New API demos showing use of tabs with fragments.
Also various cleanup in other demos.
Change-Id: I4f5669117e28312bcd4b28795c5eca5f4ab6dcfb
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabs.java b/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabs.java
new file mode 100644
index 0000000..44bce31
--- /dev/null
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabs.java
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2011 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.example.android.supportv4.app;
+
+import java.util.HashMap;
+
+import com.example.android.supportv4.R;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentActivity;
+import android.support.v4.app.FragmentTransaction;
+import android.view.View;
+import android.widget.TabHost;
+
+/**
+ * This demonstrates how you can implement switching between the tabs of a
+ * TabHost through fragments. It uses a trick (see the code below) to allow
+ * the tabs to switch between fragments instead of simple views.
+ */
+public class FragmentTabs extends FragmentActivity {
+ TabHost mTabHost;
+ TabManager mTabManager;
+
+ @Override
+ protected void onCreate(Bundle savedInstanceState) {
+ super.onCreate(savedInstanceState);
+
+ setContentView(R.layout.fragment_tabs);
+ mTabHost = (TabHost)findViewById(android.R.id.tabhost);
+ mTabHost.setup();
+
+ mTabManager = new TabManager(this, mTabHost, R.id.realtabcontent);
+
+ mTabManager.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),
+ FragmentStackSupport.CountingFragment.class, null);
+ mTabManager.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),
+ LoaderCursorSupport.CursorLoaderListFragment.class, null);
+ mTabManager.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),
+ LoaderCustomSupport.AppListFragment.class, null);
+ mTabManager.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),
+ LoaderThrottleSupport.ThrottledLoaderListFragment.class, null);
+
+ if (savedInstanceState != null) {
+ mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab"));
+ }
+ }
+
+ @Override
+ protected void onSaveInstanceState(Bundle outState) {
+ super.onSaveInstanceState(outState);
+ outState.putString("tab", mTabHost.getCurrentTabTag());
+ }
+
+ /**
+ * This is a helper class that implements a generic mechanism for
+ * associating fragments with the tabs in a tab host. It relies on a
+ * trick. Normally a tab host has a simple API for supplying a View or
+ * Intent that each tab will show. This is not sufficient for switching
+ * between fragments. So instead we make the content part of the tab host
+ * 0dp high (it is not shown) and the TabManager supplies its own dummy
+ * view to show as the tab content. It listens to changes in tabs, and takes
+ * care of switch to the correct fragment shown in a separate content area
+ * whenever the selected tab changes.
+ */
+ public static class TabManager implements TabHost.OnTabChangeListener {
+ private final FragmentActivity mActivity;
+ private final TabHost mTabHost;
+ private final int mContainerId;
+ private final HashMap<String, TabInfo> mTabs = new HashMap<String, TabInfo>();
+ TabInfo mLastTab;
+
+ static final class TabInfo {
+ private final String tag;
+ private final Class<?> clss;
+ private final Bundle args;
+ private Fragment fragment;
+
+ TabInfo(String _tag, Class<?> _class, Bundle _args) {
+ tag = _tag;
+ clss = _class;
+ args = _args;
+ }
+ }
+
+ static class DummyTabFactory implements TabHost.TabContentFactory {
+ private final Context mContext;
+
+ public DummyTabFactory(Context context) {
+ mContext = context;
+ }
+
+ @Override
+ public View createTabContent(String tag) {
+ View v = new View(mContext);
+ v.setMinimumWidth(0);
+ v.setMinimumHeight(0);
+ return v;
+ }
+ }
+
+ public TabManager(FragmentActivity activity, TabHost tabHost, int containerId) {
+ mActivity = activity;
+ mTabHost = tabHost;
+ mContainerId = containerId;
+ mTabHost.setOnTabChangedListener(this);
+ }
+
+ public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) {
+ tabSpec.setContent(new DummyTabFactory(mActivity));
+ String tag = tabSpec.getTag();
+
+ TabInfo info = new TabInfo(tag, clss, args);
+
+ // Check to see if we already have a fragment for this tab, probably
+ // from a previously saved state. If so, deactivate it, because our
+ // initial state is that a tab isn't shown.
+ info.fragment = mActivity.getSupportFragmentManager().findFragmentByTag(tag);
+ if (info.fragment != null && !info.fragment.isDetached()) {
+ FragmentTransaction ft = mActivity.getSupportFragmentManager().beginTransaction();
+ ft.detach(info.fragment);
+ ft.commit();
+ }
+
+ mTabs.put(tag, info);
+ mTabHost.addTab(tabSpec);
+ }
+
+ @Override
+ public void onTabChanged(String tabId) {
+ TabInfo newTab = mTabs.get(tabId);
+ if (mLastTab != newTab) {
+ FragmentTransaction ft = mActivity.getSupportFragmentManager().beginTransaction();
+ if (mLastTab != null) {
+ if (mLastTab.fragment != null) {
+ ft.detach(mLastTab.fragment);
+ }
+ }
+ if (newTab != null) {
+ if (newTab.fragment == null) {
+ newTab.fragment = Fragment.instantiate(mActivity,
+ newTab.clss.getName(), newTab.args);
+ ft.add(mContainerId, newTab.fragment, newTab.tag);
+ } else {
+ ft.attach(newTab.fragment);
+ }
+ }
+
+ mLastTab = newTab;
+ ft.commit();
+ mActivity.getSupportFragmentManager().executePendingTransactions();
+ }
+ }
+ }
+}
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabsPager.java b/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabsPager.java
new file mode 100644
index 0000000..6db9d3c
--- /dev/null
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentTabsPager.java
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2011 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.example.android.supportv4.app;
+
+import java.util.ArrayList;
+
+import com.example.android.supportv4.R;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentActivity;
+import android.support.v4.app.FragmentPagerAdapter;
+import android.support.v4.view.ViewPager;
+import android.view.View;
+import android.widget.TabHost;
+
+/**
+ * Demonstrates combining a TabHost with a ViewPager to implement a tab UI
+ * that switches between tabs and also allows the user to perform horizontal
+ * flicks to move between the tabs.
+ */
+public class FragmentTabsPager extends FragmentActivity {
+ TabHost mTabHost;
+ ViewPager mViewPager;
+ TabsAdapter mTabsAdapter;
+
+ @Override
+ protected void onCreate(Bundle savedInstanceState) {
+ super.onCreate(savedInstanceState);
+
+ setContentView(R.layout.fragment_tabs_pager);
+ mTabHost = (TabHost)findViewById(android.R.id.tabhost);
+ mTabHost.setup();
+
+ mViewPager = (ViewPager)findViewById(R.id.pager);
+
+ mTabsAdapter = new TabsAdapter(this, mTabHost, mViewPager);
+
+ mTabsAdapter.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),
+ FragmentStackSupport.CountingFragment.class, null);
+ mTabsAdapter.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),
+ LoaderCursorSupport.CursorLoaderListFragment.class, null);
+ mTabsAdapter.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),
+ LoaderCustomSupport.AppListFragment.class, null);
+ mTabsAdapter.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),
+ LoaderThrottleSupport.ThrottledLoaderListFragment.class, null);
+
+ if (savedInstanceState != null) {
+ mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab"));
+ }
+ }
+
+ @Override
+ protected void onSaveInstanceState(Bundle outState) {
+ super.onSaveInstanceState(outState);
+ outState.putString("tab", mTabHost.getCurrentTabTag());
+ }
+
+ /**
+ * This is a helper class that implements the management of tabs and all
+ * details of connecting a ViewPager with associated TabHost. It relies on a
+ * trick. Normally a tab host has a simple API for supplying a View or
+ * Intent that each tab will show. This is not sufficient for switching
+ * between pages. So instead we make the content part of the tab host
+ * 0dp high (it is not shown) and the TabsAdapter supplies its own dummy
+ * view to show as the tab content. It listens to changes in tabs, and takes
+ * care of switch to the correct paged in the ViewPager whenever the selected
+ * tab changes.
+ */
+ public static class TabsAdapter extends FragmentPagerAdapter
+ implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
+ private final Context mContext;
+ private final TabHost mTabHost;
+ private final ViewPager mViewPager;
+ private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
+
+ static final class TabInfo {
+ private final String tag;
+ private final Class<?> clss;
+ private final Bundle args;
+
+ TabInfo(String _tag, Class<?> _class, Bundle _args) {
+ tag = _tag;
+ clss = _class;
+ args = _args;
+ }
+ }
+
+ static class DummyTabFactory implements TabHost.TabContentFactory {
+ private final Context mContext;
+
+ public DummyTabFactory(Context context) {
+ mContext = context;
+ }
+
+ @Override
+ public View createTabContent(String tag) {
+ View v = new View(mContext);
+ v.setMinimumWidth(0);
+ v.setMinimumHeight(0);
+ return v;
+ }
+ }
+
+ public TabsAdapter(FragmentActivity activity, TabHost tabHost, ViewPager pager) {
+ super(activity.getSupportFragmentManager());
+ mContext = activity;
+ mTabHost = tabHost;
+ mViewPager = pager;
+ mTabHost.setOnTabChangedListener(this);
+ mViewPager.setAdapter(this);
+ mViewPager.setOnPageChangeListener(this);
+ }
+
+ public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) {
+ tabSpec.setContent(new DummyTabFactory(mContext));
+ String tag = tabSpec.getTag();
+
+ TabInfo info = new TabInfo(tag, clss, args);
+ mTabs.add(info);
+ mTabHost.addTab(tabSpec);
+ notifyDataSetChanged();
+ }
+
+ @Override
+ public int getCount() {
+ return mTabs.size();
+ }
+
+ @Override
+ public Fragment getItem(int position) {
+ TabInfo info = mTabs.get(position);
+ return Fragment.instantiate(mContext, info.clss.getName(), info.args);
+ }
+
+ @Override
+ public void onTabChanged(String tabId) {
+ int position = mTabHost.getCurrentTab();
+ mViewPager.setCurrentItem(position);
+ }
+
+ @Override
+ public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+ }
+
+ @Override
+ public void onPageSelected(int position) {
+ mTabHost.setCurrentTab(position);
+ }
+ }
+}
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java
index 07b9309..096316c 100644
--- a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java
@@ -81,6 +81,9 @@
new int[] { android.R.id.text1, android.R.id.text2 }, 0);
setListAdapter(mAdapter);
+ // Start out with a progress indicator.
+ setListShown(false);
+
// Prepare the loader. Either re-connect with an existing one,
// or start a new one.
getLoaderManager().initLoader(0, null, this);
@@ -147,6 +150,13 @@
// Swap the new cursor in. (The framework will take care of closing the
// old cursor once we return.)
mAdapter.swapCursor(data);
+
+ // The list should now be shown.
+ if (isResumed()) {
+ setListShown(true);
+ } else {
+ setListShownNoAnimation(true);
+ }
}
public void onLoaderReset(Loader<Cursor> loader) {
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCustomSupport.java b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCustomSupport.java
new file mode 100644
index 0000000..b222a20
--- /dev/null
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCustomSupport.java
@@ -0,0 +1,482 @@
+/*
+ * Copyright (C) 2010 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.example.android.supportv4.app;
+
+import com.example.android.supportv4.R;
+
+import java.io.File;
+import java.text.Collator;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+import android.content.BroadcastReceiver;
+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.res.Configuration;
+import android.content.res.Resources;
+import android.graphics.drawable.Drawable;
+import android.os.Bundle;
+import android.support.v4.app.FragmentActivity;
+import android.support.v4.app.FragmentManager;
+import android.support.v4.app.ListFragment;
+import android.support.v4.app.LoaderManager;
+import android.support.v4.content.AsyncTaskLoader;
+import android.support.v4.content.Loader;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ArrayAdapter;
+import android.widget.ImageView;
+import android.widget.ListView;
+import android.widget.SearchView;
+import android.widget.TextView;
+import android.widget.SearchView.OnQueryTextListener;
+
+/**
+ * Demonstration of the implementation of a custom Loader.
+ */
+public class LoaderCustomSupport extends FragmentActivity {
+
+ @Override
+ protected void onCreate(Bundle savedInstanceState) {
+ super.onCreate(savedInstanceState);
+
+ FragmentManager fm = getSupportFragmentManager();
+
+ // Create the list fragment and add it as our sole content.
+ if (fm.findFragmentById(android.R.id.content) == null) {
+ AppListFragment list = new AppListFragment();
+ fm.beginTransaction().add(android.R.id.content, list).commit();
+ }
+ }
+
+//BEGIN_INCLUDE(loader)
+ /**
+ * This class holds the per-item data in our Loader.
+ */
+ public static class AppEntry {
+ public AppEntry(AppListLoader loader, ApplicationInfo info) {
+ mLoader = loader;
+ mInfo = info;
+ mApkFile = new File(info.sourceDir);
+ }
+
+ public ApplicationInfo getApplicationInfo() {
+ return mInfo;
+ }
+
+ public String getLabel() {
+ return mLabel;
+ }
+
+ public Drawable getIcon() {
+ if (mIcon == null) {
+ if (mApkFile.exists()) {
+ mIcon = mInfo.loadIcon(mLoader.mPm);
+ return mIcon;
+ } else {
+ mMounted = false;
+ }
+ } else if (!mMounted) {
+ // If the app wasn't mounted but is now mounted, reload
+ // its icon.
+ if (mApkFile.exists()) {
+ mMounted = true;
+ mIcon = mInfo.loadIcon(mLoader.mPm);
+ return mIcon;
+ }
+ } else {
+ return mIcon;
+ }
+
+ return mLoader.getContext().getResources().getDrawable(
+ android.R.drawable.sym_def_app_icon);
+ }
+
+ @Override public String toString() {
+ return mLabel;
+ }
+
+ void loadLabel(Context context) {
+ if (mLabel == null || !mMounted) {
+ if (!mApkFile.exists()) {
+ mMounted = false;
+ mLabel = mInfo.packageName;
+ } else {
+ mMounted = true;
+ CharSequence label = mInfo.loadLabel(context.getPackageManager());
+ mLabel = label != null ? label.toString() : mInfo.packageName;
+ }
+ }
+ }
+
+ private final AppListLoader mLoader;
+ private final ApplicationInfo mInfo;
+ private final File mApkFile;
+ private String mLabel;
+ private Drawable mIcon;
+ private boolean mMounted;
+ }
+
+ /**
+ * Perform alphabetical comparison of application entry objects.
+ */
+ public static final Comparator<AppEntry> ALPHA_COMPARATOR = new Comparator<AppEntry>() {
+ private final Collator sCollator = Collator.getInstance();
+ @Override
+ public int compare(AppEntry object1, AppEntry object2) {
+ return sCollator.compare(object1.getLabel(), object2.getLabel());
+ }
+ };
+
+ /**
+ * Helper for determining if the configuration has changed in an interesting
+ * way so we need to rebuild the app list.
+ */
+ public static class InterestingConfigChanges {
+ final Configuration mLastConfiguration = new Configuration();
+ int mLastDensity;
+
+ boolean applyNewConfig(Resources res) {
+ int configChanges = mLastConfiguration.updateFrom(res.getConfiguration());
+ boolean densityChanged = mLastDensity != res.getDisplayMetrics().densityDpi;
+ if (densityChanged || (configChanges&(ActivityInfo.CONFIG_LOCALE
+ |ActivityInfo.CONFIG_UI_MODE|ActivityInfo.CONFIG_SCREEN_LAYOUT)) != 0) {
+ mLastDensity = res.getDisplayMetrics().densityDpi;
+ return true;
+ }
+ return false;
+ }
+ }
+
+ /**
+ * Helper class to look for interesting changes to the installed apps
+ * so that the loader can be updated.
+ */
+ public static class PackageIntentReceiver extends BroadcastReceiver {
+ final AppListLoader mLoader;
+
+ public PackageIntentReceiver(AppListLoader loader) {
+ mLoader = loader;
+ IntentFilter filter = new IntentFilter(Intent.ACTION_PACKAGE_ADDED);
+ filter.addAction(Intent.ACTION_PACKAGE_REMOVED);
+ filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
+ filter.addDataScheme("package");
+ mLoader.getContext().registerReceiver(this, filter);
+ // Register for events related to sdcard installation.
+ IntentFilter sdFilter = new IntentFilter();
+ sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE);
+ sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE);
+ mLoader.getContext().registerReceiver(this, sdFilter);
+ }
+
+ @Override public void onReceive(Context context, Intent intent) {
+ // Tell the loader about the change.
+ mLoader.onContentChanged();
+ }
+ }
+
+ /**
+ * A custom Loader that loads all of the installed applications.
+ */
+ public static class AppListLoader extends AsyncTaskLoader<List<AppEntry>> {
+ final InterestingConfigChanges mLastConfig = new InterestingConfigChanges();
+ final PackageManager mPm;
+
+ List<AppEntry> mApps;
+ PackageIntentReceiver mPackageObserver;
+
+ public AppListLoader(Context context) {
+ super(context);
+
+ // Retrieve the package manager for later use; note we don't
+ // use 'context' directly but instead the save global application
+ // context returned by getContext().
+ mPm = getContext().getPackageManager();
+ }
+
+ /**
+ * This is where the bulk of our work is done. This function is
+ * called in a background thread and should generate a new set of
+ * data to be published by the loader.
+ */
+ @Override public List<AppEntry> loadInBackground() {
+ // Retrieve all known applications.
+ List<ApplicationInfo> apps = mPm.getInstalledApplications(
+ PackageManager.GET_UNINSTALLED_PACKAGES |
+ PackageManager.GET_DISABLED_COMPONENTS);
+ if (apps == null) {
+ apps = new ArrayList<ApplicationInfo>();
+ }
+
+ final Context context = getContext();
+
+ // Create corresponding array of entries and load their labels.
+ List<AppEntry> entries = new ArrayList<AppEntry>(apps.size());
+ for (int i=0; i<apps.size(); i++) {
+ AppEntry entry = new AppEntry(this, apps.get(i));
+ entry.loadLabel(context);
+ entries.add(entry);
+ }
+
+ // Sort the list.
+ Collections.sort(entries, ALPHA_COMPARATOR);
+
+ // Done!
+ return entries;
+ }
+
+ /**
+ * Called when there is new data to deliver to the client. The
+ * super class will take care of delivering it; the implementation
+ * here just adds a little more logic.
+ */
+ @Override public void deliverResult(List<AppEntry> apps) {
+ if (isReset()) {
+ // An async query came in while the loader is stopped. We
+ // don't need the result.
+ if (apps != null) {
+ onReleaseResources(apps);
+ }
+ }
+ List<AppEntry> oldApps = apps;
+ mApps = apps;
+
+ if (isStarted()) {
+ // If the Loader is currently started, we can immediately
+ // deliver its results.
+ super.deliverResult(apps);
+ }
+
+ // At this point we can release the resources associated with
+ // 'oldApps' if needed; now that the new result is delivered we
+ // know that it is no longer in use.
+ if (oldApps != null) {
+ onReleaseResources(oldApps);
+ }
+ }
+
+ /**
+ * Handles a request to start the Loader.
+ */
+ @Override protected void onStartLoading() {
+ if (mApps != null) {
+ // If we currently have a result available, deliver it
+ // immediately.
+ deliverResult(mApps);
+ }
+
+ // Start watching for changes in the app data.
+ if (mPackageObserver == null) {
+ mPackageObserver = new PackageIntentReceiver(this);
+ }
+
+ // Has something interesting in the configuration changed since we
+ // last built the app list?
+ boolean configChange = mLastConfig.applyNewConfig(getContext().getResources());
+
+ if (takeContentChanged() || mApps == null || configChange) {
+ // If the data has changed since the last time it was loaded
+ // or is not currently available, start a load.
+ forceLoad();
+ }
+ }
+
+ /**
+ * Handles a request to stop the Loader.
+ */
+ @Override protected void onStopLoading() {
+ // Attempt to cancel the current load task if possible.
+ cancelLoad();
+ }
+
+ /**
+ * Handles a request to cancel a load.
+ */
+ @Override public void onCanceled(List<AppEntry> apps) {
+ super.onCanceled(apps);
+
+ // At this point we can release the resources associated with 'apps'
+ // if needed.
+ onReleaseResources(apps);
+ }
+
+ /**
+ * Handles a request to completely reset the Loader.
+ */
+ @Override protected void onReset() {
+ super.onReset();
+
+ // Ensure the loader is stopped
+ onStopLoading();
+
+ // At this point we can release the resources associated with 'apps'
+ // if needed.
+ if (mApps != null) {
+ onReleaseResources(mApps);
+ mApps = null;
+ }
+
+ // Stop monitoring for changes.
+ if (mPackageObserver != null) {
+ getContext().unregisterReceiver(mPackageObserver);
+ mPackageObserver = null;
+ }
+ }
+
+ /**
+ * Helper function to take care of releasing resources associated
+ * with an actively loaded data set.
+ */
+ protected void onReleaseResources(List<AppEntry> apps) {
+ // For a simple List<> there is nothing to do. For something
+ // like a Cursor, we would close it here.
+ }
+ }
+//END_INCLUDE(loader)
+
+//BEGIN_INCLUDE(fragment)
+ public static class AppListAdapter extends ArrayAdapter<AppEntry> {
+ private final LayoutInflater mInflater;
+
+ public AppListAdapter(Context context) {
+ super(context, android.R.layout.simple_list_item_2);
+ mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+ }
+
+ public void setData(List<AppEntry> data) {
+ clear();
+ if (data != null) {
+ addAll(data);
+ }
+ }
+
+ /**
+ * Populate new items in the list.
+ */
+ @Override public View getView(int position, View convertView, ViewGroup parent) {
+ View view;
+
+ if (convertView == null) {
+ view = mInflater.inflate(R.layout.list_item_icon_text, parent, false);
+ } else {
+ view = convertView;
+ }
+
+ AppEntry item = getItem(position);
+ ((ImageView)view.findViewById(R.id.icon)).setImageDrawable(item.getIcon());
+ ((TextView)view.findViewById(R.id.text)).setText(item.getLabel());
+
+ return view;
+ }
+ }
+
+ public static class AppListFragment extends ListFragment
+ implements OnQueryTextListener, LoaderManager.LoaderCallbacks<List<AppEntry>> {
+
+ // This is the Adapter being used to display the list's data.
+ AppListAdapter mAdapter;
+
+ // If non-null, this is the current filter the user has provided.
+ String mCurFilter;
+
+ @Override public void onActivityCreated(Bundle savedInstanceState) {
+ super.onActivityCreated(savedInstanceState);
+
+ // Give some text to display if there is no data. In a real
+ // application this would come from a resource.
+ setEmptyText("No applications");
+
+ // We have a menu item to show in action bar.
+ setHasOptionsMenu(true);
+
+ // Create an empty adapter we will use to display the loaded data.
+ mAdapter = new AppListAdapter(getActivity());
+ setListAdapter(mAdapter);
+
+ // Start out with a progress indicator.
+ setListShown(false);
+
+ // Prepare the loader. Either re-connect with an existing one,
+ // or start a new one.
+ getLoaderManager().initLoader(0, null, this);
+ }
+
+ @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+ // Place an action bar item for searching.
+ MenuItem item = menu.add("Search");
+ item.setIcon(android.R.drawable.ic_menu_search);
+ item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
+ SearchView sv = new SearchView(getActivity());
+ sv.setOnQueryTextListener(this);
+ item.setActionView(sv);
+ }
+
+ @Override public boolean onQueryTextChange(String newText) {
+ // Called when the action bar search text has changed. Since this
+ // is a simple array adapter, we can just have it do the filtering.
+ mCurFilter = !TextUtils.isEmpty(newText) ? newText : null;
+ mAdapter.getFilter().filter(mCurFilter);
+ return true;
+ }
+
+ @Override public boolean onQueryTextSubmit(String query) {
+ // Don't care about this.
+ return true;
+ }
+
+ @Override public void onListItemClick(ListView l, View v, int position, long id) {
+ // Insert desired behavior here.
+ Log.i("LoaderCustom", "Item clicked: " + id);
+ }
+
+ @Override public Loader<List<AppEntry>> onCreateLoader(int id, Bundle args) {
+ // This is called when a new Loader needs to be created. This
+ // sample only has one Loader with no arguments, so it is simple.
+ return new AppListLoader(getActivity());
+ }
+
+ @Override public void onLoadFinished(Loader<List<AppEntry>> loader, List<AppEntry> data) {
+ // Set the new data in the adapter.
+ mAdapter.setData(data);
+
+ // The list should now be shown.
+ if (isResumed()) {
+ setListShown(true);
+ } else {
+ setListShownNoAnimation(true);
+ }
+ }
+
+ @Override public void onLoaderReset(Loader<List<AppEntry>> loader) {
+ // Clear the data in the adapter.
+ mAdapter.setData(null);
+ }
+ }
+//END_INCLUDE(fragment)
+}
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderThrottleSupport.java b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderThrottleSupport.java
index d16797b..de3f937 100644
--- a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderThrottleSupport.java
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderThrottleSupport.java
@@ -410,6 +410,9 @@
new int[] { android.R.id.text1 }, 0);
setListAdapter(mAdapter);
+ // Start out with a progress indicator.
+ setListShown(false);
+
// Prepare the loader. Either re-connect with an existing one,
// or start a new one.
getLoaderManager().initLoader(0, null, this);
@@ -493,6 +496,13 @@
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
mAdapter.swapCursor(data);
+
+ // The list should now be shown.
+ if (isResumed()) {
+ setListShown(true);
+ } else {
+ setListShownNoAnimation(true);
+ }
}
public void onLoaderReset(Loader<Cursor> loader) {
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/_index.html b/samples/Support4Demos/src/com/example/android/supportv4/app/_index.html
index 286d4a0..fa9af5a 100644
--- a/samples/Support4Demos/src/com/example/android/supportv4/app/_index.html
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/_index.html
@@ -67,6 +67,15 @@
<dd>Demonstrates creating a stack of Fragment instances similar to the
traditional stack of activities.</dd>
+ <dt><a href="FragmentTabs.html">Fragment Tabs</a></dt>
+ <dd>Demonstrates the use of fragments to implement switching between
+ tabs in a TabHost.</dd>
+
+ <dt><a href="FragmentTabsPager.html">Fragment Tabs Pager</a></dt>
+ <dd>Demonstrates the use of fragments to implement switching between
+ tabs in a TabHost, using a ViewPager to manager the fragments so that
+ the user can also fling left and right to switch tabs.</dd>
+
</dl>
<h3 id="LoaderManager">LoaderManager</h3>
@@ -74,6 +83,10 @@
<dt><a href="LoaderCursorSupport.html">Loader Cursor</a></dt>
<dd>Demonstrates use of LoaderManager to perform a query for a Cursor that
populates a ListFragment.</dd>
+
+ <dt><a href="LoaderCustomSupport.html">Loader Custom</a></dt>
+ <dd>Demonstrates implementation and use of a custom Loader class. The
+ custom class here "loads" the currently installed applications.</dd>
<dt><a href="LoaderThrottleSupport.html">Loader Throttle</a></dt>
<dd>Complete end-to-end demonstration of a simple content provider that