| /* |
| * Copyright (C) 2012 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.app; |
| |
| import android.content.ComponentName; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.content.pm.ActivityInfo; |
| import android.content.pm.PackageManager; |
| import android.content.pm.PackageManager.NameNotFoundException; |
| import android.util.Log; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| |
| /** |
| * Utility class for constructing synthetic back stacks for cross-task navigation |
| * on Android 3.0 and newer. |
| * |
| * <p>In API level 11 (Android 3.0/Honeycomb) the recommended conventions for |
| * app navigation using the back key changed. The back key's behavior is local |
| * to the current task and does not capture navigation across different tasks. |
| * Navigating across tasks and easily reaching the previous task is accomplished |
| * through the "recents" UI, accessible through the software-provided Recents key |
| * on the navigation or system bar. On devices with the older hardware button configuration |
| * the recents UI can be accessed with a long press on the Home key.</p> |
| * |
| * <p>When crossing from one task stack to another post-Android 3.0, |
| * the application should synthesize a back stack/history for the new task so that |
| * the user may navigate out of the new task and back to the Launcher by repeated |
| * presses of the back key. Back key presses should not navigate across task stacks.</p> |
| * |
| * <p>TaskStackBuilder provides a way to obey the correct conventions |
| * around cross-task navigation.</p> |
| * |
| * <div class="special reference"> |
| * <h3>About Navigation</h3> |
| * For more detailed information about tasks, the back stack, and navigation design guidelines, |
| * please read |
| * <a href="{@docRoot}guide/topics/fundamentals/tasks-and-back-stack.html">Tasks and Back Stack</a> |
| * from the developer guide and <a href="{@docRoot}design/patterns/navigation.html">Navigation</a> |
| * from the design guide. |
| * </div> |
| */ |
| public class TaskStackBuilder implements Iterable<Intent> { |
| private static final String TAG = "TaskStackBuilder"; |
| |
| private final ArrayList<Intent> mIntents = new ArrayList<Intent>(); |
| private final Context mSourceContext; |
| |
| private TaskStackBuilder(Context a) { |
| mSourceContext = a; |
| } |
| |
| /** |
| * Return a new TaskStackBuilder for launching a fresh task stack consisting |
| * of a series of activities. |
| * |
| * @param context The context that will launch the new task stack or generate a PendingIntent |
| * @return A new TaskStackBuilder |
| */ |
| public static TaskStackBuilder from(Context context) { |
| return new TaskStackBuilder(context); |
| } |
| |
| /** |
| * Add a new Intent to the task stack. The most recently added Intent will invoke |
| * the Activity at the top of the final task stack. |
| * |
| * @param nextIntent Intent for the next Activity in the synthesized task stack |
| * @return This TaskStackBuilder for method chaining |
| */ |
| public TaskStackBuilder addNextIntent(Intent nextIntent) { |
| mIntents.add(nextIntent); |
| return this; |
| } |
| |
| /** |
| * Add the activity parent chain as specified by the |
| * {@link android.R.attr#parentActivityName parentActivityName} attribute of the activity |
| * (or activity-alias) element in the application's manifest to the task stack builder. |
| * |
| * @param sourceActivity All parents of this activity will be added |
| * @return This TaskStackBuilder for method chaining |
| */ |
| public TaskStackBuilder addParentStack(Activity sourceActivity) { |
| final int insertAt = mIntents.size(); |
| Intent parent = sourceActivity.getParentActivityIntent(); |
| PackageManager pm = sourceActivity.getPackageManager(); |
| while (parent != null) { |
| mIntents.add(insertAt, parent); |
| try { |
| ActivityInfo info = pm.getActivityInfo(parent.getComponent(), 0); |
| String parentActivity = info.parentActivityName; |
| if (parentActivity != null) { |
| parent = new Intent().setComponent( |
| new ComponentName(mSourceContext, parentActivity)); |
| } else { |
| parent = null; |
| } |
| } catch (NameNotFoundException e) { |
| Log.e(TAG, "Bad ComponentName while traversing activity parent metadata"); |
| throw new IllegalArgumentException(e); |
| } |
| } |
| return this; |
| } |
| |
| /** |
| * Add the activity parent chain as specified by the |
| * {@link android.R.attr#parentActivityName parentActivityName} attribute of the activity |
| * (or activity-alias) element in the application's manifest to the task stack builder. |
| * |
| * @param sourceActivityClass All parents of this activity will be added |
| * @return This TaskStackBuilder for method chaining |
| */ |
| public TaskStackBuilder addParentStack(Class<?> sourceActivityClass) { |
| final int insertAt = mIntents.size(); |
| PackageManager pm = mSourceContext.getPackageManager(); |
| try { |
| ActivityInfo info = pm.getActivityInfo( |
| new ComponentName(mSourceContext, sourceActivityClass), 0); |
| String parentActivity = info.parentActivityName; |
| Intent parent = new Intent().setComponent( |
| new ComponentName(mSourceContext, parentActivity)); |
| while (parent != null) { |
| mIntents.add(insertAt, parent); |
| info = pm.getActivityInfo(parent.getComponent(), 0); |
| parentActivity = info.parentActivityName; |
| if (parentActivity != null) { |
| parent = new Intent().setComponent( |
| new ComponentName(mSourceContext, parentActivity)); |
| } else { |
| parent = null; |
| } |
| } |
| } catch (NameNotFoundException e) { |
| Log.e(TAG, "Bad ComponentName while traversing activity parent metadata"); |
| throw new IllegalArgumentException(e); |
| } |
| return this; |
| } |
| |
| /** |
| * @return the number of intents added so far. |
| */ |
| public int getIntentCount() { |
| return mIntents.size(); |
| } |
| |
| /** |
| * Get the intent at the specified index. |
| * Useful if you need to modify the flags or extras of an intent that was previously added, |
| * for example with {@link #addParentStack(Activity)}. |
| * |
| * @param index Index from 0-getIntentCount() |
| * @return the intent at position index |
| */ |
| public Intent getIntent(int index) { |
| return mIntents.get(index); |
| } |
| |
| public Iterator<Intent> iterator() { |
| return mIntents.iterator(); |
| } |
| |
| /** |
| * Start the task stack constructed by this builder. |
| */ |
| public void startActivities() { |
| if (mIntents.isEmpty()) { |
| throw new IllegalStateException( |
| "No intents added to TaskStackBuilder; cannot startActivities"); |
| } |
| |
| Intent[] intents = mIntents.toArray(new Intent[mIntents.size()]); |
| intents[0].addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | |
| Intent.FLAG_ACTIVITY_CLEAR_TASK | |
| Intent.FLAG_ACTIVITY_TASK_ON_HOME); |
| mSourceContext.startActivities(intents); |
| } |
| |
| /** |
| * Obtain a {@link PendingIntent} for launching the task constructed by this builder so far. |
| * |
| * @param requestCode Private request code for the sender |
| * @param flags May be {@link PendingIntent#FLAG_ONE_SHOT}, |
| * {@link PendingIntent#FLAG_NO_CREATE}, {@link PendingIntent#FLAG_CANCEL_CURRENT}, |
| * {@link PendingIntent#FLAG_UPDATE_CURRENT}, or any of the flags supported by |
| * {@link Intent#fillIn(Intent, int)} to control which unspecified parts of the |
| * intent that can be supplied when the actual send happens. |
| * @return The obtained PendingIntent |
| */ |
| public PendingIntent getPendingIntent(int requestCode, int flags) { |
| Intent[] intents = mIntents.toArray(new Intent[mIntents.size()]); |
| return PendingIntent.getActivities(mSourceContext, requestCode, intents, flags); |
| } |
| } |