Refactoring PinItemDragListener into a base class to allow diffenret implementations
of multi-window drag and drop
Bug: 62702235
Change-Id: Ie87e0f7d131575bac1cb1099b0a70b230560be9a
diff --git a/src/com/android/launcher3/dragndrop/BaseItemDragListener.java b/src/com/android/launcher3/dragndrop/BaseItemDragListener.java
new file mode 100644
index 0000000..d0f2629
--- /dev/null
+++ b/src/com/android/launcher3/dragndrop/BaseItemDragListener.java
@@ -0,0 +1,214 @@
+/*
+ * 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.launcher3.dragndrop;
+
+import android.content.ClipDescription;
+import android.content.Intent;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Parcel;
+import android.os.SystemClock;
+import android.util.Log;
+import android.view.DragEvent;
+import android.view.View;
+
+import com.android.launcher3.DeleteDropTarget;
+import com.android.launcher3.DragSource;
+import com.android.launcher3.DropTarget;
+import com.android.launcher3.Launcher;
+import com.android.launcher3.R;
+import com.android.launcher3.folder.Folder;
+import com.android.launcher3.widget.PendingItemDragHelper;
+
+import java.util.UUID;
+
+/**
+ * {@link DragSource} for handling drop from a different window.
+ */
+public abstract class BaseItemDragListener implements
+ View.OnDragListener, DragSource, DragOptions.PreDragCondition {
+
+ private static final String TAG = "BaseItemDragListener";
+
+ private static final String MIME_TYPE_PREFIX = "com.android.launcher3.drag_and_drop/";
+ public static final String EXTRA_PIN_ITEM_DRAG_LISTENER = "pin_item_drag_listener";
+
+ // Position of preview relative to the touch location
+ private final Rect mPreviewRect;
+
+ private final int mPreviewBitmapWidth;
+ private final int mPreviewViewWidth;
+
+ // Randomly generated id used to verify the drag event.
+ private final String mId;
+
+ protected Launcher mLauncher;
+ private DragController mDragController;
+ private long mDragStartTime;
+
+ public BaseItemDragListener(Rect previewRect, int previewBitmapWidth, int previewViewWidth) {
+ mPreviewRect = previewRect;
+ mPreviewBitmapWidth = previewBitmapWidth;
+ mPreviewViewWidth = previewViewWidth;
+ mId = UUID.randomUUID().toString();
+ }
+
+ protected BaseItemDragListener(Parcel parcel) {
+ mPreviewRect = Rect.CREATOR.createFromParcel(parcel);
+ mPreviewBitmapWidth = parcel.readInt();
+ mPreviewViewWidth = parcel.readInt();
+ mId = parcel.readString();
+ }
+
+ protected void writeToParcel(Parcel parcel, int i) {
+ mPreviewRect.writeToParcel(parcel, i);
+ parcel.writeInt(mPreviewBitmapWidth);
+ parcel.writeInt(mPreviewViewWidth);
+ parcel.writeString(mId);
+ }
+
+ public String getMimeType() {
+ return MIME_TYPE_PREFIX + mId;
+ }
+
+ public void setLauncher(Launcher launcher) {
+ mLauncher = launcher;
+ mDragController = launcher.getDragController();
+ }
+
+ @Override
+ public boolean onDrag(View view, DragEvent event) {
+ if (mLauncher == null || mDragController == null) {
+ postCleanup();
+ return false;
+ }
+ if (event.getAction() == DragEvent.ACTION_DRAG_STARTED) {
+ if (onDragStart(event)) {
+ return true;
+ } else {
+ postCleanup();
+ return false;
+ }
+ }
+ return mDragController.onDragEvent(mDragStartTime, event);
+ }
+
+ protected boolean onDragStart(DragEvent event) {
+ ClipDescription desc = event.getClipDescription();
+ if (desc == null || !desc.hasMimeType(getMimeType())) {
+ Log.e(TAG, "Someone started a dragAndDrop before us.");
+ return false;
+ }
+
+ Point downPos = new Point((int) event.getX(), (int) event.getY());
+ DragOptions options = new DragOptions();
+ options.systemDndStartPoint = downPos;
+ options.preDragCondition = this;
+
+ // We use drag event position as the screenPos for the preview image. Since mPreviewRect
+ // already includes the view position relative to the drag event on the source window,
+ // and the absolute position (position relative to the screen) of drag event is same
+ // across windows, using drag position here give a good estimate for relative position
+ // to source window.
+ createDragHelper().startDrag(new Rect(mPreviewRect),
+ mPreviewBitmapWidth, mPreviewViewWidth, downPos, this, options);
+ mDragStartTime = SystemClock.uptimeMillis();
+ return true;
+ }
+
+ protected abstract PendingItemDragHelper createDragHelper();
+
+ @Override
+ public boolean shouldStartDrag(double distanceDragged) {
+ // Stay in pre-drag mode, if workspace is locked.
+ return !mLauncher.isWorkspaceLocked();
+ }
+
+ @Override
+ public void onPreDragStart(DropTarget.DragObject dragObject) {
+ // The predrag starts when the workspace is not yet loaded. In some cases we set
+ // the dragLayer alpha to 0 to have a nice fade-in animation. But that will prevent the
+ // dragView from being visible. Instead just skip the fade-in animation here.
+ mLauncher.getDragLayer().setAlpha(1);
+
+ dragObject.dragView.setColor(
+ mLauncher.getResources().getColor(R.color.delete_target_hover_tint));
+ }
+
+ @Override
+ public void onPreDragEnd(DropTarget.DragObject dragObject, boolean dragStarted) {
+ if (dragStarted) {
+ dragObject.dragView.setColor(0);
+ }
+ }
+
+ @Override
+ public boolean supportsAppInfoDropTarget() {
+ return false;
+ }
+
+ @Override
+ public boolean supportsDeleteDropTarget() {
+ return false;
+ }
+
+ @Override
+ public float getIntrinsicIconScaleFactor() {
+ return 1f;
+ }
+
+ @Override
+ public void onDropCompleted(View target, DropTarget.DragObject d, boolean isFlingToDelete,
+ boolean success) {
+ if (isFlingToDelete || !success || (target != mLauncher.getWorkspace() &&
+ !(target instanceof DeleteDropTarget) && !(target instanceof Folder))) {
+ // Exit spring loaded mode if we have not successfully dropped or have not handled the
+ // drop in Workspace
+ mLauncher.exitSpringLoadedDragModeDelayed(true,
+ Launcher.EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT, null);
+ }
+
+ if (!success) {
+ d.deferDragViewCleanupPostAnimation = false;
+ }
+ postCleanup();
+ }
+
+ private void postCleanup() {
+ if (mLauncher != null) {
+ // Remove any drag params from the launcher intent since the drag operation is complete.
+ Intent newIntent = new Intent(mLauncher.getIntent());
+ newIntent.removeExtra(EXTRA_PIN_ITEM_DRAG_LISTENER);
+ mLauncher.setIntent(newIntent);
+ }
+
+ new Handler(Looper.getMainLooper()).post(new Runnable() {
+ @Override
+ public void run() {
+ removeListener();
+ }
+ });
+ }
+
+ public void removeListener() {
+ if (mLauncher != null) {
+ mLauncher.getDragLayer().setOnDragListener(null);
+ }
+ }
+}