <p>
+ * If your ItemAnimator decides not to animate a ViewHolder, it should call
+ * {@link #dispatchAnimationFinished(ViewHolder)} <b>without</b> calling
+ * {@link #dispatchAnimationStarted(ViewHolder)}.
+ *
+ * @param viewHolder The ViewHolder whose animation is starting.
+ * @see #onAnimationStarted(ViewHolder)
+ */
+ public final void dispatchAnimationStarted(ViewHolder viewHolder) {
+ onAnimationStarted(viewHolder);
+ }
+
+ /**
+ * Called when a new animation is started on the given ViewHolder.
+ *
+ * @param viewHolder The ViewHolder which started animating. Note that the ViewHolder
+ * might already be animating and this might be another animation.
+ * @see #dispatchAnimationStarted(ViewHolder)
+ */
+ public void onAnimationStarted(ViewHolder viewHolder) {
+
+ }
+
+ /**
+ * Like {@link #isRunning()}, this method returns whether there are any item
+ * animations currently running. Additionally, the listener passed in will be called
+ * when there are no item animations running, either immediately (before the method
+ * returns) if no animations are currently running, or when the currently running
+ * animations are {@link #dispatchAnimationsFinished() finished}.
+ *
+ * <p>Note that the listener is transient - it is either called immediately and not
+ * stored at all, or stored only until it is called when running animations
+ * are finished sometime later.</p>
+ *
+ * @param listener A listener to be called immediately if no animations are running
+ * or later when currently-running animations have finished. A null listener is
+ * equivalent to calling {@link #isRunning()}.
+ * @return true if there are any item animations currently running, false otherwise.
+ */
+ public final boolean isRunning(ItemAnimatorFinishedListener listener) {
+ boolean running = isRunning();
+ if (listener != null) {
+ if (!running) {
+ listener.onAnimationsFinished();
+ } else {
+ mFinishedListeners.add(listener);
+ }
+ }
+ return running;
+ }
+
+ /**
+ * When an item is changed, ItemAnimator can decide whether it wants to re-use
+ * the same ViewHolder for animations or RecyclerView should create a copy of the
+ * item and ItemAnimator will use both to run the animation (e.g. cross-fade).
+ * <p>
+ * Note that this method will only be called if the {@link ViewHolder} still has the same
+ * type ({@link Adapter#getItemViewType(int)}). Otherwise, ItemAnimator will always receive
+ * both {@link ViewHolder}s in the
+ * {@link #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)} method.
+ * <p>
+ * If your application is using change payloads, you can override
+ * {@link #canReuseUpdatedViewHolder(ViewHolder, List)} to decide based on payloads.
+ *
+ * @param viewHolder The ViewHolder which represents the changed item's old content.
+ *
+ * @return True if RecyclerView should just rebind to the same ViewHolder or false if
+ * RecyclerView should create a new ViewHolder and pass this ViewHolder to the
+ * ItemAnimator to animate. Default implementation returns <code>true</code>.
+ *
+ * @see #canReuseUpdatedViewHolder(ViewHolder, List)
+ */
+ public boolean canReuseUpdatedViewHolder(@NonNull ViewHolder viewHolder) {
+ return true;
+ }
+
+ /**
+ * When an item is changed, ItemAnimator can decide whether it wants to re-use
+ * the same ViewHolder for animations or RecyclerView should create a copy of the
+ * item and ItemAnimator will use both to run the animation (e.g. cross-fade).
+ * <p>
+ * Note that this method will only be called if the {@link ViewHolder} still has the same
+ * type ({@link Adapter#getItemViewType(int)}). Otherwise, ItemAnimator will always receive
+ * both {@link ViewHolder}s in the
+ * {@link #animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)} method.
+ *
+ * @param viewHolder The ViewHolder which represents the changed item's old content.
+ * @param payloads A non-null list of merged payloads that were sent with change
+ * notifications. Can be empty if the adapter is invalidated via
+ * {@link RecyclerView.Adapter#notifyDataSetChanged()}. The same list of
+ * payloads will be passed into
+ * {@link RecyclerView.Adapter#onBindViewHolder(ViewHolder, int, List)}
+ * method <b>if</b> this method returns <code>true</code>.
+ *
+ * @return True if RecyclerView should just rebind to the same ViewHolder or false if
+ * RecyclerView should create a new ViewHolder and pass this ViewHolder to the
+ * ItemAnimator to animate. Default implementation calls
+ * {@link #canReuseUpdatedViewHolder(ViewHolder)}.
+ *
+ * @see #canReuseUpdatedViewHolder(ViewHolder)
+ */
+ public boolean canReuseUpdatedViewHolder(@NonNull ViewHolder viewHolder,
+ @NonNull List<Object> payloads) {
+ return canReuseUpdatedViewHolder(viewHolder);
+ }
+
+ /**
+ * This method should be called by ItemAnimator implementations to notify
+ * any listeners that all pending and active item animations are finished.
+ */
+ public final void dispatchAnimationsFinished() {
+ final int count = mFinishedListeners.size();
+ for (int i = 0; i < count; ++i) {
+ mFinishedListeners.get(i).onAnimationsFinished();
+ }
+ mFinishedListeners.clear();
+ }
+
+ /**
+ * Returns a new {@link ItemHolderInfo} which will be used to store information about the
+ * ViewHolder. This information will later be passed into <code>animate**</code> methods.
+ * <p>
+ * You can override this method if you want to extend {@link ItemHolderInfo} and provide
+ * your own instances.
+ *
+ * @return A new {@link ItemHolderInfo}.
+ */
+ public ItemHolderInfo obtainHolderInfo() {
+ return new ItemHolderInfo();
+ }
+
+ /**
+ * The interface to be implemented by listeners to animation events from this
+ * ItemAnimator. This is used internally and is not intended for developers to
+ * create directly.
+ */
+ interface ItemAnimatorListener {
+ void onAnimationFinished(ViewHolder item);
+ }
+
+ /**
+ * This interface is used to inform listeners when all pending or running animations
+ * in an ItemAnimator are finished. This can be used, for example, to delay an action
+ * in a data set until currently-running animations are complete.
+ *
+ * @see #isRunning(ItemAnimatorFinishedListener)
+ */
+ public interface ItemAnimatorFinishedListener {
+ /**
+ * Notifies when all pending or running animations in an ItemAnimator are finished.
+ */
+ void onAnimationsFinished();
+ }
+
+ /**
+ * A simple data structure that holds information about an item's bounds.
+ * This information is used in calculating item animations. Default implementation of
+ * {@link #recordPreLayoutInformation(RecyclerView.State, ViewHolder, int, List)} and
+ * {@link #recordPostLayoutInformation(RecyclerView.State, ViewHolder)} returns this data
+ * structure. You can extend this class if you would like to keep more information about
+ * the Views.
+ * <p>
+ * If you want to provide your own implementation but still use `super` methods to record
+ * basic information, you can override {@link #obtainHolderInfo()} to provide your own
+ * instances.
+ */
+ public static class ItemHolderInfo {
+
+ /**
+ * The left edge of the View (excluding decorations)
+ */
+ public int left;
+
+ /**
+ * The top edge of the View (excluding decorations)
+ */
+ public int top;
+
+ /**
+ * The right edge of the View (excluding decorations)
+ */
+ public int right;
+
+ /**
+ * The bottom edge of the View (excluding decorations)
+ */
+ public int bottom;
+
+ /**
+ * The change flags that were passed to
+ * {@link #recordPreLayoutInformation(RecyclerView.State, ViewHolder, int, List)}.
+ */
+ @AdapterChanges
+ public int changeFlags;
+
+ public ItemHolderInfo() {
+ }
+
+ /**
+ * Sets the {@link #left}, {@link #top}, {@link #right} and {@link #bottom} values from
+ * the given ViewHolder. Clears all {@link #changeFlags}.
+ *
+ * @param holder The ViewHolder whose bounds should be copied.
+ * @return This {@link ItemHolderInfo}
+ */
+ public ItemHolderInfo setFrom(RecyclerView.ViewHolder holder) {
+ return setFrom(holder, 0);
+ }
+
+ /**
+ * Sets the {@link #left}, {@link #top}, {@link #right} and {@link #bottom} values from
+ * the given ViewHolder and sets the {@link #changeFlags} to the given flags parameter.
+ *
+ * @param holder The ViewHolder whose bounds should be copied.
+ * @param flags The adapter change flags that were passed into
+ * {@link #recordPreLayoutInformation(RecyclerView.State, ViewHolder, int,
+ * List)}.
+ * @return This {@link ItemHolderInfo}
+ */
+ public ItemHolderInfo setFrom(RecyclerView.ViewHolder holder,
+ @AdapterChanges int flags) {
+ final View view = holder.itemView;
+ this.left = view.getLeft();
+ this.top = view.getTop();
+ this.right = view.getRight();
+ this.bottom = view.getBottom();
+ return this;
+ }
+ }
+ }
+
+ @Override
+ protected int getChildDrawingOrder(int childCount, int i) {
+ if (mChildDrawingOrderCallback == null) {
+ return super.getChildDrawingOrder(childCount, i);
+ } else {
+ return mChildDrawingOrderCallback.onGetChildDrawingOrder(childCount, i);
+ }
+ }
+
+ /**
+ * A callback interface that can be used to alter the drawing order of RecyclerView children.
+ * <p>
+ * It works using the {@link ViewGroup#getChildDrawingOrder(int, int)} method, so any case
+ * that applies to that method also applies to this callback. For example, changing the drawing
+ * order of two views will not have any effect if their elevation values are different since
+ * elevation overrides the result of this callback.
+ */
+ public interface ChildDrawingOrderCallback {
+ /**
+ * Returns the index of the child to draw for this iteration. Override this
+ * if you want to change the drawing order of children. By default, it
+ * returns i.
+ *
+ * @param i The current iteration.
+ * @return The index of the child to draw this iteration.
+ *
+ * @see RecyclerView#setChildDrawingOrderCallback(RecyclerView.ChildDrawingOrderCallback)
+ */
+ int onGetChildDrawingOrder(int childCount, int i);
+ }
+}
diff --git a/core/java/com/android/internal/widget/RecyclerViewAccessibilityDelegate.java b/core/java/com/android/internal/widget/RecyclerViewAccessibilityDelegate.java
new file mode 100644
index 0000000..282da64
--- /dev/null
+++ b/core/java/com/android/internal/widget/RecyclerViewAccessibilityDelegate.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.os.Bundle;
+import android.view.View;
+import android.view.View.AccessibilityDelegate;
+import android.view.accessibility.AccessibilityEvent;
+import android.view.accessibility.AccessibilityNodeInfo;
+
+/**
+ * The AccessibilityDelegate used by RecyclerView.
+ * <p>
+ * This class handles basic accessibility actions and delegates them to LayoutManager.
+ */
+public class RecyclerViewAccessibilityDelegate extends AccessibilityDelegate {
+ final RecyclerView mRecyclerView;
+
+
+ public RecyclerViewAccessibilityDelegate(RecyclerView recyclerView) {
+ mRecyclerView = recyclerView;
+ }
+
+ boolean shouldIgnore() {
+ return mRecyclerView.hasPendingAdapterUpdates();
+ }
+
+ @Override
+ public boolean performAccessibilityAction(View host, int action, Bundle args) {
+ if (super.performAccessibilityAction(host, action, args)) {
+ return true;
+ }
+ if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
+ return mRecyclerView.getLayoutManager().performAccessibilityAction(action, args);
+ }
+
+ return false;
+ }
+
+ @Override
+ public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
+ super.onInitializeAccessibilityNodeInfo(host, info);
+ info.setClassName(RecyclerView.class.getName());
+ if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
+ mRecyclerView.getLayoutManager().onInitializeAccessibilityNodeInfo(info);
+ }
+ }
+
+ @Override
+ public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
+ super.onInitializeAccessibilityEvent(host, event);
+ event.setClassName(RecyclerView.class.getName());
+ if (host instanceof RecyclerView && !shouldIgnore()) {
+ RecyclerView rv = (RecyclerView) host;
+ if (rv.getLayoutManager() != null) {
+ rv.getLayoutManager().onInitializeAccessibilityEvent(event);
+ }
+ }
+ }
+
+ /**
+ * Gets the AccessibilityDelegate for an individual item in the RecyclerView.
+ * A basic item delegate is provided by default, but you can override this
+ * method to provide a custom per-item delegate.
+ */
+ public AccessibilityDelegate getItemDelegate() {
+ return mItemDelegate;
+ }
+
+ final AccessibilityDelegate mItemDelegate = new AccessibilityDelegate() {
+ @Override
+ public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
+ super.onInitializeAccessibilityNodeInfo(host, info);
+ if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
+ mRecyclerView.getLayoutManager()
+ .onInitializeAccessibilityNodeInfoForItem(host, info);
+ }
+ }
+
+ @Override
+ public boolean performAccessibilityAction(View host, int action, Bundle args) {
+ if (super.performAccessibilityAction(host, action, args)) {
+ return true;
+ }
+ if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
+ return mRecyclerView.getLayoutManager()
+ .performAccessibilityActionForItem(host, action, args);
+ }
+ return false;
+ }
+ };
+}
+
diff --git a/core/java/com/android/internal/widget/ScrollbarHelper.java b/core/java/com/android/internal/widget/ScrollbarHelper.java
new file mode 100644
index 0000000..ae34e4c
--- /dev/null
+++ b/core/java/com/android/internal/widget/ScrollbarHelper.java
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.view.View;
+
+/**
+ * A helper class to do scroll offset calculations.
+ */
+class ScrollbarHelper {
+
+ /**
+ * @param startChild View closest to start of the list. (top or left)
+ * @param endChild View closest to end of the list (bottom or right)
+ */
+ static int computeScrollOffset(RecyclerView.State state, OrientationHelper orientation,
+ View startChild, View endChild, RecyclerView.LayoutManager lm,
+ boolean smoothScrollbarEnabled, boolean reverseLayout) {
+ if (lm.getChildCount() == 0 || state.getItemCount() == 0 || startChild == null
+ || endChild == null) {
+ return 0;
+ }
+ final int minPosition = Math.min(lm.getPosition(startChild),
+ lm.getPosition(endChild));
+ final int maxPosition = Math.max(lm.getPosition(startChild),
+ lm.getPosition(endChild));
+ final int itemsBefore = reverseLayout
+ ? Math.max(0, state.getItemCount() - maxPosition - 1)
+ : Math.max(0, minPosition);
+ if (!smoothScrollbarEnabled) {
+ return itemsBefore;
+ }
+ final int laidOutArea = Math.abs(orientation.getDecoratedEnd(endChild)
+ - orientation.getDecoratedStart(startChild));
+ final int itemRange = Math.abs(lm.getPosition(startChild)
+ - lm.getPosition(endChild)) + 1;
+ final float avgSizePerRow = (float) laidOutArea / itemRange;
+
+ return Math.round(itemsBefore * avgSizePerRow + (orientation.getStartAfterPadding()
+ - orientation.getDecoratedStart(startChild)));
+ }
+
+ /**
+ * @param startChild View closest to start of the list. (top or left)
+ * @param endChild View closest to end of the list (bottom or right)
+ */
+ static int computeScrollExtent(RecyclerView.State state, OrientationHelper orientation,
+ View startChild, View endChild, RecyclerView.LayoutManager lm,
+ boolean smoothScrollbarEnabled) {
+ if (lm.getChildCount() == 0 || state.getItemCount() == 0 || startChild == null
+ || endChild == null) {
+ return 0;
+ }
+ if (!smoothScrollbarEnabled) {
+ return Math.abs(lm.getPosition(startChild) - lm.getPosition(endChild)) + 1;
+ }
+ final int extend = orientation.getDecoratedEnd(endChild)
+ - orientation.getDecoratedStart(startChild);
+ return Math.min(orientation.getTotalSpace(), extend);
+ }
+
+ /**
+ * @param startChild View closest to start of the list. (top or left)
+ * @param endChild View closest to end of the list (bottom or right)
+ */
+ static int computeScrollRange(RecyclerView.State state, OrientationHelper orientation,
+ View startChild, View endChild, RecyclerView.LayoutManager lm,
+ boolean smoothScrollbarEnabled) {
+ if (lm.getChildCount() == 0 || state.getItemCount() == 0 || startChild == null
+ || endChild == null) {
+ return 0;
+ }
+ if (!smoothScrollbarEnabled) {
+ return state.getItemCount();
+ }
+ // smooth scrollbar enabled. try to estimate better.
+ final int laidOutArea = orientation.getDecoratedEnd(endChild)
+ - orientation.getDecoratedStart(startChild);
+ final int laidOutRange = Math.abs(lm.getPosition(startChild)
+ - lm.getPosition(endChild))
+ + 1;
+ // estimate a size for full list.
+ return (int) ((float) laidOutArea / laidOutRange * state.getItemCount());
+ }
+}
diff --git a/core/java/com/android/internal/widget/ScrollingView.java b/core/java/com/android/internal/widget/ScrollingView.java
new file mode 100644
index 0000000..a0205e7
--- /dev/null
+++ b/core/java/com/android/internal/widget/ScrollingView.java
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+/**
+ * An interface that can be implemented by Views to provide scroll related APIs.
+ */
+public interface ScrollingView {
+ /**
+ * <p>Compute the horizontal range that the horizontal scrollbar
+ * represents.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the
+ * units used by {@link #computeHorizontalScrollExtent()} and
+ * {@link #computeHorizontalScrollOffset()}.</p>
+ *
+ * <p>The default range is the drawing width of this view.</p>
+ *
+ * @return the total horizontal range represented by the horizontal
+ * scrollbar
+ *
+ * @see #computeHorizontalScrollExtent()
+ * @see #computeHorizontalScrollOffset()
+ * @see android.widget.ScrollBarDrawable
+ */
+ int computeHorizontalScrollRange();
+
+ /**
+ * <p>Compute the horizontal offset of the horizontal scrollbar's thumb
+ * within the horizontal range. This value is used to compute the position
+ * of the thumb within the scrollbar's track.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the
+ * units used by {@link #computeHorizontalScrollRange()} and
+ * {@link #computeHorizontalScrollExtent()}.</p>
+ *
+ * <p>The default offset is the scroll offset of this view.</p>
+ *
+ * @return the horizontal offset of the scrollbar's thumb
+ *
+ * @see #computeHorizontalScrollRange()
+ * @see #computeHorizontalScrollExtent()
+ * @see android.widget.ScrollBarDrawable
+ */
+ int computeHorizontalScrollOffset();
+
+ /**
+ * <p>Compute the horizontal extent of the horizontal scrollbar's thumb
+ * within the horizontal range. This value is used to compute the length
+ * of the thumb within the scrollbar's track.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the
+ * units used by {@link #computeHorizontalScrollRange()} and
+ * {@link #computeHorizontalScrollOffset()}.</p>
+ *
+ * <p>The default extent is the drawing width of this view.</p>
+ *
+ * @return the horizontal extent of the scrollbar's thumb
+ *
+ * @see #computeHorizontalScrollRange()
+ * @see #computeHorizontalScrollOffset()
+ * @see android.widget.ScrollBarDrawable
+ */
+ int computeHorizontalScrollExtent();
+
+ /**
+ * <p>Compute the vertical range that the vertical scrollbar represents.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the
+ * units used by {@link #computeVerticalScrollExtent()} and
+ * {@link #computeVerticalScrollOffset()}.</p>
+ *
+ * @return the total vertical range represented by the vertical scrollbar
+ *
+ * <p>The default range is the drawing height of this view.</p>
+ *
+ * @see #computeVerticalScrollExtent()
+ * @see #computeVerticalScrollOffset()
+ * @see android.widget.ScrollBarDrawable
+ */
+ int computeVerticalScrollRange();
+
+ /**
+ * <p>Compute the vertical offset of the vertical scrollbar's thumb
+ * within the horizontal range. This value is used to compute the position
+ * of the thumb within the scrollbar's track.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the
+ * units used by {@link #computeVerticalScrollRange()} and
+ * {@link #computeVerticalScrollExtent()}.</p>
+ *
+ * <p>The default offset is the scroll offset of this view.</p>
+ *
+ * @return the vertical offset of the scrollbar's thumb
+ *
+ * @see #computeVerticalScrollRange()
+ * @see #computeVerticalScrollExtent()
+ * @see android.widget.ScrollBarDrawable
+ */
+ int computeVerticalScrollOffset();
+
+ /**
+ * <p>Compute the vertical extent of the vertical scrollbar's thumb
+ * within the vertical range. This value is used to compute the length
+ * of the thumb within the scrollbar's track.</p>
+ *
+ * <p>The range is expressed in arbitrary units that must be the same as the
+ * units used by {@link #computeVerticalScrollRange()} and
+ * {@link #computeVerticalScrollOffset()}.</p>
+ *
+ * <p>The default extent is the drawing height of this view.</p>
+ *
+ * @return the vertical extent of the scrollbar's thumb
+ *
+ * @see #computeVerticalScrollRange()
+ * @see #computeVerticalScrollOffset()
+ * @see android.widget.ScrollBarDrawable
+ */
+ int computeVerticalScrollExtent();
+}
diff --git a/core/java/com/android/internal/widget/SimpleItemAnimator.java b/core/java/com/android/internal/widget/SimpleItemAnimator.java
new file mode 100644
index 0000000..f4cc753
--- /dev/null
+++ b/core/java/com/android/internal/widget/SimpleItemAnimator.java
@@ -0,0 +1,457 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.util.Log;
+import android.view.View;
+
+import com.android.internal.widget.RecyclerView.Adapter;
+import com.android.internal.widget.RecyclerView.ViewHolder;
+
+/**
+ * A wrapper class for ItemAnimator that records View bounds and decides whether it should run
+ * move, change, add or remove animations. This class also replicates the original ItemAnimator
+ * API.
+ * <p>
+ * It uses {@link ItemHolderInfo} to track the bounds information of the Views. If you would like
+ * to
+ * extend this class, you can override {@link #obtainHolderInfo()} method to provide your own info
+ * class that extends {@link ItemHolderInfo}.
+ */
+public abstract class SimpleItemAnimator extends RecyclerView.ItemAnimator {
+
+ private static final boolean DEBUG = false;
+
+ private static final String TAG = "SimpleItemAnimator";
+
+ boolean mSupportsChangeAnimations = true;
+
+ /**
+ * Returns whether this ItemAnimator supports animations of change events.
+ *
+ * @return true if change animations are supported, false otherwise
+ */
+ @SuppressWarnings("unused")
+ public boolean getSupportsChangeAnimations() {
+ return mSupportsChangeAnimations;
+ }
+
+ /**
+ * Sets whether this ItemAnimator supports animations of item change events.
+ * If you set this property to false, actions on the data set which change the
+ * contents of items will not be animated. What those animations do is left
+ * up to the discretion of the ItemAnimator subclass, in its
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)} implementation.
+ * The value of this property is true by default.
+ *
+ * @param supportsChangeAnimations true if change animations are supported by
+ * this ItemAnimator, false otherwise. If the property is false,
+ * the ItemAnimator
+ * will not receive a call to
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int,
+ * int)} when changes occur.
+ * @see Adapter#notifyItemChanged(int)
+ * @see Adapter#notifyItemRangeChanged(int, int)
+ */
+ public void setSupportsChangeAnimations(boolean supportsChangeAnimations) {
+ mSupportsChangeAnimations = supportsChangeAnimations;
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * @return True if change animations are not supported or the ViewHolder is invalid,
+ * false otherwise.
+ *
+ * @see #setSupportsChangeAnimations(boolean)
+ */
+ @Override
+ public boolean canReuseUpdatedViewHolder(@NonNull RecyclerView.ViewHolder viewHolder) {
+ return !mSupportsChangeAnimations || viewHolder.isInvalid();
+ }
+
+ @Override
+ public boolean animateDisappearance(@NonNull ViewHolder viewHolder,
+ @NonNull ItemHolderInfo preLayoutInfo, @Nullable ItemHolderInfo postLayoutInfo) {
+ int oldLeft = preLayoutInfo.left;
+ int oldTop = preLayoutInfo.top;
+ View disappearingItemView = viewHolder.itemView;
+ int newLeft = postLayoutInfo == null ? disappearingItemView.getLeft() : postLayoutInfo.left;
+ int newTop = postLayoutInfo == null ? disappearingItemView.getTop() : postLayoutInfo.top;
+ if (!viewHolder.isRemoved() && (oldLeft != newLeft || oldTop != newTop)) {
+ disappearingItemView.layout(newLeft, newTop,
+ newLeft + disappearingItemView.getWidth(),
+ newTop + disappearingItemView.getHeight());
+ if (DEBUG) {
+ Log.d(TAG, "DISAPPEARING: " + viewHolder + " with view " + disappearingItemView);
+ }
+ return animateMove(viewHolder, oldLeft, oldTop, newLeft, newTop);
+ } else {
+ if (DEBUG) {
+ Log.d(TAG, "REMOVED: " + viewHolder + " with view " + disappearingItemView);
+ }
+ return animateRemove(viewHolder);
+ }
+ }
+
+ @Override
+ public boolean animateAppearance(@NonNull ViewHolder viewHolder,
+ @Nullable ItemHolderInfo preLayoutInfo, @NonNull ItemHolderInfo postLayoutInfo) {
+ if (preLayoutInfo != null && (preLayoutInfo.left != postLayoutInfo.left
+ || preLayoutInfo.top != postLayoutInfo.top)) {
+ // slide items in if before/after locations differ
+ if (DEBUG) {
+ Log.d(TAG, "APPEARING: " + viewHolder + " with view " + viewHolder);
+ }
+ return animateMove(viewHolder, preLayoutInfo.left, preLayoutInfo.top,
+ postLayoutInfo.left, postLayoutInfo.top);
+ } else {
+ if (DEBUG) {
+ Log.d(TAG, "ADDED: " + viewHolder + " with view " + viewHolder);
+ }
+ return animateAdd(viewHolder);
+ }
+ }
+
+ @Override
+ public boolean animatePersistence(@NonNull ViewHolder viewHolder,
+ @NonNull ItemHolderInfo preInfo, @NonNull ItemHolderInfo postInfo) {
+ if (preInfo.left != postInfo.left || preInfo.top != postInfo.top) {
+ if (DEBUG) {
+ Log.d(TAG, "PERSISTENT: " + viewHolder
+ + " with view " + viewHolder.itemView);
+ }
+ return animateMove(viewHolder,
+ preInfo.left, preInfo.top, postInfo.left, postInfo.top);
+ }
+ dispatchMoveFinished(viewHolder);
+ return false;
+ }
+
+ @Override
+ public boolean animateChange(@NonNull ViewHolder oldHolder, @NonNull ViewHolder newHolder,
+ @NonNull ItemHolderInfo preInfo, @NonNull ItemHolderInfo postInfo) {
+ if (DEBUG) {
+ Log.d(TAG, "CHANGED: " + oldHolder + " with view " + oldHolder.itemView);
+ }
+ final int fromLeft = preInfo.left;
+ final int fromTop = preInfo.top;
+ final int toLeft, toTop;
+ if (newHolder.shouldIgnore()) {
+ toLeft = preInfo.left;
+ toTop = preInfo.top;
+ } else {
+ toLeft = postInfo.left;
+ toTop = postInfo.top;
+ }
+ return animateChange(oldHolder, newHolder, fromLeft, fromTop, toLeft, toTop);
+ }
+
+ /**
+ * Called when an item is removed from the RecyclerView. Implementors can choose
+ * whether and how to animate that change, but must always call
+ * {@link #dispatchRemoveFinished(ViewHolder)} when done, either
+ * immediately (if no animation will occur) or after the animation actually finishes.
+ * The return value indicates whether an animation has been set up and whether the
+ * ItemAnimator's {@link #runPendingAnimations()} method should be called at the
+ * next opportunity. This mechanism allows ItemAnimator to set up individual animations
+ * as separate calls to {@link #animateAdd(ViewHolder) animateAdd()},
+ * {@link #animateMove(ViewHolder, int, int, int, int) animateMove()},
+ * {@link #animateRemove(ViewHolder) animateRemove()}, and
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)} come in one by one,
+ * then start the animations together in the later call to {@link #runPendingAnimations()}.
+ *
+ * <p>This method may also be called for disappearing items which continue to exist in the
+ * RecyclerView, but for which the system does not have enough information to animate
+ * them out of view. In that case, the default animation for removing items is run
+ * on those items as well.</p>
+ *
+ * @param holder The item that is being removed.
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animateRemove(ViewHolder holder);
+
+ /**
+ * Called when an item is added to the RecyclerView. Implementors can choose
+ * whether and how to animate that change, but must always call
+ * {@link #dispatchAddFinished(ViewHolder)} when done, either
+ * immediately (if no animation will occur) or after the animation actually finishes.
+ * The return value indicates whether an animation has been set up and whether the
+ * ItemAnimator's {@link #runPendingAnimations()} method should be called at the
+ * next opportunity. This mechanism allows ItemAnimator to set up individual animations
+ * as separate calls to {@link #animateAdd(ViewHolder) animateAdd()},
+ * {@link #animateMove(ViewHolder, int, int, int, int) animateMove()},
+ * {@link #animateRemove(ViewHolder) animateRemove()}, and
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)} come in one by one,
+ * then start the animations together in the later call to {@link #runPendingAnimations()}.
+ *
+ * <p>This method may also be called for appearing items which were already in the
+ * RecyclerView, but for which the system does not have enough information to animate
+ * them into view. In that case, the default animation for adding items is run
+ * on those items as well.</p>
+ *
+ * @param holder The item that is being added.
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animateAdd(ViewHolder holder);
+
+ /**
+ * Called when an item is moved in the RecyclerView. Implementors can choose
+ * whether and how to animate that change, but must always call
+ * {@link #dispatchMoveFinished(ViewHolder)} when done, either
+ * immediately (if no animation will occur) or after the animation actually finishes.
+ * The return value indicates whether an animation has been set up and whether the
+ * ItemAnimator's {@link #runPendingAnimations()} method should be called at the
+ * next opportunity. This mechanism allows ItemAnimator to set up individual animations
+ * as separate calls to {@link #animateAdd(ViewHolder) animateAdd()},
+ * {@link #animateMove(ViewHolder, int, int, int, int) animateMove()},
+ * {@link #animateRemove(ViewHolder) animateRemove()}, and
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)} come in one by one,
+ * then start the animations together in the later call to {@link #runPendingAnimations()}.
+ *
+ * @param holder The item that is being moved.
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animateMove(ViewHolder holder, int fromX, int fromY,
+ int toX, int toY);
+
+ /**
+ * Called when an item is changed in the RecyclerView, as indicated by a call to
+ * {@link Adapter#notifyItemChanged(int)} or
+ * {@link Adapter#notifyItemRangeChanged(int, int)}.
+ * <p>
+ * Implementers can choose whether and how to animate changes, but must always call
+ * {@link #dispatchChangeFinished(ViewHolder, boolean)} for each non-null distinct ViewHolder,
+ * either immediately (if no animation will occur) or after the animation actually finishes.
+ * If the {@code oldHolder} is the same ViewHolder as the {@code newHolder}, you must call
+ * {@link #dispatchChangeFinished(ViewHolder, boolean)} once and only once. In that case, the
+ * second parameter of {@code dispatchChangeFinished} is ignored.
+ * <p>
+ * The return value indicates whether an animation has been set up and whether the
+ * ItemAnimator's {@link #runPendingAnimations()} method should be called at the
+ * next opportunity. This mechanism allows ItemAnimator to set up individual animations
+ * as separate calls to {@link #animateAdd(ViewHolder) animateAdd()},
+ * {@link #animateMove(ViewHolder, int, int, int, int) animateMove()},
+ * {@link #animateRemove(ViewHolder) animateRemove()}, and
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)} come in one by one,
+ * then start the animations together in the later call to {@link #runPendingAnimations()}.
+ *
+ * @param oldHolder The original item that changed.
+ * @param newHolder The new item that was created with the changed content. Might be null
+ * @param fromLeft Left of the old view holder
+ * @param fromTop Top of the old view holder
+ * @param toLeft Left of the new view holder
+ * @param toTop Top of the new view holder
+ * @return true if a later call to {@link #runPendingAnimations()} is requested,
+ * false otherwise.
+ */
+ public abstract boolean animateChange(ViewHolder oldHolder,
+ ViewHolder newHolder, int fromLeft, int fromTop, int toLeft, int toTop);
+
+ /**
+ * Method to be called by subclasses when a remove animation is done.
+ *
+ * @param item The item which has been removed
+ * @see RecyclerView.ItemAnimator#animateDisappearance(ViewHolder, ItemHolderInfo,
+ * ItemHolderInfo)
+ */
+ public final void dispatchRemoveFinished(ViewHolder item) {
+ onRemoveFinished(item);
+ dispatchAnimationFinished(item);
+ }
+
+ /**
+ * Method to be called by subclasses when a move animation is done.
+ *
+ * @param item The item which has been moved
+ * @see RecyclerView.ItemAnimator#animateDisappearance(ViewHolder, ItemHolderInfo,
+ * ItemHolderInfo)
+ * @see RecyclerView.ItemAnimator#animatePersistence(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ * @see RecyclerView.ItemAnimator#animateAppearance(ViewHolder, ItemHolderInfo, ItemHolderInfo)
+ */
+ public final void dispatchMoveFinished(ViewHolder item) {
+ onMoveFinished(item);
+ dispatchAnimationFinished(item);
+ }
+
+ /**
+ * Method to be called by subclasses when an add animation is done.
+ *
+ * @param item The item which has been added
+ */
+ public final void dispatchAddFinished(ViewHolder item) {
+ onAddFinished(item);
+ dispatchAnimationFinished(item);
+ }
+
+ /**
+ * Method to be called by subclasses when a change animation is done.
+ *
+ * @param item The item which has been changed (this method must be called for
+ * each non-null ViewHolder passed into
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)}).
+ * @param oldItem true if this is the old item that was changed, false if
+ * it is the new item that replaced the old item.
+ * @see #animateChange(ViewHolder, ViewHolder, int, int, int, int)
+ */
+ public final void dispatchChangeFinished(ViewHolder item, boolean oldItem) {
+ onChangeFinished(item, oldItem);
+ dispatchAnimationFinished(item);
+ }
+
+ /**
+ * Method to be called by subclasses when a remove animation is being started.
+ *
+ * @param item The item being removed
+ */
+ public final void dispatchRemoveStarting(ViewHolder item) {
+ onRemoveStarting(item);
+ }
+
+ /**
+ * Method to be called by subclasses when a move animation is being started.
+ *
+ * @param item The item being moved
+ */
+ public final void dispatchMoveStarting(ViewHolder item) {
+ onMoveStarting(item);
+ }
+
+ /**
+ * Method to be called by subclasses when an add animation is being started.
+ *
+ * @param item The item being added
+ */
+ public final void dispatchAddStarting(ViewHolder item) {
+ onAddStarting(item);
+ }
+
+ /**
+ * Method to be called by subclasses when a change animation is being started.
+ *
+ * @param item The item which has been changed (this method must be called for
+ * each non-null ViewHolder passed into
+ * {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)}).
+ * @param oldItem true if this is the old item that was changed, false if
+ * it is the new item that replaced the old item.
+ */
+ public final void dispatchChangeStarting(ViewHolder item, boolean oldItem) {
+ onChangeStarting(item, oldItem);
+ }
+
+ /**
+ * Called when a remove animation is being started on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ */
+ @SuppressWarnings("UnusedParameters")
+ public void onRemoveStarting(ViewHolder item) {
+ }
+
+ /**
+ * Called when a remove animation has ended on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ */
+ public void onRemoveFinished(ViewHolder item) {
+ }
+
+ /**
+ * Called when an add animation is being started on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ */
+ @SuppressWarnings("UnusedParameters")
+ public void onAddStarting(ViewHolder item) {
+ }
+
+ /**
+ * Called when an add animation has ended on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ */
+ public void onAddFinished(ViewHolder item) {
+ }
+
+ /**
+ * Called when a move animation is being started on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ */
+ @SuppressWarnings("UnusedParameters")
+ public void onMoveStarting(ViewHolder item) {
+ }
+
+ /**
+ * Called when a move animation has ended on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ */
+ public void onMoveFinished(ViewHolder item) {
+ }
+
+ /**
+ * Called when a change animation is being started on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ * @param oldItem true if this is the old item that was changed, false if
+ * it is the new item that replaced the old item.
+ */
+ @SuppressWarnings("UnusedParameters")
+ public void onChangeStarting(ViewHolder item, boolean oldItem) {
+ }
+
+ /**
+ * Called when a change animation has ended on the given ViewHolder.
+ * The default implementation does nothing. Subclasses may wish to override
+ * this method to handle any ViewHolder-specific operations linked to animation
+ * lifecycles.
+ *
+ * @param item The ViewHolder being animated.
+ * @param oldItem true if this is the old item that was changed, false if
+ * it is the new item that replaced the old item.
+ */
+ public void onChangeFinished(ViewHolder item, boolean oldItem) {
+ }
+}
+
diff --git a/core/java/com/android/internal/widget/ViewInfoStore.java b/core/java/com/android/internal/widget/ViewInfoStore.java
new file mode 100644
index 0000000..6784a85
--- /dev/null
+++ b/core/java/com/android/internal/widget/ViewInfoStore.java
@@ -0,0 +1,330 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.util.ArrayMap;
+import android.util.LongSparseArray;
+import android.util.Pools;
+
+import static com.android.internal.widget.RecyclerView.ItemAnimator.ItemHolderInfo;
+import static com.android.internal.widget.RecyclerView.ViewHolder;
+import static com.android.internal.widget.ViewInfoStore.InfoRecord.FLAG_APPEAR;
+import static com.android.internal.widget.ViewInfoStore.InfoRecord.FLAG_APPEAR_AND_DISAPPEAR;
+import static com.android.internal.widget.ViewInfoStore.InfoRecord.FLAG_APPEAR_PRE_AND_POST;
+import static com.android.internal.widget.ViewInfoStore.InfoRecord.FLAG_DISAPPEARED;
+import static com.android.internal.widget.ViewInfoStore.InfoRecord.FLAG_POST;
+import static com.android.internal.widget.ViewInfoStore.InfoRecord.FLAG_PRE;
+import static com.android.internal.widget.ViewInfoStore.InfoRecord.FLAG_PRE_AND_POST;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+/**
+ * This class abstracts all tracking for Views to run animations.
+ */
+class ViewInfoStore {
+
+ private static final boolean DEBUG = false;
+
+ /**
+ * View data records for pre-layout
+ */
+ @VisibleForTesting
+ final ArrayMap<ViewHolder, InfoRecord> mLayoutHolderMap = new ArrayMap<>();
+
+ @VisibleForTesting
+ final LongSparseArray<ViewHolder> mOldChangedHolders = new LongSparseArray<>();
+
+ /**
+ * Clears the state and all existing tracking data
+ */
+ void clear() {
+ mLayoutHolderMap.clear();
+ mOldChangedHolders.clear();
+ }
+
+ /**
+ * Adds the item information to the prelayout tracking
+ * @param holder The ViewHolder whose information is being saved
+ * @param info The information to save
+ */
+ void addToPreLayout(ViewHolder holder, ItemHolderInfo info) {
+ InfoRecord record = mLayoutHolderMap.get(holder);
+ if (record == null) {
+ record = InfoRecord.obtain();
+ mLayoutHolderMap.put(holder, record);
+ }
+ record.preInfo = info;
+ record.flags |= FLAG_PRE;
+ }
+
+ boolean isDisappearing(ViewHolder holder) {
+ final InfoRecord record = mLayoutHolderMap.get(holder);
+ return record != null && ((record.flags & FLAG_DISAPPEARED) != 0);
+ }
+
+ /**
+ * Finds the ItemHolderInfo for the given ViewHolder in preLayout list and removes it.
+ *
+ * @param vh The ViewHolder whose information is being queried
+ * @return The ItemHolderInfo for the given ViewHolder or null if it does not exist
+ */
+ @Nullable
+ ItemHolderInfo popFromPreLayout(ViewHolder vh) {
+ return popFromLayoutStep(vh, FLAG_PRE);
+ }
+
+ /**
+ * Finds the ItemHolderInfo for the given ViewHolder in postLayout list and removes it.
+ *
+ * @param vh The ViewHolder whose information is being queried
+ * @return The ItemHolderInfo for the given ViewHolder or null if it does not exist
+ */
+ @Nullable
+ ItemHolderInfo popFromPostLayout(ViewHolder vh) {
+ return popFromLayoutStep(vh, FLAG_POST);
+ }
+
+ private ItemHolderInfo popFromLayoutStep(ViewHolder vh, int flag) {
+ int index = mLayoutHolderMap.indexOfKey(vh);
+ if (index < 0) {
+ return null;
+ }
+ final InfoRecord record = mLayoutHolderMap.valueAt(index);
+ if (record != null && (record.flags & flag) != 0) {
+ record.flags &= ~flag;
+ final ItemHolderInfo info;
+ if (flag == FLAG_PRE) {
+ info = record.preInfo;
+ } else if (flag == FLAG_POST) {
+ info = record.postInfo;
+ } else {
+ throw new IllegalArgumentException("Must provide flag PRE or POST");
+ }
+ // if not pre-post flag is left, clear.
+ if ((record.flags & (FLAG_PRE | FLAG_POST)) == 0) {
+ mLayoutHolderMap.removeAt(index);
+ InfoRecord.recycle(record);
+ }
+ return info;
+ }
+ return null;
+ }
+
+ /**
+ * Adds the given ViewHolder to the oldChangeHolders list
+ * @param key The key to identify the ViewHolder.
+ * @param holder The ViewHolder to store
+ */
+ void addToOldChangeHolders(long key, ViewHolder holder) {
+ mOldChangedHolders.put(key, holder);
+ }
+
+ /**
+ * Adds the given ViewHolder to the appeared in pre layout list. These are Views added by the
+ * LayoutManager during a pre-layout pass. We distinguish them from other views that were
+ * already in the pre-layout so that ItemAnimator can choose to run a different animation for
+ * them.
+ *
+ * @param holder The ViewHolder to store
+ * @param info The information to save
+ */
+ void addToAppearedInPreLayoutHolders(ViewHolder holder, ItemHolderInfo info) {
+ InfoRecord record = mLayoutHolderMap.get(holder);
+ if (record == null) {
+ record = InfoRecord.obtain();
+ mLayoutHolderMap.put(holder, record);
+ }
+ record.flags |= FLAG_APPEAR;
+ record.preInfo = info;
+ }
+
+ /**
+ * Checks whether the given ViewHolder is in preLayout list
+ * @param viewHolder The ViewHolder to query
+ *
+ * @return True if the ViewHolder is present in preLayout, false otherwise
+ */
+ boolean isInPreLayout(ViewHolder viewHolder) {
+ final InfoRecord record = mLayoutHolderMap.get(viewHolder);
+ return record != null && (record.flags & FLAG_PRE) != 0;
+ }
+
+ /**
+ * Queries the oldChangeHolder list for the given key. If they are not tracked, simply returns
+ * null.
+ * @param key The key to be used to find the ViewHolder.
+ *
+ * @return A ViewHolder if exists or null if it does not exist.
+ */
+ ViewHolder getFromOldChangeHolders(long key) {
+ return mOldChangedHolders.get(key);
+ }
+
+ /**
+ * Adds the item information to the post layout list
+ * @param holder The ViewHolder whose information is being saved
+ * @param info The information to save
+ */
+ void addToPostLayout(ViewHolder holder, ItemHolderInfo info) {
+ InfoRecord record = mLayoutHolderMap.get(holder);
+ if (record == null) {
+ record = InfoRecord.obtain();
+ mLayoutHolderMap.put(holder, record);
+ }
+ record.postInfo = info;
+ record.flags |= FLAG_POST;
+ }
+
+ /**
+ * A ViewHolder might be added by the LayoutManager just to animate its disappearance.
+ * This list holds such items so that we can animate / recycle these ViewHolders properly.
+ *
+ * @param holder The ViewHolder which disappeared during a layout.
+ */
+ void addToDisappearedInLayout(ViewHolder holder) {
+ InfoRecord record = mLayoutHolderMap.get(holder);
+ if (record == null) {
+ record = InfoRecord.obtain();
+ mLayoutHolderMap.put(holder, record);
+ }
+ record.flags |= FLAG_DISAPPEARED;
+ }
+
+ /**
+ * Removes a ViewHolder from disappearing list.
+ * @param holder The ViewHolder to be removed from the disappearing list.
+ */
+ void removeFromDisappearedInLayout(ViewHolder holder) {
+ InfoRecord record = mLayoutHolderMap.get(holder);
+ if (record == null) {
+ return;
+ }
+ record.flags &= ~FLAG_DISAPPEARED;
+ }
+
+ void process(ProcessCallback callback) {
+ for (int index = mLayoutHolderMap.size() - 1; index >= 0; index--) {
+ final ViewHolder viewHolder = mLayoutHolderMap.keyAt(index);
+ final InfoRecord record = mLayoutHolderMap.removeAt(index);
+ if ((record.flags & FLAG_APPEAR_AND_DISAPPEAR) == FLAG_APPEAR_AND_DISAPPEAR) {
+ // Appeared then disappeared. Not useful for animations.
+ callback.unused(viewHolder);
+ } else if ((record.flags & FLAG_DISAPPEARED) != 0) {
+ // Set as "disappeared" by the LayoutManager (addDisappearingView)
+ if (record.preInfo == null) {
+ // similar to appear disappear but happened between different layout passes.
+ // this can happen when the layout manager is using auto-measure
+ callback.unused(viewHolder);
+ } else {
+ callback.processDisappeared(viewHolder, record.preInfo, record.postInfo);
+ }
+ } else if ((record.flags & FLAG_APPEAR_PRE_AND_POST) == FLAG_APPEAR_PRE_AND_POST) {
+ // Appeared in the layout but not in the adapter (e.g. entered the viewport)
+ callback.processAppeared(viewHolder, record.preInfo, record.postInfo);
+ } else if ((record.flags & FLAG_PRE_AND_POST) == FLAG_PRE_AND_POST) {
+ // Persistent in both passes. Animate persistence
+ callback.processPersistent(viewHolder, record.preInfo, record.postInfo);
+ } else if ((record.flags & FLAG_PRE) != 0) {
+ // Was in pre-layout, never been added to post layout
+ callback.processDisappeared(viewHolder, record.preInfo, null);
+ } else if ((record.flags & FLAG_POST) != 0) {
+ // Was not in pre-layout, been added to post layout
+ callback.processAppeared(viewHolder, record.preInfo, record.postInfo);
+ } else if ((record.flags & FLAG_APPEAR) != 0) {
+ // Scrap view. RecyclerView will handle removing/recycling this.
+ } else if (DEBUG) {
+ throw new IllegalStateException("record without any reasonable flag combination:/");
+ }
+ InfoRecord.recycle(record);
+ }
+ }
+
+ /**
+ * Removes the ViewHolder from all list
+ * @param holder The ViewHolder which we should stop tracking
+ */
+ void removeViewHolder(ViewHolder holder) {
+ for (int i = mOldChangedHolders.size() - 1; i >= 0; i--) {
+ if (holder == mOldChangedHolders.valueAt(i)) {
+ mOldChangedHolders.removeAt(i);
+ break;
+ }
+ }
+ final InfoRecord info = mLayoutHolderMap.remove(holder);
+ if (info != null) {
+ InfoRecord.recycle(info);
+ }
+ }
+
+ void onDetach() {
+ InfoRecord.drainCache();
+ }
+
+ public void onViewDetached(ViewHolder viewHolder) {
+ removeFromDisappearedInLayout(viewHolder);
+ }
+
+ interface ProcessCallback {
+ void processDisappeared(ViewHolder viewHolder, @NonNull ItemHolderInfo preInfo,
+ @Nullable ItemHolderInfo postInfo);
+ void processAppeared(ViewHolder viewHolder, @Nullable ItemHolderInfo preInfo,
+ ItemHolderInfo postInfo);
+ void processPersistent(ViewHolder viewHolder, @NonNull ItemHolderInfo preInfo,
+ @NonNull ItemHolderInfo postInfo);
+ void unused(ViewHolder holder);
+ }
+
+ static class InfoRecord {
+ // disappearing list
+ static final int FLAG_DISAPPEARED = 1;
+ // appear in pre layout list
+ static final int FLAG_APPEAR = 1 << 1;
+ // pre layout, this is necessary to distinguish null item info
+ static final int FLAG_PRE = 1 << 2;
+ // post layout, this is necessary to distinguish null item info
+ static final int FLAG_POST = 1 << 3;
+ static final int FLAG_APPEAR_AND_DISAPPEAR = FLAG_APPEAR | FLAG_DISAPPEARED;
+ static final int FLAG_PRE_AND_POST = FLAG_PRE | FLAG_POST;
+ static final int FLAG_APPEAR_PRE_AND_POST = FLAG_APPEAR | FLAG_PRE | FLAG_POST;
+ int flags;
+ @Nullable ItemHolderInfo preInfo;
+ @Nullable ItemHolderInfo postInfo;
+ static Pools.Pool<InfoRecord> sPool = new Pools.SimplePool<>(20);
+
+ private InfoRecord() {
+ }
+
+ static InfoRecord obtain() {
+ InfoRecord record = sPool.acquire();
+ return record == null ? new InfoRecord() : record;
+ }
+
+ static void recycle(InfoRecord record) {
+ record.flags = 0;
+ record.preInfo = null;
+ record.postInfo = null;
+ sPool.release(record);
+ }
+
+ static void drainCache() {
+ //noinspection StatementWithEmptyBody
+ while (sPool.acquire() != null);
+ }
+ }
+}
diff --git a/core/java/com/android/internal/widget/helper/ItemTouchHelper.java b/core/java/com/android/internal/widget/helper/ItemTouchHelper.java
new file mode 100644
index 0000000..9636ed8
--- /dev/null
+++ b/core/java/com/android/internal/widget/helper/ItemTouchHelper.java
@@ -0,0 +1,2391 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget.helper;
+
+import android.animation.Animator;
+import android.animation.ValueAnimator;
+import android.annotation.Nullable;
+import android.content.res.Resources;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.os.Build;
+import android.util.Log;
+import android.view.GestureDetector;
+import android.view.HapticFeedbackConstants;
+import android.view.MotionEvent;
+import android.view.VelocityTracker;
+import android.view.View;
+import android.view.ViewConfiguration;
+import android.view.ViewParent;
+import android.view.animation.Interpolator;
+
+import com.android.internal.R;
+import com.android.internal.widget.LinearLayoutManager;
+import com.android.internal.widget.RecyclerView;
+import com.android.internal.widget.RecyclerView.OnItemTouchListener;
+import com.android.internal.widget.RecyclerView.ViewHolder;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * This is a utility class to add swipe to dismiss and drag & drop support to RecyclerView.
+ * <p>
+ * It works with a RecyclerView and a Callback class, which configures what type of interactions
+ * are enabled and also receives events when user performs these actions.
+ * <p>
+ * Depending on which functionality you support, you should override
+ * {@link Callback#onMove(RecyclerView, ViewHolder, ViewHolder)} and / or
+ * {@link Callback#onSwiped(ViewHolder, int)}.
+ * <p>
+ * This class is designed to work with any LayoutManager but for certain situations, it can be
+ * optimized for your custom LayoutManager by extending methods in the
+ * {@link ItemTouchHelper.Callback} class or implementing {@link ItemTouchHelper.ViewDropHandler}
+ * interface in your LayoutManager.
+ * <p>
+ * By default, ItemTouchHelper moves the items' translateX/Y properties to reposition them. On
+ * platforms older than Honeycomb, ItemTouchHelper uses canvas translations and View's visibility
+ * property to move items in response to touch events. You can customize these behaviors by
+ * overriding {@link Callback#onChildDraw(Canvas, RecyclerView, ViewHolder, float, float, int,
+ * boolean)}
+ * or {@link Callback#onChildDrawOver(Canvas, RecyclerView, ViewHolder, float, float, int,
+ * boolean)}.
+ * <p/>
+ * Most of the time, you only need to override <code>onChildDraw</code> but due to limitations of
+ * platform prior to Honeycomb, you may need to implement <code>onChildDrawOver</code> as well.
+ */
+public class ItemTouchHelper extends RecyclerView.ItemDecoration
+ implements RecyclerView.OnChildAttachStateChangeListener {
+
+ /**
+ * Up direction, used for swipe & drag control.
+ */
+ public static final int UP = 1;
+
+ /**
+ * Down direction, used for swipe & drag control.
+ */
+ public static final int DOWN = 1 << 1;
+
+ /**
+ * Left direction, used for swipe & drag control.
+ */
+ public static final int LEFT = 1 << 2;
+
+ /**
+ * Right direction, used for swipe & drag control.
+ */
+ public static final int RIGHT = 1 << 3;
+
+ // If you change these relative direction values, update Callback#convertToAbsoluteDirection,
+ // Callback#convertToRelativeDirection.
+ /**
+ * Horizontal start direction. Resolved to LEFT or RIGHT depending on RecyclerView's layout
+ * direction. Used for swipe & drag control.
+ */
+ public static final int START = LEFT << 2;
+
+ /**
+ * Horizontal end direction. Resolved to LEFT or RIGHT depending on RecyclerView's layout
+ * direction. Used for swipe & drag control.
+ */
+ public static final int END = RIGHT << 2;
+
+ /**
+ * ItemTouchHelper is in idle state. At this state, either there is no related motion event by
+ * the user or latest motion events have not yet triggered a swipe or drag.
+ */
+ public static final int ACTION_STATE_IDLE = 0;
+
+ /**
+ * A View is currently being swiped.
+ */
+ public static final int ACTION_STATE_SWIPE = 1;
+
+ /**
+ * A View is currently being dragged.
+ */
+ public static final int ACTION_STATE_DRAG = 2;
+
+ /**
+ * Animation type for views which are swiped successfully.
+ */
+ public static final int ANIMATION_TYPE_SWIPE_SUCCESS = 1 << 1;
+
+ /**
+ * Animation type for views which are not completely swiped thus will animate back to their
+ * original position.
+ */
+ public static final int ANIMATION_TYPE_SWIPE_CANCEL = 1 << 2;
+
+ /**
+ * Animation type for views that were dragged and now will animate to their final position.
+ */
+ public static final int ANIMATION_TYPE_DRAG = 1 << 3;
+
+ static final String TAG = "ItemTouchHelper";
+
+ static final boolean DEBUG = false;
+
+ static final int ACTIVE_POINTER_ID_NONE = -1;
+
+ static final int DIRECTION_FLAG_COUNT = 8;
+
+ private static final int ACTION_MODE_IDLE_MASK = (1 << DIRECTION_FLAG_COUNT) - 1;
+
+ static final int ACTION_MODE_SWIPE_MASK = ACTION_MODE_IDLE_MASK << DIRECTION_FLAG_COUNT;
+
+ static final int ACTION_MODE_DRAG_MASK = ACTION_MODE_SWIPE_MASK << DIRECTION_FLAG_COUNT;
+
+ /**
+ * The unit we are using to track velocity
+ */
+ private static final int PIXELS_PER_SECOND = 1000;
+
+ /**
+ * Views, whose state should be cleared after they are detached from RecyclerView.
+ * This is necessary after swipe dismissing an item. We wait until animator finishes its job
+ * to clean these views.
+ */
+ final List<View> mPendingCleanup = new ArrayList<View>();
+
+ /**
+ * Re-use array to calculate dx dy for a ViewHolder
+ */
+ private final float[] mTmpPosition = new float[2];
+
+ /**
+ * Currently selected view holder
+ */
+ ViewHolder mSelected = null;
+
+ /**
+ * The reference coordinates for the action start. For drag & drop, this is the time long
+ * press is completed vs for swipe, this is the initial touch point.
+ */
+ float mInitialTouchX;
+
+ float mInitialTouchY;
+
+ /**
+ * Set when ItemTouchHelper is assigned to a RecyclerView.
+ */
+ float mSwipeEscapeVelocity;
+
+ /**
+ * Set when ItemTouchHelper is assigned to a RecyclerView.
+ */
+ float mMaxSwipeVelocity;
+
+ /**
+ * The diff between the last event and initial touch.
+ */
+ float mDx;
+
+ float mDy;
+
+ /**
+ * The coordinates of the selected view at the time it is selected. We record these values
+ * when action starts so that we can consistently position it even if LayoutManager moves the
+ * View.
+ */
+ float mSelectedStartX;
+
+ float mSelectedStartY;
+
+ /**
+ * The pointer we are tracking.
+ */
+ int mActivePointerId = ACTIVE_POINTER_ID_NONE;
+
+ /**
+ * Developer callback which controls the behavior of ItemTouchHelper.
+ */
+ Callback mCallback;
+
+ /**
+ * Current mode.
+ */
+ int mActionState = ACTION_STATE_IDLE;
+
+ /**
+ * The direction flags obtained from unmasking
+ * {@link Callback#getAbsoluteMovementFlags(RecyclerView, ViewHolder)} for the current
+ * action state.
+ */
+ int mSelectedFlags;
+
+ /**
+ * When a View is dragged or swiped and needs to go back to where it was, we create a Recover
+ * Animation and animate it to its location using this custom Animator, instead of using
+ * framework Animators.
+ * Using framework animators has the side effect of clashing with ItemAnimator, creating
+ * jumpy UIs.
+ */
+ List<RecoverAnimation> mRecoverAnimations = new ArrayList<RecoverAnimation>();
+
+ private int mSlop;
+
+ RecyclerView mRecyclerView;
+
+ /**
+ * When user drags a view to the edge, we start scrolling the LayoutManager as long as View
+ * is partially out of bounds.
+ */
+ final Runnable mScrollRunnable = new Runnable() {
+ @Override
+ public void run() {
+ if (mSelected != null && scrollIfNecessary()) {
+ if (mSelected != null) { //it might be lost during scrolling
+ moveIfNecessary(mSelected);
+ }
+ mRecyclerView.removeCallbacks(mScrollRunnable);
+ mRecyclerView.postOnAnimation(this);
+ }
+ }
+ };
+
+ /**
+ * Used for detecting fling swipe
+ */
+ VelocityTracker mVelocityTracker;
+
+ //re-used list for selecting a swap target
+ private List<ViewHolder> mSwapTargets;
+
+ //re used for for sorting swap targets
+ private List<Integer> mDistances;
+
+ /**
+ * If drag & drop is supported, we use child drawing order to bring them to front.
+ */
+ private RecyclerView.ChildDrawingOrderCallback mChildDrawingOrderCallback = null;
+
+ /**
+ * This keeps a reference to the child dragged by the user. Even after user stops dragging,
+ * until view reaches its final position (end of recover animation), we keep a reference so
+ * that it can be drawn above other children.
+ */
+ View mOverdrawChild = null;
+
+ /**
+ * We cache the position of the overdraw child to avoid recalculating it each time child
+ * position callback is called. This value is invalidated whenever a child is attached or
+ * detached.
+ */
+ int mOverdrawChildPosition = -1;
+
+ /**
+ * Used to detect long press.
+ */
+ GestureDetector mGestureDetector;
+
+ private final OnItemTouchListener mOnItemTouchListener = new OnItemTouchListener() {
+ @Override
+ public boolean onInterceptTouchEvent(RecyclerView recyclerView, MotionEvent event) {
+ mGestureDetector.onTouchEvent(event);
+ if (DEBUG) {
+ Log.d(TAG, "intercept: x:" + event.getX() + ",y:" + event.getY() + ", " + event);
+ }
+ final int action = event.getActionMasked();
+ if (action == MotionEvent.ACTION_DOWN) {
+ mActivePointerId = event.getPointerId(0);
+ mInitialTouchX = event.getX();
+ mInitialTouchY = event.getY();
+ obtainVelocityTracker();
+ if (mSelected == null) {
+ final RecoverAnimation animation = findAnimation(event);
+ if (animation != null) {
+ mInitialTouchX -= animation.mX;
+ mInitialTouchY -= animation.mY;
+ endRecoverAnimation(animation.mViewHolder, true);
+ if (mPendingCleanup.remove(animation.mViewHolder.itemView)) {
+ mCallback.clearView(mRecyclerView, animation.mViewHolder);
+ }
+ select(animation.mViewHolder, animation.mActionState);
+ updateDxDy(event, mSelectedFlags, 0);
+ }
+ }
+ } else if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
+ mActivePointerId = ACTIVE_POINTER_ID_NONE;
+ select(null, ACTION_STATE_IDLE);
+ } else if (mActivePointerId != ACTIVE_POINTER_ID_NONE) {
+ // in a non scroll orientation, if distance change is above threshold, we
+ // can select the item
+ final int index = event.findPointerIndex(mActivePointerId);
+ if (DEBUG) {
+ Log.d(TAG, "pointer index " + index);
+ }
+ if (index >= 0) {
+ checkSelectForSwipe(action, event, index);
+ }
+ }
+ if (mVelocityTracker != null) {
+ mVelocityTracker.addMovement(event);
+ }
+ return mSelected != null;
+ }
+
+ @Override
+ public void onTouchEvent(RecyclerView recyclerView, MotionEvent event) {
+ mGestureDetector.onTouchEvent(event);
+ if (DEBUG) {
+ Log.d(TAG,
+ "on touch: x:" + mInitialTouchX + ",y:" + mInitialTouchY + ", :" + event);
+ }
+ if (mVelocityTracker != null) {
+ mVelocityTracker.addMovement(event);
+ }
+ if (mActivePointerId == ACTIVE_POINTER_ID_NONE) {
+ return;
+ }
+ final int action = event.getActionMasked();
+ final int activePointerIndex = event.findPointerIndex(mActivePointerId);
+ if (activePointerIndex >= 0) {
+ checkSelectForSwipe(action, event, activePointerIndex);
+ }
+ ViewHolder viewHolder = mSelected;
+ if (viewHolder == null) {
+ return;
+ }
+ switch (action) {
+ case MotionEvent.ACTION_MOVE: {
+ // Find the index of the active pointer and fetch its position
+ if (activePointerIndex >= 0) {
+ updateDxDy(event, mSelectedFlags, activePointerIndex);
+ moveIfNecessary(viewHolder);
+ mRecyclerView.removeCallbacks(mScrollRunnable);
+ mScrollRunnable.run();
+ mRecyclerView.invalidate();
+ }
+ break;
+ }
+ case MotionEvent.ACTION_CANCEL:
+ if (mVelocityTracker != null) {
+ mVelocityTracker.clear();
+ }
+ // fall through
+ case MotionEvent.ACTION_UP:
+ select(null, ACTION_STATE_IDLE);
+ mActivePointerId = ACTIVE_POINTER_ID_NONE;
+ break;
+ case MotionEvent.ACTION_POINTER_UP: {
+ final int pointerIndex = event.getActionIndex();
+ final int pointerId = event.getPointerId(pointerIndex);
+ if (pointerId == mActivePointerId) {
+ // This was our active pointer going up. Choose a new
+ // active pointer and adjust accordingly.
+ final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
+ mActivePointerId = event.getPointerId(newPointerIndex);
+ updateDxDy(event, mSelectedFlags, pointerIndex);
+ }
+ break;
+ }
+ }
+ }
+
+ @Override
+ public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
+ if (!disallowIntercept) {
+ return;
+ }
+ select(null, ACTION_STATE_IDLE);
+ }
+ };
+
+ /**
+ * Temporary rect instance that is used when we need to lookup Item decorations.
+ */
+ private Rect mTmpRect;
+
+ /**
+ * When user started to drag scroll. Reset when we don't scroll
+ */
+ private long mDragScrollStartTimeInMs;
+
+ /**
+ * Creates an ItemTouchHelper that will work with the given Callback.
+ * <p>
+ * You can attach ItemTouchHelper to a RecyclerView via
+ * {@link #attachToRecyclerView(RecyclerView)}. Upon attaching, it will add an item decoration,
+ * an onItemTouchListener and a Child attach / detach listener to the RecyclerView.
+ *
+ * @param callback The Callback which controls the behavior of this touch helper.
+ */
+ public ItemTouchHelper(Callback callback) {
+ mCallback = callback;
+ }
+
+ private static boolean hitTest(View child, float x, float y, float left, float top) {
+ return x >= left
+ && x <= left + child.getWidth()
+ && y >= top
+ && y <= top + child.getHeight();
+ }
+
+ /**
+ * Attaches the ItemTouchHelper to the provided RecyclerView. If TouchHelper is already
+ * attached to a RecyclerView, it will first detach from the previous one. You can call this
+ * method with {@code null} to detach it from the current RecyclerView.
+ *
+ * @param recyclerView The RecyclerView instance to which you want to add this helper or
+ * {@code null} if you want to remove ItemTouchHelper from the current
+ * RecyclerView.
+ */
+ public void attachToRecyclerView(@Nullable RecyclerView recyclerView) {
+ if (mRecyclerView == recyclerView) {
+ return; // nothing to do
+ }
+ if (mRecyclerView != null) {
+ destroyCallbacks();
+ }
+ mRecyclerView = recyclerView;
+ if (mRecyclerView != null) {
+ final Resources resources = recyclerView.getResources();
+ mSwipeEscapeVelocity = resources
+ .getDimension(R.dimen.item_touch_helper_swipe_escape_velocity);
+ mMaxSwipeVelocity = resources
+ .getDimension(R.dimen.item_touch_helper_swipe_escape_max_velocity);
+ setupCallbacks();
+ }
+ }
+
+ private void setupCallbacks() {
+ ViewConfiguration vc = ViewConfiguration.get(mRecyclerView.getContext());
+ mSlop = vc.getScaledTouchSlop();
+ mRecyclerView.addItemDecoration(this);
+ mRecyclerView.addOnItemTouchListener(mOnItemTouchListener);
+ mRecyclerView.addOnChildAttachStateChangeListener(this);
+ initGestureDetector();
+ }
+
+ private void destroyCallbacks() {
+ mRecyclerView.removeItemDecoration(this);
+ mRecyclerView.removeOnItemTouchListener(mOnItemTouchListener);
+ mRecyclerView.removeOnChildAttachStateChangeListener(this);
+ // clean all attached
+ final int recoverAnimSize = mRecoverAnimations.size();
+ for (int i = recoverAnimSize - 1; i >= 0; i--) {
+ final RecoverAnimation recoverAnimation = mRecoverAnimations.get(0);
+ mCallback.clearView(mRecyclerView, recoverAnimation.mViewHolder);
+ }
+ mRecoverAnimations.clear();
+ mOverdrawChild = null;
+ mOverdrawChildPosition = -1;
+ releaseVelocityTracker();
+ }
+
+ private void initGestureDetector() {
+ if (mGestureDetector != null) {
+ return;
+ }
+ mGestureDetector = new GestureDetector(mRecyclerView.getContext(),
+ new ItemTouchHelperGestureListener());
+ }
+
+ private void getSelectedDxDy(float[] outPosition) {
+ if ((mSelectedFlags & (LEFT | RIGHT)) != 0) {
+ outPosition[0] = mSelectedStartX + mDx - mSelected.itemView.getLeft();
+ } else {
+ outPosition[0] = mSelected.itemView.getTranslationX();
+ }
+ if ((mSelectedFlags & (UP | DOWN)) != 0) {
+ outPosition[1] = mSelectedStartY + mDy - mSelected.itemView.getTop();
+ } else {
+ outPosition[1] = mSelected.itemView.getTranslationY();
+ }
+ }
+
+ @Override
+ public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
+ float dx = 0, dy = 0;
+ if (mSelected != null) {
+ getSelectedDxDy(mTmpPosition);
+ dx = mTmpPosition[0];
+ dy = mTmpPosition[1];
+ }
+ mCallback.onDrawOver(c, parent, mSelected,
+ mRecoverAnimations, mActionState, dx, dy);
+ }
+
+ @Override
+ public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
+ // we don't know if RV changed something so we should invalidate this index.
+ mOverdrawChildPosition = -1;
+ float dx = 0, dy = 0;
+ if (mSelected != null) {
+ getSelectedDxDy(mTmpPosition);
+ dx = mTmpPosition[0];
+ dy = mTmpPosition[1];
+ }
+ mCallback.onDraw(c, parent, mSelected,
+ mRecoverAnimations, mActionState, dx, dy);
+ }
+
+ /**
+ * Starts dragging or swiping the given View. Call with null if you want to clear it.
+ *
+ * @param selected The ViewHolder to drag or swipe. Can be null if you want to cancel the
+ * current action
+ * @param actionState The type of action
+ */
+ void select(ViewHolder selected, int actionState) {
+ if (selected == mSelected && actionState == mActionState) {
+ return;
+ }
+ mDragScrollStartTimeInMs = Long.MIN_VALUE;
+ final int prevActionState = mActionState;
+ // prevent duplicate animations
+ endRecoverAnimation(selected, true);
+ mActionState = actionState;
+ if (actionState == ACTION_STATE_DRAG) {
+ // we remove after animation is complete. this means we only elevate the last drag
+ // child but that should perform good enough as it is very hard to start dragging a
+ // new child before the previous one settles.
+ mOverdrawChild = selected.itemView;
+ addChildDrawingOrderCallback();
+ }
+ int actionStateMask = (1 << (DIRECTION_FLAG_COUNT + DIRECTION_FLAG_COUNT * actionState))
+ - 1;
+ boolean preventLayout = false;
+
+ if (mSelected != null) {
+ final ViewHolder prevSelected = mSelected;
+ if (prevSelected.itemView.getParent() != null) {
+ final int swipeDir = prevActionState == ACTION_STATE_DRAG ? 0
+ : swipeIfNecessary(prevSelected);
+ releaseVelocityTracker();
+ // find where we should animate to
+ final float targetTranslateX, targetTranslateY;
+ int animationType;
+ switch (swipeDir) {
+ case LEFT:
+ case RIGHT:
+ case START:
+ case END:
+ targetTranslateY = 0;
+ targetTranslateX = Math.signum(mDx) * mRecyclerView.getWidth();
+ break;
+ case UP:
+ case DOWN:
+ targetTranslateX = 0;
+ targetTranslateY = Math.signum(mDy) * mRecyclerView.getHeight();
+ break;
+ default:
+ targetTranslateX = 0;
+ targetTranslateY = 0;
+ }
+ if (prevActionState == ACTION_STATE_DRAG) {
+ animationType = ANIMATION_TYPE_DRAG;
+ } else if (swipeDir > 0) {
+ animationType = ANIMATION_TYPE_SWIPE_SUCCESS;
+ } else {
+ animationType = ANIMATION_TYPE_SWIPE_CANCEL;
+ }
+ getSelectedDxDy(mTmpPosition);
+ final float currentTranslateX = mTmpPosition[0];
+ final float currentTranslateY = mTmpPosition[1];
+ final RecoverAnimation rv = new RecoverAnimation(prevSelected, animationType,
+ prevActionState, currentTranslateX, currentTranslateY,
+ targetTranslateX, targetTranslateY) {
+ @Override
+ public void onAnimationEnd(Animator animation) {
+ super.onAnimationEnd(animation);
+ if (this.mOverridden) {
+ return;
+ }
+ if (swipeDir <= 0) {
+ // this is a drag or failed swipe. recover immediately
+ mCallback.clearView(mRecyclerView, prevSelected);
+ // full cleanup will happen on onDrawOver
+ } else {
+ // wait until remove animation is complete.
+ mPendingCleanup.add(prevSelected.itemView);
+ mIsPendingCleanup = true;
+ if (swipeDir > 0) {
+ // Animation might be ended by other animators during a layout.
+ // We defer callback to avoid editing adapter during a layout.
+ postDispatchSwipe(this, swipeDir);
+ }
+ }
+ // removed from the list after it is drawn for the last time
+ if (mOverdrawChild == prevSelected.itemView) {
+ removeChildDrawingOrderCallbackIfNecessary(prevSelected.itemView);
+ }
+ }
+ };
+ final long duration = mCallback.getAnimationDuration(mRecyclerView, animationType,
+ targetTranslateX - currentTranslateX, targetTranslateY - currentTranslateY);
+ rv.setDuration(duration);
+ mRecoverAnimations.add(rv);
+ rv.start();
+ preventLayout = true;
+ } else {
+ removeChildDrawingOrderCallbackIfNecessary(prevSelected.itemView);
+ mCallback.clearView(mRecyclerView, prevSelected);
+ }
+ mSelected = null;
+ }
+ if (selected != null) {
+ mSelectedFlags =
+ (mCallback.getAbsoluteMovementFlags(mRecyclerView, selected) & actionStateMask)
+ >> (mActionState * DIRECTION_FLAG_COUNT);
+ mSelectedStartX = selected.itemView.getLeft();
+ mSelectedStartY = selected.itemView.getTop();
+ mSelected = selected;
+
+ if (actionState == ACTION_STATE_DRAG) {
+ mSelected.itemView.performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
+ }
+ }
+ final ViewParent rvParent = mRecyclerView.getParent();
+ if (rvParent != null) {
+ rvParent.requestDisallowInterceptTouchEvent(mSelected != null);
+ }
+ if (!preventLayout) {
+ mRecyclerView.getLayoutManager().requestSimpleAnimationsInNextLayout();
+ }
+ mCallback.onSelectedChanged(mSelected, mActionState);
+ mRecyclerView.invalidate();
+ }
+
+ void postDispatchSwipe(final RecoverAnimation anim, final int swipeDir) {
+ // wait until animations are complete.
+ mRecyclerView.post(new Runnable() {
+ @Override
+ public void run() {
+ if (mRecyclerView != null && mRecyclerView.isAttachedToWindow()
+ && !anim.mOverridden
+ && anim.mViewHolder.getAdapterPosition() != RecyclerView.NO_POSITION) {
+ final RecyclerView.ItemAnimator animator = mRecyclerView.getItemAnimator();
+ // if animator is running or we have other active recover animations, we try
+ // not to call onSwiped because DefaultItemAnimator is not good at merging
+ // animations. Instead, we wait and batch.
+ if ((animator == null || !animator.isRunning(null))
+ && !hasRunningRecoverAnim()) {
+ mCallback.onSwiped(anim.mViewHolder, swipeDir);
+ } else {
+ mRecyclerView.post(this);
+ }
+ }
+ }
+ });
+ }
+
+ boolean hasRunningRecoverAnim() {
+ final int size = mRecoverAnimations.size();
+ for (int i = 0; i < size; i++) {
+ if (!mRecoverAnimations.get(i).mEnded) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * If user drags the view to the edge, trigger a scroll if necessary.
+ */
+ boolean scrollIfNecessary() {
+ if (mSelected == null) {
+ mDragScrollStartTimeInMs = Long.MIN_VALUE;
+ return false;
+ }
+ final long now = System.currentTimeMillis();
+ final long scrollDuration = mDragScrollStartTimeInMs
+ == Long.MIN_VALUE ? 0 : now - mDragScrollStartTimeInMs;
+ RecyclerView.LayoutManager lm = mRecyclerView.getLayoutManager();
+ if (mTmpRect == null) {
+ mTmpRect = new Rect();
+ }
+ int scrollX = 0;
+ int scrollY = 0;
+ lm.calculateItemDecorationsForChild(mSelected.itemView, mTmpRect);
+ if (lm.canScrollHorizontally()) {
+ int curX = (int) (mSelectedStartX + mDx);
+ final int leftDiff = curX - mTmpRect.left - mRecyclerView.getPaddingLeft();
+ if (mDx < 0 && leftDiff < 0) {
+ scrollX = leftDiff;
+ } else if (mDx > 0) {
+ final int rightDiff =
+ curX + mSelected.itemView.getWidth() + mTmpRect.right
+ - (mRecyclerView.getWidth() - mRecyclerView.getPaddingRight());
+ if (rightDiff > 0) {
+ scrollX = rightDiff;
+ }
+ }
+ }
+ if (lm.canScrollVertically()) {
+ int curY = (int) (mSelectedStartY + mDy);
+ final int topDiff = curY - mTmpRect.top - mRecyclerView.getPaddingTop();
+ if (mDy < 0 && topDiff < 0) {
+ scrollY = topDiff;
+ } else if (mDy > 0) {
+ final int bottomDiff = curY + mSelected.itemView.getHeight() + mTmpRect.bottom
+ - (mRecyclerView.getHeight() - mRecyclerView.getPaddingBottom());
+ if (bottomDiff > 0) {
+ scrollY = bottomDiff;
+ }
+ }
+ }
+ if (scrollX != 0) {
+ scrollX = mCallback.interpolateOutOfBoundsScroll(mRecyclerView,
+ mSelected.itemView.getWidth(), scrollX,
+ mRecyclerView.getWidth(), scrollDuration);
+ }
+ if (scrollY != 0) {
+ scrollY = mCallback.interpolateOutOfBoundsScroll(mRecyclerView,
+ mSelected.itemView.getHeight(), scrollY,
+ mRecyclerView.getHeight(), scrollDuration);
+ }
+ if (scrollX != 0 || scrollY != 0) {
+ if (mDragScrollStartTimeInMs == Long.MIN_VALUE) {
+ mDragScrollStartTimeInMs = now;
+ }
+ mRecyclerView.scrollBy(scrollX, scrollY);
+ return true;
+ }
+ mDragScrollStartTimeInMs = Long.MIN_VALUE;
+ return false;
+ }
+
+ private List<ViewHolder> findSwapTargets(ViewHolder viewHolder) {
+ if (mSwapTargets == null) {
+ mSwapTargets = new ArrayList<ViewHolder>();
+ mDistances = new ArrayList<Integer>();
+ } else {
+ mSwapTargets.clear();
+ mDistances.clear();
+ }
+ final int margin = mCallback.getBoundingBoxMargin();
+ final int left = Math.round(mSelectedStartX + mDx) - margin;
+ final int top = Math.round(mSelectedStartY + mDy) - margin;
+ final int right = left + viewHolder.itemView.getWidth() + 2 * margin;
+ final int bottom = top + viewHolder.itemView.getHeight() + 2 * margin;
+ final int centerX = (left + right) / 2;
+ final int centerY = (top + bottom) / 2;
+ final RecyclerView.LayoutManager lm = mRecyclerView.getLayoutManager();
+ final int childCount = lm.getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ View other = lm.getChildAt(i);
+ if (other == viewHolder.itemView) {
+ continue; //myself!
+ }
+ if (other.getBottom() < top || other.getTop() > bottom
+ || other.getRight() < left || other.getLeft() > right) {
+ continue;
+ }
+ final ViewHolder otherVh = mRecyclerView.getChildViewHolder(other);
+ if (mCallback.canDropOver(mRecyclerView, mSelected, otherVh)) {
+ // find the index to add
+ final int dx = Math.abs(centerX - (other.getLeft() + other.getRight()) / 2);
+ final int dy = Math.abs(centerY - (other.getTop() + other.getBottom()) / 2);
+ final int dist = dx * dx + dy * dy;
+
+ int pos = 0;
+ final int cnt = mSwapTargets.size();
+ for (int j = 0; j < cnt; j++) {
+ if (dist > mDistances.get(j)) {
+ pos++;
+ } else {
+ break;
+ }
+ }
+ mSwapTargets.add(pos, otherVh);
+ mDistances.add(pos, dist);
+ }
+ }
+ return mSwapTargets;
+ }
+
+ /**
+ * Checks if we should swap w/ another view holder.
+ */
+ void moveIfNecessary(ViewHolder viewHolder) {
+ if (mRecyclerView.isLayoutRequested()) {
+ return;
+ }
+ if (mActionState != ACTION_STATE_DRAG) {
+ return;
+ }
+
+ final float threshold = mCallback.getMoveThreshold(viewHolder);
+ final int x = (int) (mSelectedStartX + mDx);
+ final int y = (int) (mSelectedStartY + mDy);
+ if (Math.abs(y - viewHolder.itemView.getTop()) < viewHolder.itemView.getHeight() * threshold
+ && Math.abs(x - viewHolder.itemView.getLeft())
+ < viewHolder.itemView.getWidth() * threshold) {
+ return;
+ }
+ List<ViewHolder> swapTargets = findSwapTargets(viewHolder);
+ if (swapTargets.size() == 0) {
+ return;
+ }
+ // may swap.
+ ViewHolder target = mCallback.chooseDropTarget(viewHolder, swapTargets, x, y);
+ if (target == null) {
+ mSwapTargets.clear();
+ mDistances.clear();
+ return;
+ }
+ final int toPosition = target.getAdapterPosition();
+ final int fromPosition = viewHolder.getAdapterPosition();
+ if (mCallback.onMove(mRecyclerView, viewHolder, target)) {
+ // keep target visible
+ mCallback.onMoved(mRecyclerView, viewHolder, fromPosition,
+ target, toPosition, x, y);
+ }
+ }
+
+ @Override
+ public void onChildViewAttachedToWindow(View view) {
+ }
+
+ @Override
+ public void onChildViewDetachedFromWindow(View view) {
+ removeChildDrawingOrderCallbackIfNecessary(view);
+ final ViewHolder holder = mRecyclerView.getChildViewHolder(view);
+ if (holder == null) {
+ return;
+ }
+ if (mSelected != null && holder == mSelected) {
+ select(null, ACTION_STATE_IDLE);
+ } else {
+ endRecoverAnimation(holder, false); // this may push it into pending cleanup list.
+ if (mPendingCleanup.remove(holder.itemView)) {
+ mCallback.clearView(mRecyclerView, holder);
+ }
+ }
+ }
+
+ /**
+ * Returns the animation type or 0 if cannot be found.
+ */
+ int endRecoverAnimation(ViewHolder viewHolder, boolean override) {
+ final int recoverAnimSize = mRecoverAnimations.size();
+ for (int i = recoverAnimSize - 1; i >= 0; i--) {
+ final RecoverAnimation anim = mRecoverAnimations.get(i);
+ if (anim.mViewHolder == viewHolder) {
+ anim.mOverridden |= override;
+ if (!anim.mEnded) {
+ anim.cancel();
+ }
+ mRecoverAnimations.remove(i);
+ return anim.mAnimationType;
+ }
+ }
+ return 0;
+ }
+
+ @Override
+ public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
+ RecyclerView.State state) {
+ outRect.setEmpty();
+ }
+
+ void obtainVelocityTracker() {
+ if (mVelocityTracker != null) {
+ mVelocityTracker.recycle();
+ }
+ mVelocityTracker = VelocityTracker.obtain();
+ }
+
+ private void releaseVelocityTracker() {
+ if (mVelocityTracker != null) {
+ mVelocityTracker.recycle();
+ mVelocityTracker = null;
+ }
+ }
+
+ private ViewHolder findSwipedView(MotionEvent motionEvent) {
+ final RecyclerView.LayoutManager lm = mRecyclerView.getLayoutManager();
+ if (mActivePointerId == ACTIVE_POINTER_ID_NONE) {
+ return null;
+ }
+ final int pointerIndex = motionEvent.findPointerIndex(mActivePointerId);
+ final float dx = motionEvent.getX(pointerIndex) - mInitialTouchX;
+ final float dy = motionEvent.getY(pointerIndex) - mInitialTouchY;
+ final float absDx = Math.abs(dx);
+ final float absDy = Math.abs(dy);
+
+ if (absDx < mSlop && absDy < mSlop) {
+ return null;
+ }
+ if (absDx > absDy && lm.canScrollHorizontally()) {
+ return null;
+ } else if (absDy > absDx && lm.canScrollVertically()) {
+ return null;
+ }
+ View child = findChildView(motionEvent);
+ if (child == null) {
+ return null;
+ }
+ return mRecyclerView.getChildViewHolder(child);
+ }
+
+ /**
+ * Checks whether we should select a View for swiping.
+ */
+ boolean checkSelectForSwipe(int action, MotionEvent motionEvent, int pointerIndex) {
+ if (mSelected != null || action != MotionEvent.ACTION_MOVE
+ || mActionState == ACTION_STATE_DRAG || !mCallback.isItemViewSwipeEnabled()) {
+ return false;
+ }
+ if (mRecyclerView.getScrollState() == RecyclerView.SCROLL_STATE_DRAGGING) {
+ return false;
+ }
+ final ViewHolder vh = findSwipedView(motionEvent);
+ if (vh == null) {
+ return false;
+ }
+ final int movementFlags = mCallback.getAbsoluteMovementFlags(mRecyclerView, vh);
+
+ final int swipeFlags = (movementFlags & ACTION_MODE_SWIPE_MASK)
+ >> (DIRECTION_FLAG_COUNT * ACTION_STATE_SWIPE);
+
+ if (swipeFlags == 0) {
+ return false;
+ }
+
+ // mDx and mDy are only set in allowed directions. We use custom x/y here instead of
+ // updateDxDy to avoid swiping if user moves more in the other direction
+ final float x = motionEvent.getX(pointerIndex);
+ final float y = motionEvent.getY(pointerIndex);
+
+ // Calculate the distance moved
+ final float dx = x - mInitialTouchX;
+ final float dy = y - mInitialTouchY;
+ // swipe target is chose w/o applying flags so it does not really check if swiping in that
+ // direction is allowed. This why here, we use mDx mDy to check slope value again.
+ final float absDx = Math.abs(dx);
+ final float absDy = Math.abs(dy);
+
+ if (absDx < mSlop && absDy < mSlop) {
+ return false;
+ }
+ if (absDx > absDy) {
+ if (dx < 0 && (swipeFlags & LEFT) == 0) {
+ return false;
+ }
+ if (dx > 0 && (swipeFlags & RIGHT) == 0) {
+ return false;
+ }
+ } else {
+ if (dy < 0 && (swipeFlags & UP) == 0) {
+ return false;
+ }
+ if (dy > 0 && (swipeFlags & DOWN) == 0) {
+ return false;
+ }
+ }
+ mDx = mDy = 0f;
+ mActivePointerId = motionEvent.getPointerId(0);
+ select(vh, ACTION_STATE_SWIPE);
+ return true;
+ }
+
+ View findChildView(MotionEvent event) {
+ // first check elevated views, if none, then call RV
+ final float x = event.getX();
+ final float y = event.getY();
+ if (mSelected != null) {
+ final View selectedView = mSelected.itemView;
+ if (hitTest(selectedView, x, y, mSelectedStartX + mDx, mSelectedStartY + mDy)) {
+ return selectedView;
+ }
+ }
+ for (int i = mRecoverAnimations.size() - 1; i >= 0; i--) {
+ final RecoverAnimation anim = mRecoverAnimations.get(i);
+ final View view = anim.mViewHolder.itemView;
+ if (hitTest(view, x, y, anim.mX, anim.mY)) {
+ return view;
+ }
+ }
+ return mRecyclerView.findChildViewUnder(x, y);
+ }
+
+ /**
+ * Starts dragging the provided ViewHolder. By default, ItemTouchHelper starts a drag when a
+ * View is long pressed. You can disable that behavior by overriding
+ * {@link ItemTouchHelper.Callback#isLongPressDragEnabled()}.
+ * <p>
+ * For this method to work:
+ * <ul>
+ * <li>The provided ViewHolder must be a child of the RecyclerView to which this
+ * ItemTouchHelper
+ * is attached.</li>
+ * <li>{@link ItemTouchHelper.Callback} must have dragging enabled.</li>
+ * <li>There must be a previous touch event that was reported to the ItemTouchHelper
+ * through RecyclerView's ItemTouchListener mechanism. As long as no other ItemTouchListener
+ * grabs previous events, this should work as expected.</li>
+ * </ul>
+ *
+ * For example, if you would like to let your user to be able to drag an Item by touching one
+ * of its descendants, you may implement it as follows:
+ * <pre>
+ * viewHolder.dragButton.setOnTouchListener(new View.OnTouchListener() {
+ * public boolean onTouch(View v, MotionEvent event) {
+ * if (MotionEvent.getActionMasked(event) == MotionEvent.ACTION_DOWN) {
+ * mItemTouchHelper.startDrag(viewHolder);
+ * }
+ * return false;
+ * }
+ * });
+ * </pre>
+ * <p>
+ *
+ * @param viewHolder The ViewHolder to start dragging. It must be a direct child of
+ * RecyclerView.
+ * @see ItemTouchHelper.Callback#isItemViewSwipeEnabled()
+ */
+ public void startDrag(ViewHolder viewHolder) {
+ if (!mCallback.hasDragFlag(mRecyclerView, viewHolder)) {
+ Log.e(TAG, "Start drag has been called but dragging is not enabled");
+ return;
+ }
+ if (viewHolder.itemView.getParent() != mRecyclerView) {
+ Log.e(TAG, "Start drag has been called with a view holder which is not a child of "
+ + "the RecyclerView which is controlled by this ItemTouchHelper.");
+ return;
+ }
+ obtainVelocityTracker();
+ mDx = mDy = 0f;
+ select(viewHolder, ACTION_STATE_DRAG);
+ }
+
+ /**
+ * Starts swiping the provided ViewHolder. By default, ItemTouchHelper starts swiping a View
+ * when user swipes their finger (or mouse pointer) over the View. You can disable this
+ * behavior
+ * by overriding {@link ItemTouchHelper.Callback}
+ * <p>
+ * For this method to work:
+ * <ul>
+ * <li>The provided ViewHolder must be a child of the RecyclerView to which this
+ * ItemTouchHelper is attached.</li>
+ * <li>{@link ItemTouchHelper.Callback} must have swiping enabled.</li>
+ * <li>There must be a previous touch event that was reported to the ItemTouchHelper
+ * through RecyclerView's ItemTouchListener mechanism. As long as no other ItemTouchListener
+ * grabs previous events, this should work as expected.</li>
+ * </ul>
+ *
+ * For example, if you would like to let your user to be able to swipe an Item by touching one
+ * of its descendants, you may implement it as follows:
+ * <pre>
+ * viewHolder.dragButton.setOnTouchListener(new View.OnTouchListener() {
+ * public boolean onTouch(View v, MotionEvent event) {
+ * if (MotionEvent.getActionMasked(event) == MotionEvent.ACTION_DOWN) {
+ * mItemTouchHelper.startSwipe(viewHolder);
+ * }
+ * return false;
+ * }
+ * });
+ * </pre>
+ *
+ * @param viewHolder The ViewHolder to start swiping. It must be a direct child of
+ * RecyclerView.
+ */
+ public void startSwipe(ViewHolder viewHolder) {
+ if (!mCallback.hasSwipeFlag(mRecyclerView, viewHolder)) {
+ Log.e(TAG, "Start swipe has been called but swiping is not enabled");
+ return;
+ }
+ if (viewHolder.itemView.getParent() != mRecyclerView) {
+ Log.e(TAG, "Start swipe has been called with a view holder which is not a child of "
+ + "the RecyclerView controlled by this ItemTouchHelper.");
+ return;
+ }
+ obtainVelocityTracker();
+ mDx = mDy = 0f;
+ select(viewHolder, ACTION_STATE_SWIPE);
+ }
+
+ RecoverAnimation findAnimation(MotionEvent event) {
+ if (mRecoverAnimations.isEmpty()) {
+ return null;
+ }
+ View target = findChildView(event);
+ for (int i = mRecoverAnimations.size() - 1; i >= 0; i--) {
+ final RecoverAnimation anim = mRecoverAnimations.get(i);
+ if (anim.mViewHolder.itemView == target) {
+ return anim;
+ }
+ }
+ return null;
+ }
+
+ void updateDxDy(MotionEvent ev, int directionFlags, int pointerIndex) {
+ final float x = ev.getX(pointerIndex);
+ final float y = ev.getY(pointerIndex);
+
+ // Calculate the distance moved
+ mDx = x - mInitialTouchX;
+ mDy = y - mInitialTouchY;
+ if ((directionFlags & LEFT) == 0) {
+ mDx = Math.max(0, mDx);
+ }
+ if ((directionFlags & RIGHT) == 0) {
+ mDx = Math.min(0, mDx);
+ }
+ if ((directionFlags & UP) == 0) {
+ mDy = Math.max(0, mDy);
+ }
+ if ((directionFlags & DOWN) == 0) {
+ mDy = Math.min(0, mDy);
+ }
+ }
+
+ private int swipeIfNecessary(ViewHolder viewHolder) {
+ if (mActionState == ACTION_STATE_DRAG) {
+ return 0;
+ }
+ final int originalMovementFlags = mCallback.getMovementFlags(mRecyclerView, viewHolder);
+ final int absoluteMovementFlags = mCallback.convertToAbsoluteDirection(
+ originalMovementFlags,
+ mRecyclerView.getLayoutDirection());
+ final int flags = (absoluteMovementFlags
+ & ACTION_MODE_SWIPE_MASK) >> (ACTION_STATE_SWIPE * DIRECTION_FLAG_COUNT);
+ if (flags == 0) {
+ return 0;
+ }
+ final int originalFlags = (originalMovementFlags
+ & ACTION_MODE_SWIPE_MASK) >> (ACTION_STATE_SWIPE * DIRECTION_FLAG_COUNT);
+ int swipeDir;
+ if (Math.abs(mDx) > Math.abs(mDy)) {
+ if ((swipeDir = checkHorizontalSwipe(viewHolder, flags)) > 0) {
+ // if swipe dir is not in original flags, it should be the relative direction
+ if ((originalFlags & swipeDir) == 0) {
+ // convert to relative
+ return Callback.convertToRelativeDirection(swipeDir,
+ mRecyclerView.getLayoutDirection());
+ }
+ return swipeDir;
+ }
+ if ((swipeDir = checkVerticalSwipe(viewHolder, flags)) > 0) {
+ return swipeDir;
+ }
+ } else {
+ if ((swipeDir = checkVerticalSwipe(viewHolder, flags)) > 0) {
+ return swipeDir;
+ }
+ if ((swipeDir = checkHorizontalSwipe(viewHolder, flags)) > 0) {
+ // if swipe dir is not in original flags, it should be the relative direction
+ if ((originalFlags & swipeDir) == 0) {
+ // convert to relative
+ return Callback.convertToRelativeDirection(swipeDir,
+ mRecyclerView.getLayoutDirection());
+ }
+ return swipeDir;
+ }
+ }
+ return 0;
+ }
+
+ private int checkHorizontalSwipe(ViewHolder viewHolder, int flags) {
+ if ((flags & (LEFT | RIGHT)) != 0) {
+ final int dirFlag = mDx > 0 ? RIGHT : LEFT;
+ if (mVelocityTracker != null && mActivePointerId > -1) {
+ mVelocityTracker.computeCurrentVelocity(PIXELS_PER_SECOND,
+ mCallback.getSwipeVelocityThreshold(mMaxSwipeVelocity));
+ final float xVelocity = mVelocityTracker.getXVelocity(mActivePointerId);
+ final float yVelocity = mVelocityTracker.getYVelocity(mActivePointerId);
+ final int velDirFlag = xVelocity > 0f ? RIGHT : LEFT;
+ final float absXVelocity = Math.abs(xVelocity);
+ if ((velDirFlag & flags) != 0 && dirFlag == velDirFlag
+ && absXVelocity >= mCallback.getSwipeEscapeVelocity(mSwipeEscapeVelocity)
+ && absXVelocity > Math.abs(yVelocity)) {
+ return velDirFlag;
+ }
+ }
+
+ final float threshold = mRecyclerView.getWidth() * mCallback
+ .getSwipeThreshold(viewHolder);
+
+ if ((flags & dirFlag) != 0 && Math.abs(mDx) > threshold) {
+ return dirFlag;
+ }
+ }
+ return 0;
+ }
+
+ private int checkVerticalSwipe(ViewHolder viewHolder, int flags) {
+ if ((flags & (UP | DOWN)) != 0) {
+ final int dirFlag = mDy > 0 ? DOWN : UP;
+ if (mVelocityTracker != null && mActivePointerId > -1) {
+ mVelocityTracker.computeCurrentVelocity(PIXELS_PER_SECOND,
+ mCallback.getSwipeVelocityThreshold(mMaxSwipeVelocity));
+ final float xVelocity = mVelocityTracker.getXVelocity(mActivePointerId);
+ final float yVelocity = mVelocityTracker.getYVelocity(mActivePointerId);
+ final int velDirFlag = yVelocity > 0f ? DOWN : UP;
+ final float absYVelocity = Math.abs(yVelocity);
+ if ((velDirFlag & flags) != 0 && velDirFlag == dirFlag
+ && absYVelocity >= mCallback.getSwipeEscapeVelocity(mSwipeEscapeVelocity)
+ && absYVelocity > Math.abs(xVelocity)) {
+ return velDirFlag;
+ }
+ }
+
+ final float threshold = mRecyclerView.getHeight() * mCallback
+ .getSwipeThreshold(viewHolder);
+ if ((flags & dirFlag) != 0 && Math.abs(mDy) > threshold) {
+ return dirFlag;
+ }
+ }
+ return 0;
+ }
+
+ private void addChildDrawingOrderCallback() {
+ if (Build.VERSION.SDK_INT >= 21) {
+ return; // we use elevation on Lollipop
+ }
+ if (mChildDrawingOrderCallback == null) {
+ mChildDrawingOrderCallback = new RecyclerView.ChildDrawingOrderCallback() {
+ @Override
+ public int onGetChildDrawingOrder(int childCount, int i) {
+ if (mOverdrawChild == null) {
+ return i;
+ }
+ int childPosition = mOverdrawChildPosition;
+ if (childPosition == -1) {
+ childPosition = mRecyclerView.indexOfChild(mOverdrawChild);
+ mOverdrawChildPosition = childPosition;
+ }
+ if (i == childCount - 1) {
+ return childPosition;
+ }
+ return i < childPosition ? i : i + 1;
+ }
+ };
+ }
+ mRecyclerView.setChildDrawingOrderCallback(mChildDrawingOrderCallback);
+ }
+
+ void removeChildDrawingOrderCallbackIfNecessary(View view) {
+ if (view == mOverdrawChild) {
+ mOverdrawChild = null;
+ // only remove if we've added
+ if (mChildDrawingOrderCallback != null) {
+ mRecyclerView.setChildDrawingOrderCallback(null);
+ }
+ }
+ }
+
+ /**
+ * An interface which can be implemented by LayoutManager for better integration with
+ * {@link ItemTouchHelper}.
+ */
+ public interface ViewDropHandler {
+
+ /**
+ * Called by the {@link ItemTouchHelper} after a View is dropped over another View.
+ * <p>
+ * A LayoutManager should implement this interface to get ready for the upcoming move
+ * operation.
+ * <p>
+ * For example, LinearLayoutManager sets up a "scrollToPositionWithOffset" calls so that
+ * the View under drag will be used as an anchor View while calculating the next layout,
+ * making layout stay consistent.
+ *
+ * @param view The View which is being dragged. It is very likely that user is still
+ * dragging this View so there might be other
+ * {@link #prepareForDrop(View, View, int, int)} after this one.
+ * @param target The target view which is being dropped on.
+ * @param x The <code>left</code> offset of the View that is being dragged. This value
+ * includes the movement caused by the user.
+ * @param y The <code>top</code> offset of the View that is being dragged. This value
+ * includes the movement caused by the user.
+ */
+ void prepareForDrop(View view, View target, int x, int y);
+ }
+
+ /**
+ * This class is the contract between ItemTouchHelper and your application. It lets you control
+ * which touch behaviors are enabled per each ViewHolder and also receive callbacks when user
+ * performs these actions.
+ * <p>
+ * To control which actions user can take on each view, you should override
+ * {@link #getMovementFlags(RecyclerView, ViewHolder)} and return appropriate set
+ * of direction flags. ({@link #LEFT}, {@link #RIGHT}, {@link #START}, {@link #END},
+ * {@link #UP}, {@link #DOWN}). You can use
+ * {@link #makeMovementFlags(int, int)} to easily construct it. Alternatively, you can use
+ * {@link SimpleCallback}.
+ * <p>
+ * If user drags an item, ItemTouchHelper will call
+ * {@link Callback#onMove(RecyclerView, ViewHolder, ViewHolder)
+ * onMove(recyclerView, dragged, target)}.
+ * Upon receiving this callback, you should move the item from the old position
+ * ({@code dragged.getAdapterPosition()}) to new position ({@code target.getAdapterPosition()})
+ * in your adapter and also call {@link RecyclerView.Adapter#notifyItemMoved(int, int)}.
+ * To control where a View can be dropped, you can override
+ * {@link #canDropOver(RecyclerView, ViewHolder, ViewHolder)}. When a
+ * dragging View overlaps multiple other views, Callback chooses the closest View with which
+ * dragged View might have changed positions. Although this approach works for many use cases,
+ * if you have a custom LayoutManager, you can override
+ * {@link #chooseDropTarget(ViewHolder, java.util.List, int, int)} to select a
+ * custom drop target.
+ * <p>
+ * When a View is swiped, ItemTouchHelper animates it until it goes out of bounds, then calls
+ * {@link #onSwiped(ViewHolder, int)}. At this point, you should update your
+ * adapter (e.g. remove the item) and call related Adapter#notify event.
+ */
+ @SuppressWarnings("UnusedParameters")
+ public abstract static class Callback {
+
+ public static final int DEFAULT_DRAG_ANIMATION_DURATION = 200;
+
+ public static final int DEFAULT_SWIPE_ANIMATION_DURATION = 250;
+
+ static final int RELATIVE_DIR_FLAGS = START | END
+ | ((START | END) << DIRECTION_FLAG_COUNT)
+ | ((START | END) << (2 * DIRECTION_FLAG_COUNT));
+
+ private static final ItemTouchUIUtil sUICallback = new ItemTouchUIUtilImpl();
+
+ private static final int ABS_HORIZONTAL_DIR_FLAGS = LEFT | RIGHT
+ | ((LEFT | RIGHT) << DIRECTION_FLAG_COUNT)
+ | ((LEFT | RIGHT) << (2 * DIRECTION_FLAG_COUNT));
+
+ private static final Interpolator sDragScrollInterpolator = new Interpolator() {
+ @Override
+ public float getInterpolation(float t) {
+ return t * t * t * t * t;
+ }
+ };
+
+ private static final Interpolator sDragViewScrollCapInterpolator = new Interpolator() {
+ @Override
+ public float getInterpolation(float t) {
+ t -= 1.0f;
+ return t * t * t * t * t + 1.0f;
+ }
+ };
+
+ /**
+ * Drag scroll speed keeps accelerating until this many milliseconds before being capped.
+ */
+ private static final long DRAG_SCROLL_ACCELERATION_LIMIT_TIME_MS = 2000;
+
+ private int mCachedMaxScrollSpeed = -1;
+
+ /**
+ * Returns the {@link ItemTouchUIUtil} that is used by the {@link Callback} class for
+ * visual
+ * changes on Views in response to user interactions. {@link ItemTouchUIUtil} has different
+ * implementations for different platform versions.
+ * <p>
+ * By default, {@link Callback} applies these changes on
+ * {@link RecyclerView.ViewHolder#itemView}.
+ * <p>
+ * For example, if you have a use case where you only want the text to move when user
+ * swipes over the view, you can do the following:
+ * <pre>
+ * public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder){
+ * getDefaultUIUtil().clearView(((ItemTouchViewHolder) viewHolder).textView);
+ * }
+ * public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
+ * if (viewHolder != null){
+ * getDefaultUIUtil().onSelected(((ItemTouchViewHolder) viewHolder).textView);
+ * }
+ * }
+ * public void onChildDraw(Canvas c, RecyclerView recyclerView,
+ * RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState,
+ * boolean isCurrentlyActive) {
+ * getDefaultUIUtil().onDraw(c, recyclerView,
+ * ((ItemTouchViewHolder) viewHolder).textView, dX, dY,
+ * actionState, isCurrentlyActive);
+ * return true;
+ * }
+ * public void onChildDrawOver(Canvas c, RecyclerView recyclerView,
+ * RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState,
+ * boolean isCurrentlyActive) {
+ * getDefaultUIUtil().onDrawOver(c, recyclerView,
+ * ((ItemTouchViewHolder) viewHolder).textView, dX, dY,
+ * actionState, isCurrentlyActive);
+ * return true;
+ * }
+ * </pre>
+ *
+ * @return The {@link ItemTouchUIUtil} instance that is used by the {@link Callback}
+ */
+ public static ItemTouchUIUtil getDefaultUIUtil() {
+ return sUICallback;
+ }
+
+ /**
+ * Replaces a movement direction with its relative version by taking layout direction into
+ * account.
+ *
+ * @param flags The flag value that include any number of movement flags.
+ * @param layoutDirection The layout direction of the View. Can be obtained from
+ * {@link View#getLayoutDirection()}.
+ * @return Updated flags which uses relative flags ({@link #START}, {@link #END}) instead
+ * of {@link #LEFT}, {@link #RIGHT}.
+ * @see #convertToAbsoluteDirection(int, int)
+ */
+ public static int convertToRelativeDirection(int flags, int layoutDirection) {
+ int masked = flags & ABS_HORIZONTAL_DIR_FLAGS;
+ if (masked == 0) {
+ return flags; // does not have any abs flags, good.
+ }
+ flags &= ~masked; //remove left / right.
+ if (layoutDirection == View.LAYOUT_DIRECTION_LTR) {
+ // no change. just OR with 2 bits shifted mask and return
+ flags |= masked << 2; // START is 2 bits after LEFT, END is 2 bits after RIGHT.
+ return flags;
+ } else {
+ // add RIGHT flag as START
+ flags |= ((masked << 1) & ~ABS_HORIZONTAL_DIR_FLAGS);
+ // first clean RIGHT bit then add LEFT flag as END
+ flags |= ((masked << 1) & ABS_HORIZONTAL_DIR_FLAGS) << 2;
+ }
+ return flags;
+ }
+
+ /**
+ * Convenience method to create movement flags.
+ * <p>
+ * For instance, if you want to let your items be drag & dropped vertically and swiped
+ * left to be dismissed, you can call this method with:
+ * <code>makeMovementFlags(UP | DOWN, LEFT);</code>
+ *
+ * @param dragFlags The directions in which the item can be dragged.
+ * @param swipeFlags The directions in which the item can be swiped.
+ * @return Returns an integer composed of the given drag and swipe flags.
+ */
+ public static int makeMovementFlags(int dragFlags, int swipeFlags) {
+ return makeFlag(ACTION_STATE_IDLE, swipeFlags | dragFlags)
+ | makeFlag(ACTION_STATE_SWIPE, swipeFlags)
+ | makeFlag(ACTION_STATE_DRAG, dragFlags);
+ }
+
+ /**
+ * Shifts the given direction flags to the offset of the given action state.
+ *
+ * @param actionState The action state you want to get flags in. Should be one of
+ * {@link #ACTION_STATE_IDLE}, {@link #ACTION_STATE_SWIPE} or
+ * {@link #ACTION_STATE_DRAG}.
+ * @param directions The direction flags. Can be composed from {@link #UP}, {@link #DOWN},
+ * {@link #RIGHT}, {@link #LEFT} {@link #START} and {@link #END}.
+ * @return And integer that represents the given directions in the provided actionState.
+ */
+ public static int makeFlag(int actionState, int directions) {
+ return directions << (actionState * DIRECTION_FLAG_COUNT);
+ }
+
+ /**
+ * Should return a composite flag which defines the enabled move directions in each state
+ * (idle, swiping, dragging).
+ * <p>
+ * Instead of composing this flag manually, you can use {@link #makeMovementFlags(int,
+ * int)}
+ * or {@link #makeFlag(int, int)}.
+ * <p>
+ * This flag is composed of 3 sets of 8 bits, where first 8 bits are for IDLE state, next
+ * 8 bits are for SWIPE state and third 8 bits are for DRAG state.
+ * Each 8 bit sections can be constructed by simply OR'ing direction flags defined in
+ * {@link ItemTouchHelper}.
+ * <p>
+ * For example, if you want it to allow swiping LEFT and RIGHT but only allow starting to
+ * swipe by swiping RIGHT, you can return:
+ * <pre>
+ * makeFlag(ACTION_STATE_IDLE, RIGHT) | makeFlag(ACTION_STATE_SWIPE, LEFT | RIGHT);
+ * </pre>
+ * This means, allow right movement while IDLE and allow right and left movement while
+ * swiping.
+ *
+ * @param recyclerView The RecyclerView to which ItemTouchHelper is attached.
+ * @param viewHolder The ViewHolder for which the movement information is necessary.
+ * @return flags specifying which movements are allowed on this ViewHolder.
+ * @see #makeMovementFlags(int, int)
+ * @see #makeFlag(int, int)
+ */
+ public abstract int getMovementFlags(RecyclerView recyclerView,
+ ViewHolder viewHolder);
+
+ /**
+ * Converts a given set of flags to absolution direction which means {@link #START} and
+ * {@link #END} are replaced with {@link #LEFT} and {@link #RIGHT} depending on the layout
+ * direction.
+ *
+ * @param flags The flag value that include any number of movement flags.
+ * @param layoutDirection The layout direction of the RecyclerView.
+ * @return Updated flags which includes only absolute direction values.
+ */
+ public int convertToAbsoluteDirection(int flags, int layoutDirection) {
+ int masked = flags & RELATIVE_DIR_FLAGS;
+ if (masked == 0) {
+ return flags; // does not have any relative flags, good.
+ }
+ flags &= ~masked; //remove start / end
+ if (layoutDirection == View.LAYOUT_DIRECTION_LTR) {
+ // no change. just OR with 2 bits shifted mask and return
+ flags |= masked >> 2; // START is 2 bits after LEFT, END is 2 bits after RIGHT.
+ return flags;
+ } else {
+ // add START flag as RIGHT
+ flags |= ((masked >> 1) & ~RELATIVE_DIR_FLAGS);
+ // first clean start bit then add END flag as LEFT
+ flags |= ((masked >> 1) & RELATIVE_DIR_FLAGS) >> 2;
+ }
+ return flags;
+ }
+
+ final int getAbsoluteMovementFlags(RecyclerView recyclerView,
+ ViewHolder viewHolder) {
+ final int flags = getMovementFlags(recyclerView, viewHolder);
+ return convertToAbsoluteDirection(flags, recyclerView.getLayoutDirection());
+ }
+
+ boolean hasDragFlag(RecyclerView recyclerView, ViewHolder viewHolder) {
+ final int flags = getAbsoluteMovementFlags(recyclerView, viewHolder);
+ return (flags & ACTION_MODE_DRAG_MASK) != 0;
+ }
+
+ boolean hasSwipeFlag(RecyclerView recyclerView,
+ ViewHolder viewHolder) {
+ final int flags = getAbsoluteMovementFlags(recyclerView, viewHolder);
+ return (flags & ACTION_MODE_SWIPE_MASK) != 0;
+ }
+
+ /**
+ * Return true if the current ViewHolder can be dropped over the the target ViewHolder.
+ * <p>
+ * This method is used when selecting drop target for the dragged View. After Views are
+ * eliminated either via bounds check or via this method, resulting set of views will be
+ * passed to {@link #chooseDropTarget(ViewHolder, java.util.List, int, int)}.
+ * <p>
+ * Default implementation returns true.
+ *
+ * @param recyclerView The RecyclerView to which ItemTouchHelper is attached to.
+ * @param current The ViewHolder that user is dragging.
+ * @param target The ViewHolder which is below the dragged ViewHolder.
+ * @return True if the dragged ViewHolder can be replaced with the target ViewHolder, false
+ * otherwise.
+ */
+ public boolean canDropOver(RecyclerView recyclerView, ViewHolder current,
+ ViewHolder target) {
+ return true;
+ }
+
+ /**
+ * Called when ItemTouchHelper wants to move the dragged item from its old position to
+ * the new position.
+ * <p>
+ * If this method returns true, ItemTouchHelper assumes {@code viewHolder} has been moved
+ * to the adapter position of {@code target} ViewHolder
+ * ({@link ViewHolder#getAdapterPosition()
+ * ViewHolder#getAdapterPosition()}).
+ * <p>
+ * If you don't support drag & drop, this method will never be called.
+ *
+ * @param recyclerView The RecyclerView to which ItemTouchHelper is attached to.
+ * @param viewHolder The ViewHolder which is being dragged by the user.
+ * @param target The ViewHolder over which the currently active item is being
+ * dragged.
+ * @return True if the {@code viewHolder} has been moved to the adapter position of
+ * {@code target}.
+ * @see #onMoved(RecyclerView, ViewHolder, int, ViewHolder, int, int, int)
+ */
+ public abstract boolean onMove(RecyclerView recyclerView,
+ ViewHolder viewHolder, ViewHolder target);
+
+ /**
+ * Returns whether ItemTouchHelper should start a drag and drop operation if an item is
+ * long pressed.
+ * <p>
+ * Default value returns true but you may want to disable this if you want to start
+ * dragging on a custom view touch using {@link #startDrag(ViewHolder)}.
+ *
+ * @return True if ItemTouchHelper should start dragging an item when it is long pressed,
+ * false otherwise. Default value is <code>true</code>.
+ * @see #startDrag(ViewHolder)
+ */
+ public boolean isLongPressDragEnabled() {
+ return true;
+ }
+
+ /**
+ * Returns whether ItemTouchHelper should start a swipe operation if a pointer is swiped
+ * over the View.
+ * <p>
+ * Default value returns true but you may want to disable this if you want to start
+ * swiping on a custom view touch using {@link #startSwipe(ViewHolder)}.
+ *
+ * @return True if ItemTouchHelper should start swiping an item when user swipes a pointer
+ * over the View, false otherwise. Default value is <code>true</code>.
+ * @see #startSwipe(ViewHolder)
+ */
+ public boolean isItemViewSwipeEnabled() {
+ return true;
+ }
+
+ /**
+ * When finding views under a dragged view, by default, ItemTouchHelper searches for views
+ * that overlap with the dragged View. By overriding this method, you can extend or shrink
+ * the search box.
+ *
+ * @return The extra margin to be added to the hit box of the dragged View.
+ */
+ public int getBoundingBoxMargin() {
+ return 0;
+ }
+
+ /**
+ * Returns the fraction that the user should move the View to be considered as swiped.
+ * The fraction is calculated with respect to RecyclerView's bounds.
+ * <p>
+ * Default value is .5f, which means, to swipe a View, user must move the View at least
+ * half of RecyclerView's width or height, depending on the swipe direction.
+ *
+ * @param viewHolder The ViewHolder that is being dragged.
+ * @return A float value that denotes the fraction of the View size. Default value
+ * is .5f .
+ */
+ public float getSwipeThreshold(ViewHolder viewHolder) {
+ return .5f;
+ }
+
+ /**
+ * Returns the fraction that the user should move the View to be considered as it is
+ * dragged. After a view is moved this amount, ItemTouchHelper starts checking for Views
+ * below it for a possible drop.
+ *
+ * @param viewHolder The ViewHolder that is being dragged.
+ * @return A float value that denotes the fraction of the View size. Default value is
+ * .5f .
+ */
+ public float getMoveThreshold(ViewHolder viewHolder) {
+ return .5f;
+ }
+
+ /**
+ * Defines the minimum velocity which will be considered as a swipe action by the user.
+ * <p>
+ * You can increase this value to make it harder to swipe or decrease it to make it easier.
+ * Keep in mind that ItemTouchHelper also checks the perpendicular velocity and makes sure
+ * current direction velocity is larger then the perpendicular one. Otherwise, user's
+ * movement is ambiguous. You can change the threshold by overriding
+ * {@link #getSwipeVelocityThreshold(float)}.
+ * <p>
+ * The velocity is calculated in pixels per second.
+ * <p>
+ * The default framework value is passed as a parameter so that you can modify it with a
+ * multiplier.
+ *
+ * @param defaultValue The default value (in pixels per second) used by the
+ * ItemTouchHelper.
+ * @return The minimum swipe velocity. The default implementation returns the
+ * <code>defaultValue</code> parameter.
+ * @see #getSwipeVelocityThreshold(float)
+ * @see #getSwipeThreshold(ViewHolder)
+ */
+ public float getSwipeEscapeVelocity(float defaultValue) {
+ return defaultValue;
+ }
+
+ /**
+ * Defines the maximum velocity ItemTouchHelper will ever calculate for pointer movements.
+ * <p>
+ * To consider a movement as swipe, ItemTouchHelper requires it to be larger than the
+ * perpendicular movement. If both directions reach to the max threshold, none of them will
+ * be considered as a swipe because it is usually an indication that user rather tried to
+ * scroll then swipe.
+ * <p>
+ * The velocity is calculated in pixels per second.
+ * <p>
+ * You can customize this behavior by changing this method. If you increase the value, it
+ * will be easier for the user to swipe diagonally and if you decrease the value, user will
+ * need to make a rather straight finger movement to trigger a swipe.
+ *
+ * @param defaultValue The default value(in pixels per second) used by the ItemTouchHelper.
+ * @return The velocity cap for pointer movements. The default implementation returns the
+ * <code>defaultValue</code> parameter.
+ * @see #getSwipeEscapeVelocity(float)
+ */
+ public float getSwipeVelocityThreshold(float defaultValue) {
+ return defaultValue;
+ }
+
+ /**
+ * Called by ItemTouchHelper to select a drop target from the list of ViewHolders that
+ * are under the dragged View.
+ * <p>
+ * Default implementation filters the View with which dragged item have changed position
+ * in the drag direction. For instance, if the view is dragged UP, it compares the
+ * <code>view.getTop()</code> of the two views before and after drag started. If that value
+ * is different, the target view passes the filter.
+ * <p>
+ * Among these Views which pass the test, the one closest to the dragged view is chosen.
+ * <p>
+ * This method is called on the main thread every time user moves the View. If you want to
+ * override it, make sure it does not do any expensive operations.
+ *
+ * @param selected The ViewHolder being dragged by the user.
+ * @param dropTargets The list of ViewHolder that are under the dragged View and
+ * candidate as a drop.
+ * @param curX The updated left value of the dragged View after drag translations
+ * are applied. This value does not include margins added by
+ * {@link RecyclerView.ItemDecoration}s.
+ * @param curY The updated top value of the dragged View after drag translations
+ * are applied. This value does not include margins added by
+ * {@link RecyclerView.ItemDecoration}s.
+ * @return A ViewHolder to whose position the dragged ViewHolder should be
+ * moved to.
+ */
+ public ViewHolder chooseDropTarget(ViewHolder selected,
+ List<ViewHolder> dropTargets, int curX, int curY) {
+ int right = curX + selected.itemView.getWidth();
+ int bottom = curY + selected.itemView.getHeight();
+ ViewHolder winner = null;
+ int winnerScore = -1;
+ final int dx = curX - selected.itemView.getLeft();
+ final int dy = curY - selected.itemView.getTop();
+ final int targetsSize = dropTargets.size();
+ for (int i = 0; i < targetsSize; i++) {
+ final ViewHolder target = dropTargets.get(i);
+ if (dx > 0) {
+ int diff = target.itemView.getRight() - right;
+ if (diff < 0 && target.itemView.getRight() > selected.itemView.getRight()) {
+ final int score = Math.abs(diff);
+ if (score > winnerScore) {
+ winnerScore = score;
+ winner = target;
+ }
+ }
+ }
+ if (dx < 0) {
+ int diff = target.itemView.getLeft() - curX;
+ if (diff > 0 && target.itemView.getLeft() < selected.itemView.getLeft()) {
+ final int score = Math.abs(diff);
+ if (score > winnerScore) {
+ winnerScore = score;
+ winner = target;
+ }
+ }
+ }
+ if (dy < 0) {
+ int diff = target.itemView.getTop() - curY;
+ if (diff > 0 && target.itemView.getTop() < selected.itemView.getTop()) {
+ final int score = Math.abs(diff);
+ if (score > winnerScore) {
+ winnerScore = score;
+ winner = target;
+ }
+ }
+ }
+
+ if (dy > 0) {
+ int diff = target.itemView.getBottom() - bottom;
+ if (diff < 0 && target.itemView.getBottom() > selected.itemView.getBottom()) {
+ final int score = Math.abs(diff);
+ if (score > winnerScore) {
+ winnerScore = score;
+ winner = target;
+ }
+ }
+ }
+ }
+ return winner;
+ }
+
+ /**
+ * Called when a ViewHolder is swiped by the user.
+ * <p>
+ * If you are returning relative directions ({@link #START} , {@link #END}) from the
+ * {@link #getMovementFlags(RecyclerView, ViewHolder)} method, this method
+ * will also use relative directions. Otherwise, it will use absolute directions.
+ * <p>
+ * If you don't support swiping, this method will never be called.
+ * <p>
+ * ItemTouchHelper will keep a reference to the View until it is detached from
+ * RecyclerView.
+ * As soon as it is detached, ItemTouchHelper will call
+ * {@link #clearView(RecyclerView, ViewHolder)}.
+ *
+ * @param viewHolder The ViewHolder which has been swiped by the user.
+ * @param direction The direction to which the ViewHolder is swiped. It is one of
+ * {@link #UP}, {@link #DOWN},
+ * {@link #LEFT} or {@link #RIGHT}. If your
+ * {@link #getMovementFlags(RecyclerView, ViewHolder)}
+ * method
+ * returned relative flags instead of {@link #LEFT} / {@link #RIGHT};
+ * `direction` will be relative as well. ({@link #START} or {@link
+ * #END}).
+ */
+ public abstract void onSwiped(ViewHolder viewHolder, int direction);
+
+ /**
+ * Called when the ViewHolder swiped or dragged by the ItemTouchHelper is changed.
+ * <p/>
+ * If you override this method, you should call super.
+ *
+ * @param viewHolder The new ViewHolder that is being swiped or dragged. Might be null if
+ * it is cleared.
+ * @param actionState One of {@link ItemTouchHelper#ACTION_STATE_IDLE},
+ * {@link ItemTouchHelper#ACTION_STATE_SWIPE} or
+ * {@link ItemTouchHelper#ACTION_STATE_DRAG}.
+ * @see #clearView(RecyclerView, RecyclerView.ViewHolder)
+ */
+ public void onSelectedChanged(ViewHolder viewHolder, int actionState) {
+ if (viewHolder != null) {
+ sUICallback.onSelected(viewHolder.itemView);
+ }
+ }
+
+ private int getMaxDragScroll(RecyclerView recyclerView) {
+ if (mCachedMaxScrollSpeed == -1) {
+ mCachedMaxScrollSpeed = recyclerView.getResources().getDimensionPixelSize(
+ R.dimen.item_touch_helper_max_drag_scroll_per_frame);
+ }
+ return mCachedMaxScrollSpeed;
+ }
+
+ /**
+ * Called when {@link #onMove(RecyclerView, ViewHolder, ViewHolder)} returns true.
+ * <p>
+ * ItemTouchHelper does not create an extra Bitmap or View while dragging, instead, it
+ * modifies the existing View. Because of this reason, it is important that the View is
+ * still part of the layout after it is moved. This may not work as intended when swapped
+ * Views are close to RecyclerView bounds or there are gaps between them (e.g. other Views
+ * which were not eligible for dropping over).
+ * <p>
+ * This method is responsible to give necessary hint to the LayoutManager so that it will
+ * keep the View in visible area. For example, for LinearLayoutManager, this is as simple
+ * as calling {@link LinearLayoutManager#scrollToPositionWithOffset(int, int)}.
+ *
+ * Default implementation calls {@link RecyclerView#scrollToPosition(int)} if the View's
+ * new position is likely to be out of bounds.
+ * <p>
+ * It is important to ensure the ViewHolder will stay visible as otherwise, it might be
+ * removed by the LayoutManager if the move causes the View to go out of bounds. In that
+ * case, drag will end prematurely.
+ *
+ * @param recyclerView The RecyclerView controlled by the ItemTouchHelper.
+ * @param viewHolder The ViewHolder under user's control.
+ * @param fromPos The previous adapter position of the dragged item (before it was
+ * moved).
+ * @param target The ViewHolder on which the currently active item has been dropped.
+ * @param toPos The new adapter position of the dragged item.
+ * @param x The updated left value of the dragged View after drag translations
+ * are applied. This value does not include margins added by
+ * {@link RecyclerView.ItemDecoration}s.
+ * @param y The updated top value of the dragged View after drag translations
+ * are applied. This value does not include margins added by
+ * {@link RecyclerView.ItemDecoration}s.
+ */
+ public void onMoved(final RecyclerView recyclerView,
+ final ViewHolder viewHolder, int fromPos, final ViewHolder target, int toPos, int x,
+ int y) {
+ final RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
+ if (layoutManager instanceof ViewDropHandler) {
+ ((ViewDropHandler) layoutManager).prepareForDrop(viewHolder.itemView,
+ target.itemView, x, y);
+ return;
+ }
+
+ // if layout manager cannot handle it, do some guesswork
+ if (layoutManager.canScrollHorizontally()) {
+ final int minLeft = layoutManager.getDecoratedLeft(target.itemView);
+ if (minLeft <= recyclerView.getPaddingLeft()) {
+ recyclerView.scrollToPosition(toPos);
+ }
+ final int maxRight = layoutManager.getDecoratedRight(target.itemView);
+ if (maxRight >= recyclerView.getWidth() - recyclerView.getPaddingRight()) {
+ recyclerView.scrollToPosition(toPos);
+ }
+ }
+
+ if (layoutManager.canScrollVertically()) {
+ final int minTop = layoutManager.getDecoratedTop(target.itemView);
+ if (minTop <= recyclerView.getPaddingTop()) {
+ recyclerView.scrollToPosition(toPos);
+ }
+ final int maxBottom = layoutManager.getDecoratedBottom(target.itemView);
+ if (maxBottom >= recyclerView.getHeight() - recyclerView.getPaddingBottom()) {
+ recyclerView.scrollToPosition(toPos);
+ }
+ }
+ }
+
+ void onDraw(Canvas c, RecyclerView parent, ViewHolder selected,
+ List<ItemTouchHelper.RecoverAnimation> recoverAnimationList,
+ int actionState, float dX, float dY) {
+ final int recoverAnimSize = recoverAnimationList.size();
+ for (int i = 0; i < recoverAnimSize; i++) {
+ final ItemTouchHelper.RecoverAnimation anim = recoverAnimationList.get(i);
+ anim.update();
+ final int count = c.save();
+ onChildDraw(c, parent, anim.mViewHolder, anim.mX, anim.mY, anim.mActionState,
+ false);
+ c.restoreToCount(count);
+ }
+ if (selected != null) {
+ final int count = c.save();
+ onChildDraw(c, parent, selected, dX, dY, actionState, true);
+ c.restoreToCount(count);
+ }
+ }
+
+ void onDrawOver(Canvas c, RecyclerView parent, ViewHolder selected,
+ List<ItemTouchHelper.RecoverAnimation> recoverAnimationList,
+ int actionState, float dX, float dY) {
+ final int recoverAnimSize = recoverAnimationList.size();
+ for (int i = 0; i < recoverAnimSize; i++) {
+ final ItemTouchHelper.RecoverAnimation anim = recoverAnimationList.get(i);
+ final int count = c.save();
+ onChildDrawOver(c, parent, anim.mViewHolder, anim.mX, anim.mY, anim.mActionState,
+ false);
+ c.restoreToCount(count);
+ }
+ if (selected != null) {
+ final int count = c.save();
+ onChildDrawOver(c, parent, selected, dX, dY, actionState, true);
+ c.restoreToCount(count);
+ }
+ boolean hasRunningAnimation = false;
+ for (int i = recoverAnimSize - 1; i >= 0; i--) {
+ final RecoverAnimation anim = recoverAnimationList.get(i);
+ if (anim.mEnded && !anim.mIsPendingCleanup) {
+ recoverAnimationList.remove(i);
+ } else if (!anim.mEnded) {
+ hasRunningAnimation = true;
+ }
+ }
+ if (hasRunningAnimation) {
+ parent.invalidate();
+ }
+ }
+
+ /**
+ * Called by the ItemTouchHelper when the user interaction with an element is over and it
+ * also completed its animation.
+ * <p>
+ * This is a good place to clear all changes on the View that was done in
+ * {@link #onSelectedChanged(RecyclerView.ViewHolder, int)},
+ * {@link #onChildDraw(Canvas, RecyclerView, ViewHolder, float, float, int,
+ * boolean)} or
+ * {@link #onChildDrawOver(Canvas, RecyclerView, ViewHolder, float, float, int, boolean)}.
+ *
+ * @param recyclerView The RecyclerView which is controlled by the ItemTouchHelper.
+ * @param viewHolder The View that was interacted by the user.
+ */
+ public void clearView(RecyclerView recyclerView, ViewHolder viewHolder) {
+ sUICallback.clearView(viewHolder.itemView);
+ }
+
+ /**
+ * Called by ItemTouchHelper on RecyclerView's onDraw callback.
+ * <p>
+ * If you would like to customize how your View's respond to user interactions, this is
+ * a good place to override.
+ * <p>
+ * Default implementation translates the child by the given <code>dX</code>,
+ * <code>dY</code>.
+ * ItemTouchHelper also takes care of drawing the child after other children if it is being
+ * dragged. This is done using child re-ordering mechanism. On platforms prior to L, this
+ * is
+ * achieved via {@link android.view.ViewGroup#getChildDrawingOrder(int, int)} and on L
+ * and after, it changes View's elevation value to be greater than all other children.)
+ *
+ * @param c The canvas which RecyclerView is drawing its children
+ * @param recyclerView The RecyclerView to which ItemTouchHelper is attached to
+ * @param viewHolder The ViewHolder which is being interacted by the User or it was
+ * interacted and simply animating to its original position
+ * @param dX The amount of horizontal displacement caused by user's action
+ * @param dY The amount of vertical displacement caused by user's action
+ * @param actionState The type of interaction on the View. Is either {@link
+ * #ACTION_STATE_DRAG} or {@link #ACTION_STATE_SWIPE}.
+ * @param isCurrentlyActive True if this view is currently being controlled by the user or
+ * false it is simply animating back to its original state.
+ * @see #onChildDrawOver(Canvas, RecyclerView, ViewHolder, float, float, int,
+ * boolean)
+ */
+ public void onChildDraw(Canvas c, RecyclerView recyclerView,
+ ViewHolder viewHolder,
+ float dX, float dY, int actionState, boolean isCurrentlyActive) {
+ sUICallback.onDraw(c, recyclerView, viewHolder.itemView, dX, dY, actionState,
+ isCurrentlyActive);
+ }
+
+ /**
+ * Called by ItemTouchHelper on RecyclerView's onDraw callback.
+ * <p>
+ * If you would like to customize how your View's respond to user interactions, this is
+ * a good place to override.
+ * <p>
+ * Default implementation translates the child by the given <code>dX</code>,
+ * <code>dY</code>.
+ * ItemTouchHelper also takes care of drawing the child after other children if it is being
+ * dragged. This is done using child re-ordering mechanism. On platforms prior to L, this
+ * is
+ * achieved via {@link android.view.ViewGroup#getChildDrawingOrder(int, int)} and on L
+ * and after, it changes View's elevation value to be greater than all other children.)
+ *
+ * @param c The canvas which RecyclerView is drawing its children
+ * @param recyclerView The RecyclerView to which ItemTouchHelper is attached to
+ * @param viewHolder The ViewHolder which is being interacted by the User or it was
+ * interacted and simply animating to its original position
+ * @param dX The amount of horizontal displacement caused by user's action
+ * @param dY The amount of vertical displacement caused by user's action
+ * @param actionState The type of interaction on the View. Is either {@link
+ * #ACTION_STATE_DRAG} or {@link #ACTION_STATE_SWIPE}.
+ * @param isCurrentlyActive True if this view is currently being controlled by the user or
+ * false it is simply animating back to its original state.
+ * @see #onChildDrawOver(Canvas, RecyclerView, ViewHolder, float, float, int,
+ * boolean)
+ */
+ public void onChildDrawOver(Canvas c, RecyclerView recyclerView,
+ ViewHolder viewHolder,
+ float dX, float dY, int actionState, boolean isCurrentlyActive) {
+ sUICallback.onDrawOver(c, recyclerView, viewHolder.itemView, dX, dY, actionState,
+ isCurrentlyActive);
+ }
+
+ /**
+ * Called by the ItemTouchHelper when user action finished on a ViewHolder and now the View
+ * will be animated to its final position.
+ * <p>
+ * Default implementation uses ItemAnimator's duration values. If
+ * <code>animationType</code> is {@link #ANIMATION_TYPE_DRAG}, it returns
+ * {@link RecyclerView.ItemAnimator#getMoveDuration()}, otherwise, it returns
+ * {@link RecyclerView.ItemAnimator#getRemoveDuration()}. If RecyclerView does not have
+ * any {@link RecyclerView.ItemAnimator} attached, this method returns
+ * {@code DEFAULT_DRAG_ANIMATION_DURATION} or {@code DEFAULT_SWIPE_ANIMATION_DURATION}
+ * depending on the animation type.
+ *
+ * @param recyclerView The RecyclerView to which the ItemTouchHelper is attached to.
+ * @param animationType The type of animation. Is one of {@link #ANIMATION_TYPE_DRAG},
+ * {@link #ANIMATION_TYPE_SWIPE_CANCEL} or
+ * {@link #ANIMATION_TYPE_SWIPE_SUCCESS}.
+ * @param animateDx The horizontal distance that the animation will offset
+ * @param animateDy The vertical distance that the animation will offset
+ * @return The duration for the animation
+ */
+ public long getAnimationDuration(RecyclerView recyclerView, int animationType,
+ float animateDx, float animateDy) {
+ final RecyclerView.ItemAnimator itemAnimator = recyclerView.getItemAnimator();
+ if (itemAnimator == null) {
+ return animationType == ANIMATION_TYPE_DRAG ? DEFAULT_DRAG_ANIMATION_DURATION
+ : DEFAULT_SWIPE_ANIMATION_DURATION;
+ } else {
+ return animationType == ANIMATION_TYPE_DRAG ? itemAnimator.getMoveDuration()
+ : itemAnimator.getRemoveDuration();
+ }
+ }
+
+ /**
+ * Called by the ItemTouchHelper when user is dragging a view out of bounds.
+ * <p>
+ * You can override this method to decide how much RecyclerView should scroll in response
+ * to this action. Default implementation calculates a value based on the amount of View
+ * out of bounds and the time it spent there. The longer user keeps the View out of bounds,
+ * the faster the list will scroll. Similarly, the larger portion of the View is out of
+ * bounds, the faster the RecyclerView will scroll.
+ *
+ * @param recyclerView The RecyclerView instance to which ItemTouchHelper is
+ * attached to.
+ * @param viewSize The total size of the View in scroll direction, excluding
+ * item decorations.
+ * @param viewSizeOutOfBounds The total size of the View that is out of bounds. This value
+ * is negative if the View is dragged towards left or top edge.
+ * @param totalSize The total size of RecyclerView in the scroll direction.
+ * @param msSinceStartScroll The time passed since View is kept out of bounds.
+ * @return The amount that RecyclerView should scroll. Keep in mind that this value will
+ * be passed to {@link RecyclerView#scrollBy(int, int)} method.
+ */
+ public int interpolateOutOfBoundsScroll(RecyclerView recyclerView,
+ int viewSize, int viewSizeOutOfBounds,
+ int totalSize, long msSinceStartScroll) {
+ final int maxScroll = getMaxDragScroll(recyclerView);
+ final int absOutOfBounds = Math.abs(viewSizeOutOfBounds);
+ final int direction = (int) Math.signum(viewSizeOutOfBounds);
+ // might be negative if other direction
+ float outOfBoundsRatio = Math.min(1f, 1f * absOutOfBounds / viewSize);
+ final int cappedScroll = (int) (direction * maxScroll
+ * sDragViewScrollCapInterpolator.getInterpolation(outOfBoundsRatio));
+ final float timeRatio;
+ if (msSinceStartScroll > DRAG_SCROLL_ACCELERATION_LIMIT_TIME_MS) {
+ timeRatio = 1f;
+ } else {
+ timeRatio = (float) msSinceStartScroll / DRAG_SCROLL_ACCELERATION_LIMIT_TIME_MS;
+ }
+ final int value = (int) (cappedScroll * sDragScrollInterpolator
+ .getInterpolation(timeRatio));
+ if (value == 0) {
+ return viewSizeOutOfBounds > 0 ? 1 : -1;
+ }
+ return value;
+ }
+ }
+
+ /**
+ * A simple wrapper to the default Callback which you can construct with drag and swipe
+ * directions and this class will handle the flag callbacks. You should still override onMove
+ * or
+ * onSwiped depending on your use case.
+ *
+ * <pre>
+ * ItemTouchHelper mIth = new ItemTouchHelper(
+ * new ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP | ItemTouchHelper.DOWN,
+ * ItemTouchHelper.LEFT) {
+ * public abstract boolean onMove(RecyclerView recyclerView,
+ * ViewHolder viewHolder, ViewHolder target) {
+ * final int fromPos = viewHolder.getAdapterPosition();
+ * final int toPos = target.getAdapterPosition();
+ * // move item in `fromPos` to `toPos` in adapter.
+ * return true;// true if moved, false otherwise
+ * }
+ * public void onSwiped(ViewHolder viewHolder, int direction) {
+ * // remove from adapter
+ * }
+ * });
+ * </pre>
+ */
+ public abstract static class SimpleCallback extends Callback {
+
+ private int mDefaultSwipeDirs;
+
+ private int mDefaultDragDirs;
+
+ /**
+ * Creates a Callback for the given drag and swipe allowance. These values serve as
+ * defaults
+ * and if you want to customize behavior per ViewHolder, you can override
+ * {@link #getSwipeDirs(RecyclerView, ViewHolder)}
+ * and / or {@link #getDragDirs(RecyclerView, ViewHolder)}.
+ *
+ * @param dragDirs Binary OR of direction flags in which the Views can be dragged. Must be
+ * composed of {@link #LEFT}, {@link #RIGHT}, {@link #START}, {@link
+ * #END},
+ * {@link #UP} and {@link #DOWN}.
+ * @param swipeDirs Binary OR of direction flags in which the Views can be swiped. Must be
+ * composed of {@link #LEFT}, {@link #RIGHT}, {@link #START}, {@link
+ * #END},
+ * {@link #UP} and {@link #DOWN}.
+ */
+ public SimpleCallback(int dragDirs, int swipeDirs) {
+ mDefaultSwipeDirs = swipeDirs;
+ mDefaultDragDirs = dragDirs;
+ }
+
+ /**
+ * Updates the default swipe directions. For example, you can use this method to toggle
+ * certain directions depending on your use case.
+ *
+ * @param defaultSwipeDirs Binary OR of directions in which the ViewHolders can be swiped.
+ */
+ public void setDefaultSwipeDirs(int defaultSwipeDirs) {
+ mDefaultSwipeDirs = defaultSwipeDirs;
+ }
+
+ /**
+ * Updates the default drag directions. For example, you can use this method to toggle
+ * certain directions depending on your use case.
+ *
+ * @param defaultDragDirs Binary OR of directions in which the ViewHolders can be dragged.
+ */
+ public void setDefaultDragDirs(int defaultDragDirs) {
+ mDefaultDragDirs = defaultDragDirs;
+ }
+
+ /**
+ * Returns the swipe directions for the provided ViewHolder.
+ * Default implementation returns the swipe directions that was set via constructor or
+ * {@link #setDefaultSwipeDirs(int)}.
+ *
+ * @param recyclerView The RecyclerView to which the ItemTouchHelper is attached to.
+ * @param viewHolder The RecyclerView for which the swipe direction is queried.
+ * @return A binary OR of direction flags.
+ */
+ public int getSwipeDirs(RecyclerView recyclerView, ViewHolder viewHolder) {
+ return mDefaultSwipeDirs;
+ }
+
+ /**
+ * Returns the drag directions for the provided ViewHolder.
+ * Default implementation returns the drag directions that was set via constructor or
+ * {@link #setDefaultDragDirs(int)}.
+ *
+ * @param recyclerView The RecyclerView to which the ItemTouchHelper is attached to.
+ * @param viewHolder The RecyclerView for which the swipe direction is queried.
+ * @return A binary OR of direction flags.
+ */
+ public int getDragDirs(RecyclerView recyclerView, ViewHolder viewHolder) {
+ return mDefaultDragDirs;
+ }
+
+ @Override
+ public int getMovementFlags(RecyclerView recyclerView, ViewHolder viewHolder) {
+ return makeMovementFlags(getDragDirs(recyclerView, viewHolder),
+ getSwipeDirs(recyclerView, viewHolder));
+ }
+ }
+
+ private class ItemTouchHelperGestureListener extends GestureDetector.SimpleOnGestureListener {
+
+ ItemTouchHelperGestureListener() {
+ }
+
+ @Override
+ public boolean onDown(MotionEvent e) {
+ return true;
+ }
+
+ @Override
+ public void onLongPress(MotionEvent e) {
+ View child = findChildView(e);
+ if (child != null) {
+ ViewHolder vh = mRecyclerView.getChildViewHolder(child);
+ if (vh != null) {
+ if (!mCallback.hasDragFlag(mRecyclerView, vh)) {
+ return;
+ }
+ int pointerId = e.getPointerId(0);
+ // Long press is deferred.
+ // Check w/ active pointer id to avoid selecting after motion
+ // event is canceled.
+ if (pointerId == mActivePointerId) {
+ final int index = e.findPointerIndex(mActivePointerId);
+ final float x = e.getX(index);
+ final float y = e.getY(index);
+ mInitialTouchX = x;
+ mInitialTouchY = y;
+ mDx = mDy = 0f;
+ if (DEBUG) {
+ Log.d(TAG,
+ "onlong press: x:" + mInitialTouchX + ",y:" + mInitialTouchY);
+ }
+ if (mCallback.isLongPressDragEnabled()) {
+ select(vh, ACTION_STATE_DRAG);
+ }
+ }
+ }
+ }
+ }
+ }
+
+ private class RecoverAnimation implements Animator.AnimatorListener {
+
+ final float mStartDx;
+
+ final float mStartDy;
+
+ final float mTargetX;
+
+ final float mTargetY;
+
+ final ViewHolder mViewHolder;
+
+ final int mActionState;
+
+ private final ValueAnimator mValueAnimator;
+
+ final int mAnimationType;
+
+ public boolean mIsPendingCleanup;
+
+ float mX;
+
+ float mY;
+
+ // if user starts touching a recovering view, we put it into interaction mode again,
+ // instantly.
+ boolean mOverridden = false;
+
+ boolean mEnded = false;
+
+ private float mFraction;
+
+ RecoverAnimation(ViewHolder viewHolder, int animationType,
+ int actionState, float startDx, float startDy, float targetX, float targetY) {
+ mActionState = actionState;
+ mAnimationType = animationType;
+ mViewHolder = viewHolder;
+ mStartDx = startDx;
+ mStartDy = startDy;
+ mTargetX = targetX;
+ mTargetY = targetY;
+ mValueAnimator = ValueAnimator.ofFloat(0f, 1f);
+ mValueAnimator.addUpdateListener(
+ new ValueAnimator.AnimatorUpdateListener() {
+ @Override
+ public void onAnimationUpdate(ValueAnimator animation) {
+ setFraction(animation.getAnimatedFraction());
+ }
+ });
+ mValueAnimator.setTarget(viewHolder.itemView);
+ mValueAnimator.addListener(this);
+ setFraction(0f);
+ }
+
+ public void setDuration(long duration) {
+ mValueAnimator.setDuration(duration);
+ }
+
+ public void start() {
+ mViewHolder.setIsRecyclable(false);
+ mValueAnimator.start();
+ }
+
+ public void cancel() {
+ mValueAnimator.cancel();
+ }
+
+ public void setFraction(float fraction) {
+ mFraction = fraction;
+ }
+
+ /**
+ * We run updates on onDraw method but use the fraction from animator callback.
+ * This way, we can sync translate x/y values w/ the animators to avoid one-off frames.
+ */
+ public void update() {
+ if (mStartDx == mTargetX) {
+ mX = mViewHolder.itemView.getTranslationX();
+ } else {
+ mX = mStartDx + mFraction * (mTargetX - mStartDx);
+ }
+ if (mStartDy == mTargetY) {
+ mY = mViewHolder.itemView.getTranslationY();
+ } else {
+ mY = mStartDy + mFraction * (mTargetY - mStartDy);
+ }
+ }
+
+ @Override
+ public void onAnimationStart(Animator animation) {
+
+ }
+
+ @Override
+ public void onAnimationEnd(Animator animation) {
+ if (!mEnded) {
+ mViewHolder.setIsRecyclable(true);
+ }
+ mEnded = true;
+ }
+
+ @Override
+ public void onAnimationCancel(Animator animation) {
+ setFraction(1f); //make sure we recover the view's state.
+ }
+
+ @Override
+ public void onAnimationRepeat(Animator animation) {
+
+ }
+ }
+}
diff --git a/core/java/com/android/internal/widget/helper/ItemTouchUIUtil.java b/core/java/com/android/internal/widget/helper/ItemTouchUIUtil.java
new file mode 100644
index 0000000..e368a6d
--- /dev/null
+++ b/core/java/com/android/internal/widget/helper/ItemTouchUIUtil.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget.helper;
+
+import android.graphics.Canvas;
+import android.view.View;
+
+import com.android.internal.widget.RecyclerView;
+
+/**
+ * Utility class for {@link ItemTouchHelper} which handles item transformations for different
+ * API versions.
+ * <p/>
+ * This class has methods that map to {@link ItemTouchHelper.Callback}'s drawing methods. Default
+ * implementations in {@link ItemTouchHelper.Callback} call these methods with
+ * {@link RecyclerView.ViewHolder#itemView} and {@link ItemTouchUIUtil} makes necessary changes
+ * on the View depending on the API level. You can access the instance of {@link ItemTouchUIUtil}
+ * via {@link ItemTouchHelper.Callback#getDefaultUIUtil()} and call its methods with the children
+ * of ViewHolder that you want to apply default effects.
+ *
+ * @see ItemTouchHelper.Callback#getDefaultUIUtil()
+ */
+public interface ItemTouchUIUtil {
+
+ /**
+ * The default implementation for {@link ItemTouchHelper.Callback#onChildDraw(Canvas,
+ * RecyclerView, RecyclerView.ViewHolder, float, float, int, boolean)}
+ */
+ void onDraw(Canvas c, RecyclerView recyclerView, View view,
+ float dX, float dY, int actionState, boolean isCurrentlyActive);
+
+ /**
+ * The default implementation for {@link ItemTouchHelper.Callback#onChildDrawOver(Canvas,
+ * RecyclerView, RecyclerView.ViewHolder, float, float, int, boolean)}
+ */
+ void onDrawOver(Canvas c, RecyclerView recyclerView, View view,
+ float dX, float dY, int actionState, boolean isCurrentlyActive);
+
+ /**
+ * The default implementation for {@link ItemTouchHelper.Callback#clearView(RecyclerView,
+ * RecyclerView.ViewHolder)}
+ */
+ void clearView(View view);
+
+ /**
+ * The default implementation for {@link ItemTouchHelper.Callback#onSelectedChanged(
+ * RecyclerView.ViewHolder, int)}
+ */
+ void onSelected(View view);
+}
+
diff --git a/core/java/com/android/internal/widget/helper/ItemTouchUIUtilImpl.java b/core/java/com/android/internal/widget/helper/ItemTouchUIUtilImpl.java
new file mode 100644
index 0000000..0de240b
--- /dev/null
+++ b/core/java/com/android/internal/widget/helper/ItemTouchUIUtilImpl.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.widget.helper;
+
+import android.graphics.Canvas;
+import android.view.View;
+
+import com.android.internal.R;
+import com.android.internal.widget.RecyclerView;
+
+/**
+ * Package private class to keep implementations. Putting them inside ItemTouchUIUtil makes them
+ * public API, which is not desired in this case.
+ */
+class ItemTouchUIUtilImpl implements ItemTouchUIUtil {
+ @Override
+ public void onDraw(Canvas c, RecyclerView recyclerView, View view,
+ float dX, float dY, int actionState, boolean isCurrentlyActive) {
+ if (isCurrentlyActive) {
+ Object originalElevation = view.getTag(
+ R.id.item_touch_helper_previous_elevation);
+ if (originalElevation == null) {
+ originalElevation = view.getElevation();
+ float newElevation = 1f + findMaxElevation(recyclerView, view);
+ view.setElevation(newElevation);
+ view.setTag(R.id.item_touch_helper_previous_elevation,
+ originalElevation);
+ }
+ }
+ view.setTranslationX(dX);
+ view.setTranslationY(dY);
+ }
+
+ private float findMaxElevation(RecyclerView recyclerView, View itemView) {
+ final int childCount = recyclerView.getChildCount();
+ float max = 0;
+ for (int i = 0; i < childCount; i++) {
+ final View child = recyclerView.getChildAt(i);
+ if (child == itemView) {
+ continue;
+ }
+ final float elevation = child.getElevation();
+ if (elevation > max) {
+ max = elevation;
+ }
+ }
+ return max;
+ }
+
+ @Override
+ public void clearView(View view) {
+ final Object tag = view.getTag(
+ R.id.item_touch_helper_previous_elevation);
+ if (tag != null && tag instanceof Float) {
+ view.setElevation((Float) tag);
+ }
+ view.setTag(R.id.item_touch_helper_previous_elevation, null);
+ view.setTranslationX(0f);
+ view.setTranslationY(0f);
+ }
+
+ @Override
+ public void onSelected(View view) {
+ }
+
+ @Override
+ public void onDrawOver(Canvas c, RecyclerView recyclerView,
+ View view, float dX, float dY, int actionState, boolean isCurrentlyActive) {
+ }
+}
diff --git a/core/jni/android/graphics/FontFamily.cpp b/core/jni/android/graphics/FontFamily.cpp
index 2504e54..ac8f413 100644
--- a/core/jni/android/graphics/FontFamily.cpp
+++ b/core/jni/android/graphics/FontFamily.cpp
@@ -258,9 +258,9 @@
gListClassInfo.mGet = GetMethodIDOrDie(env, listClass, "get", "(I)Ljava/lang/Object;");
gListClassInfo.mSize = GetMethodIDOrDie(env, listClass, "size", "()I");
- jclass axisClass = FindClassOrDie(env, "android/graphics/FontListParser$Axis");
- gAxisClassInfo.mTag = GetFieldIDOrDie(env, axisClass, "tag", "I");
- gAxisClassInfo.mStyleValue = GetFieldIDOrDie(env, axisClass, "styleValue", "F");
+ jclass axisClass = FindClassOrDie(env, "android/text/FontConfig$Axis");
+ gAxisClassInfo.mTag = GetFieldIDOrDie(env, axisClass, "mTag", "I");
+ gAxisClassInfo.mStyleValue = GetFieldIDOrDie(env, axisClass, "mStyleValue", "F");
return err;
}
diff --git a/core/jni/android/graphics/FontUtils.cpp b/core/jni/android/graphics/FontUtils.cpp
new file mode 100644
index 0000000..91fec2a
--- /dev/null
+++ b/core/jni/android/graphics/FontUtils.cpp
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "FontUtils.h"
+
+#include "JNIHelp.h"
+#include <core_jni_helpers.h>
+
+namespace android {
+namespace {
+
+static struct {
+ jmethodID mGet;
+ jmethodID mSize;
+} gListClassInfo;
+
+static struct {
+ jfieldID mTag;
+ jfieldID mStyleValue;
+} gAxisClassInfo;
+
+} // namespace
+
+jint ListHelper::size() const {
+ return mEnv->CallIntMethod(mList, gListClassInfo.mSize);
+}
+
+jobject ListHelper::get(jint index) const {
+ return mEnv->CallObjectMethod(mList, gListClassInfo.mGet, index);
+}
+
+jint AxisHelper::getTag() const {
+ return mEnv->GetIntField(mAxis, gAxisClassInfo.mTag);
+}
+
+jfloat AxisHelper::getStyleValue() const {
+ return mEnv->GetFloatField(mAxis, gAxisClassInfo.mStyleValue);
+}
+
+void init_FontUtils(JNIEnv* env) {
+ jclass listClass = FindClassOrDie(env, "java/util/List");
+ gListClassInfo.mGet = GetMethodIDOrDie(env, listClass, "get", "(I)Ljava/lang/Object;");
+ gListClassInfo.mSize = GetMethodIDOrDie(env, listClass, "size", "()I");
+
+ jclass axisClass = FindClassOrDie(env, "android/text/FontConfig$Axis");
+ gAxisClassInfo.mTag = GetFieldIDOrDie(env, axisClass, "mTag", "I");
+ gAxisClassInfo.mStyleValue = GetFieldIDOrDie(env, axisClass, "mStyleValue", "F");
+}
+
+} // namespace android
diff --git a/core/res/res/values/attrs.xml b/core/res/res/values/attrs.xml
index 7c01dea..87c2b25 100644
--- a/core/res/res/values/attrs.xml
+++ b/core/res/res/values/attrs.xml
@@ -8477,4 +8477,14 @@
<attr name="font" format="reference" />
<attr name="fontWeight" format="integer" />
</declare-styleable>
+
+ <!-- @hide -->
+ <declare-styleable name="RecyclerView">
+ <attr name="layoutManager" format="string" />
+ <attr name="orientation" />
+ <attr name="descendantFocusability" />
+ <attr name="spanCount" format="integer"/>
+ <attr name="reverseLayout" format="boolean" />
+ <attr name="stackFromEnd" format="boolean" />
+ </declare-styleable>
</resources>
diff --git a/core/res/res/values/dimens.xml b/core/res/res/values/dimens.xml
index bd19521..e6358a3 100644
--- a/core/res/res/values/dimens.xml
+++ b/core/res/res/values/dimens.xml
@@ -509,4 +509,10 @@
<dimen name="tooltip_precise_anchor_threshold">96dp</dimen>
<!-- Extra tooltip offset used when anchoring to the mouse/touch position -->
<dimen name="tooltip_precise_anchor_extra_offset">8dp</dimen>
+
+ <!-- The max amount of scroll ItemTouchHelper will trigger if dragged view is out of
+ RecyclerView's bounds.-->
+ <dimen name="item_touch_helper_max_drag_scroll_per_frame">20dp</dimen>
+ <dimen name="item_touch_helper_swipe_escape_velocity">120dp</dimen>
+ <dimen name="item_touch_helper_swipe_escape_max_velocity">800dp</dimen>
</resources>
diff --git a/core/res/res/values/ids.xml b/core/res/res/values/ids.xml
index 5547706..f351b70 100644
--- a/core/res/res/values/ids.xml
+++ b/core/res/res/values/ids.xml
@@ -131,4 +131,7 @@
<item type="id" name="cross_task_transition" />
<item type="id" name="accessibilityActionClickOnClickableSpan" />
+
+ <!-- ItemTouchHelper uses this id to save a View's original elevation. -->
+ <item type="id" name="item_touch_helper_previous_elevation"/>
</resources>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index c370ef7..6eb3bee 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -2806,4 +2806,10 @@
<java-symbol type="string" name="disable_accessibility_shortcut" />
<java-symbol type="string" name="leave_accessibility_shortcut_on" />
<java-symbol type="string" name="config_defaultAccessibilityService" />
+
+ <!-- com.android.internal.widget.RecyclerView -->
+ <java-symbol type="id" name="item_touch_helper_previous_elevation"/>
+ <java-symbol type="dimen" name="item_touch_helper_max_drag_scroll_per_frame"/>
+ <java-symbol type="dimen" name="item_touch_helper_swipe_escape_velocity"/>
+ <java-symbol type="dimen" name="item_touch_helper_swipe_escape_max_velocity"/>
</resources>
diff --git a/core/tests/coretests/AndroidManifest.xml b/core/tests/coretests/AndroidManifest.xml
index cba485a..91ce7a4 100644
--- a/core/tests/coretests/AndroidManifest.xml
+++ b/core/tests/coretests/AndroidManifest.xml
@@ -1168,6 +1168,7 @@
<activity android:name="android.app.EmptyActivity">
</activity>
<activity android:name="com.android.internal.app.ChooserWrapperActivity"/>
+ <activity android:name="com.android.internal.app.ResolverWrapperActivity"/>
<receiver android:name="android.app.activity.AbortReceiver">
<intent-filter android:priority="1">
diff --git a/core/tests/coretests/src/com/android/internal/app/ChooserActivityTest.java b/core/tests/coretests/src/com/android/internal/app/ChooserActivityTest.java
index aab4698..daebf88 100644
--- a/core/tests/coretests/src/com/android/internal/app/ChooserActivityTest.java
+++ b/core/tests/coretests/src/com/android/internal/app/ChooserActivityTest.java
@@ -222,7 +222,7 @@
private List<ResolvedComponentInfo> createResolvedComponentsForTest(int numberOfResults) {
List<ResolvedComponentInfo> infoList = new ArrayList<>(numberOfResults);
for (int i = 0; i < numberOfResults; i++) {
- infoList.add(ChooserDataProvider.createResolvedComponentInfo(i));
+ infoList.add(ResolverDataProvider.createResolvedComponentInfo(i));
}
return infoList;
}
diff --git a/core/tests/coretests/src/com/android/internal/app/ChooserWrapperActivity.java b/core/tests/coretests/src/com/android/internal/app/ChooserWrapperActivity.java
index 41016e1..c446f3c 100644
--- a/core/tests/coretests/src/com/android/internal/app/ChooserWrapperActivity.java
+++ b/core/tests/coretests/src/com/android/internal/app/ChooserWrapperActivity.java
@@ -24,11 +24,10 @@
import static org.mockito.Mockito.mock;
-
-/**
- * Simple wrapper around chooser activity to be able to initiate it under test
- */
public class ChooserWrapperActivity extends ChooserActivity {
+ /*
+ * Simple wrapper around chooser activity to be able to initiate it under test
+ */
static final OverrideData sOverrides = new OverrideData();
private UsageStatsManager mUsm;
@@ -94,4 +93,4 @@
resolverListController = mock(ResolverListController.class);
}
}
-}
\ No newline at end of file
+}
diff --git a/core/tests/coretests/src/com/android/internal/app/ResolverActivityTest.java b/core/tests/coretests/src/com/android/internal/app/ResolverActivityTest.java
new file mode 100644
index 0000000..84b844a
--- /dev/null
+++ b/core/tests/coretests/src/com/android/internal/app/ResolverActivityTest.java
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.app;
+
+import com.android.internal.R;
+import com.android.internal.app.ResolverActivity.ResolvedComponentInfo;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mockito;
+
+import android.app.usage.UsageStats;
+import android.app.usage.UsageStatsManager;
+import android.content.Intent;
+import android.content.pm.ResolveInfo;
+import android.os.UserHandle;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.rule.ActivityTestRule;
+import android.support.test.runner.AndroidJUnit4;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import static android.os.SystemClock.sleep;
+import static android.support.test.espresso.Espresso.onView;
+import static android.support.test.espresso.action.ViewActions.click;
+import static android.support.test.espresso.assertion.ViewAssertions.matches;
+import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static android.support.test.espresso.matcher.ViewMatchers.withId;
+import static android.support.test.espresso.matcher.ViewMatchers.withText;
+import static com.android.internal.app.ResolverWrapperActivity.sOverrides;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * Resolver activity instrumentation tests
+ */
+@RunWith(AndroidJUnit4.class)
+public class ResolverActivityTest {
+ @Rule
+ public ActivityTestRule<ResolverWrapperActivity> mActivityRule =
+ new ActivityTestRule<>(ResolverWrapperActivity.class, false,
+ false);
+
+ @Before
+ public void cleanOverrideData() {
+ sOverrides.reset();
+ }
+
+ @Test
+ public void twoOptionsAndUserSelectsOne() throws InterruptedException {
+ Intent sendIntent = createSendImageIntent();
+ List<ResolvedComponentInfo> resolvedComponentInfos = createResolvedComponentsForTest(2);
+
+ when(sOverrides.resolverListController.getResolversForIntent(Mockito.anyBoolean(),
+ Mockito.anyBoolean(),
+ Mockito.isA(List.class))).thenReturn(resolvedComponentInfos);
+
+ final ResolverWrapperActivity activity = mActivityRule.launchActivity(sendIntent);
+ waitForIdle();
+
+ assertThat(activity.getAdapter().getCount(), is(2));
+
+ ResolveInfo[] chosen = new ResolveInfo[1];
+ sOverrides.onSafelyStartCallback = targetInfo -> {
+ chosen[0] = targetInfo.getResolveInfo();
+ return true;
+ };
+
+ ResolveInfo toChoose = resolvedComponentInfos.get(0).getResolveInfoAt(0);
+ onView(withText(toChoose.activityInfo.name))
+ .perform(click());
+ onView(withId(R.id.button_once))
+ .perform(click());
+ waitForIdle();
+ assertThat(chosen[0], is(toChoose));
+ }
+
+ @Test
+ public void hasLastChosenActivity() throws Exception {
+ Intent sendIntent = createSendImageIntent();
+ List<ResolvedComponentInfo> resolvedComponentInfos = createResolvedComponentsForTest(2);
+
+ when(sOverrides.resolverListController.getResolversForIntent(Mockito.anyBoolean(),
+ Mockito.anyBoolean(),
+ Mockito.isA(List.class))).thenReturn(resolvedComponentInfos);
+ when(sOverrides.resolverListController.getLastChosen())
+ .thenReturn(resolvedComponentInfos.get(0).getResolveInfoAt(0));
+
+ final ResolverWrapperActivity activity = mActivityRule.launchActivity(sendIntent);
+ waitForIdle();
+
+ // The other entry is filtered to the last used slot
+ assertThat(activity.getAdapter().getCount(), is(1));
+
+ ResolveInfo[] chosen = new ResolveInfo[1];
+ sOverrides.onSafelyStartCallback = targetInfo -> {
+ chosen[0] = targetInfo.getResolveInfo();
+ return true;
+ };
+
+ ResolveInfo toChoose = resolvedComponentInfos.get(0).getResolveInfoAt(0);
+ onView(withId(R.id.title)).perform(click());
+ onView(withId(R.id.button_once))
+ .perform(click());
+ waitForIdle();
+ assertThat(chosen[0], is(toChoose));
+ }
+
+ private Intent createSendImageIntent() {
+ Intent sendIntent = new Intent();
+ sendIntent.setAction(Intent.ACTION_SEND);
+ sendIntent.putExtra(Intent.EXTRA_TEXT, "testing intent sending");
+ sendIntent.setType("image/jpeg");
+ return sendIntent;
+ }
+
+ private List<ResolvedComponentInfo> createResolvedComponentsForTest(int numberOfResults) {
+ List<ResolvedComponentInfo> infoList = new ArrayList<>(numberOfResults);
+ for (int i = 0; i < numberOfResults; i++) {
+ infoList.add(ResolverDataProvider.createResolvedComponentInfo(i));
+ }
+ return infoList;
+ }
+
+ private void waitForIdle() {
+ InstrumentationRegistry.getInstrumentation().waitForIdleSync();
+ }
+}
\ No newline at end of file
diff --git a/core/tests/coretests/src/com/android/internal/app/ChooserDataProvider.java b/core/tests/coretests/src/com/android/internal/app/ResolverDataProvider.java
similarity index 94%
rename from core/tests/coretests/src/com/android/internal/app/ChooserDataProvider.java
rename to core/tests/coretests/src/com/android/internal/app/ResolverDataProvider.java
index f6f63f1..ae06306 100644
--- a/core/tests/coretests/src/com/android/internal/app/ChooserDataProvider.java
+++ b/core/tests/coretests/src/com/android/internal/app/ResolverDataProvider.java
@@ -22,16 +22,15 @@
import android.content.pm.ApplicationInfo;
import android.content.pm.ResolveInfo;
import android.os.UserHandle;
-import android.service.chooser.ChooserTarget;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
/**
- * Utility class used by chooser tests to create mock data
+ * Utility class used by resolver tests to create mock data
*/
-class ChooserDataProvider {
+class ResolverDataProvider {
static ResolverActivity.ResolvedComponentInfo createResolvedComponentInfo(int i) {
return new ResolverActivity.ResolvedComponentInfo(createComponentName(i),
diff --git a/core/tests/coretests/src/com/android/internal/app/ResolverWrapperActivity.java b/core/tests/coretests/src/com/android/internal/app/ResolverWrapperActivity.java
new file mode 100644
index 0000000..163211e
--- /dev/null
+++ b/core/tests/coretests/src/com/android/internal/app/ResolverWrapperActivity.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.app;
+
+import android.app.usage.UsageStatsManager;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.pm.PackageManager;
+import android.os.RemoteException;
+
+import java.util.function.Function;
+
+import static org.mockito.Mockito.mock;
+
+
+/*
+ * Simple wrapper around chooser activity to be able to initiate it under test
+ */
+public class ResolverWrapperActivity extends ResolverActivity {
+ static final OverrideData sOverrides = new OverrideData();
+ private UsageStatsManager mUsm;
+
+ ResolveListAdapter getAdapter() {
+ return mAdapter;
+ }
+
+ @Override
+ public boolean isVoiceInteraction() {
+ if (sOverrides.isVoiceInteraction != null) {
+ return sOverrides.isVoiceInteraction;
+ }
+ return super.isVoiceInteraction();
+ }
+
+ @Override
+ public void safelyStartActivity(TargetInfo cti) {
+ if (sOverrides.onSafelyStartCallback != null &&
+ sOverrides.onSafelyStartCallback.apply(cti)) {
+ return;
+ }
+ super.safelyStartActivity(cti);
+ }
+
+ @Override
+ protected ResolverListController createListController() {
+ return sOverrides.resolverListController;
+ }
+
+ @Override
+ public PackageManager getPackageManager() {
+ if (sOverrides.createPackageManager != null) {
+ return sOverrides.createPackageManager.apply(super.getPackageManager());
+ }
+ return super.getPackageManager();
+ }
+
+ /**
+ * We cannot directly mock the activity created since instrumentation creates it.
+ * <p>
+ * Instead, we use static instances of this object to modify behavior.
+ */
+ static class OverrideData {
+ @SuppressWarnings("Since15")
+ public Function<PackageManager, PackageManager> createPackageManager;
+ public Function<TargetInfo, Boolean> onSafelyStartCallback;
+ public ResolverListController resolverListController;
+ public Boolean isVoiceInteraction;
+
+ public void reset() {
+ onSafelyStartCallback = null;
+ isVoiceInteraction = null;
+ createPackageManager = null;
+ resolverListController = mock(ResolverListController.class);
+ }
+ }
+}
\ No newline at end of file
diff --git a/graphics/java/android/graphics/FontFamily.java b/graphics/java/android/graphics/FontFamily.java
index cd5071e8..8673e0b 100644
--- a/graphics/java/android/graphics/FontFamily.java
+++ b/graphics/java/android/graphics/FontFamily.java
@@ -17,6 +17,7 @@
package android.graphics;
import android.content.res.AssetManager;
+import android.text.FontConfig;
import android.util.Log;
import java.io.FileInputStream;
@@ -80,7 +81,7 @@
}
}
- public boolean addFontWeightStyle(ByteBuffer font, int ttcIndex, List<FontListParser.Axis> axes,
+ public boolean addFontWeightStyle(ByteBuffer font, int ttcIndex, List<FontConfig.Axis> axes,
int weight, boolean style) {
return nAddFontWeightStyle(mNativePtr, font, ttcIndex, axes, weight, style);
}
@@ -94,7 +95,7 @@
private static native void nUnrefFamily(long nativePtr);
private static native boolean nAddFont(long nativeFamily, ByteBuffer font, int ttcIndex);
private static native boolean nAddFontWeightStyle(long nativeFamily, ByteBuffer font,
- int ttcIndex, List<FontListParser.Axis> listOfAxis,
+ int ttcIndex, List<FontConfig.Axis> listOfAxis,
int weight, boolean isItalic);
private static native boolean nAddFontFromAssetManager(long nativeFamily, AssetManager mgr,
String path, int cookie, boolean isAsset);
diff --git a/graphics/java/android/graphics/FontListParser.java b/graphics/java/android/graphics/FontListParser.java
index 9490436..4ec564a 100644
--- a/graphics/java/android/graphics/FontListParser.java
+++ b/graphics/java/android/graphics/FontListParser.java
@@ -16,6 +16,7 @@
package android.graphics;
+import android.text.FontConfig;
import android.util.Xml;
import org.xmlpull.v1.XmlPullParser;
@@ -36,61 +37,8 @@
*/
public class FontListParser {
- public static class Config {
- Config() {
- families = new ArrayList<Family>();
- aliases = new ArrayList<Alias>();
- }
- public List<Family> families;
- public List<Alias> aliases;
- }
-
- public static class Axis {
- Axis(int tag, float styleValue) {
- this.tag = tag;
- this.styleValue = styleValue;
- }
- public final int tag;
- public final float styleValue;
- }
-
- public static class Font {
- Font(String fontName, int ttcIndex, List<Axis> axes, int weight, boolean isItalic) {
- this.fontName = fontName;
- this.ttcIndex = ttcIndex;
- this.axes = axes;
- this.weight = weight;
- this.isItalic = isItalic;
- }
- public String fontName;
- public int ttcIndex;
- public final List<Axis> axes;
- public int weight;
- public boolean isItalic;
- }
-
- public static class Alias {
- public String name;
- public String toName;
- public int weight;
- }
-
- public static class Family {
- public Family(String name, List<Font> fonts, String lang, String variant) {
- this.name = name;
- this.fonts = fonts;
- this.lang = lang;
- this.variant = variant;
- }
-
- public String name;
- public List<Font> fonts;
- public String lang;
- public String variant;
- }
-
/* Parse fallback list (no names) */
- public static Config parse(InputStream in) throws XmlPullParserException, IOException {
+ public static FontConfig parse(InputStream in) throws XmlPullParserException, IOException {
try {
XmlPullParser parser = Xml.newPullParser();
parser.setInput(in, null);
@@ -104,9 +52,9 @@
// Note that a well-formed variation contains a four-character tag and a float as styleValue,
// with spacers in between. The tag is enclosd either by double quotes or single quotes.
@VisibleForTesting
- public static Axis[] parseFontVariationSettings(String settings) {
+ public static FontConfig.Axis[] parseFontVariationSettings(String settings) {
String[] settingList = settings.split(",");
- ArrayList<Axis> axisList = new ArrayList<>();
+ ArrayList<FontConfig.Axis> axisList = new ArrayList<>();
settingLoop:
for (String setting : settingList) {
int pos = 0;
@@ -148,9 +96,9 @@
}
int tag = makeTag(tagString.charAt(0), tagString.charAt(1), tagString.charAt(2),
tagString.charAt(3));
- axisList.add(new Axis(tag, styleValue));
+ axisList.add(new FontConfig.Axis(tag, styleValue));
}
- return axisList.toArray(new Axis[axisList.size()]);
+ return axisList.toArray(new FontConfig.Axis[axisList.size()]);
}
@VisibleForTesting
@@ -162,17 +110,17 @@
return c == ' ' || c == '\r' || c == '\t' || c == '\n';
}
- private static Config readFamilies(XmlPullParser parser)
+ private static FontConfig readFamilies(XmlPullParser parser)
throws XmlPullParserException, IOException {
- Config config = new Config();
+ FontConfig config = new FontConfig();
parser.require(XmlPullParser.START_TAG, null, "familyset");
while (parser.next() != XmlPullParser.END_TAG) {
if (parser.getEventType() != XmlPullParser.START_TAG) continue;
String tag = parser.getName();
if (tag.equals("family")) {
- config.families.add(readFamily(parser));
+ config.getFamilies().add(readFamily(parser));
} else if (tag.equals("alias")) {
- config.aliases.add(readAlias(parser));
+ config.getAliases().add(readAlias(parser));
} else {
skip(parser);
}
@@ -180,12 +128,12 @@
return config;
}
- private static Family readFamily(XmlPullParser parser)
+ private static FontConfig.Family readFamily(XmlPullParser parser)
throws XmlPullParserException, IOException {
String name = parser.getAttributeValue(null, "name");
String lang = parser.getAttributeValue(null, "lang");
String variant = parser.getAttributeValue(null, "variant");
- List<Font> fonts = new ArrayList<Font>();
+ List<FontConfig.Font> fonts = new ArrayList<FontConfig.Font>();
while (parser.next() != XmlPullParser.END_TAG) {
if (parser.getEventType() != XmlPullParser.START_TAG) continue;
String tag = parser.getName();
@@ -195,18 +143,18 @@
skip(parser);
}
}
- return new Family(name, fonts, lang, variant);
+ return new FontConfig.Family(name, fonts, lang, variant);
}
/** Matches leading and trailing XML whitespace. */
private static final Pattern FILENAME_WHITESPACE_PATTERN =
Pattern.compile("^[ \\n\\r\\t]+|[ \\n\\r\\t]+$");
- private static Font readFont(XmlPullParser parser)
+ private static FontConfig.Font readFont(XmlPullParser parser)
throws XmlPullParserException, IOException {
String indexStr = parser.getAttributeValue(null, "index");
int index = indexStr == null ? 0 : Integer.parseInt(indexStr);
- List<Axis> axes = new ArrayList<Axis>();
+ List<FontConfig.Axis> axes = new ArrayList<FontConfig.Axis>();
String weightStr = parser.getAttributeValue(null, "weight");
int weight = weightStr == null ? 400 : Integer.parseInt(weightStr);
boolean isItalic = "italic".equals(parser.getAttributeValue(null, "style"));
@@ -225,7 +173,7 @@
}
String fullFilename = "/system/fonts/" +
FILENAME_WHITESPACE_PATTERN.matcher(filename).replaceAll("");
- return new Font(fullFilename, index, axes, weight, isItalic);
+ return new FontConfig.Font(fullFilename, index, axes, weight, isItalic);
}
/** The 'tag' attribute value is read as four character values between U+0020 and U+007E
@@ -239,7 +187,7 @@
private static final Pattern STYLE_VALUE_PATTERN =
Pattern.compile("-?(([0-9]+(\\.[0-9]+)?)|(\\.[0-9]+))");
- private static Axis readAxis(XmlPullParser parser)
+ private static FontConfig.Axis readAxis(XmlPullParser parser)
throws XmlPullParserException, IOException {
int tag = 0;
String tagStr = parser.getAttributeValue(null, "tag");
@@ -258,22 +206,22 @@
}
skip(parser); // axis tag is empty, ignore any contents and consume end tag
- return new Axis(tag, styleValue);
+ return new FontConfig.Axis(tag, styleValue);
}
- private static Alias readAlias(XmlPullParser parser)
+ private static FontConfig.Alias readAlias(XmlPullParser parser)
throws XmlPullParserException, IOException {
- Alias alias = new Alias();
- alias.name = parser.getAttributeValue(null, "name");
- alias.toName = parser.getAttributeValue(null, "to");
+ String name = parser.getAttributeValue(null, "name");
+ String toName = parser.getAttributeValue(null, "to");
String weightStr = parser.getAttributeValue(null, "weight");
+ int weight;
if (weightStr == null) {
- alias.weight = 400;
+ weight = 400;
} else {
- alias.weight = Integer.parseInt(weightStr);
+ weight = Integer.parseInt(weightStr);
}
skip(parser); // alias tag is empty, ignore any contents and consume end tag
- return alias;
+ return new FontConfig.Alias(name, toName, weight);
}
private static void skip(XmlPullParser parser) throws XmlPullParserException, IOException {
diff --git a/graphics/java/android/graphics/Typeface.java b/graphics/java/android/graphics/Typeface.java
index eebe538..0a349e9 100644
--- a/graphics/java/android/graphics/Typeface.java
+++ b/graphics/java/android/graphics/Typeface.java
@@ -18,6 +18,7 @@
import android.annotation.NonNull;
import android.content.res.AssetManager;
+import android.text.FontConfig;
import android.util.Log;
import android.util.LongSparseArray;
import android.util.LruCache;
@@ -319,25 +320,25 @@
mStyle = nativeGetStyle(ni);
}
- private static FontFamily makeFamilyFromParsed(FontListParser.Family family,
+ private static FontFamily makeFamilyFromParsed(FontConfig.Family family,
Map<String, ByteBuffer> bufferForPath) {
- FontFamily fontFamily = new FontFamily(family.lang, family.variant);
- for (FontListParser.Font font : family.fonts) {
- ByteBuffer fontBuffer = bufferForPath.get(font.fontName);
+ FontFamily fontFamily = new FontFamily(family.getLanguage(), family.getVariant());
+ for (FontConfig.Font font : family.getFonts()) {
+ ByteBuffer fontBuffer = bufferForPath.get(font.getFontName());
if (fontBuffer == null) {
- try (FileInputStream file = new FileInputStream(font.fontName)) {
+ try (FileInputStream file = new FileInputStream(font.getFontName())) {
FileChannel fileChannel = file.getChannel();
long fontSize = fileChannel.size();
fontBuffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, fontSize);
- bufferForPath.put(font.fontName, fontBuffer);
+ bufferForPath.put(font.getFontName(), fontBuffer);
} catch (IOException e) {
- Log.e(TAG, "Error mapping font file " + font.fontName);
+ Log.e(TAG, "Error mapping font file " + font.getFontName());
continue;
}
}
- if (!fontFamily.addFontWeightStyle(fontBuffer, font.ttcIndex, font.axes,
- font.weight, font.isItalic)) {
- Log.e(TAG, "Error creating font " + font.fontName + "#" + font.ttcIndex);
+ if (!fontFamily.addFontWeightStyle(fontBuffer, font.getTtcIndex(), font.getAxes(),
+ font.getWeight(), font.isItalic())) {
+ Log.e(TAG, "Error creating font " + font.getFontName() + "#" + font.getTtcIndex());
}
}
return fontFamily;
@@ -354,16 +355,16 @@
File configFilename = new File(systemFontConfigLocation, FONTS_CONFIG);
try {
FileInputStream fontsIn = new FileInputStream(configFilename);
- FontListParser.Config fontConfig = FontListParser.parse(fontsIn);
+ FontConfig fontConfig = FontListParser.parse(fontsIn);
Map<String, ByteBuffer> bufferForPath = new HashMap<String, ByteBuffer>();
List<FontFamily> familyList = new ArrayList<FontFamily>();
// Note that the default typeface is always present in the fallback list;
// this is an enhancement from pre-Minikin behavior.
- for (int i = 0; i < fontConfig.families.size(); i++) {
- FontListParser.Family f = fontConfig.families.get(i);
- if (i == 0 || f.name == null) {
+ for (int i = 0; i < fontConfig.getFamilies().size(); i++) {
+ FontConfig.Family f = fontConfig.getFamilies().get(i);
+ if (i == 0 || f.getName() == null) {
familyList.add(makeFamilyFromParsed(f, bufferForPath));
}
}
@@ -371,10 +372,10 @@
setDefault(Typeface.createFromFamilies(sFallbackFonts));
Map<String, Typeface> systemFonts = new HashMap<String, Typeface>();
- for (int i = 0; i < fontConfig.families.size(); i++) {
+ for (int i = 0; i < fontConfig.getFamilies().size(); i++) {
Typeface typeface;
- FontListParser.Family f = fontConfig.families.get(i);
- if (f.name != null) {
+ FontConfig.Family f = fontConfig.getFamilies().get(i);
+ if (f.getName() != null) {
if (i == 0) {
// The first entry is the default typeface; no sense in
// duplicating the corresponding FontFamily.
@@ -384,17 +385,17 @@
FontFamily[] families = { fontFamily };
typeface = Typeface.createFromFamiliesWithDefault(families);
}
- systemFonts.put(f.name, typeface);
+ systemFonts.put(f.getName(), typeface);
}
}
- for (FontListParser.Alias alias : fontConfig.aliases) {
- Typeface base = systemFonts.get(alias.toName);
+ for (FontConfig.Alias alias : fontConfig.getAliases()) {
+ Typeface base = systemFonts.get(alias.getToName());
Typeface newFace = base;
- int weight = alias.weight;
+ int weight = alias.getWeight();
if (weight != 400) {
newFace = new Typeface(nativeCreateWeightAlias(base.native_instance, weight));
}
- systemFonts.put(alias.name, newFace);
+ systemFonts.put(alias.getName(), newFace);
}
sSystemFontMap = systemFonts;
diff --git a/graphics/tests/graphicstests/src/android/graphics/VariationParserTest.java b/graphics/tests/graphicstests/src/android/graphics/VariationParserTest.java
index d046c11..2b4e6c2 100644
--- a/graphics/tests/graphicstests/src/android/graphics/VariationParserTest.java
+++ b/graphics/tests/graphicstests/src/android/graphics/VariationParserTest.java
@@ -17,50 +17,53 @@
package android.graphics;
import android.test.suitebuilder.annotation.SmallTest;
+import android.text.FontConfig;
import junit.framework.TestCase;
+import java.util.List;
+
public class VariationParserTest extends TestCase {
@SmallTest
public void testParseFontVariationSetting() {
int tag = FontListParser.makeTag('w', 'd', 't', 'h');
- FontListParser.Axis[] axis = FontListParser.parseFontVariationSettings("'wdth' 1");
- assertEquals(tag, axis[0].tag);
- assertEquals(1.0f, axis[0].styleValue);
+ FontConfig.Axis[] axis = FontListParser.parseFontVariationSettings("'wdth' 1");
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(1.0f, axis[0].getStyleValue());
axis = FontListParser.parseFontVariationSettings("\"wdth\" 100");
- assertEquals(tag, axis[0].tag);
- assertEquals(100.0f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(100.0f, axis[0].getStyleValue());
axis = FontListParser.parseFontVariationSettings(" 'wdth' 100");
- assertEquals(tag, axis[0].tag);
- assertEquals(100.0f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(100.0f, axis[0].getStyleValue());
axis = FontListParser.parseFontVariationSettings("\t'wdth' 0.5");
- assertEquals(tag, axis[0].tag);
- assertEquals(0.5f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(0.5f, axis[0].getStyleValue());
tag = FontListParser.makeTag('A', 'X', ' ', ' ');
axis = FontListParser.parseFontVariationSettings("'AX ' 1");
- assertEquals(tag, axis[0].tag);
- assertEquals(1.0f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(1.0f, axis[0].getStyleValue());
axis = FontListParser.parseFontVariationSettings("'AX '\t1");
- assertEquals(tag, axis[0].tag);
- assertEquals(1.0f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(1.0f, axis[0].getStyleValue());
axis = FontListParser.parseFontVariationSettings("'AX '\n1");
- assertEquals(tag, axis[0].tag);
- assertEquals(1.0f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(1.0f, axis[0].getStyleValue());
axis = FontListParser.parseFontVariationSettings("'AX '\r1");
- assertEquals(tag, axis[0].tag);
- assertEquals(1.0f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(1.0f, axis[0].getStyleValue());
axis = FontListParser.parseFontVariationSettings("'AX '\r\t\n 1");
- assertEquals(tag, axis[0].tag);
- assertEquals(1.0f, axis[0].styleValue);
+ assertEquals(tag, axis[0].getTag());
+ assertEquals(1.0f, axis[0].getStyleValue());
// Test for invalid input
axis = FontListParser.parseFontVariationSettings("");
@@ -87,26 +90,26 @@
@SmallTest
public void testParseFontVariationStyleSettings() {
- FontListParser.Axis[] axis =
+ FontConfig.Axis[] axis =
FontListParser.parseFontVariationSettings("'wdth' 10,'AX '\r1");
int tag1 = FontListParser.makeTag('w', 'd', 't', 'h');
int tag2 = FontListParser.makeTag('A', 'X', ' ', ' ');
- assertEquals(tag1, axis[0].tag);
- assertEquals(10.0f, axis[0].styleValue);
- assertEquals(tag2, axis[1].tag);
- assertEquals(1.0f, axis[1].styleValue);
+ assertEquals(tag1, axis[0].getTag());
+ assertEquals(10.0f, axis[0].getStyleValue());
+ assertEquals(tag2, axis[1].getTag());
+ assertEquals(1.0f, axis[1].getStyleValue());
// Test only spacers are allowed before tag
axis = FontListParser.parseFontVariationSettings(" 'wdth' 10,ab'wdth' 1");
tag1 = FontListParser.makeTag('w', 'd', 't', 'h');
- assertEquals(tag1, axis[0].tag);
- assertEquals(10.0f, axis[0].styleValue);
+ assertEquals(tag1, axis[0].getTag());
+ assertEquals(10.0f, axis[0].getStyleValue());
assertEquals(1, axis.length);
}
@SmallTest
public void testInvalidTagCharacters() {
- FontListParser.Axis[] axis =
+ FontConfig.Axis[] axis =
FontListParser.parseFontVariationSettings("'\u0000\u0000\u0000\u0000' 10");
assertEquals(0, axis.length);
axis = FontListParser.parseFontVariationSettings("'\u3042\u3044\u3046\u3048' 10");
diff --git a/libs/hwui/FrameBuilder.cpp b/libs/hwui/FrameBuilder.cpp
index a53a55a..1d8b021 100644
--- a/libs/hwui/FrameBuilder.cpp
+++ b/libs/hwui/FrameBuilder.cpp
@@ -180,16 +180,18 @@
}
}
- if (!backdrop.isEmpty()) {
- // content node translation to catch up with backdrop
- float dx = contentDrawBounds.left - backdrop.left;
- float dy = contentDrawBounds.top - backdrop.top;
+ if (!nodes[1]->nothingToDraw()) {
+ if (!backdrop.isEmpty()) {
+ // content node translation to catch up with backdrop
+ float dx = contentDrawBounds.left - backdrop.left;
+ float dy = contentDrawBounds.top - backdrop.top;
- Rect contentLocalClip = backdrop;
- contentLocalClip.translate(dx, dy);
- deferRenderNode(-dx, -dy, contentLocalClip, *nodes[1]);
- } else {
- deferRenderNode(*nodes[1]);
+ Rect contentLocalClip = backdrop;
+ contentLocalClip.translate(dx, dy);
+ deferRenderNode(-dx, -dy, contentLocalClip, *nodes[1]);
+ } else {
+ deferRenderNode(*nodes[1]);
+ }
}
// remaining overlay nodes, simply defer
diff --git a/libs/hwui/tests/common/LeakChecker.cpp b/libs/hwui/tests/common/LeakChecker.cpp
index d935382..8a0b64b 100644
--- a/libs/hwui/tests/common/LeakChecker.cpp
+++ b/libs/hwui/tests/common/LeakChecker.cpp
@@ -67,6 +67,12 @@
}
void LeakChecker::checkForLeaks() {
+ // TODO: Re-enable, disabled to workaround b/34586922
+ if ((true)) {
+ cout << "checkForLeaks disabled, see b/34586922" << endl;
+ return;
+ }
+
// TODO: Until we can shutdown the RT thread we need to do this in
// two passes as GetUnreachableMemory has limited insight into
// thread-local caches so some leaks will not be properly tagged as leaks
diff --git a/libs/hwui/tests/common/TestUtils.cpp b/libs/hwui/tests/common/TestUtils.cpp
index 275ce16..79daa3f 100644
--- a/libs/hwui/tests/common/TestUtils.cpp
+++ b/libs/hwui/tests/common/TestUtils.cpp
@@ -193,10 +193,9 @@
}
SkRect TestUtils::getClipBounds(const SkCanvas* canvas) {
- SkClipStack::BoundsType boundType;
- SkRect clipBounds;
- canvas->getClipStack()->getBounds(&clipBounds, &boundType);
- return clipBounds;
+ SkIRect bounds;
+ (void)canvas->getClipDeviceBounds(&bounds);
+ return SkRect::Make(bounds);
}
SkRect TestUtils::getLocalClipBounds(const SkCanvas* canvas) {
diff --git a/libs/hwui/tests/unit/RenderNodeDrawableTests.cpp b/libs/hwui/tests/unit/RenderNodeDrawableTests.cpp
index f5ff058..2f1eae3 100644
--- a/libs/hwui/tests/unit/RenderNodeDrawableTests.cpp
+++ b/libs/hwui/tests/unit/RenderNodeDrawableTests.cpp
@@ -865,10 +865,8 @@
void onDrawPaint(const SkPaint&) {
switch (mDrawCounter++) {
case 0:
- // While this mirrors FrameBuilder::colorOp_unbounded, this value is different
- // because there is no root (root is clipped in SkiaPipeline::renderFrame).
- // SkiaPipeline.clipped and clip_replace verify the root clip.
- EXPECT_TRUE(TestUtils::getClipBounds(this).isEmpty());
+ EXPECT_EQ(SkRect::MakeWH(CANVAS_WIDTH, CANVAS_HEIGHT),
+ TestUtils::getClipBounds(this));
break;
case 1:
EXPECT_EQ(SkRect::MakeWH(10, 10), TestUtils::getClipBounds(this));
diff --git a/libs/hwui/tests/unit/SkiaRenderPropertiesTests.cpp b/libs/hwui/tests/unit/SkiaRenderPropertiesTests.cpp
index 92d9d3d..95c6ed6 100644
--- a/libs/hwui/tests/unit/SkiaRenderPropertiesTests.cpp
+++ b/libs/hwui/tests/unit/SkiaRenderPropertiesTests.cpp
@@ -87,14 +87,7 @@
testProperty([](RenderProperties& properties) {
properties.mutableRevealClip().set(true, 50, 50, 25);
}, [](const SkCanvas& canvas) {
- SkClipStack::Iter it(*canvas.getClipStack(), SkClipStack::Iter::kBottom_IterStart);
- const SkClipStack::Element *top = it.next();
- ASSERT_NE(nullptr, top);
- SkPath clip;
- top->asPath(&clip);
- SkRect rect;
- EXPECT_TRUE(clip.isOval(&rect));
- EXPECT_EQ(SkRect::MakeLTRB(25, 25, 75, 75), rect);
+ EXPECT_EQ(SkRect::MakeLTRB(25, 25, 75, 75), TestUtils::getClipBounds(&canvas));
});
}
@@ -103,14 +96,7 @@
properties.mutableOutline().setShouldClip(true);
properties.mutableOutline().setRoundRect(10, 20, 30, 40, 5.0f, 0.5f);
}, [](const SkCanvas& canvas) {
- SkClipStack::Iter it(*canvas.getClipStack(), SkClipStack::Iter::kBottom_IterStart);
- const SkClipStack::Element *top = it.next();
- ASSERT_NE(nullptr, top);
- SkPath clip;
- top->asPath(&clip);
- SkRRect rrect;
- EXPECT_TRUE(clip.isRRect(&rrect));
- EXPECT_EQ(SkRRect::MakeRectXY(SkRect::MakeLTRB(10, 20, 30, 40), 5.0f, 5.0f), rrect);
+ EXPECT_EQ(SkRect::MakeLTRB(10, 20, 30, 40), TestUtils::getClipBounds(&canvas));
});
}
diff --git a/preloaded-classes b/preloaded-classes
index 86cbb69..2fad5dd 100644
--- a/preloaded-classes
+++ b/preloaded-classes
@@ -823,11 +823,6 @@
android.graphics.EmbossMaskFilter
android.graphics.FontFamily
android.graphics.FontListParser
-android.graphics.FontListParser$Alias
-android.graphics.FontListParser$Axis
-android.graphics.FontListParser$Config
-android.graphics.FontListParser$Family
-android.graphics.FontListParser$Font
android.graphics.Insets
android.graphics.Interpolator
android.graphics.Interpolator$Result
@@ -1001,10 +996,6 @@
android.hardware.input.InputDeviceIdentifier$1
android.hardware.input.InputManager
android.hardware.input.InputManager$InputDevicesChangedListener
-# These cannot be preloaded and need to be refactored into system server. b/17791590, b/21935130
-# android.hardware.location.ActivityRecognitionHardware
-# android.hardware.location.IActivityRecognitionHardware
-# android.hardware.location.IActivityRecognitionHardware$Stub
android.hardware.location.ContextHubManager
android.hardware.location.IContextHubService
android.hardware.location.IContextHubService$Stub
@@ -1847,6 +1838,11 @@
android.text.DynamicLayout$ChangeWatcher
android.text.Editable
android.text.Editable$Factory
+android.text.FontConfig
+android.text.FontConfig$Alias
+android.text.FontConfig$Axis
+android.text.FontConfig$Family
+android.text.FontConfig$Font
android.text.GetChars
android.text.GraphicsOperations
android.text.Html
diff --git a/services/core/java/com/android/server/FontManagerService.java b/services/core/java/com/android/server/FontManagerService.java
new file mode 100644
index 0000000..593c322
--- /dev/null
+++ b/services/core/java/com/android/server/FontManagerService.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server;
+
+import android.content.Context;
+import android.graphics.FontListParser;
+import android.os.ParcelFileDescriptor;
+import android.text.FontConfig;
+import android.util.Slog;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.font.IFontManager;
+
+import org.xmlpull.v1.XmlPullParserException;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+public class FontManagerService extends IFontManager.Stub {
+ private static final String TAG = "FontManagerService";
+ private static final String FONTS_CONFIG = "/system/etc/fonts.xml";
+
+ @GuardedBy("mLock")
+ private FontConfig mConfig;
+ private final Object mLock = new Object();
+
+ public static final class Lifecycle extends SystemService {
+ private final FontManagerService mService;
+
+ public Lifecycle(Context context) {
+ super(context);
+ mService = new FontManagerService();
+ }
+
+ @Override
+ public void onStart() {
+ try {
+ publishBinderService(Context.FONT_SERVICE, mService);
+ } catch (Throwable t) {
+ // Starting this service is not critical to the running of this device and should
+ // therefore not crash the device. If it fails, log the error and continue.
+ Slog.e(TAG, "Could not start the FontManagerService.", t);
+ }
+ }
+ }
+
+ @Override
+ public FontConfig getSystemFonts() {
+ synchronized (mLock) {
+ if (mConfig != null) {
+ return new FontConfig(mConfig);
+ }
+
+ FontConfig config = loadFromSystem();
+ if (config == null) {
+ return null;
+ }
+
+ final int size = config.getFamilies().size();
+ for (int i = 0; i < size; ++i) {
+ FontConfig.Family family = config.getFamilies().get(i);
+ for (int j = 0; j < family.getFonts().size(); ++j) {
+ FontConfig.Font font = family.getFonts().get(j);
+ File fontFile = new File(font.getFontName());
+ try {
+ font.setFd(ParcelFileDescriptor.open(
+ fontFile, ParcelFileDescriptor.MODE_READ_ONLY));
+ } catch (IOException e) {
+ Slog.e(TAG, "Error opening font file " + font.getFontName(), e);
+ }
+ }
+ }
+
+ mConfig = config;
+ return new FontConfig(mConfig);
+ }
+ }
+
+ private FontConfig loadFromSystem() {
+ File configFilename = new File(FONTS_CONFIG);
+ try {
+ FileInputStream fontsIn = new FileInputStream(configFilename);
+ return FontListParser.parse(fontsIn);
+ } catch (IOException | XmlPullParserException e) {
+ Slog.e(TAG, "Error opening " + configFilename, e);
+ }
+ return null;
+ }
+
+ public FontManagerService() {
+ }
+}
diff --git a/services/core/java/com/android/server/LocationManagerService.java b/services/core/java/com/android/server/LocationManagerService.java
index c9b59ade..6cc72de 100644
--- a/services/core/java/com/android/server/LocationManagerService.java
+++ b/services/core/java/com/android/server/LocationManagerService.java
@@ -16,6 +16,7 @@
package com.android.server;
+import android.app.ActivityManager;
import android.content.pm.PackageManagerInternal;
import com.android.internal.content.PackageMonitor;
import com.android.internal.location.ProviderProperties;
@@ -138,6 +139,9 @@
// The maximum interval a location request can have and still be considered "high power".
private static final long HIGH_POWER_INTERVAL_MS = 5 * 60 * 1000;
+ // default background throttling interval if not overriden in settings
+ private static final long DEFAULT_BACKGROUND_THROTTLE_INTERVAL_MS = 30 * 1000;
+
// Location Providers may sometimes deliver location updates
// slightly faster that requested - provide grace period so
// we don't unnecessarily filter events that are otherwise on
@@ -157,6 +161,7 @@
private GeofenceManager mGeofenceManager;
private PackageManager mPackageManager;
private PowerManager mPowerManager;
+ private ActivityManager mActivityManager;
private UserManager mUserManager;
private GeocoderProxy mGeocodeProvider;
private IGnssStatusProvider mGnssStatusProvider;
@@ -171,47 +176,47 @@
// --- fields below are protected by mLock ---
// Set of providers that are explicitly enabled
// Only used by passive, fused & test. Network & GPS are controlled separately, and not listed.
- private final Set<String> mEnabledProviders = new HashSet<String>();
+ private final Set<String> mEnabledProviders = new HashSet<>();
// Set of providers that are explicitly disabled
- private final Set<String> mDisabledProviders = new HashSet<String>();
+ private final Set<String> mDisabledProviders = new HashSet<>();
// Mock (test) providers
private final HashMap<String, MockProvider> mMockProviders =
- new HashMap<String, MockProvider>();
+ new HashMap<>();
// all receivers
- private final HashMap<Object, Receiver> mReceivers = new HashMap<Object, Receiver>();
+ private final HashMap<Object, Receiver> mReceivers = new HashMap<>();
// currently installed providers (with mocks replacing real providers)
private final ArrayList<LocationProviderInterface> mProviders =
- new ArrayList<LocationProviderInterface>();
+ new ArrayList<>();
// real providers, saved here when mocked out
private final HashMap<String, LocationProviderInterface> mRealProviders =
- new HashMap<String, LocationProviderInterface>();
+ new HashMap<>();
// mapping from provider name to provider
private final HashMap<String, LocationProviderInterface> mProvidersByName =
- new HashMap<String, LocationProviderInterface>();
+ new HashMap<>();
// mapping from provider name to all its UpdateRecords
private final HashMap<String, ArrayList<UpdateRecord>> mRecordsByProvider =
- new HashMap<String, ArrayList<UpdateRecord>>();
+ new HashMap<>();
private final LocationRequestStatistics mRequestStatistics = new LocationRequestStatistics();
// mapping from provider name to last known location
- private final HashMap<String, Location> mLastLocation = new HashMap<String, Location>();
+ private final HashMap<String, Location> mLastLocation = new HashMap<>();
// same as mLastLocation, but is not updated faster than LocationFudger.FASTEST_INTERVAL_MS.
// locations stored here are not fudged for coarse permissions.
private final HashMap<String, Location> mLastLocationCoarseInterval =
- new HashMap<String, Location>();
+ new HashMap<>();
// all providers that operate over proxy, for authorizing incoming location
private final ArrayList<LocationProviderProxy> mProxyProviders =
- new ArrayList<LocationProviderProxy>();
+ new ArrayList<>();
// current active user on the device - other users are denied location data
private int mCurrentUserId = UserHandle.USER_SYSTEM;
@@ -252,6 +257,10 @@
// fetch power manager
mPowerManager = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
+ // fetch activity manager
+ mActivityManager
+ = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
+
// prepare worker thread
mLocationHandler = new LocationWorkerHandler(BackgroundThread.get().getLooper());
@@ -286,6 +295,40 @@
};
mPackageManager.addOnPermissionsChangeListener(permissionListener);
+ // listen for background/foreground changes
+ ActivityManager.OnUidImportanceListener uidImportanceListener
+ = new ActivityManager.OnUidImportanceListener() {
+ @Override
+ public void onUidImportance(int uid, int importance) {
+ boolean foreground = isImportanceForeground(importance);
+ HashSet<String> affectedProviders = new HashSet<>(mRecordsByProvider.size());
+ synchronized (mLock) {
+ for (Map.Entry<String, ArrayList<UpdateRecord>> entry
+ : mRecordsByProvider.entrySet()) {
+ String provider = entry.getKey();
+ for (UpdateRecord record : entry.getValue()) {
+ if (record.mReceiver.mUid == uid
+ && record.mIsForegroundUid != foreground) {
+ if (D) Log.d(TAG, "request from uid " + uid + " is now "
+ + (foreground ? "foreground" : "background)"));
+ record.mIsForegroundUid = foreground;
+
+ if (!isThrottlingExemptLocked(record.mReceiver)) {
+ affectedProviders.add(provider);
+ }
+ }
+ }
+ }
+ for (String provider : affectedProviders) {
+ applyRequirementsLocked(provider);
+ }
+ }
+
+ }
+ };
+ mActivityManager.addOnUidImportanceListener(uidImportanceListener,
+ ActivityManager.RunningAppProcessInfo.IMPORTANCE_PERCEPTIBLE);
+
mUserManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
updateUserProfiles(mCurrentUserId);
@@ -305,6 +348,17 @@
}
}
}, UserHandle.USER_ALL);
+ mContext.getContentResolver().registerContentObserver(
+ Settings.Global.getUriFor(Settings.Global.LOCATION_BACKGROUND_THROTTLE_INTERVAL_MS),
+ true,
+ new ContentObserver(mLocationHandler) {
+ @Override
+ public void onChange(boolean selfChange) {
+ synchronized (mLock) {
+ updateProvidersLocked();
+ }
+ }
+ }, UserHandle.USER_ALL);
mPackageMonitor.register(mContext, mLocationHandler.getLooper(), true);
// listen for user change
@@ -334,6 +388,10 @@
}, UserHandle.ALL, intentFilter, null, mLocationHandler);
}
+ private static boolean isImportanceForeground(int importance) {
+ return importance <= ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND_SERVICE;
+ }
+
/**
* Provides a way for components held by the {@link LocationManagerService} to clean-up
* gracefully on system's shutdown.
@@ -483,7 +541,7 @@
that matches the signature of at least one package on this list.
*/
Resources resources = mContext.getResources();
- ArrayList<String> providerPackageNames = new ArrayList<String>();
+ ArrayList<String> providerPackageNames = new ArrayList<>();
String[] pkgs = resources.getStringArray(
com.android.internal.R.array.config_locationProviderPackageNames);
if (D) Log.d(TAG, "certificates for location providers pulled from: " +
@@ -651,7 +709,7 @@
final boolean mHideFromAppOps; // True if AppOps should not monitor this receiver.
final Object mKey;
- final HashMap<String,UpdateRecord> mUpdateRecords = new HashMap<String,UpdateRecord>();
+ final HashMap<String,UpdateRecord> mUpdateRecords = new HashMap<>();
// True if app ops has started monitoring this receiver for locations.
boolean mOpMonitoring;
@@ -691,10 +749,7 @@
@Override
public boolean equals(Object otherObj) {
- if (otherObj instanceof Receiver) {
- return mKey.equals(((Receiver)otherObj).mKey);
- }
- return false;
+ return (otherObj instanceof Receiver) && mKey.equals(((Receiver) otherObj).mKey);
}
@Override
@@ -1011,13 +1066,25 @@
mProvidersByName.remove(provider.getName());
}
+ private boolean isOverlayProviderPackageLocked(String packageName) {
+ for (LocationProviderInterface provider : mProviders) {
+ if (provider instanceof LocationProviderProxy) {
+ if (packageName.equals(
+ ((LocationProviderProxy) provider).getConnectedPackageName())) {
+ return true;
+ }
+ }
+ }
+
+ return false;
+ }
+
/**
* Returns "true" if access to the specified location provider is allowed by the current
* user's settings. Access to all location providers is forbidden to non-location-provider
* processes belonging to background users.
*
* @param provider the name of the location provider
- * @return
*/
private boolean isAllowedByCurrentUserSettingsLocked(String provider) {
if (mEnabledProviders.contains(provider)) {
@@ -1039,7 +1106,6 @@
*
* @param provider the name of the location provider
* @param uid the requestor's UID
- * @return
*/
private boolean isAllowedByUserSettingsLocked(String provider, int uid) {
if (!isCurrentProfile(UserHandle.getUserId(uid)) && !isUidALocationProvider(uid)) {
@@ -1197,11 +1263,7 @@
}
}
- if (getAllowedResolutionLevel(pid, uid) < allowedResolutionLevel) {
- return false;
- }
-
- return true;
+ return getAllowedResolutionLevel(pid, uid) >= allowedResolutionLevel;
}
boolean checkLocationAccess(int pid, int uid, String packageName, int allowedResolutionLevel) {
@@ -1212,11 +1274,7 @@
}
}
- if (getAllowedResolutionLevel(pid, uid) < allowedResolutionLevel) {
- return false;
- }
-
- return true;
+ return getAllowedResolutionLevel(pid, uid) >= allowedResolutionLevel;
}
/**
@@ -1228,7 +1286,7 @@
public List<String> getAllProviders() {
ArrayList<String> out;
synchronized (mLock) {
- out = new ArrayList<String>(mProviders.size());
+ out = new ArrayList<>(mProviders.size());
for (LocationProviderInterface provider : mProviders) {
String name = provider.getName();
if (LocationManager.FUSED_PROVIDER.equals(name)) {
@@ -1251,11 +1309,11 @@
public List<String> getProviders(Criteria criteria, boolean enabledOnly) {
int allowedResolutionLevel = getCallerAllowedResolutionLevel();
ArrayList<String> out;
- int uid = Binder.getCallingUid();;
+ int uid = Binder.getCallingUid();
long identity = Binder.clearCallingIdentity();
try {
synchronized (mLock) {
- out = new ArrayList<String>(mProviders.size());
+ out = new ArrayList<>(mProviders.size());
for (LocationProviderInterface provider : mProviders) {
String name = provider.getName();
if (LocationManager.FUSED_PROVIDER.equals(name)) {
@@ -1370,14 +1428,12 @@
ArrayList<UpdateRecord> records = mRecordsByProvider.get(provider);
if (records != null) {
- final int N = records.size();
- for (int i = 0; i < N; i++) {
- UpdateRecord record = records.get(i);
+ for (UpdateRecord record : records) {
if (isCurrentProfile(UserHandle.getUserId(record.mReceiver.mUid))) {
// Sends a notification message to the receiver
if (!record.mReceiver.callProviderEnabledLocked(provider, enabled)) {
if (deadReceivers == null) {
- deadReceivers = new ArrayList<Receiver>();
+ deadReceivers = new ArrayList<>();
}
deadReceivers.add(record.mReceiver);
}
@@ -1410,6 +1466,12 @@
WorkSource worksource = new WorkSource();
ProviderRequest providerRequest = new ProviderRequest();
+ ContentResolver resolver = mContext.getContentResolver();
+ long backgroundThrottleInterval = Settings.Global.getLong(
+ resolver,
+ Settings.Global.LOCATION_BACKGROUND_THROTTLE_INTERVAL_MS,
+ DEFAULT_BACKGROUND_THROTTLE_INTERVAL_MS);
+
if (records != null) {
for (UpdateRecord record : records) {
if (isCurrentProfile(UserHandle.getUserId(record.mReceiver.mUid))) {
@@ -1419,10 +1481,22 @@
record.mReceiver.mPackageName,
record.mReceiver.mAllowedResolutionLevel)) {
LocationRequest locationRequest = record.mRequest;
+ long interval = locationRequest.getInterval();
+
+ if (!isThrottlingExemptLocked(record.mReceiver)) {
+ if (!record.mIsForegroundUid) {
+ interval = Math.max(interval, backgroundThrottleInterval);
+ }
+ if (interval != locationRequest.getInterval()) {
+ locationRequest = new LocationRequest(locationRequest);
+ locationRequest.setInterval(interval);
+ }
+ }
+
providerRequest.locationRequests.add(locationRequest);
- if (locationRequest.getInterval() < providerRequest.interval) {
+ if (interval < providerRequest.interval) {
providerRequest.reportLocation = true;
- providerRequest.interval = locationRequest.getInterval();
+ providerRequest.interval = interval;
}
}
}
@@ -1468,10 +1542,15 @@
p.setRequest(providerRequest, worksource);
}
+ private boolean isThrottlingExemptLocked(Receiver recevier) {
+ return isOverlayProviderPackageLocked(recevier.mPackageName);
+ }
+
private class UpdateRecord {
final String mProvider;
final LocationRequest mRequest;
final Receiver mReceiver;
+ boolean mIsForegroundUid;
Location mLastFixBroadcast;
long mLastStatusBroadcast;
@@ -1482,10 +1561,12 @@
mProvider = provider;
mRequest = request;
mReceiver = receiver;
+ mIsForegroundUid = isImportanceForeground(
+ mActivityManager.getPackageImportance(mReceiver.mPackageName));
ArrayList<UpdateRecord> records = mRecordsByProvider.get(provider);
if (records == null) {
- records = new ArrayList<UpdateRecord>();
+ records = new ArrayList<>();
mRecordsByProvider.put(provider, records);
}
if (!records.contains(this)) {
@@ -1517,7 +1598,7 @@
receiverRecords.remove(this.mProvider);
// and also remove the Receiver if it has no more update records
- if (removeReceiver && receiverRecords.size() == 0) {
+ if (receiverRecords.size() == 0) {
removeUpdatesLocked(mReceiver);
}
}
@@ -1525,14 +1606,9 @@
@Override
public String toString() {
- StringBuilder s = new StringBuilder();
- s.append("UpdateRecord[");
- s.append(mProvider);
- s.append(' ').append(mReceiver.mPackageName).append('(');
- s.append(mReceiver.mUid).append(')');
- s.append(' ').append(mRequest);
- s.append(']');
- return s.toString();
+ return "UpdateRecord[" + mProvider + " " + mReceiver.mPackageName
+ + "(" + mReceiver.mUid + (mIsForegroundUid ? " foreground" : " background")
+ + ")" + " " + mRequest + "]";
}
}
@@ -1681,14 +1757,17 @@
throw new IllegalArgumentException("provider name must not be null");
}
- if (D) Log.d(TAG, "request " + Integer.toHexString(System.identityHashCode(receiver))
- + " " + name + " " + request + " from " + packageName + "(" + uid + ")");
LocationProviderInterface provider = mProvidersByName.get(name);
if (provider == null) {
throw new IllegalArgumentException("provider doesn't exist: " + name);
}
UpdateRecord record = new UpdateRecord(name, request, receiver);
+ if (D) Log.d(TAG, "request " + Integer.toHexString(System.identityHashCode(receiver))
+ + " " + name + " " + request + " from " + packageName + "(" + uid + " "
+ + (record.mIsForegroundUid ? "foreground" : "background")
+ + (isOverlayProviderPackageLocked(receiver.mPackageName) ? " [whitelisted]" : "") + ")");
+
UpdateRecord oldRecord = receiver.mUpdateRecords.put(name, record);
if (oldRecord != null) {
oldRecord.disposeLocked(false);
@@ -1743,7 +1822,7 @@
receiver.updateMonitoring(false);
// Record which providers were associated with this listener
- HashSet<String> providers = new HashSet<String>();
+ HashSet<String> providers = new HashSet<>();
HashMap<String, UpdateRecord> oldRecords = receiver.mUpdateRecords;
if (oldRecords != null) {
// Call dispose() on the obsolete update records.
@@ -2084,9 +2163,7 @@
try {
synchronized (mLock) {
LocationProviderInterface p = mProvidersByName.get(provider);
- if (p == null) return false;
-
- return isAllowedByUserSettingsLocked(provider, uid);
+ return p != null && isAllowedByUserSettingsLocked(provider, uid);
}
} finally {
Binder.restoreCallingIdentity(identity);
@@ -2197,11 +2274,7 @@
}
// Check whether the expiry date has passed
- if (record.mRequest.getExpireAt() < now) {
- return false;
- }
-
- return true;
+ return record.mRequest.getExpireAt() >= now;
}
private void handleLocationChangedLocked(Location location, boolean passive) {
@@ -2216,7 +2289,7 @@
// Update last known locations
Location noGPSLocation = location.getExtraLocation(Location.EXTRA_NO_GPS_LOCATION);
- Location lastNoGPSLocation = null;
+ Location lastNoGPSLocation;
Location lastLocation = mLastLocation.get(provider);
if (lastLocation == null) {
lastLocation = new Location(provider);
@@ -2296,7 +2369,7 @@
continue;
}
- Location notifyLocation = null;
+ Location notifyLocation;
if (receiver.mAllowedResolutionLevel < RESOLUTION_LEVEL_FINE) {
notifyLocation = coarseLocation; // use coarse location
} else {
@@ -2333,14 +2406,14 @@
// track expired records
if (r.mRequest.getNumUpdates() <= 0 || r.mRequest.getExpireAt() < now) {
if (deadUpdateRecords == null) {
- deadUpdateRecords = new ArrayList<UpdateRecord>();
+ deadUpdateRecords = new ArrayList<>();
}
deadUpdateRecords.add(r);
}
// track dead receivers
if (receiverDead) {
if (deadReceivers == null) {
- deadReceivers = new ArrayList<Receiver>();
+ deadReceivers = new ArrayList<>();
}
if (!deadReceivers.contains(receiver)) {
deadReceivers.add(receiver);
@@ -2417,7 +2490,7 @@
for (Receiver receiver : mReceivers.values()) {
if (receiver.mPackageName.equals(packageName)) {
if (deadReceivers == null) {
- deadReceivers = new ArrayList<Receiver>();
+ deadReceivers = new ArrayList<>();
}
deadReceivers.add(receiver);
}
@@ -2694,6 +2767,13 @@
pw.println(" " + record);
}
}
+ pw.println(" Overlay Provider Packages:");
+ for (LocationProviderInterface provider : mProviders) {
+ if (provider instanceof LocationProviderProxy) {
+ pw.println(" " + provider.getName() + ": "
+ + ((LocationProviderProxy) provider).getConnectedPackageName());
+ }
+ }
pw.println(" Historical Records by Provider:");
for (Map.Entry<PackageProviderKey, PackageStatistics> entry
: mRequestStatistics.statistics.entrySet()) {
diff --git a/services/core/java/com/android/server/am/ActiveServices.java b/services/core/java/com/android/server/am/ActiveServices.java
index 4b89b40..1bba7ec 100644
--- a/services/core/java/com/android/server/am/ActiveServices.java
+++ b/services/core/java/com/android/server/am/ActiveServices.java
@@ -707,7 +707,7 @@
try {
ServiceRecord r = findServiceLocked(className, token, userId);
if (r != null) {
- setServiceForegroundInnerLocked(r, userId, notification, flags);
+ setServiceForegroundInnerLocked(r, id, notification, flags);
}
} finally {
Binder.restoreCallingIdentity(origId);
diff --git a/services/core/java/com/android/server/pm/ShortcutService.java b/services/core/java/com/android/server/pm/ShortcutService.java
index ae709fe..56d679e 100644
--- a/services/core/java/com/android/server/pm/ShortcutService.java
+++ b/services/core/java/com/android/server/pm/ShortcutService.java
@@ -1529,10 +1529,11 @@
if (UserHandle.getUserId(callingUid) != userId) {
throw new SecurityException("Invalid user-ID");
}
- if (injectGetPackageUid(packageName, userId) == callingUid) {
- return; // Caller is valid.
+ if (injectGetPackageUid(packageName, userId) != callingUid) {
+ throw new SecurityException("Calling package name mismatch");
}
- throw new SecurityException("Calling package name mismatch");
+ Preconditions.checkState(!isEphemeralApp(packageName, userId),
+ "Ephemeral apps can't use ShortcutManager");
}
// Overridden in unit tests to execute r synchronously.
@@ -3073,6 +3074,10 @@
return (ai != null) && (ai.flags & ApplicationInfo.FLAG_INSTALLED) != 0;
}
+ private static boolean isEphemeralApp(@Nullable ApplicationInfo ai) {
+ return (ai != null) && ai.isEphemeralApp();
+ }
+
private static boolean isInstalled(@Nullable PackageInfo pi) {
return (pi != null) && isInstalled(pi.applicationInfo);
}
@@ -3097,6 +3102,10 @@
return getApplicationInfo(packageName, userId) != null;
}
+ boolean isEphemeralApp(String packageName, int userId) {
+ return isEphemeralApp(getApplicationInfo(packageName, userId));
+ }
+
@Nullable
XmlResourceParser injectXmlMetaData(ActivityInfo activityInfo, String key) {
return activityInfo.loadXmlMetaData(mContext.getPackageManager(), key);
diff --git a/services/core/java/com/android/server/webkit/SystemImpl.java b/services/core/java/com/android/server/webkit/SystemImpl.java
index 02b46ec..4fd51b2 100644
--- a/services/core/java/com/android/server/webkit/SystemImpl.java
+++ b/services/core/java/com/android/server/webkit/SystemImpl.java
@@ -35,6 +35,7 @@
import android.provider.Settings;
import android.util.AndroidRuntimeException;
import android.util.Log;
+import android.webkit.UserPackage;
import android.webkit.WebViewFactory;
import android.webkit.WebViewProviderInfo;
import android.webkit.WebViewZygote;
@@ -271,6 +272,12 @@
}
@Override
+ public List<UserPackage> getPackageInfoForProviderAllUsers(Context context,
+ WebViewProviderInfo configInfo) {
+ return UserPackage.getPackageInfosAllUsers(context, configInfo.packageName, PACKAGE_FLAGS);
+ }
+
+ @Override
public int getMultiProcessSetting(Context context) {
return Settings.Global.getInt(context.getContentResolver(),
Settings.Global.WEBVIEW_MULTIPROCESS, 0);
diff --git a/services/core/java/com/android/server/webkit/SystemInterface.java b/services/core/java/com/android/server/webkit/SystemInterface.java
index fd137eb..b06f829 100644
--- a/services/core/java/com/android/server/webkit/SystemInterface.java
+++ b/services/core/java/com/android/server/webkit/SystemInterface.java
@@ -20,8 +20,11 @@
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.database.ContentObserver;
+import android.webkit.UserPackage;
import android.webkit.WebViewProviderInfo;
+import java.util.List;
+
/**
* System interface for the WebViewUpdateService.
* This interface provides a way to test the WebView preparation mechanism - during normal use this
@@ -49,6 +52,14 @@
public boolean systemIsDebuggable();
public PackageInfo getPackageInfoForProvider(WebViewProviderInfo configInfo)
throws NameNotFoundException;
+ /**
+ * Get the PackageInfos of all users for the package represented by {@param configInfo}.
+ * @return an array of UserPackages for a certain package, each UserPackage being belonging to a
+ * certain user. The returned array can contain null PackageInfos if the given package
+ * is uninstalled for some user.
+ */
+ public List<UserPackage> getPackageInfoForProviderAllUsers(Context context,
+ WebViewProviderInfo configInfo);
public int getMultiProcessSetting(Context context);
public void setMultiProcessSetting(Context context, int value);
diff --git a/services/core/java/com/android/server/webkit/WebViewUpdateService.java b/services/core/java/com/android/server/webkit/WebViewUpdateService.java
index 311570e..4a105e1 100644
--- a/services/core/java/com/android/server/webkit/WebViewUpdateService.java
+++ b/services/core/java/com/android/server/webkit/WebViewUpdateService.java
@@ -94,6 +94,9 @@
case Intent.ACTION_USER_ADDED:
mImpl.handleNewUser(userId);
break;
+ case Intent.ACTION_USER_REMOVED:
+ mImpl.handleUserRemoved(userId);
+ break;
}
}
};
@@ -112,6 +115,7 @@
IntentFilter userAddedFilter = new IntentFilter();
userAddedFilter.addAction(Intent.ACTION_USER_ADDED);
+ userAddedFilter.addAction(Intent.ACTION_USER_REMOVED);
getContext().registerReceiverAsUser(mWebViewUpdatedReceiver, UserHandle.ALL,
userAddedFilter, null /* broadcast permission */, null /* handler */);
diff --git a/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java b/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
index edfb11c..f016830 100644
--- a/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
+++ b/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
@@ -24,6 +24,7 @@
import android.os.UserHandle;
import android.util.Base64;
import android.util.Slog;
+import android.webkit.UserPackage;
import android.webkit.WebViewFactory;
import android.webkit.WebViewProviderInfo;
import android.webkit.WebViewProviderResponse;
@@ -100,32 +101,41 @@
private boolean existsValidNonFallbackProvider(WebViewProviderInfo[] providers) {
for (WebViewProviderInfo provider : providers) {
if (provider.availableByDefault && !provider.isFallback) {
- try {
- PackageInfo packageInfo = mSystemInterface.getPackageInfoForProvider(provider);
- if (isInstalledPackage(packageInfo) && isEnabledPackage(packageInfo)
- && mWebViewUpdater.isValidProvider(provider, packageInfo)) {
- return true;
- }
- } catch (NameNotFoundException e) {
- // A non-existent provider is neither valid nor enabled
+ // userPackages can contain null objects.
+ List<UserPackage> userPackages =
+ mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider);
+ if (isInstalledAndEnabledForAllUsers(userPackages) &&
+ // Checking validity of the package for the system user (rather than all
+ // users) since package validity depends not on the user but on the package
+ // itself.
+ mWebViewUpdater.isValidProvider(provider,
+ userPackages.get(UserHandle.USER_SYSTEM).getPackageInfo())) {
+ return true;
}
}
}
return false;
}
- /**
- * Called when a new user has been added to update the state of its fallback package.
- */
void handleNewUser(int userId) {
- if (!mSystemInterface.isFallbackLogicEnabled()) return;
+ handleUserChange();
+ }
- WebViewProviderInfo[] webviewProviders = mSystemInterface.getWebViewPackages();
- WebViewProviderInfo fallbackProvider = getFallbackProvider(webviewProviders);
- if (fallbackProvider == null) return;
+ void handleUserRemoved(int userId) {
+ handleUserChange();
+ }
- mSystemInterface.enablePackageForUser(fallbackProvider.packageName,
- !existsValidNonFallbackProvider(webviewProviders), userId);
+ /**
+ * Called when a user was added or removed to ensure fallback logic and WebView preparation are
+ * triggered. This has to be done since the WebView package we use depends on the enabled-state
+ * of packages for all users (so adding or removing a user might cause us to change package).
+ */
+ private void handleUserChange() {
+ if (mSystemInterface.isFallbackLogicEnabled()) {
+ updateFallbackState(mSystemInterface.getWebViewPackages());
+ }
+ // Potentially trigger package-changing logic.
+ mWebViewUpdater.updateCurrentWebViewPackage(null);
}
void notifyRelroCreationCompleted() {
@@ -141,7 +151,7 @@
}
WebViewProviderInfo[] getValidWebViewPackages() {
- return mWebViewUpdater.getValidAndInstalledWebViewPackages();
+ return mWebViewUpdater.getValidWebViewPackages();
}
WebViewProviderInfo[] getWebViewPackages() {
@@ -160,7 +170,7 @@
if (!mSystemInterface.isFallbackLogicEnabled()) return;
WebViewProviderInfo[] webviewProviders = mSystemInterface.getWebViewPackages();
- updateFallbackState(webviewProviders, true);
+ updateFallbackState(webviewProviders);
}
/**
@@ -185,35 +195,23 @@
}
}
if (!changedPackageAvailableByDefault) return;
- updateFallbackState(webviewProviders, false);
+ updateFallbackState(webviewProviders);
}
- private void updateFallbackState(WebViewProviderInfo[] webviewProviders, boolean isBoot) {
+ private void updateFallbackState(WebViewProviderInfo[] webviewProviders) {
// If there exists a valid and enabled non-fallback package - disable the fallback
// package, otherwise, enable it.
WebViewProviderInfo fallbackProvider = getFallbackProvider(webviewProviders);
if (fallbackProvider == null) return;
boolean existsValidNonFallbackProvider = existsValidNonFallbackProvider(webviewProviders);
- boolean isFallbackEnabled = false;
- try {
- isFallbackEnabled = isEnabledPackage(
- mSystemInterface.getPackageInfoForProvider(fallbackProvider));
- } catch (NameNotFoundException e) {
- // No fallback package installed -> early out.
- return;
- }
-
- if (existsValidNonFallbackProvider
- // During an OTA the primary user's WebView state might differ from other users', so
- // ignore the state of that user during boot.
- && (isFallbackEnabled || isBoot)) {
+ List<UserPackage> userPackages =
+ mSystemInterface.getPackageInfoForProviderAllUsers(mContext, fallbackProvider);
+ if (existsValidNonFallbackProvider && !isDisabledForAllUsers(userPackages)) {
mSystemInterface.uninstallAndDisablePackageForAllUsers(mContext,
fallbackProvider.packageName);
} else if (!existsValidNonFallbackProvider
- // During an OTA the primary user's WebView state might differ from other users', so
- // ignore the state of that user during boot.
- && (!isFallbackEnabled || isBoot)) {
+ && !isInstalledAndEnabledForAllUsers(userPackages)) {
// Enable the fallback package for all users.
mSystemInterface.enablePackageForAllUsers(mContext,
fallbackProvider.packageName, true);
@@ -376,38 +374,8 @@
* or the replacement are done).
*/
public String changeProviderAndSetting(String newProviderName) {
- PackageInfo oldPackage = null;
- PackageInfo newPackage = null;
- boolean providerChanged = false;
- synchronized(mLock) {
- oldPackage = mCurrentWebViewPackage;
- mSystemInterface.updateUserSetting(mContext, newProviderName);
-
- try {
- newPackage = findPreferredWebViewPackage();
- providerChanged = (oldPackage == null)
- || !newPackage.packageName.equals(oldPackage.packageName);
- } catch (WebViewPackageMissingException e) {
- mCurrentWebViewPackage = null;
- Slog.e(TAG, "Tried to change WebView provider but failed to fetch WebView " +
- "package " + e);
- // If we don't perform the user change but don't have an installed WebView
- // package, we will have changed the setting and it will be used when a package
- // is available.
- return "";
- }
- // Perform the provider change if we chose a new provider
- if (providerChanged) {
- onWebViewProviderChanged(newPackage);
- }
- }
- // Kill apps using the old provider only if we changed provider
- if (providerChanged && oldPackage != null) {
- mSystemInterface.killPackageDependents(oldPackage.packageName);
- }
- // Return the new provider, this is not necessarily the one we were asked to switch to
- // But the persistent setting will now be pointing to the provider we were asked to
- // switch to anyway
+ PackageInfo newPackage = updateCurrentWebViewPackage(newProviderName);
+ if (newPackage == null) return "";
return newPackage.packageName;
}
@@ -437,15 +405,14 @@
}
}
- private ProviderAndPackageInfo[] getValidWebViewPackagesAndInfos(boolean onlyInstalled) {
+ private ProviderAndPackageInfo[] getValidWebViewPackagesAndInfos() {
WebViewProviderInfo[] allProviders = mSystemInterface.getWebViewPackages();
List<ProviderAndPackageInfo> providers = new ArrayList<>();
for(int n = 0; n < allProviders.length; n++) {
try {
PackageInfo packageInfo =
mSystemInterface.getPackageInfoForProvider(allProviders[n]);
- if ((!onlyInstalled || isInstalledPackage(packageInfo))
- && isValidProvider(allProviders[n], packageInfo)) {
+ if (isValidProvider(allProviders[n], packageInfo)) {
providers.add(new ProviderAndPackageInfo(allProviders[n], packageInfo));
}
} catch (NameNotFoundException e) {
@@ -458,9 +425,8 @@
/**
* Fetch only the currently valid WebView packages.
**/
- public WebViewProviderInfo[] getValidAndInstalledWebViewPackages() {
- ProviderAndPackageInfo[] providersAndPackageInfos =
- getValidWebViewPackagesAndInfos(true /* only fetch installed packages */);
+ public WebViewProviderInfo[] getValidWebViewPackages() {
+ ProviderAndPackageInfo[] providersAndPackageInfos = getValidWebViewPackagesAndInfos();
WebViewProviderInfo[] providers =
new WebViewProviderInfo[providersAndPackageInfos.length];
for(int n = 0; n < providersAndPackageInfos.length; n++) {
@@ -487,39 +453,49 @@
*
*/
private PackageInfo findPreferredWebViewPackage() throws WebViewPackageMissingException {
- ProviderAndPackageInfo[] providers =
- getValidWebViewPackagesAndInfos(false /* onlyInstalled */);
+ ProviderAndPackageInfo[] providers = getValidWebViewPackagesAndInfos();
String userChosenProvider = mSystemInterface.getUserChosenWebViewProvider(mContext);
- // If the user has chosen provider, use that
+ // If the user has chosen provider, use that (if it's installed and enabled for all
+ // users).
for (ProviderAndPackageInfo providerAndPackage : providers) {
- if (providerAndPackage.provider.packageName.equals(userChosenProvider)
- && isInstalledPackage(providerAndPackage.packageInfo)
- && isEnabledPackage(providerAndPackage.packageInfo)) {
- return providerAndPackage.packageInfo;
+ if (providerAndPackage.provider.packageName.equals(userChosenProvider)) {
+ // userPackages can contain null objects.
+ List<UserPackage> userPackages =
+ mSystemInterface.getPackageInfoForProviderAllUsers(mContext,
+ providerAndPackage.provider);
+ if (isInstalledAndEnabledForAllUsers(userPackages)) {
+ return providerAndPackage.packageInfo;
+ }
}
}
// User did not choose, or the choice failed; use the most stable provider that is
- // installed and enabled for the device owner, and available by default (not through
+ // installed and enabled for all users, and available by default (not through
// user choice).
for (ProviderAndPackageInfo providerAndPackage : providers) {
- if (providerAndPackage.provider.availableByDefault
- && isInstalledPackage(providerAndPackage.packageInfo)
- && isEnabledPackage(providerAndPackage.packageInfo)) {
- return providerAndPackage.packageInfo;
+ if (providerAndPackage.provider.availableByDefault) {
+ // userPackages can contain null objects.
+ List<UserPackage> userPackages =
+ mSystemInterface.getPackageInfoForProviderAllUsers(mContext,
+ providerAndPackage.provider);
+ if (isInstalledAndEnabledForAllUsers(userPackages)) {
+ return providerAndPackage.packageInfo;
+ }
}
}
// Could not find any installed and enabled package either, use the most stable and
// default-available provider.
+ // TODO(gsennton) remove this when we have a functional WebView stub.
for (ProviderAndPackageInfo providerAndPackage : providers) {
if (providerAndPackage.provider.availableByDefault) {
return providerAndPackage.packageInfo;
}
}
+ // This should never happen during normal operation (only with modified system images).
mAnyWebViewInstalled = false;
throw new WebViewPackageMissingException("Could not find a loadable WebView package");
}
@@ -702,6 +678,48 @@
mAnyWebViewInstalled));
}
}
+
+ /**
+ * Update the current WebView package.
+ * @param newProviderName the package to switch to, null if no package has been explicitly
+ * chosen.
+ */
+ public PackageInfo updateCurrentWebViewPackage(String newProviderName) {
+ PackageInfo oldPackage = null;
+ PackageInfo newPackage = null;
+ boolean providerChanged = false;
+ synchronized(mLock) {
+ oldPackage = mCurrentWebViewPackage;
+
+ if (newProviderName != null) {
+ mSystemInterface.updateUserSetting(mContext, newProviderName);
+ }
+
+ try {
+ newPackage = findPreferredWebViewPackage();
+ providerChanged = (oldPackage == null)
+ || !newPackage.packageName.equals(oldPackage.packageName);
+ } catch (WebViewPackageMissingException e) {
+ // If updated the Setting but don't have an installed WebView package, the
+ // Setting will be used when a package is available.
+ mCurrentWebViewPackage = null;
+ Slog.e(TAG, "Couldn't find WebView package to use " + e);
+ return null;
+ }
+ // Perform the provider change if we chose a new provider
+ if (providerChanged) {
+ onWebViewProviderChanged(newPackage);
+ }
+ }
+ // Kill apps using the old provider only if we changed provider
+ if (providerChanged && oldPackage != null) {
+ mSystemInterface.killPackageDependents(oldPackage.packageName);
+ }
+ // Return the new provider, this is not necessarily the one we were asked to switch to,
+ // but the persistent setting will now be pointing to the provider we were asked to
+ // switch to anyway.
+ return newPackage;
+ }
}
private static boolean providerHasValidSignature(WebViewProviderInfo provider,
@@ -730,20 +748,27 @@
}
/**
- * Returns whether the given package is enabled.
- * This state can be changed by the user from Settings->Apps
+ * Return true iff {@param packageInfos} point to only installed and enabled packages.
+ * The given packages {@param packageInfos} should all be pointing to the same package, but each
+ * PackageInfo representing a different user's package.
*/
- private static boolean isEnabledPackage(PackageInfo packageInfo) {
- return packageInfo.applicationInfo.enabled;
+ private static boolean isInstalledAndEnabledForAllUsers(
+ List<UserPackage> userPackages) {
+ for (UserPackage userPackage : userPackages) {
+ if (!userPackage.isInstalledPackage() || !userPackage.isEnabledPackage()) {
+ return false;
+ }
+ }
+ return true;
}
- /**
- * Return true if the package is installed and not hidden
- */
- private static boolean isInstalledPackage(PackageInfo packageInfo) {
- return (((packageInfo.applicationInfo.flags & ApplicationInfo.FLAG_INSTALLED) != 0)
- && ((packageInfo.applicationInfo.privateFlags
- & ApplicationInfo.PRIVATE_FLAG_HIDDEN) == 0));
+ private static boolean isDisabledForAllUsers(List<UserPackage> userPackages) {
+ for (UserPackage userPackage : userPackages) {
+ if (userPackage.getPackageInfo() != null && userPackage.isEnabledPackage()) {
+ return false;
+ }
+ }
+ return true;
}
/**
diff --git a/services/java/com/android/server/SystemServer.java b/services/java/com/android/server/SystemServer.java
index cac9853..c3ef23b 100644
--- a/services/java/com/android/server/SystemServer.java
+++ b/services/java/com/android/server/SystemServer.java
@@ -939,6 +939,12 @@
traceEnd();
}
+ if (!disableNonCoreServices) {
+ traceBeginAndSlog("StartFontServiceManager");
+ mSystemServiceManager.startService(FontManagerService.Lifecycle.class);
+ traceEnd();
+ }
+
if (!disableNonCoreServices && !disableTextServices) {
traceBeginAndSlog("StartTextServicesManager");
mSystemServiceManager.startService(TextServicesManagerService.Lifecycle.class);
diff --git a/services/tests/servicestests/src/com/android/server/pm/BaseShortcutManagerTest.java b/services/tests/servicestests/src/com/android/server/pm/BaseShortcutManagerTest.java
index 167b33a..9835c88 100644
--- a/services/tests/servicestests/src/com/android/server/pm/BaseShortcutManagerTest.java
+++ b/services/tests/servicestests/src/com/android/server/pm/BaseShortcutManagerTest.java
@@ -566,6 +566,7 @@
protected Map<String, PackageInfo> mInjectedPackages;
protected Set<PackageWithUser> mUninstalledPackages;
+ protected Set<PackageWithUser> mEphemeralPackages;
protected Set<String> mSystemPackages;
protected PackageManager mMockPackageManager;
@@ -731,6 +732,7 @@
mUninstalledPackages = new HashSet<>();
mSystemPackages = new HashSet<>();
+ mEphemeralPackages = new HashSet<>();
mInjectedFilePathRoot = new File(getTestContext().getCacheDir(), "test-files");
@@ -1034,6 +1036,9 @@
if (mUninstalledPackages.contains(PackageWithUser.of(userId, packageName))) {
ret.applicationInfo.flags &= ~ApplicationInfo.FLAG_INSTALLED;
}
+ if (mEphemeralPackages.contains(PackageWithUser.of(userId, packageName))) {
+ ret.applicationInfo.privateFlags |= ApplicationInfo.PRIVATE_FLAG_EPHEMERAL;
+ }
if (mSystemPackages.contains(packageName)) {
ret.applicationInfo.flags |= ApplicationInfo.FLAG_SYSTEM;
}
diff --git a/services/tests/servicestests/src/com/android/server/pm/PackageManagerPresubmitTest.java b/services/tests/servicestests/src/com/android/server/pm/PackageManagerPresubmitTest.java
index 9409b39..e6b4540f 100644
--- a/services/tests/servicestests/src/com/android/server/pm/PackageManagerPresubmitTest.java
+++ b/services/tests/servicestests/src/com/android/server/pm/PackageManagerPresubmitTest.java
@@ -103,12 +103,10 @@
// if privapp permissions are enforced, platform permissions must be whitelisted
// in SystemConfig
if (platformPermission && RoSystemProperties.CONTROL_PRIVAPP_PERMISSIONS_ENFORCE) {
- assertTrue("Permission " + pName
- + " should be declared in "
- + "/etc/permissions/privapp-permissions-platform.xml "
- + "or privapp-permissions-<device>.xml file for package "
+ assertTrue("Permission " + pName + " should be declared in "
+ + "privapp-permissions-<category>.xml file for package "
+ packageName,
- privAppPermissions.contains(pName));
+ privAppPermissions != null && privAppPermissions.contains(pName));
}
assertTrue("Permission " + pName + " should be granted to " + packageName, granted);
}
diff --git a/services/tests/servicestests/src/com/android/server/pm/ShortcutManagerTest2.java b/services/tests/servicestests/src/com/android/server/pm/ShortcutManagerTest2.java
index d25923c..562de414 100644
--- a/services/tests/servicestests/src/com/android/server/pm/ShortcutManagerTest2.java
+++ b/services/tests/servicestests/src/com/android/server/pm/ShortcutManagerTest2.java
@@ -46,6 +46,7 @@
import com.android.frameworks.servicestests.R;
import com.android.server.pm.ShortcutService.ConfigConstants;
+import com.android.server.pm.ShortcutUser.PackageWithUser;
import java.io.File;
import java.io.FileWriter;
@@ -2037,4 +2038,32 @@
assertFalse(mService.isUserUnlockedL(USER_0));
assertFalse(mService.isUserUnlockedL(USER_10));
}
+
+ public void testEphemeralApp() {
+ mRunningUsers.put(USER_10, true); // this test needs user 10.
+
+ runWithCaller(CALLING_PACKAGE_1, USER_0, () -> {
+ assertWith(mManager.getDynamicShortcuts()).isEmpty();
+ });
+ runWithCaller(CALLING_PACKAGE_1, USER_10, () -> {
+ assertWith(mManager.getDynamicShortcuts()).isEmpty();
+ });
+ runWithCaller(CALLING_PACKAGE_2, USER_0, () -> {
+ assertWith(mManager.getDynamicShortcuts()).isEmpty();
+ });
+ // Make package 1 ephemeral.
+ mEphemeralPackages.add(PackageWithUser.of(USER_0, CALLING_PACKAGE_1));
+
+ runWithCaller(CALLING_PACKAGE_1, USER_0, () -> {
+ assertExpectException(IllegalStateException.class, "Ephemeral apps", () -> {
+ mManager.getDynamicShortcuts();
+ });
+ });
+ runWithCaller(CALLING_PACKAGE_1, USER_10, () -> {
+ assertWith(mManager.getDynamicShortcuts()).isEmpty();
+ });
+ runWithCaller(CALLING_PACKAGE_2, USER_0, () -> {
+ assertWith(mManager.getDynamicShortcuts()).isEmpty();
+ });
+ }
}
diff --git a/services/tests/servicestests/src/com/android/server/webkit/TestSystemImpl.java b/services/tests/servicestests/src/com/android/server/webkit/TestSystemImpl.java
index 83a61ca..67e78d4 100644
--- a/services/tests/servicestests/src/com/android/server/webkit/TestSystemImpl.java
+++ b/services/tests/servicestests/src/com/android/server/webkit/TestSystemImpl.java
@@ -19,25 +19,39 @@
import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.pm.UserInfo;
+import android.webkit.UserPackage;
import android.webkit.WebViewProviderInfo;
+import java.util.ArrayList;
import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
public class TestSystemImpl implements SystemInterface {
private String mUserProvider = null;
private final WebViewProviderInfo[] mPackageConfigs;
- HashMap<String, PackageInfo> mPackages = new HashMap();
+ List<Integer> mUsers = new ArrayList<>();
+ // Package -> [user, package]
+ Map<String, Map<Integer, PackageInfo>> mPackages = new HashMap();
private boolean mFallbackLogicEnabled;
private final int mNumRelros;
private final boolean mIsDebuggable;
private int mMultiProcessSetting;
+ public static final int PRIMARY_USER_ID = 0;
+
public TestSystemImpl(WebViewProviderInfo[] packageConfigs, boolean fallbackLogicEnabled,
int numRelros, boolean isDebuggable) {
mPackageConfigs = packageConfigs;
mFallbackLogicEnabled = fallbackLogicEnabled;
mNumRelros = numRelros;
mIsDebuggable = isDebuggable;
+ mUsers.add(PRIMARY_USER_ID);
+ }
+
+ public void addUser(int userId) {
+ mUsers.add(userId);
}
@Override
@@ -78,17 +92,20 @@
@Override
public void enablePackageForAllUsers(Context context, String packageName, boolean enable) {
- enablePackageForUser(packageName, enable, 0);
+ for(int userId : mUsers) {
+ enablePackageForUser(packageName, enable, userId);
+ }
}
@Override
public void enablePackageForUser(String packageName, boolean enable, int userId) {
- PackageInfo packageInfo = mPackages.get(packageName);
- if (packageInfo == null) {
+ Map<Integer, PackageInfo> userPackages = mPackages.get(packageName);
+ if (userPackages == null) {
throw new IllegalArgumentException("There is no package called " + packageName);
}
+ PackageInfo packageInfo = userPackages.get(userId);
packageInfo.applicationInfo.enabled = enable;
- setPackageInfo(packageInfo);
+ setPackageInfoForUser(userId, packageInfo);
}
@Override
@@ -97,23 +114,61 @@
@Override
public PackageInfo getPackageInfoForProvider(WebViewProviderInfo info) throws
NameNotFoundException {
- PackageInfo ret = mPackages.get(info.packageName);
+ Map<Integer, PackageInfo> userPackages = mPackages.get(info.packageName);
+ if (userPackages == null) throw new NameNotFoundException(info.packageName);
+ PackageInfo ret = userPackages.get(PRIMARY_USER_ID);
if (ret == null) throw new NameNotFoundException(info.packageName);
return ret;
}
- public void setPackageInfo(PackageInfo pi) {
- mPackages.put(pi.packageName, pi);
+ @Override
+ public List<UserPackage> getPackageInfoForProviderAllUsers(
+ Context context, WebViewProviderInfo info) {
+ Map<Integer, PackageInfo> userPackages = mPackages.get(info.packageName);
+ List<UserPackage> ret = new ArrayList();
+ // Loop over defined users, and find the corresponding package for each user.
+ for (int userId : mUsers) {
+ ret.add(new UserPackage(createUserInfo(userId),
+ userPackages == null ? null : userPackages.get(userId)));
+ }
+ return ret;
}
+ private static UserInfo createUserInfo(int userId) {
+ return new UserInfo(userId, "User nr. " + userId, 0 /* flags */);
+ }
+
+ /**
+ * Set package for primary user.
+ */
+ public void setPackageInfo(PackageInfo pi) {
+ setPackageInfoForUser(PRIMARY_USER_ID, pi);
+ }
+
+ public void setPackageInfoForUser(int userId, PackageInfo pi) {
+ if (!mUsers.contains(userId)) {
+ throw new IllegalArgumentException("User nr. " + userId + " doesn't exist");
+ }
+ if (!mPackages.containsKey(pi.packageName)) {
+ mPackages.put(pi.packageName, new HashMap<Integer, PackageInfo>());
+ }
+ mPackages.get(pi.packageName).put(userId, pi);
+ }
+
+ /**
+ * Removes the package {@param packageName} for the primary user.
+ */
public void removePackageInfo(String packageName) {
- mPackages.remove(packageName);
+ mPackages.get(packageName).remove(PRIMARY_USER_ID);
}
@Override
public int getFactoryPackageVersion(String packageName) throws NameNotFoundException {
PackageInfo pi = null;
- pi = mPackages.get(packageName);
+ Map<Integer, PackageInfo> userPackages = mPackages.get(packageName);
+ if (userPackages == null) throw new NameNotFoundException();
+
+ pi = userPackages.get(PRIMARY_USER_ID);
if (pi != null && pi.applicationInfo.isSystemApp()) {
return pi.applicationInfo.versionCode;
}
diff --git a/services/tests/servicestests/src/com/android/server/webkit/WebViewUpdateServiceTest.java b/services/tests/servicestests/src/com/android/server/webkit/WebViewUpdateServiceTest.java
index 0519448..33cedfa 100644
--- a/services/tests/servicestests/src/com/android/server/webkit/WebViewUpdateServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/webkit/WebViewUpdateServiceTest.java
@@ -92,9 +92,15 @@
}
private void setEnabledAndValidPackageInfos(WebViewProviderInfo[] providers) {
+ // Set package infos for the primary user (user 0).
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, providers);
+ }
+
+ private void setEnabledAndValidPackageInfosForUser(int userId,
+ WebViewProviderInfo[] providers) {
for(WebViewProviderInfo wpi : providers) {
- mTestSystemImpl.setPackageInfo(createPackageInfo(wpi.packageName, true /* enabled */,
- true /* valid */, true /* installed */));
+ mTestSystemImpl.setPackageInfoForUser(userId, createPackageInfo(wpi.packageName,
+ true /* enabled */, true /* valid */, true /* installed */));
}
}
@@ -335,7 +341,7 @@
setEnabledAndValidPackageInfos(packages);
mWebViewUpdateServiceImpl.packageStateChanged(singlePackage,
- WebViewUpdateService.PACKAGE_ADDED, 0);
+ WebViewUpdateService.PACKAGE_ADDED, TestSystemImpl.PRIMARY_USER_ID);
checkPreparationPhasesForPackage(singlePackage, 1 /* number of finished preparations */);
assertEquals(singlePackage,
@@ -344,7 +350,7 @@
// Remove the package again
mTestSystemImpl.removePackageInfo(singlePackage);
mWebViewUpdateServiceImpl.packageStateChanged(singlePackage,
- WebViewUpdateService.PACKAGE_ADDED, 0);
+ WebViewUpdateService.PACKAGE_ADDED, TestSystemImpl.PRIMARY_USER_ID);
// Package removed - ensure our interface states that there is no package
response = mWebViewUpdateServiceImpl.waitForAndGetProvider();
@@ -374,7 +380,7 @@
createPackageInfo(wpi.packageName, true /* enabled */, true /* valid */,
true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(wpi.packageName,
- WebViewUpdateService.PACKAGE_ADDED_REPLACED, 0);
+ WebViewUpdateService.PACKAGE_ADDED_REPLACED, TestSystemImpl.PRIMARY_USER_ID);
checkPreparationPhasesForPackage(wpi.packageName, 1);
}
@@ -429,16 +435,8 @@
new WebViewProviderInfo(firstPackage, "", true, false, null),
new WebViewProviderInfo(secondPackage, "", true, false, null)};
setupWithPackages(packages);
- if (settingsChange) {
- // Have all packages be enabled, so that we can change provider however we want to
- setEnabledAndValidPackageInfos(packages);
- } else {
- // Have all packages be disabled so that we can change one to enabled later
- for(WebViewProviderInfo wpi : packages) {
- mTestSystemImpl.setPackageInfo(createPackageInfo(wpi.packageName,
- false /* enabled */, true /* valid */, true /* installed */));
- }
- }
+ // Have all packages be enabled, so that we can change provider however we want to
+ setEnabledAndValidPackageInfos(packages);
CountDownLatch countdown = new CountDownLatch(1);
@@ -457,8 +455,12 @@
mWebViewUpdateServiceImpl.waitForAndGetProvider();
assertEquals(WebViewFactory.LIBLOAD_SUCCESS, threadResponse.status);
assertEquals(secondPackage, threadResponse.packageInfo.packageName);
- // Verify that we killed the first package
- Mockito.verify(mTestSystemImpl).killPackageDependents(Mockito.eq(firstPackage));
+ // Verify that we killed the first package if we performed a settings change -
+ // otherwise we had to disable the first package, in which case its dependents
+ // should have been killed by the framework.
+ if (settingsChange) {
+ Mockito.verify(mTestSystemImpl).killPackageDependents(Mockito.eq(firstPackage));
+ }
countdown.countDown();
}
}).start();
@@ -470,11 +472,21 @@
if (settingsChange) {
mWebViewUpdateServiceImpl.changeProviderAndSetting(secondPackage);
} else {
- // Switch provider by enabling the second one
+ // Enable the second provider
mTestSystemImpl.setPackageInfo(createPackageInfo(secondPackage, true /* enabled */,
true /* valid */, true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(
- secondPackage, WebViewUpdateService.PACKAGE_CHANGED, 0);
+ secondPackage, WebViewUpdateService.PACKAGE_CHANGED, TestSystemImpl.PRIMARY_USER_ID);
+
+ // Ensure we haven't changed package yet.
+ assertEquals(firstPackage,
+ mWebViewUpdateServiceImpl.getCurrentWebViewPackage().packageName);
+
+ // Switch provider by disabling the first one
+ mTestSystemImpl.setPackageInfo(createPackageInfo(firstPackage, false /* enabled */,
+ true /* valid */, true /* installed */));
+ mWebViewUpdateServiceImpl.packageStateChanged(
+ firstPackage, WebViewUpdateService.PACKAGE_CHANGED, TestSystemImpl.PRIMARY_USER_ID);
}
mWebViewUpdateServiceImpl.notifyRelroCreationCompleted();
// first package done, should start on second
@@ -528,7 +540,7 @@
mTestSystemImpl.setPackageInfo(createPackageInfo(fallbackPackage, true /* enabled */,
true /* valid */, true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(
- fallbackPackage, WebViewUpdateService.PACKAGE_CHANGED, 0);
+ fallbackPackage, WebViewUpdateService.PACKAGE_CHANGED, TestSystemImpl.PRIMARY_USER_ID);
if (fallbackLogicEnabled) {
// Check that we have now disabled the fallback package twice
@@ -573,7 +585,7 @@
createPackageInfo(primaryPackage, true /* enabled */ , true /* valid */,
true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(primaryPackage,
- WebViewUpdateService.PACKAGE_ADDED_REPLACED, 0);
+ WebViewUpdateService.PACKAGE_ADDED_REPLACED, TestSystemImpl.PRIMARY_USER_ID);
// Verify fallback disabled, primary package used as provider, and fallback package killed
Mockito.verify(mTestSystemImpl).uninstallAndDisablePackageForAllUsers(
@@ -583,7 +595,31 @@
}
@Test
- public void testFallbackChangesEnabledState() {
+ public void testFallbackChangesEnabledStateSingleUser() {
+ for (PackageRemovalType removalType : REMOVAL_TYPES) {
+ checkFallbackChangesEnabledState(false /* multiUser */, removalType);
+ }
+ }
+
+ @Test
+ public void testFallbackChangesEnabledStateMultiUser() {
+ for (PackageRemovalType removalType : REMOVAL_TYPES) {
+ checkFallbackChangesEnabledState(true /* multiUser */, removalType);
+ }
+ }
+
+ /**
+ * Represents how to remove a package during a tests (disabling it / uninstalling it / hiding
+ * it).
+ */
+ private enum PackageRemovalType {
+ UNINSTALL, DISABLE, HIDE
+ }
+
+ private PackageRemovalType[] REMOVAL_TYPES = PackageRemovalType.class.getEnumConstants();
+
+ public void checkFallbackChangesEnabledState(boolean multiUser,
+ PackageRemovalType removalType) {
String primaryPackage = "primary";
String fallbackPackage = "fallback";
WebViewProviderInfo[] packages = new WebViewProviderInfo[] {
@@ -592,46 +628,68 @@
new WebViewProviderInfo(
fallbackPackage, "", true /* default available */, true /* fallback */, null)};
setupWithPackages(packages, true /* fallbackLogicEnabled */);
- setEnabledAndValidPackageInfos(packages);
+ int secondaryUserId = 10;
+ int userIdToChangePackageFor = multiUser ? secondaryUserId : TestSystemImpl.PRIMARY_USER_ID;
+ if (multiUser) {
+ mTestSystemImpl.addUser(secondaryUserId);
+ setEnabledAndValidPackageInfosForUser(secondaryUserId, packages);
+ }
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, packages);
runWebViewBootPreparationOnMainSync();
// Verify fallback disabled at boot when primary package enabled
- Mockito.verify(mTestSystemImpl).enablePackageForUser(
- Mockito.eq(fallbackPackage), Mockito.eq(false) /* enable */,
- Matchers.anyInt());
+ checkEnablePackageForUserCalled(fallbackPackage, false, multiUser
+ ? new int[] {TestSystemImpl.PRIMARY_USER_ID, secondaryUserId}
+ : new int[] {TestSystemImpl.PRIMARY_USER_ID}, 1 /* numUsages */);
checkPreparationPhasesForPackage(primaryPackage, 1);
+ boolean enabled = !(removalType == PackageRemovalType.DISABLE);
+ boolean installed = !(removalType == PackageRemovalType.UNINSTALL);
+ boolean hidden = (removalType == PackageRemovalType.HIDE);
// Disable primary package and ensure fallback becomes enabled and used
- mTestSystemImpl.setPackageInfo(
- createPackageInfo(primaryPackage, false /* enabled */, true /* valid */,
- true /* installed */));
+ mTestSystemImpl.setPackageInfoForUser(userIdToChangePackageFor,
+ createPackageInfo(primaryPackage, enabled /* enabled */, true /* valid */,
+ installed /* installed */, null /* signature */, 0 /* updateTime */,
+ hidden /* hidden */));
mWebViewUpdateServiceImpl.packageStateChanged(primaryPackage,
- WebViewUpdateService.PACKAGE_CHANGED, 0);
+ removalType == PackageRemovalType.DISABLE
+ ? WebViewUpdateService.PACKAGE_CHANGED : WebViewUpdateService.PACKAGE_REMOVED,
+ userIdToChangePackageFor); // USER ID
- Mockito.verify(mTestSystemImpl).enablePackageForUser(
- Mockito.eq(fallbackPackage), Mockito.eq(true) /* enable */,
- Matchers.anyInt());
+ checkEnablePackageForUserCalled(fallbackPackage, true, multiUser
+ ? new int[] {TestSystemImpl.PRIMARY_USER_ID, secondaryUserId}
+ : new int[] {TestSystemImpl.PRIMARY_USER_ID}, 1 /* numUsages */);
checkPreparationPhasesForPackage(fallbackPackage, 1);
// Again enable primary package and verify primary is used and fallback becomes disabled
- mTestSystemImpl.setPackageInfo(
+ mTestSystemImpl.setPackageInfoForUser(userIdToChangePackageFor,
createPackageInfo(primaryPackage, true /* enabled */, true /* valid */,
true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(primaryPackage,
- WebViewUpdateService.PACKAGE_CHANGED, 0);
+ removalType == PackageRemovalType.DISABLE
+ ? WebViewUpdateService.PACKAGE_CHANGED : WebViewUpdateService.PACKAGE_ADDED,
+ userIdToChangePackageFor);
// Verify fallback is disabled a second time when primary package becomes enabled
- Mockito.verify(mTestSystemImpl, Mockito.times(2)).enablePackageForUser(
- Mockito.eq(fallbackPackage), Mockito.eq(false) /* enable */,
- Matchers.anyInt());
+ checkEnablePackageForUserCalled(fallbackPackage, false, multiUser
+ ? new int[] {TestSystemImpl.PRIMARY_USER_ID, secondaryUserId}
+ : new int[] {TestSystemImpl.PRIMARY_USER_ID}, 2 /* numUsages */);
checkPreparationPhasesForPackage(primaryPackage, 2);
}
+ private void checkEnablePackageForUserCalled(String packageName, boolean expectEnabled,
+ int[] userIds, int numUsages) {
+ for (int userId : userIds) {
+ Mockito.verify(mTestSystemImpl, Mockito.times(numUsages)).enablePackageForUser(
+ Mockito.eq(packageName), Mockito.eq(expectEnabled), Mockito.eq(userId));
+ }
+ }
+
@Test
public void testAddUserWhenFallbackLogicEnabled() {
checkAddingNewUser(true);
@@ -651,8 +709,10 @@
new WebViewProviderInfo(
fallbackPackage, "", true /* default available */, true /* fallback */, null)};
setupWithPackages(packages, fallbackLogicEnabled);
- setEnabledAndValidPackageInfos(packages);
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, packages);
int newUser = 100;
+ mTestSystemImpl.addUser(newUser);
+ setEnabledAndValidPackageInfosForUser(newUser, packages);
mWebViewUpdateServiceImpl.handleNewUser(newUser);
if (fallbackLogicEnabled) {
// Verify fallback package becomes disabled for new user
@@ -668,6 +728,42 @@
}
/**
+ * Ensures that adding a new user for which the current WebView package is uninstalled causes a
+ * change of WebView provider.
+ */
+ @Test
+ public void testAddingNewUserWithUninstalledPackage() {
+ String primaryPackage = "primary";
+ String fallbackPackage = "fallback";
+ WebViewProviderInfo[] packages = new WebViewProviderInfo[] {
+ new WebViewProviderInfo(
+ primaryPackage, "", true /* default available */, false /* fallback */, null),
+ new WebViewProviderInfo(
+ fallbackPackage, "", true /* default available */, true /* fallback */, null)};
+ setupWithPackages(packages, true /* fallbackLogicEnabled */);
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, packages);
+ int newUser = 100;
+ mTestSystemImpl.addUser(newUser);
+ // Let the primary package be uninstalled for the new user
+ mTestSystemImpl.setPackageInfoForUser(newUser,
+ createPackageInfo(primaryPackage, true /* enabled */, true /* valid */,
+ false /* installed */));
+ mTestSystemImpl.setPackageInfoForUser(newUser,
+ createPackageInfo(fallbackPackage, false /* enabled */, true /* valid */,
+ true /* installed */));
+ mWebViewUpdateServiceImpl.handleNewUser(newUser);
+ // Verify fallback package doesn't become disabled for the primary user.
+ Mockito.verify(mTestSystemImpl, Mockito.never()).enablePackageForUser(
+ Mockito.anyObject(), Mockito.eq(false) /* enable */,
+ Mockito.eq(TestSystemImpl.PRIMARY_USER_ID) /* user */);
+ // Verify that we enable the fallback package for the secondary user.
+ Mockito.verify(mTestSystemImpl, Mockito.times(1)).enablePackageForUser(
+ Mockito.eq(fallbackPackage), Mockito.eq(true) /* enable */,
+ Mockito.eq(newUser) /* user */);
+ checkPreparationPhasesForPackage(fallbackPackage, 1 /* numRelros */);
+ }
+
+ /**
* Timing dependent test where we verify that the list of valid webview packages becoming empty
* at a certain point doesn't crash us or break our state.
*/
@@ -713,7 +809,7 @@
1 /* updateTime */ ));
mWebViewUpdateServiceImpl.packageStateChanged(firstPackage,
- WebViewUpdateService.PACKAGE_ADDED_REPLACED, 0);
+ WebViewUpdateService.PACKAGE_ADDED_REPLACED, TestSystemImpl.PRIMARY_USER_ID);
// Ensure we use firstPackage
checkPreparationPhasesForPackage(firstPackage, 2 /* second preparation for this package */);
@@ -742,14 +838,14 @@
mTestSystemImpl.setPackageInfo(createPackageInfo(secondPackage, true /* enabled */,
false /* valid */, true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(secondPackage,
- WebViewUpdateService.PACKAGE_ADDED, 0);
+ WebViewUpdateService.PACKAGE_ADDED, TestSystemImpl.PRIMARY_USER_ID);
checkPreparationPhasesForPackage(firstPackage, 2 /* second time for this package */);
// Now make the second package valid again and verify that it is used again
mTestSystemImpl.setPackageInfo(createPackageInfo(secondPackage, true /* enabled */,
true /* valid */, true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(secondPackage,
- WebViewUpdateService.PACKAGE_ADDED, 0);
+ WebViewUpdateService.PACKAGE_ADDED, TestSystemImpl.PRIMARY_USER_ID);
checkPreparationPhasesForPackage(secondPackage, 2 /* second time for this package */);
}
@@ -820,7 +916,7 @@
mWebViewUpdateServiceImpl.changeProviderAndSetting(secondPackage);
} else {
mWebViewUpdateServiceImpl.packageStateChanged(secondPackage,
- WebViewUpdateService.PACKAGE_ADDED_REPLACED, 0);
+ WebViewUpdateService.PACKAGE_ADDED_REPLACED, TestSystemImpl.PRIMARY_USER_ID);
}
WebViewProviderResponse response = mWebViewUpdateServiceImpl.waitForAndGetProvider();
@@ -831,7 +927,7 @@
true /* valid */, true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(secondPackage,
- WebViewUpdateService.PACKAGE_ADDED_REPLACED, 0);
+ WebViewUpdateService.PACKAGE_ADDED_REPLACED, TestSystemImpl.PRIMARY_USER_ID);
checkPreparationPhasesForPackage(secondPackage, 1);
@@ -863,11 +959,11 @@
createPackageInfo(firstPackage, true /* enabled */, false /* valid */,
true /* installed */));
mWebViewUpdateServiceImpl.packageStateChanged(firstPackage,
- WebViewUpdateService.PACKAGE_ADDED_REPLACED, 0);
+ WebViewUpdateService.PACKAGE_ADDED_REPLACED, TestSystemImpl.PRIMARY_USER_ID);
} else {
mTestSystemImpl.removePackageInfo(firstPackage);
mWebViewUpdateServiceImpl.packageStateChanged(firstPackage,
- WebViewUpdateService.PACKAGE_REMOVED, 0);
+ WebViewUpdateService.PACKAGE_REMOVED, TestSystemImpl.PRIMARY_USER_ID);
}
checkPreparationPhasesForPackage(secondPackage, 1);
@@ -1098,8 +1194,10 @@
}
}
- // Ensure that the update service uses an uninstalled package if that is the only package
- // available.
+ /**
+ * Ensure that the update service does use an uninstalled package when that is the only
+ * package available.
+ */
@Test
public void testWithSingleUninstalledPackage() {
String testPackageName = "test.package.name";
@@ -1113,21 +1211,32 @@
runWebViewBootPreparationOnMainSync();
checkPreparationPhasesForPackage(testPackageName, 1 /* first preparation phase */);
+ // TODO(gsennton) change this logic to use the code below when we have created a functional
+ // stub.
+ //Mockito.verify(mTestSystemImpl, Mockito.never()).onWebViewProviderChanged(
+ // Matchers.anyObject());
+ //WebViewProviderResponse response = mWebViewUpdateServiceImpl.waitForAndGetProvider();
+ //assertEquals(WebViewFactory.LIBLOAD_FAILED_LISTING_WEBVIEW_PACKAGES, response.status);
+ //assertEquals(null, mWebViewUpdateServiceImpl.getCurrentWebViewPackage());
}
@Test
public void testNonhiddenPackageUserOverHidden() {
- checkVisiblePackageUserOverNonVisible(false /* true == uninstalled, false == hidden */);
+ checkVisiblePackageUserOverNonVisible(false /* multiUser*/, PackageRemovalType.HIDE);
+ checkVisiblePackageUserOverNonVisible(true /* multiUser*/, PackageRemovalType.HIDE);
}
@Test
public void testInstalledPackageUsedOverUninstalled() {
- checkVisiblePackageUserOverNonVisible(true /* true == uninstalled, false == hidden */);
+ checkVisiblePackageUserOverNonVisible(false /* multiUser*/, PackageRemovalType.UNINSTALL);
+ checkVisiblePackageUserOverNonVisible(true /* multiUser*/, PackageRemovalType.UNINSTALL);
}
- private void checkVisiblePackageUserOverNonVisible(boolean uninstalledNotHidden) {
- boolean testUninstalled = uninstalledNotHidden;
- boolean testHidden = !uninstalledNotHidden;
+ private void checkVisiblePackageUserOverNonVisible(boolean multiUser,
+ PackageRemovalType removalType) {
+ assert removalType != PackageRemovalType.DISABLE;
+ boolean testUninstalled = removalType == PackageRemovalType.UNINSTALL;
+ boolean testHidden = removalType == PackageRemovalType.HIDE;
String installedPackage = "installedPackage";
String uninstalledPackage = "uninstalledPackage";
WebViewProviderInfo[] webviewPackages = new WebViewProviderInfo[] {
@@ -1137,11 +1246,25 @@
false /* fallback */, null)};
setupWithPackages(webviewPackages, true /* fallback logic enabled */, 1 /* numRelros */);
- mTestSystemImpl.setPackageInfo(createPackageInfo(installedPackage, true /* enabled */,
- true /* valid */, true /* installed */));
- mTestSystemImpl.setPackageInfo(createPackageInfo(uninstalledPackage, true /* enabled */,
+ int secondaryUserId = 5;
+ if (multiUser) {
+ mTestSystemImpl.addUser(secondaryUserId);
+ // Install all packages for the primary user.
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, webviewPackages);
+ mTestSystemImpl.setPackageInfoForUser(secondaryUserId, createPackageInfo(
+ installedPackage, true /* enabled */, true /* valid */, true /* installed */));
+ // Hide or uninstall the primary package for the second user
+ mTestSystemImpl.setPackageInfo(createPackageInfo(uninstalledPackage, true /* enabled */,
true /* valid */, (testUninstalled ? false : true) /* installed */,
null /* signatures */, 0 /* updateTime */, (testHidden ? true : false)));
+ } else {
+ mTestSystemImpl.setPackageInfo(createPackageInfo(installedPackage, true /* enabled */,
+ true /* valid */, true /* installed */));
+ // Hide or uninstall the primary package
+ mTestSystemImpl.setPackageInfo(createPackageInfo(uninstalledPackage, true /* enabled */,
+ true /* valid */, (testUninstalled ? false : true) /* installed */,
+ null /* signatures */, 0 /* updateTime */, (testHidden ? true : false)));
+ }
runWebViewBootPreparationOnMainSync();
@@ -1160,9 +1283,7 @@
}
/**
- * Ensure that we won't prioritize an uninstalled (or hidden) package even if it is user-chosen,
- * and that an uninstalled (or hidden) package is not considered valid (in the
- * getValidWebViewPackages() API).
+ * Ensure that we won't prioritize an uninstalled (or hidden) package even if it is user-chosen.
*/
private void checkCantSwitchToNonVisiblePackage(boolean uninstalledNotHidden) {
boolean testUninstalled = uninstalledNotHidden;
@@ -1176,27 +1297,31 @@
false /* fallback */, null)};
setupWithPackages(webviewPackages, true /* fallback logic enabled */, 1 /* numRelros */);
- mTestSystemImpl.setPackageInfo(createPackageInfo(installedPackage, true /* enabled */,
- true /* valid */, true /* installed */));
- mTestSystemImpl.setPackageInfo(createPackageInfo(uninstalledPackage, true /* enabled */,
- true /* valid */, (testUninstalled ? false : true) /* installed */,
- null /* signatures */, 0 /* updateTime */,
- (testHidden ? true : false) /* hidden */));
+ int secondaryUserId = 412;
+ mTestSystemImpl.addUser(secondaryUserId);
+
+ // Let all packages be installed and enabled for the primary user.
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, webviewPackages);
+ // Only uninstall the 'uninstalled package' for the secondary user.
+ mTestSystemImpl.setPackageInfoForUser(secondaryUserId, createPackageInfo(installedPackage,
+ true /* enabled */, true /* valid */, true /* installed */));
+ mTestSystemImpl.setPackageInfoForUser(secondaryUserId, createPackageInfo(uninstalledPackage,
+ true /* enabled */, true /* valid */, !testUninstalled /* installed */,
+ null /* signatures */, 0 /* updateTime */, testHidden /* hidden */));
runWebViewBootPreparationOnMainSync();
checkPreparationPhasesForPackage(installedPackage, 1 /* first preparation phase */);
- // Ensure that only the installed package is considered valid
- WebViewProviderInfo[] validPackages = mWebViewUpdateServiceImpl.getValidWebViewPackages();
- assertEquals(1, validPackages.length);
- assertEquals(installedPackage, validPackages[0].packageName);
-
// ensure that we don't switch to the uninstalled package (it will be used if it becomes
// installed later)
assertEquals(installedPackage,
mWebViewUpdateServiceImpl.changeProviderAndSetting(uninstalledPackage));
+ // Ensure both packages are considered valid.
+ assertEquals(2, mWebViewUpdateServiceImpl.getValidWebViewPackages().length);
+
+
// We should only have called onWebViewProviderChanged once (before calling
// changeProviderAndSetting
Mockito.verify(mTestSystemImpl, Mockito.times(1)).onWebViewProviderChanged(
@@ -1227,12 +1352,16 @@
false /* fallback */, null)};
setupWithPackages(webviewPackages, true /* fallback logic enabled */, 1 /* numRelros */);
- mTestSystemImpl.setPackageInfo(createPackageInfo(installedPackage, true /* enabled */,
- true /* valid */, true /* installed */));
- mTestSystemImpl.setPackageInfo(createPackageInfo(uninstalledPackage, true /* enabled */,
- true /* valid */, (testUninstalled ? false : true) /* installed */,
- null /* signatures */, 0 /* updateTime */,
- (testHidden ? true : false) /* hidden */));
+ int secondaryUserId = 4;
+ mTestSystemImpl.addUser(secondaryUserId);
+
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, webviewPackages);
+ mTestSystemImpl.setPackageInfoForUser(secondaryUserId, createPackageInfo(installedPackage,
+ true /* enabled */, true /* valid */, true /* installed */));
+ mTestSystemImpl.setPackageInfoForUser(secondaryUserId, createPackageInfo(uninstalledPackage,
+ true /* enabled */, true /* valid */,
+ (testUninstalled ? false : true) /* installed */, null /* signatures */,
+ 0 /* updateTime */, (testHidden ? true : false) /* hidden */));
// Start with the setting pointing to the uninstalled package
mTestSystemImpl.updateUserSetting(null, uninstalledPackage);
@@ -1242,12 +1371,21 @@
checkPreparationPhasesForPackage(installedPackage, 1 /* first preparation phase */);
}
+ @Test
+ public void testFallbackEnabledIfPrimaryUninstalledSingleUser() {
+ checkFallbackEnabledIfPrimaryUninstalled(false /* multiUser */);
+ }
+
+ @Test
+ public void testFallbackEnabledIfPrimaryUninstalledMultiUser() {
+ checkFallbackEnabledIfPrimaryUninstalled(true /* multiUser */);
+ }
+
/**
- * Ensures that fallback becomes enabled if the primary package is uninstalled for the current
+ * Ensures that fallback becomes enabled at boot if the primary package is uninstalled for some
* user.
*/
- @Test
- public void testFallbackEnabledIfPrimaryUninstalled() {
+ private void checkFallbackEnabledIfPrimaryUninstalled(boolean multiUser) {
String primaryPackage = "primary";
String fallbackPackage = "fallback";
WebViewProviderInfo[] packages = new WebViewProviderInfo[] {
@@ -1256,10 +1394,24 @@
new WebViewProviderInfo(
fallbackPackage, "", true /* default available */, true /* fallback */, null)};
setupWithPackages(packages, true /* fallback logic enabled */);
- mTestSystemImpl.setPackageInfo(createPackageInfo(primaryPackage, true /* enabled */,
+ int secondaryUserId = 5;
+ if (multiUser) {
+ mTestSystemImpl.addUser(secondaryUserId);
+ // Install all packages for the primary user.
+ setEnabledAndValidPackageInfosForUser(TestSystemImpl.PRIMARY_USER_ID, packages);
+ // Only install fallback package for secondary user.
+ mTestSystemImpl.setPackageInfoForUser(secondaryUserId,
+ createPackageInfo(primaryPackage, true /* enabled */,
+ true /* valid */, false /* installed */));
+ mTestSystemImpl.setPackageInfoForUser(secondaryUserId,
+ createPackageInfo(fallbackPackage, false /* enabled */,
+ true /* valid */, true /* installed */));
+ } else {
+ mTestSystemImpl.setPackageInfo(createPackageInfo(primaryPackage, true /* enabled */,
true /* valid */, false /* installed */));
- mTestSystemImpl.setPackageInfo(createPackageInfo(fallbackPackage, true /* enabled */,
+ mTestSystemImpl.setPackageInfo(createPackageInfo(fallbackPackage, false /* enabled */,
true /* valid */, true /* installed */));
+ }
runWebViewBootPreparationOnMainSync();
// Verify that we enable the fallback package
diff --git a/telecomm/java/android/telecom/TelecomManager.java b/telecomm/java/android/telecom/TelecomManager.java
index 00e8f9f..ba7b6a1 100644
--- a/telecomm/java/android/telecom/TelecomManager.java
+++ b/telecomm/java/android/telecom/TelecomManager.java
@@ -58,12 +58,15 @@
* Input: get*Extra field {@link #EXTRA_PHONE_ACCOUNT_HANDLE} contains the component name of the
* {@link android.telecom.ConnectionService} that Telecom should bind to. Telecom will then
* ask the connection service for more information about the call prior to showing any UI.
+ *
+ * @deprecated Use {@link #addNewIncomingCall} instead.
*/
public static final String ACTION_INCOMING_CALL = "android.telecom.action.INCOMING_CALL";
/**
* Similar to {@link #ACTION_INCOMING_CALL}, but is used only by Telephony to add a new
* sim-initiated MO call for carrier testing.
+ * @deprecated Use {@link #addNewUnknownCall} instead.
* @hide
*/
public static final String ACTION_NEW_UNKNOWN_CALL = "android.telecom.action.NEW_UNKNOWN_CALL";
diff --git a/tools/layoutlib/bridge/src/android/graphics/FontFamily_Delegate.java b/tools/layoutlib/bridge/src/android/graphics/FontFamily_Delegate.java
index 50efc7f..d0c9599 100644
--- a/tools/layoutlib/bridge/src/android/graphics/FontFamily_Delegate.java
+++ b/tools/layoutlib/bridge/src/android/graphics/FontFamily_Delegate.java
@@ -16,6 +16,7 @@
package android.graphics;
+import android.text.FontConfig;
import com.android.ide.common.rendering.api.AssetRepository;
import com.android.ide.common.rendering.api.LayoutLog;
import com.android.layoutlib.bridge.Bridge;
@@ -284,7 +285,7 @@
@LayoutlibDelegate
/*package*/ static boolean nAddFontWeightStyle(long nativeFamily, ByteBuffer font,
- int ttcIndex, List<FontListParser.Axis> listOfAxis,
+ int ttcIndex, List<FontConfig.Axis> listOfAxis,
int weight, boolean isItalic) {
assert false : "The only client of this method has been overriden.";
return false;
diff --git a/tools/layoutlib/bridge/src/android/graphics/Typeface_Delegate.java b/tools/layoutlib/bridge/src/android/graphics/Typeface_Delegate.java
index 5cd34f6..6e337d5 100644
--- a/tools/layoutlib/bridge/src/android/graphics/Typeface_Delegate.java
+++ b/tools/layoutlib/bridge/src/android/graphics/Typeface_Delegate.java
@@ -16,6 +16,7 @@
package android.graphics;
+import android.text.FontConfig;
import com.android.layoutlib.bridge.impl.DelegateManager;
import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
@@ -208,12 +209,12 @@
}
@LayoutlibDelegate
- /*package*/ static FontFamily makeFamilyFromParsed(FontListParser.Family family,
+ /*package*/ static FontFamily makeFamilyFromParsed(FontConfig.Family family,
Map<String, ByteBuffer> bufferForPath) {
- FontFamily fontFamily = new FontFamily(family.lang, family.variant);
- for (FontListParser.Font font : family.fonts) {
- FontFamily_Delegate.addFont(fontFamily.mNativePtr, font.fontName, font.weight,
- font.isItalic);
+ FontFamily fontFamily = new FontFamily(family.getLanguage(), family.getVariant());
+ for (FontConfig.Font font : family.getFonts()) {
+ FontFamily_Delegate.addFont(fontFamily.mNativePtr, font.getFontName(),
+ font.getWeight(), font.isItalic());
}
return fontFamily;
}