xref: /frameworks/base/core/java/android/app/Activity.java

/*
 * Copyright (C) 2006 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.annotation.NonNull;
import android.os.PersistableBundle;
import android.transition.Scene;
import android.transition.TransitionManager;
import android.util.ArrayMap;
import android.util.SuperNotCalledException;
import android.widget.Toolbar;

import com.android.internal.app.IVoiceInteractor;
import com.android.internal.app.WindowDecorActionBar;
import com.android.internal.app.ToolbarActionBar;
import com.android.internal.policy.PolicyManager;

import android.annotation.IntDef;
import android.annotation.Nullable;
import android.annotation.SystemApi;
import android.app.admin.DevicePolicyManager;
import android.content.ComponentCallbacks2;
import android.content.ComponentName;
import android.content.ContentResolver;
import android.content.Context;
import android.content.CursorLoader;
import android.content.IIntentSender;
import android.content.Intent;
import android.content.IntentSender;
import android.content.SharedPreferences;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.media.AudioManager;
import android.media.session.MediaController;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.Parcelable;
import android.os.RemoteException;
import android.os.StrictMode;
import android.os.UserHandle;
import android.text.Selection;
import android.text.SpannableStringBuilder;
import android.text.TextUtils;
import android.text.method.TextKeyListener;
import android.util.AttributeSet;
import android.util.EventLog;
import android.util.Log;
import android.util.PrintWriterPrinter;
import android.util.Slog;
import android.util.SparseArray;
import android.view.ActionMode;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.ContextThemeWrapper;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnCreateContextMenuListener;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewManager;
import android.view.Window;
import android.view.WindowManager;
import android.view.WindowManagerGlobal;
import android.view.accessibility.AccessibilityEvent;
import android.widget.AdapterView;

import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.HashMap;

/**
 * An activity is a single, focused thing that the user can do.  Almost all
 * activities interact with the user, so the Activity class takes care of
 * creating a window for you in which you can place your UI with
 * {@link #setContentView}.  While activities are often presented to the user
 * as full-screen windows, they can also be used in other ways: as floating
 * windows (via a theme with {@link android.R.attr#windowIsFloating} set)
 * or embedded inside of another activity (using {@link ActivityGroup}).
 *
 * There are two methods almost all subclasses of Activity will implement:
 *
 * <ul>
 *     <li> {@link #onCreate} is where you initialize your activity.  Most
 *     importantly, here you will usually call {@link #setContentView(int)}
 *     with a layout resource defining your UI, and using {@link #findViewById}
 *     to retrieve the widgets in that UI that you need to interact with
 *     programmatically.
 *
 *     <li> {@link #onPause} is where you deal with the user leaving your
 *     activity.  Most importantly, any changes made by the user should at this
 *     point be committed (usually to the
 *     {@link android.content.ContentProvider} holding the data).
 * </ul>
 *
 * <p>To be of use with {@link android.content.Context#startActivity Context.startActivity()}, all
 * activity classes must have a corresponding
 * {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
 * declaration in their package's <code>AndroidManifest.xml</code>.</p>
 *
 * <p>Topics covered here:
 * <ol>
 * <li><a href="#Fragments">Fragments</a>
 * <li><a href="#ActivityLifecycle">Activity Lifecycle</a>
 * <li><a href="#ConfigurationChanges">Configuration Changes</a>
 * <li><a href="#StartingActivities">Starting Activities and Getting Results</a>
 * <li><a href="#SavingPersistentState">Saving Persistent State</a>
 * <li><a href="#Permissions">Permissions</a>
 * <li><a href="#ProcessLifecycle">Process Lifecycle</a>
 * </ol>
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>The Activity class is an important part of an application's overall lifecycle,
 * and the way activities are launched and put together is a fundamental
 * part of the platform's application model. For a detailed perspective on the structure of an
 * Android application and how activities behave, please read the
 * <a href="{@docRoot}guide/topics/fundamentals.html">Application Fundamentals</a> and
 * <a href="{@docRoot}guide/topics/fundamentals/tasks-and-back-stack.html">Tasks and Back Stack</a>
 * developer guides.</p>
 *
 * <p>You can also find a detailed discussion about how to create activities in the
 * <a href="{@docRoot}guide/topics/fundamentals/activities.html">Activities</a>
 * developer guide.</p>
 * </div>
 *
 * <a name="Fragments"></a>
 * <h3>Fragments</h3>
 *
 * <p>Starting with {@link android.os.Build.VERSION_CODES#HONEYCOMB}, Activity
 * implementations can make use of the {@link Fragment} class to better
 * modularize their code, build more sophisticated user interfaces for larger
 * screens, and help scale their application between small and large screens.
 *
 * <a name="ActivityLifecycle"></a>
 * <h3>Activity Lifecycle</h3>
 *
 * <p>Activities in the system are managed as an <em>activity stack</em>.
 * When a new activity is started, it is placed on the top of the stack
 * and becomes the running activity -- the previous activity always remains
 * below it in the stack, and will not come to the foreground again until
 * the new activity exits.</p>
 *
 * <p>An activity has essentially four states:</p>
 * <ul>
 *     <li> If an activity in the foreground of the screen (at the top of
 *         the stack),
 *         it is <em>active</em> or  <em>running</em>. </li>
 *     <li>If an activity has lost focus but is still visible (that is, a new non-full-sized
 *         or transparent activity has focus on top of your activity), it
 *         is <em>paused</em>. A paused activity is completely alive (it
 *         maintains all state and member information and remains attached to
 *         the window manager), but can be killed by the system in extreme
 *         low memory situations.
 *     <li>If an activity is completely obscured by another activity,
 *         it is <em>stopped</em>. It still retains all state and member information,
 *         however, it is no longer visible to the user so its window is hidden
 *         and it will often be killed by the system when memory is needed
 *         elsewhere.</li>
 *     <li>If an activity is paused or stopped, the system can drop the activity
 *         from memory by either asking it to finish, or simply killing its
 *         process.  When it is displayed again to the user, it must be
 *         completely restarted and restored to its previous state.</li>
 * </ul>
 *
 * <p>The following diagram shows the important state paths of an Activity.
 * The square rectangles represent callback methods you can implement to
 * perform operations when the Activity moves between states.  The colored
 * ovals are major states the Activity can be in.</p>
 *
 * <p><img src="../../../images/activity_lifecycle.png"
 *      alt="State diagram for an Android Activity Lifecycle." border="0" /></p>
 *
 * <p>There are three key loops you may be interested in monitoring within your
 * activity:
 *
 * <ul>
 * <li>The <b>entire lifetime</b> of an activity happens between the first call
 * to {@link android.app.Activity#onCreate} through to a single final call
 * to {@link android.app.Activity#onDestroy}.  An activity will do all setup
 * of "global" state in onCreate(), and release all remaining resources in
 * onDestroy().  For example, if it has a thread running in the background
 * to download data from the network, it may create that thread in onCreate()
 * and then stop the thread in onDestroy().
 *
 * <li>The <b>visible lifetime</b> of an activity happens between a call to
 * {@link android.app.Activity#onStart} until a corresponding call to
 * {@link android.app.Activity#onStop}.  During this time the user can see the
 * activity on-screen, though it may not be in the foreground and interacting
 * with the user.  Between these two methods you can maintain resources that
 * are needed to show the activity to the user.  For example, you can register
 * a {@link android.content.BroadcastReceiver} in onStart() to monitor for changes
 * that impact your UI, and unregister it in onStop() when the user no
 * longer sees what you are displaying.  The onStart() and onStop() methods
 * can be called multiple times, as the activity becomes visible and hidden
 * to the user.
 *
 * <li>The <b>foreground lifetime</b> of an activity happens between a call to
 * {@link android.app.Activity#onResume} until a corresponding call to
 * {@link android.app.Activity#onPause}.  During this time the activity is
 * in front of all other activities and interacting with the user.  An activity
 * can frequently go between the resumed and paused states -- for example when
 * the device goes to sleep, when an activity result is delivered, when a new
 * intent is delivered -- so the code in these methods should be fairly
 * lightweight.
 * </ul>
 *
 * <p>The entire lifecycle of an activity is defined by the following
 * Activity methods.  All of these are hooks that you can override
 * to do appropriate work when the activity changes state.  All
 * activities will implement {@link android.app.Activity#onCreate}
 * to do their initial setup; many will also implement
 * {@link android.app.Activity#onPause} to commit changes to data and
 * otherwise prepare to stop interacting with the user.  You should always
 * call up to your superclass when implementing these methods.</p>
 *
 * </p>
 * <pre class="prettyprint">
 * public class Activity extends ApplicationContext {
 *     protected void onCreate(Bundle savedInstanceState);
 *
 *     protected void onStart();
 *
 *     protected void onRestart();
 *
 *     protected void onResume();
 *
 *     protected void onPause();
 *
 *     protected void onStop();
 *
 *     protected void onDestroy();
 * }
 * </pre>
 *
 * <p>In general the movement through an activity's lifecycle looks like
 * this:</p>
 *
 * <table border="2" width="85%" align="center" frame="hsides" rules="rows">
 *     <colgroup align="left" span="3" />
 *     <colgroup align="left" />
 *     <colgroup align="center" />
 *     <colgroup align="center" />
 *
 *     <thead>
 *     <tr><th colspan="3">Method</th> <th>Description</th> <th>Killable?</th> <th>Next</th></tr>
 *     </thead>
 *
 *     <tbody>
 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onCreate onCreate()}</th>
 *         <td>Called when the activity is first created.
 *             This is where you should do all of your normal static set up:
 *             create views, bind data to lists, etc.  This method also
 *             provides you with a Bundle containing the activity's previously
 *             frozen state, if there was one.
 *             <p>Always followed by <code>onStart()</code>.</td>
 *         <td align="center">No</td>
 *         <td align="center"><code>onStart()</code></td>
 *     </tr>
 *
 *     <tr><td rowspan="5" style="border-left: none; border-right: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
 *         <th colspan="2" align="left" border="0">{@link android.app.Activity#onRestart onRestart()}</th>
 *         <td>Called after your activity has been stopped, prior to it being
 *             started again.
 *             <p>Always followed by <code>onStart()</code></td>
 *         <td align="center">No</td>
 *         <td align="center"><code>onStart()</code></td>
 *     </tr>
 *
 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStart onStart()}</th>
 *         <td>Called when the activity is becoming visible to the user.
 *             <p>Followed by <code>onResume()</code> if the activity comes
 *             to the foreground, or <code>onStop()</code> if it becomes hidden.</td>
 *         <td align="center">No</td>
 *         <td align="center"><code>onResume()</code> or <code>onStop()</code></td>
 *     </tr>
 *
 *     <tr><td rowspan="2" style="border-left: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
 *         <th align="left" border="0">{@link android.app.Activity#onResume onResume()}</th>
 *         <td>Called when the activity will start
 *             interacting with the user.  At this point your activity is at
 *             the top of the activity stack, with user input going to it.
 *             <p>Always followed by <code>onPause()</code>.</td>
 *         <td align="center">No</td>
 *         <td align="center"><code>onPause()</code></td>
 *     </tr>
 *
 *     <tr><th align="left" border="0">{@link android.app.Activity#onPause onPause()}</th>
 *         <td>Called when the system is about to start resuming a previous
 *             activity.  This is typically used to commit unsaved changes to
 *             persistent data, stop animations and other things that may be consuming
 *             CPU, etc.  Implementations of this method must be very quick because
 *             the next activity will not be resumed until this method returns.
 *             <p>Followed by either <code>onResume()</code> if the activity
 *             returns back to the front, or <code>onStop()</code> if it becomes
 *             invisible to the user.</td>
 *         <td align="center"><font color="#800000"><strong>Pre-{@link android.os.Build.VERSION_CODES#HONEYCOMB}</strong></font></td>
 *         <td align="center"><code>onResume()</code> or<br>
 *                 <code>onStop()</code></td>
 *     </tr>
 *
 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStop onStop()}</th>
 *         <td>Called when the activity is no longer visible to the user, because
 *             another activity has been resumed and is covering this one.  This
 *             may happen either because a new activity is being started, an existing
 *             one is being brought in front of this one, or this one is being
 *             destroyed.
 *             <p>Followed by either <code>onRestart()</code> if
 *             this activity is coming back to interact with the user, or
 *             <code>onDestroy()</code> if this activity is going away.</td>
 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
 *         <td align="center"><code>onRestart()</code> or<br>
 *                 <code>onDestroy()</code></td>
 *     </tr>
 *
 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onDestroy onDestroy()}</th>
 *         <td>The final call you receive before your
 *             activity is destroyed.  This can happen either because the
 *             activity is finishing (someone called {@link Activity#finish} on
 *             it, or because the system is temporarily destroying this
 *             instance of the activity to save space.  You can distinguish
 *             between these two scenarios with the {@link
 *             Activity#isFinishing} method.</td>
 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
 *         <td align="center"><em>nothing</em></td>
 *     </tr>
 *     </tbody>
 * </table>
 *
 * <p>Note the "Killable" column in the above table -- for those methods that
 * are marked as being killable, after that method returns the process hosting the
 * activity may killed by the system <em>at any time</em> without another line
 * of its code being executed.  Because of this, you should use the
 * {@link #onPause} method to write any persistent data (such as user edits)
 * to storage.  In addition, the method
 * {@link #onSaveInstanceState(Bundle)} is called before placing the activity
 * in such a background state, allowing you to save away any dynamic instance
 * state in your activity into the given Bundle, to be later received in
 * {@link #onCreate} if the activity needs to be re-created.
 * See the <a href="#ProcessLifecycle">Process Lifecycle</a>
 * section for more information on how the lifecycle of a process is tied
 * to the activities it is hosting.  Note that it is important to save
 * persistent data in {@link #onPause} instead of {@link #onSaveInstanceState}
 * because the latter is not part of the lifecycle callbacks, so will not
 * be called in every situation as described in its documentation.</p>
 *
 * <p class="note">Be aware that these semantics will change slightly between
 * applications targeting platforms starting with {@link android.os.Build.VERSION_CODES#HONEYCOMB}
 * vs. those targeting prior platforms.  Starting with Honeycomb, an application
 * is not in the killable state until its {@link #onStop} has returned.  This
 * impacts when {@link #onSaveInstanceState(Bundle)} may be called (it may be
 * safely called after {@link #onPause()} and allows and application to safely
 * wait until {@link #onStop()} to save persistent state.</p>
 *
 * <p>For those methods that are not marked as being killable, the activity's
 * process will not be killed by the system starting from the time the method
 * is called and continuing after it returns.  Thus an activity is in the killable
 * state, for example, between after <code>onPause()</code> to the start of
 * <code>onResume()</code>.</p>
 *
 * <a name="ConfigurationChanges"></a>
 * <h3>Configuration Changes</h3>
 *
 * <p>If the configuration of the device (as defined by the
 * {@link Configuration Resources.Configuration} class) changes,
 * then anything displaying a user interface will need to update to match that
 * configuration.  Because Activity is the primary mechanism for interacting
 * with the user, it includes special support for handling configuration
 * changes.</p>
 *
 * <p>Unless you specify otherwise, a configuration change (such as a change
 * in screen orientation, language, input devices, etc) will cause your
 * current activity to be <em>destroyed</em>, going through the normal activity
 * lifecycle process of {@link #onPause},
 * {@link #onStop}, and {@link #onDestroy} as appropriate.  If the activity
 * had been in the foreground or visible to the user, once {@link #onDestroy} is
 * called in that instance then a new instance of the activity will be
 * created, with whatever savedInstanceState the previous instance had generated
 * from {@link #onSaveInstanceState}.</p>
 *
 * <p>This is done because any application resource,
 * including layout files, can change based on any configuration value.  Thus
 * the only safe way to handle a configuration change is to re-retrieve all
 * resources, including layouts, drawables, and strings.  Because activities
 * must already know how to save their state and re-create themselves from
 * that state, this is a convenient way to have an activity restart itself
 * with a new configuration.</p>
 *
 * <p>In some special cases, you may want to bypass restarting of your
 * activity based on one or more types of configuration changes.  This is
 * done with the {@link android.R.attr#configChanges android:configChanges}
 * attribute in its manifest.  For any types of configuration changes you say
 * that you handle there, you will receive a call to your current activity's
 * {@link #onConfigurationChanged} method instead of being restarted.  If
 * a configuration change involves any that you do not handle, however, the
 * activity will still be restarted and {@link #onConfigurationChanged}
 * will not be called.</p>
 *
 * <a name="StartingActivities"></a>
 * <h3>Starting Activities and Getting Results</h3>
 *
 * <p>The {@link android.app.Activity#startActivity}
 * method is used to start a
 * new activity, which will be placed at the top of the activity stack.  It
 * takes a single argument, an {@link android.content.Intent Intent},
 * which describes the activity
 * to be executed.</p>
 *
 * <p>Sometimes you want to get a result back from an activity when it
 * ends.  For example, you may start an activity that lets the user pick
 * a person in a list of contacts; when it ends, it returns the person
 * that was selected.  To do this, you call the
 * {@link android.app.Activity#startActivityForResult(Intent, int)}
 * version with a second integer parameter identifying the call.  The result
 * will come back through your {@link android.app.Activity#onActivityResult}
 * method.</p>
 *
 * <p>When an activity exits, it can call
 * {@link android.app.Activity#setResult(int)}
 * to return data back to its parent.  It must always supply a result code,
 * which can be the standard results RESULT_CANCELED, RESULT_OK, or any
 * custom values starting at RESULT_FIRST_USER.  In addition, it can optionally
 * return back an Intent containing any additional data it wants.  All of this
 * information appears back on the
 * parent's <code>Activity.onActivityResult()</code>, along with the integer
 * identifier it originally supplied.</p>
 *
 * <p>If a child activity fails for any reason (such as crashing), the parent
 * activity will receive a result with the code RESULT_CANCELED.</p>
 *
 * <pre class="prettyprint">
 * public class MyActivity extends Activity {
 *     ...
 *
 *     static final int PICK_CONTACT_REQUEST = 0;
 *
 *     public boolean onKeyDown(int keyCode, KeyEvent event) {
 *         if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
 *             // When the user center presses, let them pick a contact.
 *             startActivityForResult(
 *                 new Intent(Intent.ACTION_PICK,
 *                 new Uri("content://contacts")),
 *                 PICK_CONTACT_REQUEST);
 *            return true;
 *         }
 *         return false;
 *     }
 *
 *     protected void onActivityResult(int requestCode, int resultCode,
 *             Intent data) {
 *         if (requestCode == PICK_CONTACT_REQUEST) {
 *             if (resultCode == RESULT_OK) {
 *                 // A contact was picked.  Here we will just display it
 *                 // to the user.
 *                 startActivity(new Intent(Intent.ACTION_VIEW, data));
 *             }
 *         }
 *     }
 * }
 * </pre>
 *
 * <a name="SavingPersistentState"></a>
 * <h3>Saving Persistent State</h3>
 *
 * <p>There are generally two kinds of persistent state than an activity
 * will deal with: shared document-like data (typically stored in a SQLite
 * database using a {@linkplain android.content.ContentProvider content provider})
 * and internal state such as user preferences.</p>
 *
 * <p>For content provider data, we suggest that activities use a
 * "edit in place" user model.  That is, any edits a user makes are effectively
 * made immediately without requiring an additional confirmation step.
 * Supporting this model is generally a simple matter of following two rules:</p>
 *
 * <ul>
 *     <li> <p>When creating a new document, the backing database entry or file for
 *             it is created immediately.  For example, if the user chooses to write
 *             a new e-mail, a new entry for that e-mail is created as soon as they
 *             start entering data, so that if they go to any other activity after
 *             that point this e-mail will now appear in the list of drafts.</p>
 *     <li> <p>When an activity's <code>onPause()</code> method is called, it should
 *             commit to the backing content provider or file any changes the user
 *             has made.  This ensures that those changes will be seen by any other
 *             activity that is about to run.  You will probably want to commit
 *             your data even more aggressively at key times during your
 *             activity's lifecycle: for example before starting a new
 *             activity, before finishing your own activity, when the user
 *             switches between input fields, etc.</p>
 * </ul>
 *
 * <p>This model is designed to prevent data loss when a user is navigating
 * between activities, and allows the system to safely kill an activity (because
 * system resources are needed somewhere else) at any time after it has been
 * paused.  Note this implies
 * that the user pressing BACK from your activity does <em>not</em>
 * mean "cancel" -- it means to leave the activity with its current contents
 * saved away.  Canceling edits in an activity must be provided through
 * some other mechanism, such as an explicit "revert" or "undo" option.</p>
 *
 * <p>See the {@linkplain android.content.ContentProvider content package} for
 * more information about content providers.  These are a key aspect of how
 * different activities invoke and propagate data between themselves.</p>
 *
 * <p>The Activity class also provides an API for managing internal persistent state
 * associated with an activity.  This can be used, for example, to remember
 * the user's preferred initial display in a calendar (day view or week view)
 * or the user's default home page in a web browser.</p>
 *
 * <p>Activity persistent state is managed
 * with the method {@link #getPreferences},
 * allowing you to retrieve and
 * modify a set of name/value pairs associated with the activity.  To use
 * preferences that are shared across multiple application components
 * (activities, receivers, services, providers), you can use the underlying
 * {@link Context#getSharedPreferences Context.getSharedPreferences()} method
 * to retrieve a preferences
 * object stored under a specific name.
 * (Note that it is not possible to share settings data across application
 * packages -- for that you will need a content provider.)</p>
 *
 * <p>Here is an excerpt from a calendar activity that stores the user's
 * preferred view mode in its persistent settings:</p>
 *
 * <pre class="prettyprint">
 * public class CalendarActivity extends Activity {
 *     ...
 *
 *     static final int DAY_VIEW_MODE = 0;
 *     static final int WEEK_VIEW_MODE = 1;
 *
 *     private SharedPreferences mPrefs;
 *     private int mCurViewMode;
 *
 *     protected void onCreate(Bundle savedInstanceState) {
 *         super.onCreate(savedInstanceState);
 *
 *         SharedPreferences mPrefs = getSharedPreferences();
 *         mCurViewMode = mPrefs.getInt("view_mode", DAY_VIEW_MODE);
 *     }
 *
 *     protected void onPause() {
 *         super.onPause();
 *
 *         SharedPreferences.Editor ed = mPrefs.edit();
 *         ed.putInt("view_mode", mCurViewMode);
 *         ed.commit();
 *     }
 * }
 * </pre>
 *
 * <a name="Permissions"></a>
 * <h3>Permissions</h3>
 *
 * <p>The ability to start a particular Activity can be enforced when it is
 * declared in its
 * manifest's {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
 * tag.  By doing so, other applications will need to declare a corresponding
 * {@link android.R.styleable#AndroidManifestUsesPermission &lt;uses-permission&gt;}
 * element in their own manifest to be able to start that activity.
 *
 * <p>When starting an Activity you can set {@link Intent#FLAG_GRANT_READ_URI_PERMISSION
 * Intent.FLAG_GRANT_READ_URI_PERMISSION} and/or {@link Intent#FLAG_GRANT_WRITE_URI_PERMISSION
 * Intent.FLAG_GRANT_WRITE_URI_PERMISSION} on the Intent.  This will grant the
 * Activity access to the specific URIs in the Intent.  Access will remain
 * until the Activity has finished (it will remain across the hosting
 * process being killed and other temporary destruction).  As of
 * {@link android.os.Build.VERSION_CODES#GINGERBREAD}, if the Activity
 * was already created and a new Intent is being delivered to
 * {@link #onNewIntent(Intent)}, any newly granted URI permissions will be added
 * to the existing ones it holds.
 *
 * <p>See the <a href="{@docRoot}guide/topics/security/security.html">Security and Permissions</a>
 * document for more information on permissions and security in general.
 *
 * <a name="ProcessLifecycle"></a>
 * <h3>Process Lifecycle</h3>
 *
 * <p>The Android system attempts to keep application process around for as
 * long as possible, but eventually will need to remove old processes when
 * memory runs low.  As described in <a href="#ActivityLifecycle">Activity
 * Lifecycle</a>, the decision about which process to remove is intimately
 * tied to the state of the user's interaction with it.  In general, there
 * are four states a process can be in based on the activities running in it,
 * listed here in order of importance.  The system will kill less important
 * processes (the last ones) before it resorts to killing more important
 * processes (the first ones).
 *
 * <ol>
 * <li> <p>The <b>foreground activity</b> (the activity at the top of the screen
 * that the user is currently interacting with) is considered the most important.
 * Its process will only be killed as a last resort, if it uses more memory
 * than is available on the device.  Generally at this point the device has
 * reached a memory paging state, so this is required in order to keep the user
 * interface responsive.
 * <li> <p>A <b>visible activity</b> (an activity that is visible to the user
 * but not in the foreground, such as one sitting behind a foreground dialog)
 * is considered extremely important and will not be killed unless that is
 * required to keep the foreground activity running.
 * <li> <p>A <b>background activity</b> (an activity that is not visible to
 * the user and has been paused) is no longer critical, so the system may
 * safely kill its process to reclaim memory for other foreground or
 * visible processes.  If its process needs to be killed, when the user navigates
 * back to the activity (making it visible on the screen again), its
 * {@link #onCreate} method will be called with the savedInstanceState it had previously
 * supplied in {@link #onSaveInstanceState} so that it can restart itself in the same
 * state as the user last left it.
 * <li> <p>An <b>empty process</b> is one hosting no activities or other
 * application components (such as {@link Service} or
 * {@link android.content.BroadcastReceiver} classes).  These are killed very
 * quickly by the system as memory becomes low.  For this reason, any
 * background operation you do outside of an activity must be executed in the
 * context of an activity BroadcastReceiver or Service to ensure that the system
 * knows it needs to keep your process around.
 * </ol>
 *
 * <p>Sometimes an Activity may need to do a long-running operation that exists
 * independently of the activity lifecycle itself.  An example may be a camera
 * application that allows you to upload a picture to a web site.  The upload
 * may take a long time, and the application should allow the user to leave
 * the application will it is executing.  To accomplish this, your Activity
 * should start a {@link Service} in which the upload takes place.  This allows
 * the system to properly prioritize your process (considering it to be more
 * important than other non-visible applications) for the duration of the
 * upload, independent of whether the original activity is paused, stopped,
 * or finished.
 */
public class Activity extends ContextThemeWrapper
        implements LayoutInflater.Factory2,
        Window.Callback, KeyEvent.Callback,
        OnCreateContextMenuListener, ComponentCallbacks2,
        Window.OnWindowDismissedCallback {
    private static final String TAG = "Activity";
    private static final boolean DEBUG_LIFECYCLE = false;

    /** Standard activity result: operation canceled. */
    public static final int RESULT_CANCELED    = 0;
    /** Standard activity result: operation succeeded. */
    public static final int RESULT_OK           = -1;
    /** Start of user-defined activity results. */
    public static final int RESULT_FIRST_USER   = 1;

    static final String FRAGMENTS_TAG = "android:fragments";

    private static final String WINDOW_HIERARCHY_TAG = "android:viewHierarchyState";
    private static final String SAVED_DIALOG_IDS_KEY = "android:savedDialogIds";
    private static final String SAVED_DIALOGS_TAG = "android:savedDialogs";
    private static final String SAVED_DIALOG_KEY_PREFIX = "android:dialog_";
    private static final String SAVED_DIALOG_ARGS_KEY_PREFIX = "android:dialog_args_";

    private static class ManagedDialog {
        Dialog mDialog;
        Bundle mArgs;
    }
    private SparseArray<ManagedDialog> mManagedDialogs;

    // set by the thread after the constructor and before onCreate(Bundle savedInstanceState) is called.
    private Instrumentation mInstrumentation;
    private IBinder mToken;
    private int mIdent;
    /*package*/ String mEmbeddedID;
    private Application mApplication;
    /*package*/ Intent mIntent;
    /*package*/ String mReferrer;
    private ComponentName mComponent;
    /*package*/ ActivityInfo mActivityInfo;
    /*package*/ ActivityThread mMainThread;
    Activity mParent;
    boolean mCalled;
    boolean mCheckedForLoaderManager;
    boolean mLoadersStarted;
    /*package*/ boolean mResumed;
    private boolean mStopped;
    boolean mFinished;
    boolean mStartedActivity;
    private boolean mDestroyed;
    private boolean mDoReportFullyDrawn = true;
    /** true if the activity is going through a transient pause */
    /*package*/ boolean mTemporaryPause = false;
    /** true if the activity is being destroyed in order to recreate it with a new configuration */
    /*package*/ boolean mChangingConfigurations = false;
    /*package*/ int mConfigChangeFlags;
    /*package*/ Configuration mCurrentConfig;
    private SearchManager mSearchManager;
    private MenuInflater mMenuInflater;

    static final class NonConfigurationInstances {
        Object activity;
        HashMap<String, Object> children;
        ArrayList<Fragment> fragments;
        ArrayMap<String, LoaderManagerImpl> loaders;
        VoiceInteractor voiceInteractor;
    }
    /* package */ NonConfigurationInstances mLastNonConfigurationInstances;

    private Window mWindow;

    private WindowManager mWindowManager;
    /*package*/ View mDecor = null;
    /*package*/ boolean mWindowAdded = false;
    /*package*/ boolean mVisibleFromServer = false;
    /*package*/ boolean mVisibleFromClient = true;
    /*package*/ ActionBar mActionBar = null;
    private boolean mEnableDefaultActionBarUp;

    private VoiceInteractor mVoiceInteractor;

    private CharSequence mTitle;
    private int mTitleColor = 0;

    final FragmentManagerImpl mFragments = new FragmentManagerImpl();
    final FragmentContainer mContainer = new FragmentContainer() {
        @Override
        public View findViewById(int id) {
            return Activity.this.findViewById(id);
        }
        @Override
        public boolean hasView() {
            Window window = Activity.this.getWindow();
            return (window != null && window.peekDecorView() != null);
        }
    };

    // Most recent call to requestVisibleBehind().
    boolean mVisibleBehind;

    ArrayMap<String, LoaderManagerImpl> mAllLoaderManagers;
    LoaderManagerImpl mLoaderManager;

    private static final class ManagedCursor {
        ManagedCursor(Cursor cursor) {
            mCursor = cursor;
            mReleased = false;
            mUpdated = false;
        }

        private final Cursor mCursor;
        private boolean mReleased;
        private boolean mUpdated;
    }
    private final ArrayList<ManagedCursor> mManagedCursors =
        new ArrayList<ManagedCursor>();

    // protected by synchronized (this)
    int mResultCode = RESULT_CANCELED;
    Intent mResultData = null;

    private TranslucentConversionListener mTranslucentCallback;
    private boolean mChangeCanvasToTranslucent;

    private boolean mTitleReady = false;

    private int mDefaultKeyMode = DEFAULT_KEYS_DISABLE;
    private SpannableStringBuilder mDefaultKeySsb = null;

    protected static final int[] FOCUSED_STATE_SET = {com.android.internal.R.attr.state_focused};

    @SuppressWarnings("unused")
    private final Object mInstanceTracker = StrictMode.trackActivity(this);

    private Thread mUiThread;
    final Handler mHandler = new Handler();

    ActivityTransitionState mActivityTransitionState = new ActivityTransitionState();
    SharedElementCallback mEnterTransitionListener = SharedElementCallback.NULL_CALLBACK;
    SharedElementCallback mExitTransitionListener = SharedElementCallback.NULL_CALLBACK;

    /** Return the intent that started this activity. */
    public Intent getIntent() {
        return mIntent;
    }

    /**
     * Change the intent returned by {@link #getIntent}.  This holds a
     * reference to the given intent; it does not copy it.  Often used in
     * conjunction with {@link #onNewIntent}.
     *
     * @param newIntent The new Intent object to return from getIntent
     *
     * @see #getIntent
     * @see #onNewIntent
     */
    public void setIntent(Intent newIntent) {
        mIntent = newIntent;
    }

    /** Return the application that owns this activity. */
    public final Application getApplication() {
        return mApplication;
    }

    /** Is this activity embedded inside of another activity? */
    public final boolean isChild() {
        return mParent != null;
    }

    /** Return the parent activity if this view is an embedded child. */
    public final Activity getParent() {
        return mParent;
    }

    /** Retrieve the window manager for showing custom windows. */
    public WindowManager getWindowManager() {
        return mWindowManager;
    }

    /**
     * Retrieve the current {@link android.view.Window} for the activity.
     * This can be used to directly access parts of the Window API that
     * are not available through Activity/Screen.
     *
     * @return Window The current window, or null if the activity is not
     *         visual.
     */
    public Window getWindow() {
        return mWindow;
    }

    /**
     * Return the LoaderManager for this activity, creating it if needed.
     */
    public LoaderManager getLoaderManager() {
        if (mLoaderManager != null) {
            return mLoaderManager;
        }
        mCheckedForLoaderManager = true;
        mLoaderManager = getLoaderManager("(root)", mLoadersStarted, true);
        return mLoaderManager;
    }

    LoaderManagerImpl getLoaderManager(String who, boolean started, boolean create) {
        if (mAllLoaderManagers == null) {
            mAllLoaderManagers = new ArrayMap<String, LoaderManagerImpl>();
        }
        LoaderManagerImpl lm = mAllLoaderManagers.get(who);
        if (lm == null) {
            if (create) {
                lm = new LoaderManagerImpl(who, this, started);
                mAllLoaderManagers.put(who, lm);
            }
        } else {
            lm.updateActivity(this);
        }
        return lm;
    }

    /**
     * Calls {@link android.view.Window#getCurrentFocus} on the
     * Window of this Activity to return the currently focused view.
     *
     * @return View The current View with focus or null.
     *
     * @see #getWindow
     * @see android.view.Window#getCurrentFocus
     */
    @Nullable
    public View getCurrentFocus() {
        return mWindow != null ? mWindow.getCurrentFocus() : null;
    }

    /**
     * Called when the activity is starting.  This is where most initialization
     * should go: calling {@link #setContentView(int)} to inflate the
     * activity's UI, using {@link #findViewById} to programmatically interact
     * with widgets in the UI, calling
     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)} to retrieve
     * cursors for data being displayed, etc.
     *
     * <p>You can call {@link #finish} from within this function, in
     * which case onDestroy() will be immediately called without any of the rest
     * of the activity lifecycle ({@link #onStart}, {@link #onResume},
     * {@link #onPause}, etc) executing.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @param savedInstanceState If the activity is being re-initialized after
     *     previously being shut down then this Bundle contains the data it most
     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
     *
     * @see #onStart
     * @see #onSaveInstanceState
     * @see #onRestoreInstanceState
     * @see #onPostCreate
     */
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onCreate " + this + ": " + savedInstanceState);
        if (mLastNonConfigurationInstances != null) {
            mAllLoaderManagers = mLastNonConfigurationInstances.loaders;
        }
        if (mActivityInfo.parentActivityName != null) {
            if (mActionBar == null) {
                mEnableDefaultActionBarUp = true;
            } else {
                mActionBar.setDefaultDisplayHomeAsUpEnabled(true);
            }
        }
        if (savedInstanceState != null) {
            Parcelable p = savedInstanceState.getParcelable(FRAGMENTS_TAG);
            mFragments.restoreAllState(p, mLastNonConfigurationInstances != null
                    ? mLastNonConfigurationInstances.fragments : null);
        }
        mFragments.dispatchCreate();
        getApplication().dispatchActivityCreated(this, savedInstanceState);
        if (mVoiceInteractor != null) {
            mVoiceInteractor.attachActivity(this);
        }
        mCalled = true;
    }

    /**
     * Same as {@link #onCreate(android.os.Bundle)} but called for those activities created with
     * the attribute {@link android.R.attr#persistableMode} set to
     * <code>persistAcrossReboots</code>.
     *
     * @param savedInstanceState if the activity is being re-initialized after
     *     previously being shut down then this Bundle contains the data it most
     *     recently supplied in {@link #onSaveInstanceState}.
     *     <b><i>Note: Otherwise it is null.</i></b>
     * @param persistentState if the activity is being re-initialized after
     *     previously being shut down or powered off then this Bundle contains the data it most
     *     recently supplied to outPersistentState in {@link #onSaveInstanceState}.
     *     <b><i>Note: Otherwise it is null.</i></b>
     *
     * @see #onCreate(android.os.Bundle)
     * @see #onStart
     * @see #onSaveInstanceState
     * @see #onRestoreInstanceState
     * @see #onPostCreate
     */
    public void onCreate(@Nullable Bundle savedInstanceState,
            @Nullable PersistableBundle persistentState) {
        onCreate(savedInstanceState);
    }

    /**
     * The hook for {@link ActivityThread} to restore the state of this activity.
     *
     * Calls {@link #onSaveInstanceState(android.os.Bundle)} and
     * {@link #restoreManagedDialogs(android.os.Bundle)}.
     *
     * @param savedInstanceState contains the saved state
     */
    final void performRestoreInstanceState(Bundle savedInstanceState) {
        onRestoreInstanceState(savedInstanceState);
        restoreManagedDialogs(savedInstanceState);
    }

    /**
     * The hook for {@link ActivityThread} to restore the state of this activity.
     *
     * Calls {@link #onSaveInstanceState(android.os.Bundle)} and
     * {@link #restoreManagedDialogs(android.os.Bundle)}.
     *
     * @param savedInstanceState contains the saved state
     * @param persistentState contains the persistable saved state
     */
    final void performRestoreInstanceState(Bundle savedInstanceState,
            PersistableBundle persistentState) {
        onRestoreInstanceState(savedInstanceState, persistentState);
        if (savedInstanceState != null) {
            restoreManagedDialogs(savedInstanceState);
        }
    }

    /**
     * This method is called after {@link #onStart} when the activity is
     * being re-initialized from a previously saved state, given here in
     * <var>savedInstanceState</var>.  Most implementations will simply use {@link #onCreate}
     * to restore their state, but it is sometimes convenient to do it here
     * after all of the initialization has been done or to allow subclasses to
     * decide whether to use your default implementation.  The default
     * implementation of this method performs a restore of any view state that
     * had previously been frozen by {@link #onSaveInstanceState}.
     *
     * <p>This method is called between {@link #onStart} and
     * {@link #onPostCreate}.
     *
     * @param savedInstanceState the data most recently supplied in {@link #onSaveInstanceState}.
     *
     * @see #onCreate
     * @see #onPostCreate
     * @see #onResume
     * @see #onSaveInstanceState
     */
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        if (mWindow != null) {
            Bundle windowState = savedInstanceState.getBundle(WINDOW_HIERARCHY_TAG);
            if (windowState != null) {
                mWindow.restoreHierarchyState(windowState);
            }
        }
    }

    /**
     * This is the same as {@link #onRestoreInstanceState(Bundle)} but is called for activities
     * created with the attribute {@link android.R.attr#persistableMode} set to
     * <code>persistAcrossReboots</code>. The {@link android.os.PersistableBundle} passed
     * came from the restored PersistableBundle first
     * saved in {@link #onSaveInstanceState(Bundle, PersistableBundle)}.
     *
     * <p>This method is called between {@link #onStart} and
     * {@link #onPostCreate}.
     *
     * <p>If this method is called {@link #onRestoreInstanceState(Bundle)} will not be called.
     *
     * @param savedInstanceState the data most recently supplied in {@link #onSaveInstanceState}.
     * @param persistentState the data most recently supplied in {@link #onSaveInstanceState}.
     *
     * @see #onRestoreInstanceState(Bundle)
     * @see #onCreate
     * @see #onPostCreate
     * @see #onResume
     * @see #onSaveInstanceState
     */
    public void onRestoreInstanceState(Bundle savedInstanceState,
            PersistableBundle persistentState) {
        if (savedInstanceState != null) {
            onRestoreInstanceState(savedInstanceState);
        }
    }

    /**
     * Restore the state of any saved managed dialogs.
     *
     * @param savedInstanceState The bundle to restore from.
     */
    private void restoreManagedDialogs(Bundle savedInstanceState) {
        final Bundle b = savedInstanceState.getBundle(SAVED_DIALOGS_TAG);
        if (b == null) {
            return;
        }

        final int[] ids = b.getIntArray(SAVED_DIALOG_IDS_KEY);
        final int numDialogs = ids.length;
        mManagedDialogs = new SparseArray<ManagedDialog>(numDialogs);
        for (int i = 0; i < numDialogs; i++) {
            final Integer dialogId = ids[i];
            Bundle dialogState = b.getBundle(savedDialogKeyFor(dialogId));
            if (dialogState != null) {
                // Calling onRestoreInstanceState() below will invoke dispatchOnCreate
                // so tell createDialog() not to do it, otherwise we get an exception
                final ManagedDialog md = new ManagedDialog();
                md.mArgs = b.getBundle(savedDialogArgsKeyFor(dialogId));
                md.mDialog = createDialog(dialogId, dialogState, md.mArgs);
                if (md.mDialog != null) {
                    mManagedDialogs.put(dialogId, md);
                    onPrepareDialog(dialogId, md.mDialog, md.mArgs);
                    md.mDialog.onRestoreInstanceState(dialogState);
                }
            }
        }
    }

    private Dialog createDialog(Integer dialogId, Bundle state, Bundle args) {
        final Dialog dialog = onCreateDialog(dialogId, args);
        if (dialog == null) {
            return null;
        }
        dialog.dispatchOnCreate(state);
        return dialog;
    }

    private static String savedDialogKeyFor(int key) {
        return SAVED_DIALOG_KEY_PREFIX + key;
    }

    private static String savedDialogArgsKeyFor(int key) {
        return SAVED_DIALOG_ARGS_KEY_PREFIX + key;
    }

    /**
     * Called when activity start-up is complete (after {@link #onStart}
     * and {@link #onRestoreInstanceState} have been called).  Applications will
     * generally not implement this method; it is intended for system
     * classes to do final initialization after application code has run.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @param savedInstanceState If the activity is being re-initialized after
     *     previously being shut down then this Bundle contains the data it most
     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
     * @see #onCreate
     */
    protected void onPostCreate(@Nullable Bundle savedInstanceState) {
        if (!isChild()) {
            mTitleReady = true;
            onTitleChanged(getTitle(), getTitleColor());
        }
        mCalled = true;
    }

    /**
     * This is the same as {@link #onPostCreate(Bundle)} but is called for activities
     * created with the attribute {@link android.R.attr#persistableMode} set to
     * <code>persistAcrossReboots</code>.
     *
     * @param savedInstanceState The data most recently supplied in {@link #onSaveInstanceState}
     * @param persistentState The data caming from the PersistableBundle first
     * saved in {@link #onSaveInstanceState(Bundle, PersistableBundle)}.
     *
     * @see #onCreate
     */
    public void onPostCreate(@Nullable Bundle savedInstanceState,
            @Nullable PersistableBundle persistentState) {
        onPostCreate(savedInstanceState);
    }

    /**
     * Called after {@link #onCreate} &mdash; or after {@link #onRestart} when
     * the activity had been stopped, but is now again being displayed to the
     * user.  It will be followed by {@link #onResume}.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @see #onCreate
     * @see #onStop
     * @see #onResume
     */
    protected void onStart() {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onStart " + this);
        mCalled = true;

        if (!mLoadersStarted) {
            mLoadersStarted = true;
            if (mLoaderManager != null) {
                mLoaderManager.doStart();
            } else if (!mCheckedForLoaderManager) {
                mLoaderManager = getLoaderManager("(root)", mLoadersStarted, false);
            }
            mCheckedForLoaderManager = true;
        }

        getApplication().dispatchActivityStarted(this);
    }

    /**
     * Called after {@link #onStop} when the current activity is being
     * re-displayed to the user (the user has navigated back to it).  It will
     * be followed by {@link #onStart} and then {@link #onResume}.
     *
     * <p>For activities that are using raw {@link Cursor} objects (instead of
     * creating them through
     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)},
     * this is usually the place
     * where the cursor should be requeried (because you had deactivated it in
     * {@link #onStop}.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @see #onStop
     * @see #onStart
     * @see #onResume
     */
    protected void onRestart() {
        mCalled = true;
    }

    /**
     * Called after {@link #onRestoreInstanceState}, {@link #onRestart}, or
     * {@link #onPause}, for your activity to start interacting with the user.
     * This is a good place to begin animations, open exclusive-access devices
     * (such as the camera), etc.
     *
     * <p>Keep in mind that onResume is not the best indicator that your activity
     * is visible to the user; a system window such as the keyguard may be in
     * front.  Use {@link #onWindowFocusChanged} to know for certain that your
     * activity is visible to the user (for example, to resume a game).
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @see #onRestoreInstanceState
     * @see #onRestart
     * @see #onPostResume
     * @see #onPause
     */
    protected void onResume() {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onResume " + this);
        getApplication().dispatchActivityResumed(this);
        mActivityTransitionState.onResume();
        mCalled = true;
    }

    /**
     * Called when activity resume is complete (after {@link #onResume} has
     * been called). Applications will generally not implement this method;
     * it is intended for system classes to do final setup after application
     * resume code has run.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @see #onResume
     */
    protected void onPostResume() {
        final Window win = getWindow();
        if (win != null) win.makeActive();
        if (mActionBar != null) mActionBar.setShowHideAnimationEnabled(true);
        mCalled = true;
    }

    /**
     * @hide
     * Check whether this activity is running as part of a voice interaction with the user.
     * If true, it should perform its interaction with the user through the
     * {@link VoiceInteractor} returned by {@link #getVoiceInteractor}.
     */
    @SystemApi
    public boolean isVoiceInteraction() {
        return mVoiceInteractor != null;
    }

    /**
     * @hide
     * Retrieve the active {@link VoiceInteractor} that the user is going through to
     * interact with this activity.
     */
    @SystemApi
    public VoiceInteractor getVoiceInteractor() {
        return mVoiceInteractor;
    }

    /**
     * This is called for activities that set launchMode to "singleTop" in
     * their package, or if a client used the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP}
     * flag when calling {@link #startActivity}.  In either case, when the
     * activity is re-launched while at the top of the activity stack instead
     * of a new instance of the activity being started, onNewIntent() will be
     * called on the existing instance with the Intent that was used to
     * re-launch it.
     *
     * <p>An activity will always be paused before receiving a new intent, so
     * you can count on {@link #onResume} being called after this method.
     *
     * <p>Note that {@link #getIntent} still returns the original Intent.  You
     * can use {@link #setIntent} to update it to this new Intent.
     *
     * @param intent The new intent that was started for the activity.
     *
     * @see #getIntent
     * @see #setIntent
     * @see #onResume
     */
    protected void onNewIntent(Intent intent) {
    }

    /**
     * The hook for {@link ActivityThread} to save the state of this activity.
     *
     * Calls {@link #onSaveInstanceState(android.os.Bundle)}
     * and {@link #saveManagedDialogs(android.os.Bundle)}.
     *
     * @param outState The bundle to save the state to.
     */
    final void performSaveInstanceState(Bundle outState) {
        onSaveInstanceState(outState);
        saveManagedDialogs(outState);
        mActivityTransitionState.saveState(outState);
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onSaveInstanceState " + this + ": " + outState);
    }

    /**
     * The hook for {@link ActivityThread} to save the state of this activity.
     *
     * Calls {@link #onSaveInstanceState(android.os.Bundle)}
     * and {@link #saveManagedDialogs(android.os.Bundle)}.
     *
     * @param outState The bundle to save the state to.
     * @param outPersistentState The bundle to save persistent state to.
     */
    final void performSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
        onSaveInstanceState(outState, outPersistentState);
        saveManagedDialogs(outState);
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onSaveInstanceState " + this + ": " + outState +
                ", " + outPersistentState);
    }

    /**
     * Called to retrieve per-instance state from an activity before being killed
     * so that the state can be restored in {@link #onCreate} or
     * {@link #onRestoreInstanceState} (the {@link Bundle} populated by this method
     * will be passed to both).
     *
     * <p>This method is called before an activity may be killed so that when it
     * comes back some time in the future it can restore its state.  For example,
     * if activity B is launched in front of activity A, and at some point activity
     * A is killed to reclaim resources, activity A will have a chance to save the
     * current state of its user interface via this method so that when the user
     * returns to activity A, the state of the user interface can be restored
     * via {@link #onCreate} or {@link #onRestoreInstanceState}.
     *
     * <p>Do not confuse this method with activity lifecycle callbacks such as
     * {@link #onPause}, which is always called when an activity is being placed
     * in the background or on its way to destruction, or {@link #onStop} which
     * is called before destruction.  One example of when {@link #onPause} and
     * {@link #onStop} is called and not this method is when a user navigates back
     * from activity B to activity A: there is no need to call {@link #onSaveInstanceState}
     * on B because that particular instance will never be restored, so the
     * system avoids calling it.  An example when {@link #onPause} is called and
     * not {@link #onSaveInstanceState} is when activity B is launched in front of activity A:
     * the system may avoid calling {@link #onSaveInstanceState} on activity A if it isn't
     * killed during the lifetime of B since the state of the user interface of
     * A will stay intact.
     *
     * <p>The default implementation takes care of most of the UI per-instance
     * state for you by calling {@link android.view.View#onSaveInstanceState()} on each
     * view in the hierarchy that has an id, and by saving the id of the currently
     * focused view (all of which is restored by the default implementation of
     * {@link #onRestoreInstanceState}).  If you override this method to save additional
     * information not captured by each individual view, you will likely want to
     * call through to the default implementation, otherwise be prepared to save
     * all of the state of each view yourself.
     *
     * <p>If called, this method will occur before {@link #onStop}.  There are
     * no guarantees about whether it will occur before or after {@link #onPause}.
     *
     * @param outState Bundle in which to place your saved state.
     *
     * @see #onCreate
     * @see #onRestoreInstanceState
     * @see #onPause
     */
    protected void onSaveInstanceState(Bundle outState) {
        outState.putBundle(WINDOW_HIERARCHY_TAG, mWindow.saveHierarchyState());
        Parcelable p = mFragments.saveAllState();
        if (p != null) {
            outState.putParcelable(FRAGMENTS_TAG, p);
        }
        getApplication().dispatchActivitySaveInstanceState(this, outState);
    }

    /**
     * This is the same as {@link #onSaveInstanceState} but is called for activities
     * created with the attribute {@link android.R.attr#persistableMode} set to
     * <code>persistAcrossReboots</code>. The {@link android.os.PersistableBundle} passed
     * in will be saved and presented in {@link #onCreate(Bundle, PersistableBundle)}
     * the first time that this activity is restarted following the next device reboot.
     *
     * @param outState Bundle in which to place your saved state.
     * @param outPersistentState State which will be saved across reboots.
     *
     * @see #onSaveInstanceState(Bundle)
     * @see #onCreate
     * @see #onRestoreInstanceState(Bundle, PersistableBundle)
     * @see #onPause
     */
    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
        onSaveInstanceState(outState);
    }

    /**
     * Save the state of any managed dialogs.
     *
     * @param outState place to store the saved state.
     */
    private void saveManagedDialogs(Bundle outState) {
        if (mManagedDialogs == null) {
            return;
        }

        final int numDialogs = mManagedDialogs.size();
        if (numDialogs == 0) {
            return;
        }

        Bundle dialogState = new Bundle();

        int[] ids = new int[mManagedDialogs.size()];

        // save each dialog's bundle, gather the ids
        for (int i = 0; i < numDialogs; i++) {
            final int key = mManagedDialogs.keyAt(i);
            ids[i] = key;
            final ManagedDialog md = mManagedDialogs.valueAt(i);
            dialogState.putBundle(savedDialogKeyFor(key), md.mDialog.onSaveInstanceState());
            if (md.mArgs != null) {
                dialogState.putBundle(savedDialogArgsKeyFor(key), md.mArgs);
            }
        }

        dialogState.putIntArray(SAVED_DIALOG_IDS_KEY, ids);
        outState.putBundle(SAVED_DIALOGS_TAG, dialogState);
    }


    /**
     * Called as part of the activity lifecycle when an activity is going into
     * the background, but has not (yet) been killed.  The counterpart to
     * {@link #onResume}.
     *
     * <p>When activity B is launched in front of activity A, this callback will
     * be invoked on A.  B will not be created until A's {@link #onPause} returns,
     * so be sure to not do anything lengthy here.
     *
     * <p>This callback is mostly used for saving any persistent state the
     * activity is editing, to present a "edit in place" model to the user and
     * making sure nothing is lost if there are not enough resources to start
     * the new activity without first killing this one.  This is also a good
     * place to do things like stop animations and other things that consume a
     * noticeable amount of CPU in order to make the switch to the next activity
     * as fast as possible, or to close resources that are exclusive access
     * such as the camera.
     *
     * <p>In situations where the system needs more memory it may kill paused
     * processes to reclaim resources.  Because of this, you should be sure
     * that all of your state is saved by the time you return from
     * this function.  In general {@link #onSaveInstanceState} is used to save
     * per-instance state in the activity and this method is used to store
     * global persistent data (in content providers, files, etc.)
     *
     * <p>After receiving this call you will usually receive a following call
     * to {@link #onStop} (after the next activity has been resumed and
     * displayed), however in some cases there will be a direct call back to
     * {@link #onResume} without going through the stopped state.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @see #onResume
     * @see #onSaveInstanceState
     * @see #onStop
     */
    protected void onPause() {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onPause " + this);
        getApplication().dispatchActivityPaused(this);
        mCalled = true;
    }

    /**
     * Called as part of the activity lifecycle when an activity is about to go
     * into the background as the result of user choice.  For example, when the
     * user presses the Home key, {@link #onUserLeaveHint} will be called, but
     * when an incoming phone call causes the in-call Activity to be automatically
     * brought to the foreground, {@link #onUserLeaveHint} will not be called on
     * the activity being interrupted.  In cases when it is invoked, this method
     * is called right before the activity's {@link #onPause} callback.
     *
     * <p>This callback and {@link #onUserInteraction} are intended to help
     * activities manage status bar notifications intelligently; specifically,
     * for helping activities determine the proper time to cancel a notfication.
     *
     * @see #onUserInteraction()
     */
    protected void onUserLeaveHint() {
    }

    /**
     * Generate a new thumbnail for this activity.  This method is called before
     * pausing the activity, and should draw into <var>outBitmap</var> the
     * imagery for the desired thumbnail in the dimensions of that bitmap.  It
     * can use the given <var>canvas</var>, which is configured to draw into the
     * bitmap, for rendering if desired.
     *
     * <p>The default implementation returns fails and does not draw a thumbnail;
     * this will result in the platform creating its own thumbnail if needed.
     *
     * @param outBitmap The bitmap to contain the thumbnail.
     * @param canvas Can be used to render into the bitmap.
     *
     * @return Return true if you have drawn into the bitmap; otherwise after
     *         you return it will be filled with a default thumbnail.
     *
     * @see #onCreateDescription
     * @see #onSaveInstanceState
     * @see #onPause
     */
    public boolean onCreateThumbnail(Bitmap outBitmap, Canvas canvas) {
        return false;
    }

    /**
     * Generate a new description for this activity.  This method is called
     * before pausing the activity and can, if desired, return some textual
     * description of its current state to be displayed to the user.
     *
     * <p>The default implementation returns null, which will cause you to
     * inherit the description from the previous activity.  If all activities
     * return null, generally the label of the top activity will be used as the
     * description.
     *
     * @return A description of what the user is doing.  It should be short and
     *         sweet (only a few words).
     *
     * @see #onCreateThumbnail
     * @see #onSaveInstanceState
     * @see #onPause
     */
    @Nullable
    public CharSequence onCreateDescription() {
        return null;
    }

    /**
     * This is called when the user is requesting an assist, to build a full
     * {@link Intent#ACTION_ASSIST} Intent with all of the context of the current
     * application.  You can override this method to place into the bundle anything
     * you would like to appear in the {@link Intent#EXTRA_ASSIST_CONTEXT} part
     * of the assist Intent.  The default implementation does nothing.
     *
     * <p>This function will be called after any global assist callbacks that had
     * been registered with {@link Application#registerOnProvideAssistDataListener
     * Application.registerOnProvideAssistDataListener}.
     */
    public void onProvideAssistData(Bundle data) {
    }

    /**
     * Called when you are no longer visible to the user.  You will next
     * receive either {@link #onRestart}, {@link #onDestroy}, or nothing,
     * depending on later user activity.
     *
     * <p>Note that this method may never be called, in low memory situations
     * where the system does not have enough memory to keep your activity's
     * process running after its {@link #onPause} method is called.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @see #onRestart
     * @see #onResume
     * @see #onSaveInstanceState
     * @see #onDestroy
     */
    protected void onStop() {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onStop " + this);
        if (mActionBar != null) mActionBar.setShowHideAnimationEnabled(false);
        mActivityTransitionState.onStop();
        getApplication().dispatchActivityStopped(this);
        mTranslucentCallback = null;
        mCalled = true;
    }

    /**
     * Perform any final cleanup before an activity is destroyed.  This can
     * happen either because the activity is finishing (someone called
     * {@link #finish} on it, or because the system is temporarily destroying
     * this instance of the activity to save space.  You can distinguish
     * between these two scenarios with the {@link #isFinishing} method.
     *
     * <p><em>Note: do not count on this method being called as a place for
     * saving data! For example, if an activity is editing data in a content
     * provider, those edits should be committed in either {@link #onPause} or
     * {@link #onSaveInstanceState}, not here.</em> This method is usually implemented to
     * free resources like threads that are associated with an activity, so
     * that a destroyed activity does not leave such things around while the
     * rest of its application is still running.  There are situations where
     * the system will simply kill the activity's hosting process without
     * calling this method (or any others) in it, so it should not be used to
     * do things that are intended to remain around after the process goes
     * away.
     *
     * <p><em>Derived classes must call through to the super class's
     * implementation of this method.  If they do not, an exception will be
     * thrown.</em></p>
     *
     * @see #onPause
     * @see #onStop
     * @see #finish
     * @see #isFinishing
     */
    protected void onDestroy() {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onDestroy " + this);
        mCalled = true;

        // dismiss any dialogs we are managing.
        if (mManagedDialogs != null) {
            final int numDialogs = mManagedDialogs.size();
            for (int i = 0; i < numDialogs; i++) {
                final ManagedDialog md = mManagedDialogs.valueAt(i);
                if (md.mDialog.isShowing()) {
                    md.mDialog.dismiss();
                }
            }
            mManagedDialogs = null;
        }

        // close any cursors we are managing.
        synchronized (mManagedCursors) {
            int numCursors = mManagedCursors.size();
            for (int i = 0; i < numCursors; i++) {
                ManagedCursor c = mManagedCursors.get(i);
                if (c != null) {
                    c.mCursor.close();
                }
            }
            mManagedCursors.clear();
        }

        // Close any open search dialog
        if (mSearchManager != null) {
            mSearchManager.stopSearch();
        }

        getApplication().dispatchActivityDestroyed(this);
    }

    /**
     * Report to the system that your app is now fully drawn, purely for diagnostic
     * purposes (calling it does not impact the visible behavior of the activity).
     * This is only used to help instrument application launch times, so that the
     * app can report when it is fully in a usable state; without this, the only thing
     * the system itself can determine is the point at which the activity's window
     * is <em>first</em> drawn and displayed.  To participate in app launch time
     * measurement, you should always call this method after first launch (when
     * {@link #onCreate(android.os.Bundle)} is called), at the point where you have
     * entirely drawn your UI and populated with all of the significant data.  You
     * can safely call this method any time after first launch as well, in which case
     * it will simply be ignored.
     */
    public void reportFullyDrawn() {
        if (mDoReportFullyDrawn) {
            mDoReportFullyDrawn = false;
            try {
                ActivityManagerNative.getDefault().reportActivityFullyDrawn(mToken);
            } catch (RemoteException e) {
            }
        }
    }

    /**
     * Called by the system when the device configuration changes while your
     * activity is running.  Note that this will <em>only</em> be called if
     * you have selected configurations you would like to handle with the
     * {@link android.R.attr#configChanges} attribute in your manifest.  If
     * any configuration change occurs that is not selected to be reported
     * by that attribute, then instead of reporting it the system will stop
     * and restart the activity (to have it launched with the new
     * configuration).
     *
     * <p>At the time that this function has been called, your Resources
     * object will have been updated to return resource values matching the
     * new configuration.
     *
     * @param newConfig The new device configuration.
     */
    public void onConfigurationChanged(Configuration newConfig) {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onConfigurationChanged " + this + ": " + newConfig);
        mCalled = true;

        mFragments.dispatchConfigurationChanged(newConfig);

        if (mWindow != null) {
            // Pass the configuration changed event to the window
            mWindow.onConfigurationChanged(newConfig);
        }

        if (mActionBar != null) {
            // Do this last; the action bar will need to access
            // view changes from above.
            mActionBar.onConfigurationChanged(newConfig);
        }
    }

    /**
     * If this activity is being destroyed because it can not handle a
     * configuration parameter being changed (and thus its
     * {@link #onConfigurationChanged(Configuration)} method is
     * <em>not</em> being called), then you can use this method to discover
     * the set of changes that have occurred while in the process of being
     * destroyed.  Note that there is no guarantee that these will be
     * accurate (other changes could have happened at any time), so you should
     * only use this as an optimization hint.
     *
     * @return Returns a bit field of the configuration parameters that are
     * changing, as defined by the {@link android.content.res.Configuration}
     * class.
     */
    public int getChangingConfigurations() {
        return mConfigChangeFlags;
    }

    /**
     * Retrieve the non-configuration instance data that was previously
     * returned by {@link #onRetainNonConfigurationInstance()}.  This will
     * be available from the initial {@link #onCreate} and
     * {@link #onStart} calls to the new instance, allowing you to extract
     * any useful dynamic state from the previous instance.
     *
     * <p>Note that the data you retrieve here should <em>only</em> be used
     * as an optimization for handling configuration changes.  You should always
     * be able to handle getting a null pointer back, and an activity must
     * still be able to restore itself to its previous state (through the
     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
     * function returns null.
     *
     * @return Returns the object previously returned by
     * {@link #onRetainNonConfigurationInstance()}.
     *
     * @deprecated Use the new {@link Fragment} API
     * {@link Fragment#setRetainInstance(boolean)} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Nullable
    @Deprecated
    public Object getLastNonConfigurationInstance() {
        return mLastNonConfigurationInstances != null
                ? mLastNonConfigurationInstances.activity : null;
    }

    /**
     * Called by the system, as part of destroying an
     * activity due to a configuration change, when it is known that a new
     * instance will immediately be created for the new configuration.  You
     * can return any object you like here, including the activity instance
     * itself, which can later be retrieved by calling
     * {@link #getLastNonConfigurationInstance()} in the new activity
     * instance.
     *
     * <em>If you are targeting {@link android.os.Build.VERSION_CODES#HONEYCOMB}
     * or later, consider instead using a {@link Fragment} with
     * {@link Fragment#setRetainInstance(boolean)
     * Fragment.setRetainInstance(boolean}.</em>
     *
     * <p>This function is called purely as an optimization, and you must
     * not rely on it being called.  When it is called, a number of guarantees
     * will be made to help optimize configuration switching:
     * <ul>
     * <li> The function will be called between {@link #onStop} and
     * {@link #onDestroy}.
     * <li> A new instance of the activity will <em>always</em> be immediately
     * created after this one's {@link #onDestroy()} is called.  In particular,
     * <em>no</em> messages will be dispatched during this time (when the returned
     * object does not have an activity to be associated with).
     * <li> The object you return here will <em>always</em> be available from
     * the {@link #getLastNonConfigurationInstance()} method of the following
     * activity instance as described there.
     * </ul>
     *
     * <p>These guarantees are designed so that an activity can use this API
     * to propagate extensive state from the old to new activity instance, from
     * loaded bitmaps, to network connections, to evenly actively running
     * threads.  Note that you should <em>not</em> propagate any data that
     * may change based on the configuration, including any data loaded from
     * resources such as strings, layouts, or drawables.
     *
     * <p>The guarantee of no message handling during the switch to the next
     * activity simplifies use with active objects.  For example if your retained
     * state is an {@link android.os.AsyncTask} you are guaranteed that its
     * call back functions (like {@link android.os.AsyncTask#onPostExecute}) will
     * not be called from the call here until you execute the next instance's
     * {@link #onCreate(Bundle)}.  (Note however that there is of course no such
     * guarantee for {@link android.os.AsyncTask#doInBackground} since that is
     * running in a separate thread.)
     *
     * @return Return any Object holding the desired state to propagate to the
     * next activity instance.
     *
     * @deprecated Use the new {@link Fragment} API
     * {@link Fragment#setRetainInstance(boolean)} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    public Object onRetainNonConfigurationInstance() {
        return null;
    }

    /**
     * Retrieve the non-configuration instance data that was previously
     * returned by {@link #onRetainNonConfigurationChildInstances()}.  This will
     * be available from the initial {@link #onCreate} and
     * {@link #onStart} calls to the new instance, allowing you to extract
     * any useful dynamic state from the previous instance.
     *
     * <p>Note that the data you retrieve here should <em>only</em> be used
     * as an optimization for handling configuration changes.  You should always
     * be able to handle getting a null pointer back, and an activity must
     * still be able to restore itself to its previous state (through the
     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
     * function returns null.
     *
     * @return Returns the object previously returned by
     * {@link #onRetainNonConfigurationChildInstances()}
     */
    @Nullable
    HashMap<String, Object> getLastNonConfigurationChildInstances() {
        return mLastNonConfigurationInstances != null
                ? mLastNonConfigurationInstances.children : null;
    }

    /**
     * This method is similar to {@link #onRetainNonConfigurationInstance()} except that
     * it should return either a mapping from  child activity id strings to arbitrary objects,
     * or null.  This method is intended to be used by Activity framework subclasses that control a
     * set of child activities, such as ActivityGroup.  The same guarantees and restrictions apply
     * as for {@link #onRetainNonConfigurationInstance()}.  The default implementation returns null.
     */
    @Nullable
    HashMap<String,Object> onRetainNonConfigurationChildInstances() {
        return null;
    }

    NonConfigurationInstances retainNonConfigurationInstances() {
        Object activity = onRetainNonConfigurationInstance();
        HashMap<String, Object> children = onRetainNonConfigurationChildInstances();
        ArrayList<Fragment> fragments = mFragments.retainNonConfig();
        boolean retainLoaders = false;
        if (mAllLoaderManagers != null) {
            // prune out any loader managers that were already stopped and so
            // have nothing useful to retain.
            final int N = mAllLoaderManagers.size();
            LoaderManagerImpl loaders[] = new LoaderManagerImpl[N];
            for (int i=N-1; i>=0; i--) {
                loaders[i] = mAllLoaderManagers.valueAt(i);
            }
            for (int i=0; i<N; i++) {
                LoaderManagerImpl lm = loaders[i];
                if (lm.mRetaining) {
                    retainLoaders = true;
                } else {
                    lm.doDestroy();
                    mAllLoaderManagers.remove(lm.mWho);
                }
            }
        }
        if (activity == null && children == null && fragments == null && !retainLoaders
                && mVoiceInteractor == null) {
            return null;
        }

        NonConfigurationInstances nci = new NonConfigurationInstances();
        nci.activity = activity;
        nci.children = children;
        nci.fragments = fragments;
        nci.loaders = mAllLoaderManagers;
        nci.voiceInteractor = mVoiceInteractor;
        return nci;
    }

    public void onLowMemory() {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onLowMemory " + this);
        mCalled = true;
        mFragments.dispatchLowMemory();
    }

    public void onTrimMemory(int level) {
        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onTrimMemory " + this + ": " + level);
        mCalled = true;
        mFragments.dispatchTrimMemory(level);
    }

    /**
     * Return the FragmentManager for interacting with fragments associated
     * with this activity.
     */
    public FragmentManager getFragmentManager() {
        return mFragments;
    }

    void invalidateFragment(String who) {
        //Log.v(TAG, "invalidateFragmentIndex: index=" + index);
        if (mAllLoaderManagers != null) {
            LoaderManagerImpl lm = mAllLoaderManagers.get(who);
            if (lm != null && !lm.mRetaining) {
                lm.doDestroy();
                mAllLoaderManagers.remove(who);
            }
        }
    }

    /**
     * Called when a Fragment is being attached to this activity, immediately
     * after the call to its {@link Fragment#onAttach Fragment.onAttach()}
     * method and before {@link Fragment#onCreate Fragment.onCreate()}.
     */
    public void onAttachFragment(Fragment fragment) {
    }

    /**
     * Wrapper around
     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
     * that gives the resulting {@link Cursor} to call
     * {@link #startManagingCursor} so that the activity will manage its
     * lifecycle for you.
     *
     * <em>If you are targeting {@link android.os.Build.VERSION_CODES#HONEYCOMB}
     * or later, consider instead using {@link LoaderManager} instead, available
     * via {@link #getLoaderManager()}.</em>
     *
     * <p><strong>Warning:</strong> Do not call {@link Cursor#close()} on a cursor obtained using
     * this method, because the activity will do that for you at the appropriate time. However, if
     * you call {@link #stopManagingCursor} on a cursor from a managed query, the system <em>will
     * not</em> automatically close the cursor and, in that case, you must call
     * {@link Cursor#close()}.</p>
     *
     * @param uri The URI of the content provider to query.
     * @param projection List of columns to return.
     * @param selection SQL WHERE clause.
     * @param sortOrder SQL ORDER BY clause.
     *
     * @return The Cursor that was returned by query().
     *
     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
     * @see #startManagingCursor
     * @hide
     *
     * @deprecated Use {@link CursorLoader} instead.
     */
    @Deprecated
    public final Cursor managedQuery(Uri uri, String[] projection, String selection,
            String sortOrder) {
        Cursor c = getContentResolver().query(uri, projection, selection, null, sortOrder);
        if (c != null) {
            startManagingCursor(c);
        }
        return c;
    }

    /**
     * Wrapper around
     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
     * that gives the resulting {@link Cursor} to call
     * {@link #startManagingCursor} so that the activity will manage its
     * lifecycle for you.
     *
     * <em>If you are targeting {@link android.os.Build.VERSION_CODES#HONEYCOMB}
     * or later, consider instead using {@link LoaderManager} instead, available
     * via {@link #getLoaderManager()}.</em>
     *
     * <p><strong>Warning:</strong> Do not call {@link Cursor#close()} on a cursor obtained using
     * this method, because the activity will do that for you at the appropriate time. However, if
     * you call {@link #stopManagingCursor} on a cursor from a managed query, the system <em>will
     * not</em> automatically close the cursor and, in that case, you must call
     * {@link Cursor#close()}.</p>
     *
     * @param uri The URI of the content provider to query.
     * @param projection List of columns to return.
     * @param selection SQL WHERE clause.
     * @param selectionArgs The arguments to selection, if any ?s are pesent
     * @param sortOrder SQL ORDER BY clause.
     *
     * @return The Cursor that was returned by query().
     *
     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
     * @see #startManagingCursor
     *
     * @deprecated Use {@link CursorLoader} instead.
     */
    @Deprecated
    public final Cursor managedQuery(Uri uri, String[] projection, String selection,
            String[] selectionArgs, String sortOrder) {
        Cursor c = getContentResolver().query(uri, projection, selection, selectionArgs, sortOrder);
        if (c != null) {
            startManagingCursor(c);
        }
        return c;
    }

    /**
     * This method allows the activity to take care of managing the given
     * {@link Cursor}'s lifecycle for you based on the activity's lifecycle.
     * That is, when the activity is stopped it will automatically call
     * {@link Cursor#deactivate} on the given Cursor, and when it is later restarted
     * it will call {@link Cursor#requery} for you.  When the activity is
     * destroyed, all managed Cursors will be closed automatically.
     *
     * <em>If you are targeting {@link android.os.Build.VERSION_CODES#HONEYCOMB}
     * or later, consider instead using {@link LoaderManager} instead, available
     * via {@link #getLoaderManager()}.</em>
     *
     * <p><strong>Warning:</strong> Do not call {@link Cursor#close()} on cursor obtained from
     * {@link #managedQuery}, because the activity will do that for you at the appropriate time.
     * However, if you call {@link #stopManagingCursor} on a cursor from a managed query, the system
     * <em>will not</em> automatically close the cursor and, in that case, you must call
     * {@link Cursor#close()}.</p>
     *
     * @param c The Cursor to be managed.
     *
     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
     * @see #stopManagingCursor
     *
     * @deprecated Use the new {@link android.content.CursorLoader} class with
     * {@link LoaderManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Deprecated
    public void startManagingCursor(Cursor c) {
        synchronized (mManagedCursors) {
            mManagedCursors.add(new ManagedCursor(c));
        }
    }

    /**
     * Given a Cursor that was previously given to
     * {@link #startManagingCursor}, stop the activity's management of that
     * cursor.
     *
     * <p><strong>Warning:</strong> After calling this method on a cursor from a managed query,
     * the system <em>will not</em> automatically close the cursor and you must call
     * {@link Cursor#close()}.</p>
     *
     * @param c The Cursor that was being managed.
     *
     * @see #startManagingCursor
     *
     * @deprecated Use the new {@link android.content.CursorLoader} class with
     * {@link LoaderManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Deprecated
    public void stopManagingCursor(Cursor c) {
        synchronized (mManagedCursors) {
            final int N = mManagedCursors.size();
            for (int i=0; i<N; i++) {
                ManagedCursor mc = mManagedCursors.get(i);
                if (mc.mCursor == c) {
                    mManagedCursors.remove(i);
                    break;
                }
            }
        }
    }

    /**
     * @deprecated As of {@link android.os.Build.VERSION_CODES#GINGERBREAD}
     * this is a no-op.
     * @hide
     */
    @Deprecated
    public void setPersistent(boolean isPersistent) {
    }

    /**
     * Finds a view that was identified by the id attribute from the XML that
     * was processed in {@link #onCreate}.
     *
     * @return The view if found or null otherwise.
     */
    public View findViewById(int id) {
        return getWindow().findViewById(id);
    }

    /**
     * Retrieve a reference to this activity's ActionBar.
     *
     * @return The Activity's ActionBar, or null if it does not have one.
     */
    @Nullable
    public ActionBar getActionBar() {
        initWindowDecorActionBar();
        return mActionBar;
    }

    /**
     * Set a {@link android.widget.Toolbar Toolbar} to act as the {@link ActionBar} for this
     * Activity window.
     *
     * <p>When set to a non-null value the {@link #getActionBar()} method will return
     * an {@link ActionBar} object that can be used to control the given toolbar as if it were
     * a traditional window decor action bar. The toolbar's menu will be populated with the
     * Activity's options menu and the navigation button will be wired through the standard
     * {@link android.R.id#home home} menu select action.</p>
     *
     * <p>In order to use a Toolbar within the Activity's window content the application
     * must not request the window feature {@link Window#FEATURE_ACTION_BAR FEATURE_ACTION_BAR}.</p>
     *
     * @param toolbar Toolbar to set as the Activity's action bar
     */
    public void setActionBar(@Nullable Toolbar toolbar) {
        if (getActionBar() instanceof WindowDecorActionBar) {
            throw new IllegalStateException("This Activity already has an action bar supplied " +
                    "by the window decor. Do not request Window.FEATURE_ACTION_BAR and set " +
                    "android:windowActionBar to false in your theme to use a Toolbar instead.");
        }
        ToolbarActionBar tbab = new ToolbarActionBar(toolbar, getTitle(), this);
        mActionBar = tbab;
        mWindow.setCallback(tbab.getWrappedWindowCallback());
        mActionBar.invalidateOptionsMenu();
    }

    /**
     * Creates a new ActionBar, locates the inflated ActionBarView,
     * initializes the ActionBar with the view, and sets mActionBar.
     */
    private void initWindowDecorActionBar() {
        Window window = getWindow();

        // Initializing the window decor can change window feature flags.
        // Make sure that we have the correct set before performing the test below.
        window.getDecorView();

        if (isChild() || !window.hasFeature(Window.FEATURE_ACTION_BAR) || mActionBar != null) {
            return;
        }

        mActionBar = new WindowDecorActionBar(this);
        mActionBar.setDefaultDisplayHomeAsUpEnabled(mEnableDefaultActionBarUp);

        mWindow.setDefaultIcon(mActivityInfo.getIconResource());
        mWindow.setDefaultLogo(mActivityInfo.getLogoResource());
    }

    /**
     * Set the activity content from a layout resource.  The resource will be
     * inflated, adding all top-level views to the activity.
     *
     * @param layoutResID Resource ID to be inflated.
     *
     * @see #setContentView(android.view.View)
     * @see #setContentView(android.view.View, android.view.ViewGroup.LayoutParams)
     */
    public void setContentView(int layoutResID) {
        getWindow().setContentView(layoutResID);
        initWindowDecorActionBar();
    }

    /**
     * Set the activity content to an explicit view.  This view is placed
     * directly into the activity's view hierarchy.  It can itself be a complex
     * view hierarchy.  When calling this method, the layout parameters of the
     * specified view are ignored.  Both the width and the height of the view are
     * set by default to {@link ViewGroup.LayoutParams#MATCH_PARENT}. To use
     * your own layout parameters, invoke
     * {@link #setContentView(android.view.View, android.view.ViewGroup.LayoutParams)}
     * instead.
     *
     * @param view The desired content to display.
     *
     * @see #setContentView(int)
     * @see #setContentView(android.view.View, android.view.ViewGroup.LayoutParams)
     */
    public void setContentView(View view) {
        getWindow().setContentView(view);
        initWindowDecorActionBar();
    }

    /**
     * Set the activity content to an explicit view.  This view is placed
     * directly into the activity's view hierarchy.  It can itself be a complex
     * view hierarchy.
     *
     * @param view The desired content to display.
     * @param params Layout parameters for the view.
     *
     * @see #setContentView(android.view.View)
     * @see #setContentView(int)
     */
    public void setContentView(View view, ViewGroup.LayoutParams params) {
        getWindow().setContentView(view, params);
        initWindowDecorActionBar();
    }

    /**
     * Add an additional content view to the activity.  Added after any existing
     * ones in the activity -- existing views are NOT removed.
     *
     * @param view The desired content to display.
     * @param params Layout parameters for the view.
     */
    public void addContentView(View view, ViewGroup.LayoutParams params) {
        getWindow().addContentView(view, params);
        initWindowDecorActionBar();
    }

    /**
     * Retrieve the {@link TransitionManager} responsible for default transitions in this window.
     * Requires {@link Window#FEATURE_CONTENT_TRANSITIONS}.
     *
     * <p>This method will return non-null after content has been initialized (e.g. by using
     * {@link #setContentView}) if {@link Window#FEATURE_CONTENT_TRANSITIONS} has been granted.</p>
     *
     * @return This window's content TransitionManager or null if none is set.
     */
    public TransitionManager getContentTransitionManager() {
        return getWindow().getTransitionManager();
    }

    /**
     * Set the {@link TransitionManager} to use for default transitions in this window.
     * Requires {@link Window#FEATURE_CONTENT_TRANSITIONS}.
     *
     * @param tm The TransitionManager to use for scene changes.
     */
    public void setContentTransitionManager(TransitionManager tm) {
        getWindow().setTransitionManager(tm);
    }

    /**
     * Retrieve the {@link Scene} representing this window's current content.
     * Requires {@link Window#FEATURE_CONTENT_TRANSITIONS}.
     *
     * <p>This method will return null if the current content is not represented by a Scene.</p>
     *
     * @return Current Scene being shown or null
     */
    public Scene getContentScene() {
        return getWindow().getContentScene();
    }

    /**
     * Sets whether this activity is finished when touched outside its window's
     * bounds.
     */
    public void setFinishOnTouchOutside(boolean finish) {
        mWindow.setCloseOnTouchOutside(finish);
    }

    /** @hide */
    @IntDef({
            DEFAULT_KEYS_DISABLE,
            DEFAULT_KEYS_DIALER,
            DEFAULT_KEYS_SHORTCUT,
            DEFAULT_KEYS_SEARCH_LOCAL,
            DEFAULT_KEYS_SEARCH_GLOBAL})
    @Retention(RetentionPolicy.SOURCE)
    @interface DefaultKeyMode {}

    /**
     * Use with {@link #setDefaultKeyMode} to turn off default handling of
     * keys.
     *
     * @see #setDefaultKeyMode
     */
    static public final int DEFAULT_KEYS_DISABLE = 0;
    /**
     * Use with {@link #setDefaultKeyMode} to launch the dialer during default
     * key handling.
     *
     * @see #setDefaultKeyMode
     */
    static public final int DEFAULT_KEYS_DIALER = 1;
    /**
     * Use with {@link #setDefaultKeyMode} to execute a menu shortcut in
     * default key handling.
     *
     * <p>That is, the user does not need to hold down the menu key to execute menu shortcuts.
     *
     * @see #setDefaultKeyMode
     */
    static public final int DEFAULT_KEYS_SHORTCUT = 2;
    /**
     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
     * will start an application-defined search.  (If the application or activity does not
     * actually define a search, the the keys will be ignored.)
     *
     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
     *
     * @see #setDefaultKeyMode
     */
    static public final int DEFAULT_KEYS_SEARCH_LOCAL = 3;

    /**
     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
     * will start a global search (typically web search, but some platforms may define alternate
     * methods for global search)
     *
     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
     *
     * @see #setDefaultKeyMode
     */
    static public final int DEFAULT_KEYS_SEARCH_GLOBAL = 4;

    /**
     * Select the default key handling for this activity.  This controls what
     * will happen to key events that are not otherwise handled.  The default
     * mode ({@link #DEFAULT_KEYS_DISABLE}) will simply drop them on the
     * floor. Other modes allow you to launch the dialer
     * ({@link #DEFAULT_KEYS_DIALER}), execute a shortcut in your options
     * menu without requiring the menu key be held down
     * ({@link #DEFAULT_KEYS_SHORTCUT}), or launch a search ({@link #DEFAULT_KEYS_SEARCH_LOCAL}
     * and {@link #DEFAULT_KEYS_SEARCH_GLOBAL}).
     *
     * <p>Note that the mode selected here does not impact the default
     * handling of system keys, such as the "back" and "menu" keys, and your
     * activity and its views always get a first chance to receive and handle
     * all application keys.
     *
     * @param mode The desired default key mode constant.
     *
     * @see #DEFAULT_KEYS_DISABLE
     * @see #DEFAULT_KEYS_DIALER
     * @see #DEFAULT_KEYS_SHORTCUT
     * @see #DEFAULT_KEYS_SEARCH_LOCAL
     * @see #DEFAULT_KEYS_SEARCH_GLOBAL
     * @see #onKeyDown
     */
    public final void setDefaultKeyMode(@DefaultKeyMode int mode) {
        mDefaultKeyMode = mode;

        // Some modes use a SpannableStringBuilder to track & dispatch input events
        // This list must remain in sync with the switch in onKeyDown()
        switch (mode) {
        case DEFAULT_KEYS_DISABLE:
        case DEFAULT_KEYS_SHORTCUT:
            mDefaultKeySsb = null;      // not used in these modes
            break;
        case DEFAULT_KEYS_DIALER:
        case DEFAULT_KEYS_SEARCH_LOCAL:
        case DEFAULT_KEYS_SEARCH_GLOBAL:
            mDefaultKeySsb = new SpannableStringBuilder();
            Selection.setSelection(mDefaultKeySsb,0);
            break;
        default:
            throw new IllegalArgumentException();
        }
    }

    /**
     * Called when a key was pressed down and not handled by any of the views
     * inside of the activity. So, for example, key presses while the cursor
     * is inside a TextView will not trigger the event (unless it is a navigation
     * to another object) because TextView handles its own key presses.
     *
     * <p>If the focused view didn't want this event, this method is called.
     *
     * <p>The default implementation takes care of {@link KeyEvent#KEYCODE_BACK}
     * by calling {@link #onBackPressed()}, though the behavior varies based
     * on the application compatibility mode: for
     * {@link android.os.Build.VERSION_CODES#ECLAIR} or later applications,
     * it will set up the dispatch to call {@link #onKeyUp} where the action
     * will be performed; for earlier applications, it will perform the
     * action immediately in on-down, as those versions of the platform
     * behaved.
     *
     * <p>Other additional default key handling may be performed
     * if configured with {@link #setDefaultKeyMode}.
     *
     * @return Return <code>true</code> to prevent this event from being propagated
     * further, or <code>false</code> to indicate that you have not handled
     * this event and it should continue to be propagated.
     * @see #onKeyUp
     * @see android.view.KeyEvent
     */
    public boolean onKeyDown(int keyCode, KeyEvent event)  {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            if (getApplicationInfo().targetSdkVersion
                    >= Build.VERSION_CODES.ECLAIR) {
                event.startTracking();
            } else {
                onBackPressed();
            }
            return true;
        }

        if (mDefaultKeyMode == DEFAULT_KEYS_DISABLE) {
            return false;
        } else if (mDefaultKeyMode == DEFAULT_KEYS_SHORTCUT) {
            if (getWindow().performPanelShortcut(Window.FEATURE_OPTIONS_PANEL,
                    keyCode, event, Menu.FLAG_ALWAYS_PERFORM_CLOSE)) {
                return true;
            }
            return false;
        } else {
            // Common code for DEFAULT_KEYS_DIALER & DEFAULT_KEYS_SEARCH_*
            boolean clearSpannable = false;
            boolean handled;
            if ((event.getRepeatCount() != 0) || event.isSystem()) {
                clearSpannable = true;
                handled = false;
            } else {
                handled = TextKeyListener.getInstance().onKeyDown(
                        null, mDefaultKeySsb, keyCode, event);
                if (handled && mDefaultKeySsb.length() > 0) {
                    // something useable has been typed - dispatch it now.

                    final String str = mDefaultKeySsb.toString();
                    clearSpannable = true;

                    switch (mDefaultKeyMode) {
                    case DEFAULT_KEYS_DIALER:
                        Intent intent = new Intent(Intent.ACTION_DIAL,  Uri.parse("tel:" + str));
                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                        startActivity(intent);
                        break;
                    case DEFAULT_KEYS_SEARCH_LOCAL:
                        startSearch(str, false, null, false);
                        break;
                    case DEFAULT_KEYS_SEARCH_GLOBAL:
                        startSearch(str, false, null, true);
                        break;
                    }
                }
            }
            if (clearSpannable) {
                mDefaultKeySsb.clear();
                mDefaultKeySsb.clearSpans();
                Selection.setSelection(mDefaultKeySsb,0);
            }
            return handled;
        }
    }

    /**
     * Default implementation of {@link KeyEvent.Callback#onKeyLongPress(int, KeyEvent)
     * KeyEvent.Callback.onKeyLongPress()}: always returns false (doesn't handle
     * the event).
     */
    public boolean onKeyLongPress(int keyCode, KeyEvent event) {
        return false;
    }

    /**
     * Called when a key was released and not handled by any of the views
     * inside of the activity. So, for example, key presses while the cursor
     * is inside a TextView will not trigger the event (unless it is a navigation
     * to another object) because TextView handles its own key presses.
     *
     * <p>The default implementation handles KEYCODE_BACK to stop the activity
     * and go back.
     *
     * @return Return <code>true</code> to prevent this event from being propagated
     * further, or <code>false</code> to indicate that you have not handled
     * this event and it should continue to be propagated.
     * @see #onKeyDown
     * @see KeyEvent
     */
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        if (getApplicationInfo().targetSdkVersion
                >= Build.VERSION_CODES.ECLAIR) {
            if (keyCode == KeyEvent.KEYCODE_BACK && event.isTracking()
                    && !event.isCanceled()) {
                onBackPressed();
                return true;
            }
        }
        return false;
    }

    /**
     * Default implementation of {@link KeyEvent.Callback#onKeyMultiple(int, int, KeyEvent)
     * KeyEvent.Callback.onKeyMultiple()}: always returns false (doesn't handle
     * the event).
     */
    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
        return false;
    }

    /**
     * Called when the activity has detected the user's press of the back
     * key.  The default implementation simply finishes the current activity,
     * but you can override this to do whatever you want.
     */
    public void onBackPressed() {
        if (mActionBar != null && mActionBar.collapseActionView()) {
            return;
        }

        if (!mFragments.popBackStackImmediate()) {
            finishAfterTransition();
        }
    }

    /**
     * Called when a key shortcut event is not handled by any of the views in the Activity.
     * Override this method to implement global key shortcuts for the Activity.
     * Key shortcuts can also be implemented by setting the
     * {@link MenuItem#setShortcut(char, char) shortcut} property of menu items.
     *
     * @param keyCode The value in event.getKeyCode().
     * @param event Description of the key event.
     * @return True if the key shortcut was handled.
     */
    public boolean onKeyShortcut(int keyCode, KeyEvent event) {
        return false;
    }

    /**
     * Called when a touch screen event was not handled by any of the views
     * under it.  This is most useful to process touch events that happen
     * outside of your window bounds, where there is no view to receive it.
     *
     * @param event The touch screen event being processed.
     *
     * @return Return true if you have consumed the event, false if you haven't.
     * The default implementation always returns false.
     */
    public boolean onTouchEvent(MotionEvent event) {
        if (mWindow.shouldCloseOnTouch(this, event)) {
            finish();
            return true;
        }

        return false;
    }

    /**
     * Called when the trackball was moved and not handled by any of the
     * views inside of the activity.  So, for example, if the trackball moves
     * while focus is on a button, you will receive a call here because
     * buttons do not normally do anything with trackball events.  The call
     * here happens <em>before</em> trackball movements are converted to
     * DPAD key events, which then get sent back to the view hierarchy, and
     * will be processed at the point for things like focus navigation.
     *
     * @param event The trackball event being processed.
     *
     * @return Return true if you have consumed the event, false if you haven't.
     * The default implementation always returns false.
     */
    public boolean onTrackballEvent(MotionEvent event) {
        return false;
    }

    /**
     * Called when a generic motion event was not handled by any of the
     * views inside of the activity.
     * <p>
     * Generic motion events describe joystick movements, mouse hovers, track pad
     * touches, scroll wheel movements and other input events.  The
     * {@link MotionEvent#getSource() source} of the motion event specifies
     * the class of input that was received.  Implementations of this method
     * must examine the bits in the source before processing the event.
     * The following code example shows how this is done.
     * </p><p>
     * Generic motion events with source class
     * {@link android.view.InputDevice#SOURCE_CLASS_POINTER}
     * are delivered to the view under the pointer.  All other generic motion events are
     * delivered to the focused view.
     * </p><p>
     * See {@link View#onGenericMotionEvent(MotionEvent)} for an example of how to
     * handle this event.
     * </p>
     *
     * @param event The generic motion event being processed.
     *
     * @return Return true if you have consumed the event, false if you haven't.
     * The default implementation always returns false.
     */
    public boolean onGenericMotionEvent(MotionEvent event) {
        return false;
    }

    /**
     * Called whenever a key, touch, or trackball event is dispatched to the
     * activity.  Implement this method if you wish to know that the user has
     * interacted with the device in some way while your activity is running.
     * This callback and {@link #onUserLeaveHint} are intended to help
     * activities manage status bar notifications intelligently; specifically,
     * for helping activities determine the proper time to cancel a notfication.
     *
     * <p>All calls to your activity's {@link #onUserLeaveHint} callback will
     * be accompanied by calls to {@link #onUserInteraction}.  This
     * ensures that your activity will be told of relevant user activity such
     * as pulling down the notification pane and touching an item there.
     *
     * <p>Note that this callback will be invoked for the touch down action
     * that begins a touch gesture, but may not be invoked for the touch-moved
     * and touch-up actions that follow.
     *
     * @see #onUserLeaveHint()
     */
    public void onUserInteraction() {
    }

    public void onWindowAttributesChanged(WindowManager.LayoutParams params) {
        // Update window manager if: we have a view, that view is
        // attached to its parent (which will be a RootView), and
        // this activity is not embedded.
        if (mParent == null) {
            View decor = mDecor;
            if (decor != null && decor.getParent() != null) {
                getWindowManager().updateViewLayout(decor, params);
            }
        }
    }

    public void onContentChanged() {
    }

    /**
     * Called when the current {@link Window} of the activity gains or loses
     * focus.  This is the best indicator of whether this activity is visible
     * to the user.  The default implementation clears the key tracking
     * state, so should always be called.
     *
     * <p>Note that this provides information about global focus state, which
     * is managed independently of activity lifecycles.  As such, while focus
     * changes will generally have some relation to lifecycle changes (an
     * activity that is stopped will not generally get window focus), you
     * should not rely on any particular order between the callbacks here and
     * those in the other lifecycle methods such as {@link #onResume}.
     *
     * <p>As a general rule, however, a resumed activity will have window
     * focus...  unless it has displayed other dialogs or popups that take
     * input focus, in which case the activity itself will not have focus
     * when the other windows have it.  Likewise, the system may display
     * system-level windows (such as the status bar notification panel or
     * a system alert) which will temporarily take window input focus without
     * pausing the foreground activity.
     *
     * @param hasFocus Whether the window of this activity has focus.
     *
     * @see #hasWindowFocus()
     * @see #onResume
     * @see View#onWindowFocusChanged(boolean)
     */
    public void onWindowFocusChanged(boolean hasFocus) {
    }

    /**
     * Called when the main window associated with the activity has been
     * attached to the window manager.
     * See {@link View#onAttachedToWindow() View.onAttachedToWindow()}
     * for more information.
     * @see View#onAttachedToWindow
     */
    public void onAttachedToWindow() {
    }

    /**
     * Called when the main window associated with the activity has been
     * detached from the window manager.
     * See {@link View#onDetachedFromWindow() View.onDetachedFromWindow()}
     * for more information.
     * @see View#onDetachedFromWindow
     */
    public void onDetachedFromWindow() {
    }

    /**
     * Returns true if this activity's <em>main</em> window currently has window focus.
     * Note that this is not the same as the view itself having focus.
     *
     * @return True if this activity's main window currently has window focus.
     *
     * @see #onWindowAttributesChanged(android.view.WindowManager.LayoutParams)
     */
    public boolean hasWindowFocus() {
        Window w = getWindow();
        if (w != null) {
            View d = w.getDecorView();
            if (d != null) {
                return d.hasWindowFocus();
            }
        }
        return false;
    }

    /**
     * Called when the main window associated with the activity has been dismissed.
     * @hide
     */
    @Override
    public void onWindowDismissed() {
        finish();
    }

    /**
     * Called to process key events.  You can override this to intercept all
     * key events before they are dispatched to the window.  Be sure to call
     * this implementation for key events that should be handled normally.
     *
     * @param event The key event.
     *
     * @return boolean Return true if this event was consumed.
     */
    public boolean dispatchKeyEvent(KeyEvent event) {
        onUserInteraction();

        // Let action bars open menus in response to the menu key prioritized over
        // the window handling it
        if (event.getKeyCode() == KeyEvent.KEYCODE_MENU &&
                mActionBar != null && mActionBar.onMenuKeyEvent(event)) {
            return true;
        }

        Window win = getWindow();
        if (win.superDispatchKeyEvent(event)) {
            return true;
        }
        View decor = mDecor;
        if (decor == null) decor = win.getDecorView();
        return event.dispatch(this, decor != null
                ? decor.getKeyDispatcherState() : null, this);
    }

    /**
     * Called to process a key shortcut event.
     * You can override this to intercept all key shortcut events before they are
     * dispatched to the window.  Be sure to call this implementation for key shortcut
     * events that should be handled normally.
     *
     * @param event The key shortcut event.
     * @return True if this event was consumed.
     */
    public boolean dispatchKeyShortcutEvent(KeyEvent event) {
        onUserInteraction();
        if (getWindow().superDispatchKeyShortcutEvent(event)) {
            return true;
        }
        return onKeyShortcut(event.getKeyCode(), event);
    }

    /**
     * Called to process touch screen events.  You can override this to
     * intercept all touch screen events before they are dispatched to the
     * window.  Be sure to call this implementation for touch screen events
     * that should be handled normally.
     *
     * @param ev The touch screen event.
     *
     * @return boolean Return true if this event was consumed.
     */
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
            onUserInteraction();
        }
        if (getWindow().superDispatchTouchEvent(ev)) {
            return true;
        }
        return onTouchEvent(ev);
    }

    /**
     * Called to process trackball events.  You can override this to
     * intercept all trackball events before they are dispatched to the
     * window.  Be sure to call this implementation for trackball events
     * that should be handled normally.
     *
     * @param ev The trackball event.
     *
     * @return boolean Return true if this event was consumed.
     */
    public boolean dispatchTrackballEvent(MotionEvent ev) {
        onUserInteraction();
        if (getWindow().superDispatchTrackballEvent(ev)) {
            return true;
        }
        return onTrackballEvent(ev);
    }

    /**
     * Called to process generic motion events.  You can override this to
     * intercept all generic motion events before they are dispatched to the
     * window.  Be sure to call this implementation for generic motion events
     * that should be handled normally.
     *
     * @param ev The generic motion event.
     *
     * @return boolean Return true if this event was consumed.
     */
    public boolean dispatchGenericMotionEvent(MotionEvent ev) {
        onUserInteraction();
        if (getWindow().superDispatchGenericMotionEvent(ev)) {
            return true;
        }
        return onGenericMotionEvent(ev);
    }

    public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) {
        event.setClassName(getClass().getName());
        event.setPackageName(getPackageName());

        LayoutParams params = getWindow().getAttributes();
        boolean isFullScreen = (params.width == LayoutParams.MATCH_PARENT) &&
            (params.height == LayoutParams.MATCH_PARENT);
        event.setFullScreen(isFullScreen);

        CharSequence title = getTitle();
        if (!TextUtils.isEmpty(title)) {
           event.getText().add(title);
        }

        return true;
    }

    /**
     * Default implementation of
     * {@link android.view.Window.Callback#onCreatePanelView}
     * for activities. This
     * simply returns null so that all panel sub-windows will have the default
     * menu behavior.
     */
    @Nullable
    public View onCreatePanelView(int featureId) {
        return null;
    }

    /**
     * Default implementation of
     * {@link android.view.Window.Callback#onCreatePanelMenu}
     * for activities.  This calls through to the new
     * {@link #onCreateOptionsMenu} method for the
     * {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
     * so that subclasses of Activity don't need to deal with feature codes.
     */
    public boolean onCreatePanelMenu(int featureId, Menu menu) {
        if (featureId == Window.FEATURE_OPTIONS_PANEL) {
            boolean show = onCreateOptionsMenu(menu);
            show |= mFragments.dispatchCreateOptionsMenu(menu, getMenuInflater());
            return show;
        }
        return false;
    }

    /**
     * Default implementation of
     * {@link android.view.Window.Callback#onPreparePanel}
     * for activities.  This
     * calls through to the new {@link #onPrepareOptionsMenu} method for the
     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
     * panel, so that subclasses of
     * Activity don't need to deal with feature codes.
     */
    public boolean onPreparePanel(int featureId, View view, Menu menu) {
        if (featureId == Window.FEATURE_OPTIONS_PANEL && menu != null) {
            boolean goforit = onPrepareOptionsMenu(menu);
            goforit |= mFragments.dispatchPrepareOptionsMenu(menu);
            return goforit;
        }
        return true;
    }

    /**
     * {@inheritDoc}
     *
     * @return The default implementation returns true.
     */
    public boolean onMenuOpened(int featureId, Menu menu) {
        if (featureId == Window.FEATURE_ACTION_BAR) {
            initWindowDecorActionBar();
            if (mActionBar != null) {
                mActionBar.dispatchMenuVisibilityChanged(true);
            } else {
                Log.e(TAG, "Tried to open action bar menu with no action bar");
            }
        }
        return true;
    }

    /**
     * Default implementation of
     * {@link android.view.Window.Callback#onMenuItemSelected}
     * for activities.  This calls through to the new
     * {@link #onOptionsItemSelected} method for the
     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
     * panel, so that subclasses of
     * Activity don't need to deal with feature codes.
     */
    public boolean onMenuItemSelected(int featureId, MenuItem item) {
        CharSequence titleCondensed = item.getTitleCondensed();

        switch (featureId) {
            case Window.FEATURE_OPTIONS_PANEL:
                // Put event logging here so it gets called even if subclass
                // doesn't call through to superclass's implmeentation of each
                // of these methods below
                if(titleCondensed != null) {
                    EventLog.writeEvent(50000, 0, titleCondensed.toString());
                }
                if (onOptionsItemSelected(item)) {
                    return true;
                }
                if (mFragments.dispatchOptionsItemSelected(item)) {
                    return true;
                }
                if (item.getItemId() == android.R.id.home && mActionBar != null &&
                        (mActionBar.getDisplayOptions() & ActionBar.DISPLAY_HOME_AS_UP) != 0) {
                    if (mParent == null) {
                        return onNavigateUp();
                    } else {
                        return mParent.onNavigateUpFromChild(this);
                    }
                }
                return false;

            case Window.FEATURE_CONTEXT_MENU:
                if(titleCondensed != null) {
                    EventLog.writeEvent(50000, 1, titleCondensed.toString());
                }
                if (onContextItemSelected(item)) {
                    return true;
                }
                return mFragments.dispatchContextItemSelected(item);

            default:
                return false;
        }
    }

    /**
     * Default implementation of
     * {@link android.view.Window.Callback#onPanelClosed(int, Menu)} for
     * activities. This calls through to {@link #onOptionsMenuClosed(Menu)}
     * method for the {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
     * so that subclasses of Activity don't need to deal with feature codes.
     * For context menus ({@link Window#FEATURE_CONTEXT_MENU}), the
     * {@link #onContextMenuClosed(Menu)} will be called.
     */
    public void onPanelClosed(int featureId, Menu menu) {
        switch (featureId) {
            case Window.FEATURE_OPTIONS_PANEL:
                mFragments.dispatchOptionsMenuClosed(menu);
                onOptionsMenuClosed(menu);
                break;

            case Window.FEATURE_CONTEXT_MENU:
                onContextMenuClosed(menu);
                break;

            case Window.FEATURE_ACTION_BAR:
                initWindowDecorActionBar();
                mActionBar.dispatchMenuVisibilityChanged(false);
                break;
        }
    }

    /**
     * Declare that the options menu has changed, so should be recreated.
     * The {@link #onCreateOptionsMenu(Menu)} method will be called the next
     * time it needs to be displayed.
     */
    public void invalidateOptionsMenu() {
        if (mActionBar == null || !mActionBar.invalidateOptionsMenu()) {
            mWindow.invalidatePanelMenu(Window.FEATURE_OPTIONS_PANEL);
        }
    }

    /**
     * Initialize the contents of the Activity's standard options menu.  You
     * should place your menu items in to <var>menu</var>.
     *
     * <p>This is only called once, the first time the options menu is
     * displayed.  To update the menu every time it is displayed, see
     * {@link #onPrepareOptionsMenu}.
     *
     * <p>The default implementation populates the menu with standard system
     * menu items.  These are placed in the {@link Menu#CATEGORY_SYSTEM} group so that
     * they will be correctly ordered with application-defined menu items.
     * Deriving classes should always call through to the base implementation.
     *
     * <p>You can safely hold on to <var>menu</var> (and any items created
     * from it), making modifications to it as desired, until the next
     * time onCreateOptionsMenu() is called.
     *
     * <p>When you add items to the menu, you can implement the Activity's
     * {@link #onOptionsItemSelected} method to handle them there.
     *
     * @param menu The options menu in which you place your items.
     *
     * @return You must return true for the menu to be displayed;
     *         if you return false it will not be shown.
     *
     * @see #onPrepareOptionsMenu
     * @see #onOptionsItemSelected
     */
    public boolean onCreateOptionsMenu(Menu menu) {
        if (mParent != null) {
            return mParent.onCreateOptionsMenu(menu);
        }
        return true;
    }

    /**
     * Prepare the Screen's standard options menu to be displayed.  This is
     * called right before the menu is shown, every time it is shown.  You can
     * use this method to efficiently enable/disable items or otherwise
     * dynamically modify the contents.
     *
     * <p>The default implementation updates the system menu items based on the
     * activity's state.  Deriving classes should always call through to the
     * base class implementation.
     *
     * @param menu The options menu as last shown or first initialized by
     *             onCreateOptionsMenu().
     *
     * @return You must return true for the menu to be displayed;
     *         if you return false it will not be shown.
     *
     * @see #onCreateOptionsMenu
     */
    public boolean onPrepareOptionsMenu(Menu menu) {
        if (mParent != null) {
            return mParent.onPrepareOptionsMenu(menu);
        }
        return true;
    }

    /**
     * This hook is called whenever an item in your options menu is selected.
     * The default implementation simply returns false to have the normal
     * processing happen (calling the item's Runnable or sending a message to
     * its Handler as appropriate).  You can use this method for any items
     * for which you would like to do processing without those other
     * facilities.
     *
     * <p>Derived classes should call through to the base class for it to
     * perform the default menu handling.</p>
     *
     * @param item The menu item that was selected.
     *
     * @return boolean Return false to allow normal menu processing to
     *         proceed, true to consume it here.
     *
     * @see #onCreateOptionsMenu
     */
    public boolean onOptionsItemSelected(MenuItem item) {
        if (mParent != null) {
            return mParent.onOptionsItemSelected(item);
        }
        return false;
    }

    /**
     * This method is called whenever the user chooses to navigate Up within your application's
     * activity hierarchy from the action bar.
     *
     * <p>If the attribute {@link android.R.attr#parentActivityName parentActivityName}
     * was specified in the manifest for this activity or an activity-alias to it,
     * default Up navigation will be handled automatically. If any activity
     * along the parent chain requires extra Intent arguments, the Activity subclass
     * should override the method {@link #onPrepareNavigateUpTaskStack(TaskStackBuilder)}
     * to supply those arguments.</p>
     *
     * <p>See <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 for more information about navigating within your app.</p>
     *
     * <p>See the {@link TaskStackBuilder} class and the Activity methods
     * {@link #getParentActivityIntent()}, {@link #shouldUpRecreateTask(Intent)}, and
     * {@link #navigateUpTo(Intent)} for help implementing custom Up navigation.
     * The AppNavigation sample application in the Android SDK is also available for reference.</p>
     *
     * @return true if Up navigation completed successfully and this Activity was finished,
     *         false otherwise.
     */
    public boolean onNavigateUp() {
        // Automatically handle hierarchical Up navigation if the proper
        // metadata is available.
        Intent upIntent = getParentActivityIntent();
        if (upIntent != null) {
            if (mActivityInfo.taskAffinity == null) {
                // Activities with a null affinity are special; they really shouldn't
                // specify a parent activity intent in the first place. Just finish
                // the current activity and call it a day.
                finish();
            } else if (shouldUpRecreateTask(upIntent)) {
                TaskStackBuilder b = TaskStackBuilder.create(this);
                onCreateNavigateUpTaskStack(b);
                onPrepareNavigateUpTaskStack(b);
                b.startActivities();

                // We can't finishAffinity if we have a result.
                // Fall back and simply finish the current activity instead.
                if (mResultCode != RESULT_CANCELED || mResultData != null) {
                    // Tell the developer what's going on to avoid hair-pulling.
                    Log.i(TAG, "onNavigateUp only finishing topmost activity to return a result");
                    finish();
                } else {
                    finishAffinity();
                }
            } else {
                navigateUpTo(upIntent);
            }
            return true;
        }
        return false;
    }

    /**
     * This is called when a child activity of this one attempts to navigate up.
     * The default implementation simply calls onNavigateUp() on this activity (the parent).
     *
     * @param child The activity making the call.
     */
    public boolean onNavigateUpFromChild(Activity child) {
        return onNavigateUp();
    }

    /**
     * Define the synthetic task stack that will be generated during Up navigation from
     * a different task.
     *
     * <p>The default implementation of this method adds the parent chain of this activity
     * as specified in the manifest to the supplied {@link TaskStackBuilder}. Applications
     * may choose to override this method to construct the desired task stack in a different
     * way.</p>
     *
     * <p>This method will be invoked by the default implementation of {@link #onNavigateUp()}
     * if {@link #shouldUpRecreateTask(Intent)} returns true when supplied with the intent
     * returned by {@link #getParentActivityIntent()}.</p>
     *
     * <p>Applications that wish to supply extra Intent parameters to the parent stack defined
     * by the manifest should override {@link #onPrepareNavigateUpTaskStack(TaskStackBuilder)}.</p>
     *
     * @param builder An empty TaskStackBuilder - the application should add intents representing
     *                the desired task stack
     */
    public void onCreateNavigateUpTaskStack(TaskStackBuilder builder) {
        builder.addParentStack(this);
    }

    /**
     * Prepare the synthetic task stack that will be generated during Up navigation
     * from a different task.
     *
     * <p>This method receives the {@link TaskStackBuilder} with the constructed series of
     * Intents as generated by {@link #onCreateNavigateUpTaskStack(TaskStackBuilder)}.
     * If any extra data should be added to these intents before launching the new task,
     * the application should override this method and add that data here.</p>
     *
     * @param builder A TaskStackBuilder that has been populated with Intents by
     *                onCreateNavigateUpTaskStack.
     */
    public void onPrepareNavigateUpTaskStack(TaskStackBuilder builder) {
    }

    /**
     * This hook is called whenever the options menu is being closed (either by the user canceling
     * the menu with the back/menu button, or when an item is selected).
     *
     * @param menu The options menu as last shown or first initialized by
     *             onCreateOptionsMenu().
     */
    public void onOptionsMenuClosed(Menu menu) {
        if (mParent != null) {
            mParent.onOptionsMenuClosed(menu);
        }
    }

    /**
     * Programmatically opens the options menu. If the options menu is already
     * open, this method does nothing.
     */
    public void openOptionsMenu() {
        if (mActionBar == null || !mActionBar.openOptionsMenu()) {
            mWindow.openPanel(Window.FEATURE_OPTIONS_PANEL, null);
        }
    }

    /**
     * Progammatically closes the options menu. If the options menu is already
     * closed, this method does nothing.
     */
    public void closeOptionsMenu() {
        mWindow.closePanel(Window.FEATURE_OPTIONS_PANEL);
    }

    /**
     * Called when a context menu for the {@code view} is about to be shown.
     * Unlike {@link #onCreateOptionsMenu(Menu)}, this will be called every
     * time the context menu is about to be shown and should be populated for
     * the view (or item inside the view for {@link AdapterView} subclasses,
     * this can be found in the {@code menuInfo})).
     * <p>
     * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an
     * item has been selected.
     * <p>
     * It is not safe to hold onto the context menu after this method returns.
     *
     */
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
    }

    /**
     * Registers a context menu to be shown for the given view (multiple views
     * can show the context menu). This method will set the
     * {@link OnCreateContextMenuListener} on the view to this activity, so
     * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be
     * called when it is time to show the context menu.
     *
     * @see #unregisterForContextMenu(View)
     * @param view The view that should show a context menu.
     */
    public void registerForContextMenu(View view) {
        view.setOnCreateContextMenuListener(this);
    }

    /**
     * Prevents a context menu to be shown for the given view. This method will remove the
     * {@link OnCreateContextMenuListener} on the view.
     *
     * @see #registerForContextMenu(View)
     * @param view The view that should stop showing a context menu.
     */
    public void unregisterForContextMenu(View view) {
        view.setOnCreateContextMenuListener(null);
    }

    /**
     * Programmatically opens the context menu for a particular {@code view}.
     * The {@code view} should have been added via
     * {@link #registerForContextMenu(View)}.
     *
     * @param view The view to show the context menu for.
     */
    public void openContextMenu(View view) {
        view.showContextMenu();
    }

    /**
     * Programmatically closes the most recently opened context menu, if showing.
     */
    public void closeContextMenu() {
        mWindow.closePanel(Window.FEATURE_CONTEXT_MENU);
    }

    /**
     * This hook is called whenever an item in a context menu is selected. The
     * default implementation simply returns false to have the normal processing
     * happen (calling the item's Runnable or sending a message to its Handler
     * as appropriate). You can use this method for any items for which you
     * would like to do processing without those other facilities.
     * <p>
     * Use {@link MenuItem#getMenuInfo()} to get extra information set by the
     * View that added this menu item.
     * <p>
     * Derived classes should call through to the base class for it to perform
     * the default menu handling.
     *
     * @param item The context menu item that was selected.
     * @return boolean Return false to allow normal context menu processing to
     *         proceed, true to consume it here.
     */
    public boolean onContextItemSelected(MenuItem item) {
        if (mParent != null) {
            return mParent.onContextItemSelected(item);
        }
        return false;
    }

    /**
     * This hook is called whenever the context menu is being closed (either by
     * the user canceling the menu with the back/menu button, or when an item is
     * selected).
     *
     * @param menu The context menu that is being closed.
     */
    public void onContextMenuClosed(Menu menu) {
        if (mParent != null) {
            mParent.onContextMenuClosed(menu);
        }
    }

    /**
     * @deprecated Old no-arguments version of {@link #onCreateDialog(int, Bundle)}.
     */
    @Deprecated
    protected Dialog onCreateDialog(int id) {
        return null;
    }

    /**
     * Callback for creating dialogs that are managed (saved and restored) for you
     * by the activity.  The default implementation calls through to
     * {@link #onCreateDialog(int)} for compatibility.
     *
     * <em>If you are targeting {@link android.os.Build.VERSION_CODES#HONEYCOMB}
     * or later, consider instead using a {@link DialogFragment} instead.</em>
     *
     * <p>If you use {@link #showDialog(int)}, the activity will call through to
     * this method the first time, and hang onto it thereafter.  Any dialog
     * that is created by this method will automatically be saved and restored
     * for you, including whether it is showing.
     *
     * <p>If you would like the activity to manage saving and restoring dialogs
     * for you, you should override this method and handle any ids that are
     * passed to {@link #showDialog}.
     *
     * <p>If you would like an opportunity to prepare your dialog before it is shown,
     * override {@link #onPrepareDialog(int, Dialog, Bundle)}.
     *
     * @param id The id of the dialog.
     * @param args The dialog arguments provided to {@link #showDialog(int, Bundle)}.
     * @return The dialog.  If you return null, the dialog will not be created.
     *
     * @see #onPrepareDialog(int, Dialog, Bundle)
     * @see #showDialog(int, Bundle)
     * @see #dismissDialog(int)
     * @see #removeDialog(int)
     *
     * @deprecated Use the new {@link DialogFragment} class with
     * {@link FragmentManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Nullable
    @Deprecated
    protected Dialog onCreateDialog(int id, Bundle args) {
        return onCreateDialog(id);
    }

    /**
     * @deprecated Old no-arguments version of
     * {@link #onPrepareDialog(int, Dialog, Bundle)}.
     */
    @Deprecated
    protected void onPrepareDialog(int id, Dialog dialog) {
        dialog.setOwnerActivity(this);
    }

    /**
     * Provides an opportunity to prepare a managed dialog before it is being
     * shown.  The default implementation calls through to
     * {@link #onPrepareDialog(int, Dialog)} for compatibility.
     *
     * <p>
     * Override this if you need to update a managed dialog based on the state
     * of the application each time it is shown. For example, a time picker
     * dialog might want to be updated with the current time. You should call
     * through to the superclass's implementation. The default implementation
     * will set this Activity as the owner activity on the Dialog.
     *
     * @param id The id of the managed dialog.
     * @param dialog The dialog.
     * @param args The dialog arguments provided to {@link #showDialog(int, Bundle)}.
     * @see #onCreateDialog(int, Bundle)
     * @see #showDialog(int)
     * @see #dismissDialog(int)
     * @see #removeDialog(int)
     *
     * @deprecated Use the new {@link DialogFragment} class with
     * {@link FragmentManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Deprecated
    protected void onPrepareDialog(int id, Dialog dialog, Bundle args) {
        onPrepareDialog(id, dialog);
    }

    /**
     * Simple version of {@link #showDialog(int, Bundle)} that does not
     * take any arguments.  Simply calls {@link #showDialog(int, Bundle)}
     * with null arguments.
     *
     * @deprecated Use the new {@link DialogFragment} class with
     * {@link FragmentManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Deprecated
    public final void showDialog(int id) {
        showDialog(id, null);
    }

    /**
     * Show a dialog managed by this activity.  A call to {@link #onCreateDialog(int, Bundle)}
     * will be made with the same id the first time this is called for a given
     * id.  From thereafter, the dialog will be automatically saved and restored.
     *
     * <em>If you are targeting {@link android.os.Build.VERSION_CODES#HONEYCOMB}
     * or later, consider instead using a {@link DialogFragment} instead.</em>
     *
     * <p>Each time a dialog is shown, {@link #onPrepareDialog(int, Dialog, Bundle)} will
     * be made to provide an opportunity to do any timely preparation.
     *
     * @param id The id of the managed dialog.
     * @param args Arguments to pass through to the dialog.  These will be saved
     * and restored for you.  Note that if the dialog is already created,
     * {@link #onCreateDialog(int, Bundle)} will not be called with the new
     * arguments but {@link #onPrepareDialog(int, Dialog, Bundle)} will be.
     * If you need to rebuild the dialog, call {@link #removeDialog(int)} first.
     * @return Returns true if the Dialog was created; false is returned if
     * it is not created because {@link #onCreateDialog(int, Bundle)} returns false.
     *
     * @see Dialog
     * @see #onCreateDialog(int, Bundle)
     * @see #onPrepareDialog(int, Dialog, Bundle)
     * @see #dismissDialog(int)
     * @see #removeDialog(int)
     *
     * @deprecated Use the new {@link DialogFragment} class with
     * {@link FragmentManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Nullable
    @Deprecated
    public final boolean showDialog(int id, Bundle args) {
        if (mManagedDialogs == null) {
            mManagedDialogs = new SparseArray<ManagedDialog>();
        }
        ManagedDialog md = mManagedDialogs.get(id);
        if (md == null) {
            md = new ManagedDialog();
            md.mDialog = createDialog(id, null, args);
            if (md.mDialog == null) {
                return false;
            }
            mManagedDialogs.put(id, md);
        }

        md.mArgs = args;
        onPrepareDialog(id, md.mDialog, args);
        md.mDialog.show();
        return true;
    }

    /**
     * Dismiss a dialog that was previously shown via {@link #showDialog(int)}.
     *
     * @param id The id of the managed dialog.
     *
     * @throws IllegalArgumentException if the id was not previously shown via
     *   {@link #showDialog(int)}.
     *
     * @see #onCreateDialog(int, Bundle)
     * @see #onPrepareDialog(int, Dialog, Bundle)
     * @see #showDialog(int)
     * @see #removeDialog(int)
     *
     * @deprecated Use the new {@link DialogFragment} class with
     * {@link FragmentManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Deprecated
    public final void dismissDialog(int id) {
        if (mManagedDialogs == null) {
            throw missingDialog(id);
        }

        final ManagedDialog md = mManagedDialogs.get(id);
        if (md == null) {
            throw missingDialog(id);
        }
        md.mDialog.dismiss();
    }

    /**
     * Creates an exception to throw if a user passed in a dialog id that is
     * unexpected.
     */
    private IllegalArgumentException missingDialog(int id) {
        return new IllegalArgumentException("no dialog with id " + id + " was ever "
                + "shown via Activity#showDialog");
    }

    /**
     * Removes any internal references to a dialog managed by this Activity.
     * If the dialog is showing, it will dismiss it as part of the clean up.
     *
     * <p>This can be useful if you know that you will never show a dialog again and
     * want to avoid the overhead of saving and restoring it in the future.
     *
     * <p>As of {@link android.os.Build.VERSION_CODES#GINGERBREAD}, this function
     * will not throw an exception if you try to remove an ID that does not
     * currently have an associated dialog.</p>
     *
     * @param id The id of the managed dialog.
     *
     * @see #onCreateDialog(int, Bundle)
     * @see #onPrepareDialog(int, Dialog, Bundle)
     * @see #showDialog(int)
     * @see #dismissDialog(int)
     *
     * @deprecated Use the new {@link DialogFragment} class with
     * {@link FragmentManager} instead; this is also
     * available on older platforms through the Android compatibility package.
     */
    @Deprecated
    public final void removeDialog(int id) {
        if (mManagedDialogs != null) {
            final ManagedDialog md = mManagedDialogs.get(id);
            if (md != null) {
                md.mDialog.dismiss();
                mManagedDialogs.remove(id);
            }
        }
    }

    /**
     * This hook is called when the user signals the desire to start a search.
     *
     * <p>You can use this function as a simple way to launch the search UI, in response to a
     * menu item, search button, or other widgets within your activity. Unless overidden,
     * calling this function is the same as calling
     * {@link #startSearch startSearch(null, false, null, false)}, which launches
     * search for the current activity as specified in its manifest, see {@link SearchManager}.
     *
     * <p>You can override this function to force global search, e.g. in response to a dedicated
     * search key, or to block search entirely (by simply returning false).
     *
     * <p>Note: when running in a {@link Configuration#UI_MODE_TYPE_TELEVISION}, the default
     * implementation changes to simply return false and you must supply your own custom
     * implementation if you want to support search.</p>
     *
     * @return Returns {@code true} if search launched, and {@code false} if the activity does
     * not respond to search.  The default implementation always returns {@code true}, except
     * when in {@link Configuration#UI_MODE_TYPE_TELEVISION} mode where it returns false.
     *
     * @see android.app.SearchManager
     */
    public boolean onSearchRequested() {
        if ((getResources().getConfiguration().uiMode&Configuration.UI_MODE_TYPE_MASK)
                != Configuration.UI_MODE_TYPE_TELEVISION) {
            startSearch(null, false, null, false);
            return true;
        } else {
            return false;
        }
    }

    /**
     * This hook is called to launch the search UI.
     *
     * <p>It is typically called from onSearchRequested(), either directly from
     * Activity.onSearchRequested() or from an overridden version in any given
     * Activity.  If your goal is simply to activate search, it is preferred to call
     * onSearchRequested(), which may have been overridden elsewhere in your Activity.  If your goal
     * is to inject specific data such as context data, it is preferred to <i>override</i>
     * onSearchRequested(), so that any callers to it will benefit from the override.
     *
     * @param initialQuery Any non-null non-empty string will be inserted as
     * pre-entered text in the search query box.
     * @param selectInitialQuery If true, the initial query will be preselected, which means that
     * any further typing will replace it.  This is useful for cases where an entire pre-formed
     * query is being inserted.  If false, the selection point will be placed at the end of the
     * inserted query.  This is useful when the inserted query is text that the user entered,
     * and the user would expect to be able to keep typing.  <i>This parameter is only meaningful
     * if initialQuery is a non-empty string.</i>
     * @param appSearchData An application can insert application-specific
     * context here, in order to improve quality or specificity of its own
     * searches.  This data will be returned with SEARCH intent(s).  Null if
     * no extra data is required.
     * @param globalSearch If false, this will only launch the search that has been specifically
     * defined by the application (which is usually defined as a local search).  If no default
     * search is defined in the current application or activity, global search will be launched.
     * If true, this will always launch a platform-global (e.g. web-based) search instead.
     *
     * @see android.app.SearchManager
     * @see #onSearchRequested
     */
    public void startSearch(@Nullable String initialQuery, boolean selectInitialQuery,
            @Nullable Bundle appSearchData, boolean globalSearch) {
        ensureSearchManager();
        mSearchManager.startSearch(initialQuery, selectInitialQuery, getComponentName(),
                appSearchData, globalSearch);
    }

    /**
     * Similar to {@link #startSearch}, but actually fires off the search query after invoking
     * the search dialog.  Made available for testing purposes.
     *
     * @param query The query to trigger.  If empty, the request will be ignored.
     * @param appSearchData An application can insert application-specific
     * context here, in order to improve quality or specificity of its own
     * searches.  This data will be returned with SEARCH intent(s).  Null if
     * no extra data is required.
     */
    public void triggerSearch(String query, @Nullable Bundle appSearchData) {
        ensureSearchManager();
        mSearchManager.triggerSearch(query, getComponentName(), appSearchData);
    }

    /**
     * Request that key events come to this activity. Use this if your
     * activity has no views with focus, but the activity still wants
     * a chance to process key events.
     *
     * @see android.view.Window#takeKeyEvents
     */
    public void takeKeyEvents(boolean get) {
        getWindow().takeKeyEvents(get);
    }

    /**
     * Enable extended window features.  This is a convenience for calling
     * {@link android.view.Window#requestFeature getWindow().requestFeature()}.
     *
     * @param featureId The desired feature as defined in
     *                  {@link android.view.Window}.
     * @return Returns true if the requested feature is supported and now
     *         enabled.
     *
     * @see android.view.Window#requestFeature
     */
    public final boolean requestWindowFeature(int featureId) {
        return getWindow().requestFeature(featureId);
    }

    /**
     * Convenience for calling
     * {@link android.view.Window#setFeatureDrawableResource}.
     */
    public final void setFeatureDrawableResource(int featureId, int resId) {
        getWindow().setFeatureDrawableResource(featureId, resId);
    }

    /**
     * Convenience for calling
     * {@link android.view.Window#setFeatureDrawableUri}.
     */
    public final void setFeatureDrawableUri(int featureId, Uri uri) {
        getWindow().setFeatureDrawableUri(featureId, uri);
    }

    /**
     * Convenience for calling
     * {@link android.view.Window#setFeatureDrawable(int, Drawable)}.
     */
    public final void setFeatureDrawable(int featureId, Drawable drawable) {
        getWindow().setFeatureDrawable(featureId, drawable);
    }

    /**
     * Convenience for calling
     * {@link android.view.Window#setFeatureDrawableAlpha}.
     */
    public final void setFeatureDrawableAlpha(int featureId, int alpha) {
        getWindow().setFeatureDrawableAlpha(featureId, alpha);
    }

    /**
     * Convenience for calling
     * {@link android.view.Window#getLayoutInflater}.
     */
    @NonNull
    public LayoutInflater getLayoutInflater() {
        return getWindow().getLayoutInflater();
    }

    /**
     * Returns a {@link MenuInflater} with this context.
     */
    @NonNull
    public MenuInflater getMenuInflater() {
        // Make sure that action views can get an appropriate theme.
        if (mMenuInflater == null) {
            initWindowDecorActionBar();
            if (mActionBar != null) {
                mMenuInflater = new MenuInflater(mActionBar.getThemedContext(), this);
            } else {
                mMenuInflater = new MenuInflater(this);
            }
        }
        return mMenuInflater;
    }

    @Override
    protected void onApplyThemeResource(Resources.Theme theme, int resid,
            boolean first) {
        if (mParent == null) {
            super.onApplyThemeResource(theme, resid, first);
        } else {
            try {
                theme.setTo(mParent.getTheme());
            } catch (Exception e) {
                // Empty
            }
            theme.applyStyle(resid, false);
        }

        // Get the primary color and update the TaskDescription for this activity
        if (theme != null) {
            TypedArray a = theme.obtainStyledAttributes(com.android.internal.R.styleable.Theme);
            int colorPrimary = a.getColor(com.android.internal.R.styleable.Theme_colorPrimary, 0);
            a.recycle();
            if (colorPrimary != 0) {
                ActivityManager.TaskDescription v = new ActivityManager.TaskDescription(null, null,
                        colorPrimary);
                setTaskDescription(v);
            }
        }
    }

    /**
     * Same as calling {@link #startActivityForResult(Intent, int, Bundle)}
     * with no options.
     *
     * @param intent The intent to start.
     * @param requestCode If >= 0, this code will be returned in
     *                    onActivityResult() when the activity exits.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see #startActivity
     */
    public void startActivityForResult(Intent intent, int requestCode) {
        startActivityForResult(intent, requestCode, null);
    }

    /**
     * Launch an activity for which you would like a result when it finished.
     * When this activity exits, your
     * onActivityResult() method will be called with the given requestCode.
     * Using a negative requestCode is the same as calling
     * {@link #startActivity} (the activity is not launched as a sub-activity).
     *
     * <p>Note that this method should only be used with Intent protocols
     * that are defined to return a result.  In other protocols (such as
     * {@link Intent#ACTION_MAIN} or {@link Intent#ACTION_VIEW}), you may
     * not get the result when you expect.  For example, if the activity you
     * are launching uses the singleTask launch mode, it will not run in your
     * task and thus you will immediately receive a cancel result.
     *
     * <p>As a special case, if you call startActivityForResult() with a requestCode
     * >= 0 during the initial onCreate(Bundle savedInstanceState)/onResume() of your
     * activity, then your window will not be displayed until a result is
     * returned back from the started activity.  This is to avoid visible
     * flickering when redirecting to another activity.
     *
     * <p>This method throws {@link android.content.ActivityNotFoundException}
     * if there was no Activity found to run the given Intent.
     *
     * @param intent The intent to start.
     * @param requestCode If >= 0, this code will be returned in
     *                    onActivityResult() when the activity exits.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see #startActivity
     */
    public void startActivityForResult(Intent intent, int requestCode, @Nullable Bundle options) {
        if (mParent == null) {
            Instrumentation.ActivityResult ar =
                mInstrumentation.execStartActivity(
                    this, mMainThread.getApplicationThread(), mToken, this,
                    intent, requestCode, options);
            if (ar != null) {
                mMainThread.sendActivityResult(
                    mToken, mEmbeddedID, requestCode, ar.getResultCode(),
                    ar.getResultData());
            }
            if (requestCode >= 0) {
                // If this start is requesting a result, we can avoid making
                // the activity visible until the result is received.  Setting
                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
                // activity hidden during this time, to avoid flickering.
                // This can only be done when a result is requested because
                // that guarantees we will get information back when the
                // activity is finished, no matter what happens to it.
                mStartedActivity = true;
            }

            final View decor = mWindow != null ? mWindow.peekDecorView() : null;
            if (decor != null) {
                decor.cancelPendingInputEvents();
            }
            // TODO Consider clearing/flushing other event sources and events for child windows.
        } else {
            if (options != null) {
                mParent.startActivityFromChild(this, intent, requestCode, options);
            } else {
                // Note we want to go through this method for compatibility with
                // existing applications that may have overridden it.
                mParent.startActivityFromChild(this, intent, requestCode);
            }
        }
        if (options != null && !isTopOfTask()) {
            mActivityTransitionState.startExitOutTransition(this, options);
        }
    }

    /**
     * @hide Implement to provide correct calling token.
     */
    public void startActivityForResultAsUser(Intent intent, int requestCode, UserHandle user) {
        startActivityForResultAsUser(intent, requestCode, null, user);
    }

    /**
     * @hide Implement to provide correct calling token.
     */
    public void startActivityForResultAsUser(Intent intent, int requestCode,
            @Nullable Bundle options, UserHandle user) {
        if (options != null) {
            mActivityTransitionState.startExitOutTransition(this, options);
        }
        if (mParent != null) {
            throw new RuntimeException("Can't be called from a child");
        }
        Instrumentation.ActivityResult ar = mInstrumentation.execStartActivity(
                this, mMainThread.getApplicationThread(), mToken, this, intent, requestCode,
                options, user);
        if (ar != null) {
            mMainThread.sendActivityResult(
                mToken, mEmbeddedID, requestCode, ar.getResultCode(), ar.getResultData());
        }
        if (requestCode >= 0) {
            // If this start is requesting a result, we can avoid making
            // the activity visible until the result is received.  Setting
            // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
            // activity hidden during this time, to avoid flickering.
            // This can only be done when a result is requested because
            // that guarantees we will get information back when the
            // activity is finished, no matter what happens to it.
            mStartedActivity = true;
        }

        final View decor = mWindow != null ? mWindow.peekDecorView() : null;
        if (decor != null) {
            decor.cancelPendingInputEvents();
        }
    }

    /**
     * @hide Implement to provide correct calling token.
     */
    public void startActivityAsUser(Intent intent, UserHandle user) {
        startActivityAsUser(intent, null, user);
    }

    /**
     * @hide Implement to provide correct calling token.
     */
    public void startActivityAsUser(Intent intent, Bundle options, UserHandle user) {
        if (mParent != null) {
            throw new RuntimeException("Can't be called from a child");
        }
        Instrumentation.ActivityResult ar =
                mInstrumentation.execStartActivity(
                        this, mMainThread.getApplicationThread(), mToken, this,
                        intent, -1, options, user);
        if (ar != null) {
            mMainThread.sendActivityResult(
                mToken, mEmbeddedID, -1, ar.getResultCode(),
                ar.getResultData());
        }
    }

    /**
     * Start a new activity as if it was started by the activity that started our
     * current activity.  This is for the resolver and chooser activities, which operate
     * as intermediaries that dispatch their intent to the target the user selects -- to
     * do this, they must perform all security checks including permission grants as if
     * their launch had come from the original activity.
     * @hide
     */
    public void startActivityAsCaller(Intent intent, @Nullable Bundle options, int userId) {
        if (mParent != null) {
            throw new RuntimeException("Can't be called from a child");
        }
        Instrumentation.ActivityResult ar =
                mInstrumentation.execStartActivityAsCaller(
                        this, mMainThread.getApplicationThread(), mToken, this,
                        intent, -1, options, userId);
        if (ar != null) {
            mMainThread.sendActivityResult(
                mToken, mEmbeddedID, -1, ar.getResultCode(),
                ar.getResultData());
        }
    }

    /**
     * Same as calling {@link #startIntentSenderForResult(IntentSender, int,
     * Intent, int, int, int, Bundle)} with no options.
     *
     * @param intent The IntentSender to launch.
     * @param requestCode If >= 0, this code will be returned in
     *                    onActivityResult() when the activity exits.
     * @param fillInIntent If non-null, this will be provided as the
     * intent parameter to {@link IntentSender#sendIntent}.
     * @param flagsMask Intent flags in the original IntentSender that you
     * would like to change.
     * @param flagsValues Desired values for any bits set in
     * <var>flagsMask</var>
     * @param extraFlags Always set to 0.
     */
    public void startIntentSenderForResult(IntentSender intent, int requestCode,
            @Nullable Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags)
            throws IntentSender.SendIntentException {
        startIntentSenderForResult(intent, requestCode, fillInIntent, flagsMask,
                flagsValues, extraFlags, null);
    }

    /**
     * Like {@link #startActivityForResult(Intent, int)}, but allowing you
     * to use a IntentSender to describe the activity to be started.  If
     * the IntentSender is for an activity, that activity will be started
     * as if you had called the regular {@link #startActivityForResult(Intent, int)}
     * here; otherwise, its associated action will be executed (such as
     * sending a broadcast) as if you had called
     * {@link IntentSender#sendIntent IntentSender.sendIntent} on it.
     *
     * @param intent The IntentSender to launch.
     * @param requestCode If >= 0, this code will be returned in
     *                    onActivityResult() when the activity exits.
     * @param fillInIntent If non-null, this will be provided as the
     * intent parameter to {@link IntentSender#sendIntent}.
     * @param flagsMask Intent flags in the original IntentSender that you
     * would like to change.
     * @param flagsValues Desired values for any bits set in
     * <var>flagsMask</var>
     * @param extraFlags Always set to 0.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.  If options
     * have also been supplied by the IntentSender, options given here will
     * override any that conflict with those given by the IntentSender.
     */
    public void startIntentSenderForResult(IntentSender intent, int requestCode,
            @Nullable Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags,
            Bundle options) throws IntentSender.SendIntentException {
        if (mParent == null) {
            startIntentSenderForResultInner(intent, requestCode, fillInIntent,
                    flagsMask, flagsValues, this, options);
        } else if (options != null) {
            mParent.startIntentSenderFromChild(this, intent, requestCode,
                    fillInIntent, flagsMask, flagsValues, extraFlags, options);
        } else {
            // Note we want to go through this call for compatibility with
            // existing applications that may have overridden the method.
            mParent.startIntentSenderFromChild(this, intent, requestCode,
                    fillInIntent, flagsMask, flagsValues, extraFlags);
        }
    }

    private void startIntentSenderForResultInner(IntentSender intent, int requestCode,
            Intent fillInIntent, int flagsMask, int flagsValues, Activity activity,
            Bundle options)
            throws IntentSender.SendIntentException {
        try {
            String resolvedType = null;
            if (fillInIntent != null) {
                fillInIntent.migrateExtraStreamToClipData();
                fillInIntent.prepareToLeaveProcess();
                resolvedType = fillInIntent.resolveTypeIfNeeded(getContentResolver());
            }
            int result = ActivityManagerNative.getDefault()
                .startActivityIntentSender(mMainThread.getApplicationThread(), intent,
                        fillInIntent, resolvedType, mToken, activity.mEmbeddedID,
                        requestCode, flagsMask, flagsValues, options);
            if (result == ActivityManager.START_CANCELED) {
                throw new IntentSender.SendIntentException();
            }
            Instrumentation.checkStartActivityResult(result, null);
        } catch (RemoteException e) {
        }
        if (requestCode >= 0) {
            // If this start is requesting a result, we can avoid making
            // the activity visible until the result is received.  Setting
            // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
            // activity hidden during this time, to avoid flickering.
            // This can only be done when a result is requested because
            // that guarantees we will get information back when the
            // activity is finished, no matter what happens to it.
            mStartedActivity = true;
        }
    }

    /**
     * Same as {@link #startActivity(Intent, Bundle)} with no options
     * specified.
     *
     * @param intent The intent to start.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see {@link #startActivity(Intent, Bundle)}
     * @see #startActivityForResult
     */
    @Override
    public void startActivity(Intent intent) {
        this.startActivity(intent, null);
    }

    /**
     * Launch a new activity.  You will not receive any information about when
     * the activity exits.  This implementation overrides the base version,
     * providing information about
     * the activity performing the launch.  Because of this additional
     * information, the {@link Intent#FLAG_ACTIVITY_NEW_TASK} launch flag is not
     * required; if not specified, the new activity will be added to the
     * task of the caller.
     *
     * <p>This method throws {@link android.content.ActivityNotFoundException}
     * if there was no Activity found to run the given Intent.
     *
     * @param intent The intent to start.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see {@link #startActivity(Intent)}
     * @see #startActivityForResult
     */
    @Override
    public void startActivity(Intent intent, @Nullable Bundle options) {
        if (options != null) {
            startActivityForResult(intent, -1, options);
        } else {
            // Note we want to go through this call for compatibility with
            // applications that may have overridden the method.
            startActivityForResult(intent, -1);
        }
    }

    /**
     * Same as {@link #startActivities(Intent[], Bundle)} with no options
     * specified.
     *
     * @param intents The intents to start.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see {@link #startActivities(Intent[], Bundle)}
     * @see #startActivityForResult
     */
    @Override
    public void startActivities(Intent[] intents) {
        startActivities(intents, null);
    }

    /**
     * Launch a new activity.  You will not receive any information about when
     * the activity exits.  This implementation overrides the base version,
     * providing information about
     * the activity performing the launch.  Because of this additional
     * information, the {@link Intent#FLAG_ACTIVITY_NEW_TASK} launch flag is not
     * required; if not specified, the new activity will be added to the
     * task of the caller.
     *
     * <p>This method throws {@link android.content.ActivityNotFoundException}
     * if there was no Activity found to run the given Intent.
     *
     * @param intents The intents to start.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see {@link #startActivities(Intent[])}
     * @see #startActivityForResult
     */
    @Override
    public void startActivities(Intent[] intents, @Nullable Bundle options) {
        mInstrumentation.execStartActivities(this, mMainThread.getApplicationThread(),
                mToken, this, intents, options);
    }

    /**
     * Same as calling {@link #startIntentSender(IntentSender, Intent, int, int, int, Bundle)}
     * with no options.
     *
     * @param intent The IntentSender to launch.
     * @param fillInIntent If non-null, this will be provided as the
     * intent parameter to {@link IntentSender#sendIntent}.
     * @param flagsMask Intent flags in the original IntentSender that you
     * would like to change.
     * @param flagsValues Desired values for any bits set in
     * <var>flagsMask</var>
     * @param extraFlags Always set to 0.
     */
    public void startIntentSender(IntentSender intent,
            @Nullable Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags)
            throws IntentSender.SendIntentException {
        startIntentSender(intent, fillInIntent, flagsMask, flagsValues,
                extraFlags, null);
    }

    /**
     * Like {@link #startActivity(Intent, Bundle)}, but taking a IntentSender
     * to start; see
     * {@link #startIntentSenderForResult(IntentSender, int, Intent, int, int, int, Bundle)}
     * for more information.
     *
     * @param intent The IntentSender to launch.
     * @param fillInIntent If non-null, this will be provided as the
     * intent parameter to {@link IntentSender#sendIntent}.
     * @param flagsMask Intent flags in the original IntentSender that you
     * would like to change.
     * @param flagsValues Desired values for any bits set in
     * <var>flagsMask</var>
     * @param extraFlags Always set to 0.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.  If options
     * have also been supplied by the IntentSender, options given here will
     * override any that conflict with those given by the IntentSender.
     */
    public void startIntentSender(IntentSender intent,
            @Nullable Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags,
            Bundle options) throws IntentSender.SendIntentException {
        if (options != null) {
            startIntentSenderForResult(intent, -1, fillInIntent, flagsMask,
                    flagsValues, extraFlags, options);
        } else {
            // Note we want to go through this call for compatibility with
            // applications that may have overridden the method.
            startIntentSenderForResult(intent, -1, fillInIntent, flagsMask,
                    flagsValues, extraFlags);
        }
    }

    /**
     * Same as calling {@link #startActivityIfNeeded(Intent, int, Bundle)}
     * with no options.
     *
     * @param intent The intent to start.
     * @param requestCode If >= 0, this code will be returned in
     *         onActivityResult() when the activity exits, as described in
     *         {@link #startActivityForResult}.
     *
     * @return If a new activity was launched then true is returned; otherwise
     *         false is returned and you must handle the Intent yourself.
     *
     * @see #startActivity
     * @see #startActivityForResult
     */
    public boolean startActivityIfNeeded(@NonNull Intent intent, int requestCode) {
        return startActivityIfNeeded(intent, requestCode, null);
    }

    /**
     * A special variation to launch an activity only if a new activity
     * instance is needed to handle the given Intent.  In other words, this is
     * just like {@link #startActivityForResult(Intent, int)} except: if you are
     * using the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP} flag, or
     * singleTask or singleTop
     * {@link android.R.styleable#AndroidManifestActivity_launchMode launchMode},
     * and the activity
     * that handles <var>intent</var> is the same as your currently running
     * activity, then a new instance is not needed.  In this case, instead of
     * the normal behavior of calling {@link #onNewIntent} this function will
     * return and you can handle the Intent yourself.
     *
     * <p>This function can only be called from a top-level activity; if it is
     * called from a child activity, a runtime exception will be thrown.
     *
     * @param intent The intent to start.
     * @param requestCode If >= 0, this code will be returned in
     *         onActivityResult() when the activity exits, as described in
     *         {@link #startActivityForResult}.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.
     *
     * @return If a new activity was launched then true is returned; otherwise
     *         false is returned and you must handle the Intent yourself.
     *
     * @see #startActivity
     * @see #startActivityForResult
     */
    public boolean startActivityIfNeeded(@NonNull Intent intent, int requestCode,
            @Nullable Bundle options) {
        if (mParent == null) {
            int result = ActivityManager.START_RETURN_INTENT_TO_CALLER;
            try {
                intent.migrateExtraStreamToClipData();
                intent.prepareToLeaveProcess();
                result = ActivityManagerNative.getDefault()
                    .startActivity(mMainThread.getApplicationThread(), getBasePackageName(),
                            intent, intent.resolveTypeIfNeeded(getContentResolver()), mToken,
                            mEmbeddedID, requestCode, ActivityManager.START_FLAG_ONLY_IF_NEEDED,
                            null, options);
            } catch (RemoteException e) {
                // Empty
            }

            Instrumentation.checkStartActivityResult(result, intent);

            if (requestCode >= 0) {
                // If this start is requesting a result, we can avoid making
                // the activity visible until the result is received.  Setting
                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
                // activity hidden during this time, to avoid flickering.
                // This can only be done when a result is requested because
                // that guarantees we will get information back when the
                // activity is finished, no matter what happens to it.
                mStartedActivity = true;
            }
            return result != ActivityManager.START_RETURN_INTENT_TO_CALLER;
        }

        throw new UnsupportedOperationException(
            "startActivityIfNeeded can only be called from a top-level activity");
    }

    /**
     * Same as calling {@link #startNextMatchingActivity(Intent, Bundle)} with
     * no options.
     *
     * @param intent The intent to dispatch to the next activity.  For
     * correct behavior, this must be the same as the Intent that started
     * your own activity; the only changes you can make are to the extras
     * inside of it.
     *
     * @return Returns a boolean indicating whether there was another Activity
     * to start: true if there was a next activity to start, false if there
     * wasn't.  In general, if true is returned you will then want to call
     * finish() on yourself.
     */
    public boolean startNextMatchingActivity(@NonNull Intent intent) {
        return startNextMatchingActivity(intent, null);
    }

    /**
     * Special version of starting an activity, for use when you are replacing
     * other activity components.  You can use this to hand the Intent off
     * to the next Activity that can handle it.  You typically call this in
     * {@link #onCreate} with the Intent returned by {@link #getIntent}.
     *
     * @param intent The intent to dispatch to the next activity.  For
     * correct behavior, this must be the same as the Intent that started
     * your own activity; the only changes you can make are to the extras
     * inside of it.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.
     *
     * @return Returns a boolean indicating whether there was another Activity
     * to start: true if there was a next activity to start, false if there
     * wasn't.  In general, if true is returned you will then want to call
     * finish() on yourself.
     */
    public boolean startNextMatchingActivity(@NonNull Intent intent, @Nullable Bundle options) {
        if (mParent == null) {
            try {
                intent.migrateExtraStreamToClipData();
                intent.prepareToLeaveProcess();
                return ActivityManagerNative.getDefault()
                    .startNextMatchingActivity(mToken, intent, options);
            } catch (RemoteException e) {
                // Empty
            }
            return false;
        }

        throw new UnsupportedOperationException(
            "startNextMatchingActivity can only be called from a top-level activity");
    }

    /**
     * Same as calling {@link #startActivityFromChild(Activity, Intent, int, Bundle)}
     * with no options.
     *
     * @param child The activity making the call.
     * @param intent The intent to start.
     * @param requestCode Reply request code.  < 0 if reply is not requested.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see #startActivity
     * @see #startActivityForResult
     */
    public void startActivityFromChild(@NonNull Activity child, Intent intent,
            int requestCode) {
        startActivityFromChild(child, intent, requestCode, null);
    }

    /**
     * This is called when a child activity of this one calls its
     * {@link #startActivity} or {@link #startActivityForResult} method.
     *
     * <p>This method throws {@link android.content.ActivityNotFoundException}
     * if there was no Activity found to run the given Intent.
     *
     * @param child The activity making the call.
     * @param intent The intent to start.
     * @param requestCode Reply request code.  < 0 if reply is not requested.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see #startActivity
     * @see #startActivityForResult
     */
    public void startActivityFromChild(@NonNull Activity child, Intent intent,
            int requestCode, @Nullable Bundle options) {
        Instrumentation.ActivityResult ar =
            mInstrumentation.execStartActivity(
                this, mMainThread.getApplicationThread(), mToken, child,
                intent, requestCode, options);
        if (ar != null) {
            mMainThread.sendActivityResult(
                mToken, child.mEmbeddedID, requestCode,
                ar.getResultCode(), ar.getResultData());
        }
    }

    /**
     * Same as calling {@link #startActivityFromFragment(Fragment, Intent, int, Bundle)}
     * with no options.
     *
     * @param fragment The fragment making the call.
     * @param intent The intent to start.
     * @param requestCode Reply request code.  < 0 if reply is not requested.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see Fragment#startActivity
     * @see Fragment#startActivityForResult
     */
    public void startActivityFromFragment(@NonNull Fragment fragment, Intent intent,
            int requestCode) {
        startActivityFromFragment(fragment, intent, requestCode, null);
    }

    /**
     * This is called when a Fragment in this activity calls its
     * {@link Fragment#startActivity} or {@link Fragment#startActivityForResult}
     * method.
     *
     * <p>This method throws {@link android.content.ActivityNotFoundException}
     * if there was no Activity found to run the given Intent.
     *
     * @param fragment The fragment making the call.
     * @param intent The intent to start.
     * @param requestCode Reply request code.  < 0 if reply is not requested.
     * @param options Additional options for how the Activity should be started.
     * See {@link android.content.Context#startActivity(Intent, Bundle)
     * Context.startActivity(Intent, Bundle)} for more details.
     *
     * @throws android.content.ActivityNotFoundException
     *
     * @see Fragment#startActivity
     * @see Fragment#startActivityForResult
     */
    public void startActivityFromFragment(@NonNull Fragment fragment, Intent intent,
            int requestCode, @Nullable Bundle options) {
        if (options != null) {
            mActivityTransitionState.startExitOutTransition(this, options);
        }
        Instrumentation.ActivityResult ar =
            mInstrumentation.execStartActivity(
                this, mMainThread.getApplicationThread(), mToken, fragment,
                intent, requestCode, options);
        if (ar != null) {
            mMainThread.sendActivityResult(
                mToken, fragment.mWho, requestCode,
                ar.getResultCode(), ar.getResultData());
        }
    }

    /**
     * Same as calling {@link #startIntentSenderFromChild(Activity, IntentSender,
     * int, Intent, int, int, int, Bundle)} with no options.
     */
    public void startIntentSenderFromChild(Activity child, IntentSender intent,
            int requestCode, Intent fillInIntent, int flagsMask, int flagsValues,
            int extraFlags)
            throws IntentSender.SendIntentException {
        startIntentSenderFromChild(child, intent, requestCode, fillInIntent,
                flagsMask, flagsValues, extraFlags, null);
    }

    /**
     * Like {@link #startActivityFromChild(Activity, Intent, int)}, but
     * taking a IntentSender; see
     * {@link #startIntentSenderForResult(IntentSender, int, Intent, int, int, int)}
     * for more information.
     */
    public void startIntentSenderFromChild(Activity child, IntentSender intent,
            int requestCode, Intent fillInIntent, int flagsMask, int flagsValues,
            int extraFlags, @Nullable Bundle options)
            throws IntentSender.SendIntentException {
        startIntentSenderForResultInner(intent, requestCode, fillInIntent,
                flagsMask, flagsValues, child, options);
    }

    /**
     * Call immediately after one of the flavors of {@link #startActivity(Intent)}
     * or {@link #finish} to specify an explicit transition animation to
     * perform next.
     *
     * <p>As of {@link android.os.Build.VERSION_CODES#JELLY_BEAN} an alternative
     * to using this with starting activities is to supply the desired animation
     * information through a {@link ActivityOptions} bundle to
     * {@link #startActivity(Intent, Bundle) or a related function.  This allows
     * you to specify a custom animation even when starting an activity from
     * outside the context of the current top activity.
     *
     * @param enterAnim A resource ID of the animation resource to use for
     * the incoming activity.  Use 0 for no animation.
     * @param exitAnim A resource ID of the animation resource to use for
     * the outgoing activity.  Use 0 for no animation.
     */
    public void overridePendingTransition(int enterAnim, int exitAnim) {
        try {
            ActivityManagerNative.getDefault().overridePendingTransition(
                    mToken, getPackageName(), enterAnim, exitAnim);
        } catch (RemoteException e) {
        }
    }

    /**
     * Call this to set the result that your activity will return to its
     * caller.
     *
     * @param resultCode The result code to propagate back to the originating
     *                   activity, often RESULT_CANCELED or RESULT_OK
     *
     * @see #RESULT_CANCELED
     * @see #RESULT_OK
     * @see #RESULT_FIRST_USER
     * @see #setResult(int, Intent)
     */
    public final void setResult(int resultCode) {
        synchronized (this) {
            mResultCode = resultCode;
            mResultData = null;
        }
    }

    /**
     * Call this to set the result that your activity will return to its
     * caller.
     *
     * <p>As of {@link android.os.Build.VERSION_CODES#GINGERBREAD}, the Intent
     * you supply here can have {@link Intent#FLAG_GRANT_READ_URI_PERMISSION
     * Intent.FLAG_GRANT_READ_URI_PERMISSION} and/or {@link Intent#FLAG_GRANT_WRITE_URI_PERMISSION
     * Intent.FLAG_GRANT_WRITE_URI_PERMISSION} set.  This will grant the
     * Activity receiving the result access to the specific URIs in the Intent.
     * Access will remain until the Activity has finished (it will remain across the hosting
     * process being killed and other temporary destruction) and will be added
     * to any existing set of URI permissions it already holds.
     *
     * @param resultCode The result code to propagate back to the originating
     *                   activity, often RESULT_CANCELED or RESULT_OK
     * @param data The data to propagate back to the originating activity.
     *
     * @see #RESULT_CANCELED
     * @see #RESULT_OK
     * @see #RESULT_FIRST_USER
     * @see #setResult(int)
     */
    public final void setResult(int resultCode, Intent data) {
        synchronized (this) {
            mResultCode = resultCode;
            mResultData = data;
        }
    }

    /**
     * Return information about who launched this activity.  If the launching Intent
     * contains an {@link android.content.Intent#EXTRA_REFERRER Intent.EXTRA_REFERRER},
     * that will be returned as-is; otherwise, if known, an
     * {@link Intent#URI_ANDROID_APP_SCHEME android-app:} referrer URI containing the
     * package name that started the Intent will be returned.  This may return null if no
     * referrer can be identified -- it is neither explicitly specified, nor is it known which
     * application package was involved.
     *
     * <p>If called while inside the handling of {@link #onNewIntent}, this function will
     * return the referrer that submitted that new intent to the activity.  Otherwise, it
     * always returns the referrer of the original Intent.</p>
     *
     * <p>Note that this is <em>not</em> a security feature -- you can not trust the
     * referrer information, applications can spoof it.</p>
     */
    @Nullable
    public Uri getReferrer() {
        Intent intent = getIntent();
        Uri referrer = intent.getParcelableExtra(Intent.EXTRA_REFERRER);
        if (referrer != null) {
            return referrer;
        }
        String referrerName = intent.getStringExtra(Intent.EXTRA_REFERRER_NAME);
        if (referrerName != null) {
            return Uri.parse(referrerName);
        }
        if (mReferrer != null) {
            return new Uri.Builder().scheme("android-app").authority(mReferrer).build();
        }
        return null;
    }

    /**
     * Return the name of the package that invoked this activity.  This is who
     * the data in {@link #setResult setResult()} will be sent to.  You can
     * use this information to validate that the recipient is allowed to
     * receive the data.
     *
     * <p class="note">Note: if the calling activity is not expecting a result (that is it
     * did not use the {@link #startActivityForResult}
     * form that includes a request code), then the calling package will be
     * null.</p>
     *
     * <p class="note">Note: prior to {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR2},
     * the result from this method was unstable.  If the process hosting the calling
     * package was no longer running, it would return null instead of the proper package
     * name.  You can use {@link #getCallingActivity()} and retrieve the package name
     * from that instead.</p>
     *
     * @return The package of the activity that will receive your
     *         reply, or null if none.
     */
    @Nullable
    public String getCallingPackage() {
        try {
            return ActivityManagerNative.getDefault().getCallingPackage(mToken);
        } catch (RemoteException e) {
            return null;
        }
    }

    /**
     * Return the name of the activity that invoked this activity.  This is
     * who the data in {@link #setResult setResult()} will be sent to.  You
     * can use this information to validate that the recipient is allowed to
     * receive the data.
     *
     * <p class="note">Note: if the calling activity is not expecting a result (that is it
     * did not use the {@link #startActivityForResult}
     * form that includes a request code), then the calling package will be
     * null.
     *
     * @return The ComponentName of the activity that will receive your
     *         reply, or null if none.
     */
    @Nullable
    public ComponentName getCallingActivity() {
        try {
            return ActivityManagerNative.getDefault().getCallingActivity(mToken);
        } catch (RemoteException e) {
            return null;
        }
    }

    /**
     * Control whether this activity's main window is visible.  This is intended
     * only for the special case of an activity that is not going to show a
     * UI itself, but can't just finish prior to onResume() because it needs
     * to wait for a service binding or such.  Setting this to false allows
     * you to prevent your UI from being shown during that time.
     *
     * <p>The default value for this is taken from the
     * {@link android.R.attr#windowNoDisplay} attribute of the activity's theme.
     */
    public void setVisible(boolean visible) {
        if (mVisibleFromClient != visible) {
            mVisibleFromClient = visible;
            if (mVisibleFromServer) {
                if (visible) makeVisible();
                else mDecor.setVisibility(View.INVISIBLE);
            }
        }
    }

    void makeVisible() {
        if (!mWindowAdded) {
            ViewManager wm = getWindowManager();
            wm.addView(mDecor, getWindow().getAttributes());
            mWindowAdded = true;
        }
        mDecor.setVisibility(View.VISIBLE);
    }

    /**
     * Check to see whether this activity is in the process of finishing,
     * either because you called {@link #finish} on it or someone else
     * has requested that it finished.  This is often used in
     * {@link #onPause} to determine whether the activity is simply pausing or
     * completely finishing.
     *
     * @return If the activity is finishing, returns true; else returns false.
     *
     * @see #finish
     */
    public boolean isFinishing() {
        return mFinished;
    }

    /**
     * Returns true if the final {@link #onDestroy()} call has been made
     * on the Activity, so this instance is now dead.
     */
    public boolean isDestroyed() {
        return mDestroyed;
    }

    /**
     * Check to see whether this activity is in the process of being destroyed in order to be
     * recreated with a new configuration. This is often used in
     * {@link #onStop} to determine whether the state needs to be cleaned up or will be passed
     * on to the next instance of the activity via {@link #onRetainNonConfigurationInstance()}.
     *
     * @return If the activity is being torn down in order to be recreated with a new configuration,
     * returns true; else returns false.
     */
    public boolean isChangingConfigurations() {
        return mChangingConfigurations;
    }

    /**
     * Cause this Activity to be recreated with a new instance.  This results
     * in essentially the same flow as when the Activity is created due to
     * a configuration change -- the current instance will go through its
     * lifecycle to {@link #onDestroy} and a new instance then created after it.
     */
    public void recreate() {
        if (mParent != null) {
            throw new IllegalStateException("Can only be called on top-level activity");
        }
        if (Looper.myLooper() != mMainThread.getLooper()) {
            throw new IllegalStateException("Must be called from main thread");
        }
        mMainThread.requestRelaunchActivity(mToken, null, null, 0, false, null, false);
    }

    /**
     * Finishes the current activity and specifies whether to remove the task associated with this
     * activity.
     */
    private void finish(boolean finishTask) {
        if (mParent == null) {
            int resultCode;
            Intent resultData;
            synchronized (this) {
                resultCode = mResultCode;
                resultData = mResultData;
            }
            if (false) Log.v(TAG, "Finishing self: token=" + mToken);
            try {
                if (resultData != null) {
                    resultData.prepareToLeaveProcess();
                }
                if (ActivityManagerNative.getDefault()
                        .finishActivity(mToken, resultCode, resultData, finishTask)) {
                    mFinished = true;
                }
            } catch (RemoteException e) {
                // Empty
            }
        } else {
            mParent.finishFromChild(this);
        }
    }

    /**
     * Call this when your activity is done and should be closed.  The
     * ActivityResult is propagated back to whoever launched you via
     * onActivityResult().
     */
    public void finish() {
        finish(false);
    }

    /**
     * Finish this activity as well as all activities immediately below it
     * in the current task that have the same affinity.  This is typically
     * used when an application can be launched on to another task (such as
     * from an ACTION_VIEW of a content type it understands) and the user
     * has used the up navigation to switch out of the current task and in
     * to its own task.  In this case, if the user has navigated down into
     * any other activities of the second application, all of those should
     * be removed from the original task as part of the task switch.
     *
     * <p>Note that this finish does <em>not</em> allow you to deliver results
     * to the previous activity, and an exception will be thrown if you are trying
     * to do so.</p>
     */
    public void finishAffinity() {
        if (mParent != null) {
            throw new IllegalStateException("Can not be called from an embedded activity");
        }
        if (mResultCode != RESULT_CANCELED || mResultData != null) {
            throw new IllegalStateException("Can not be called to deliver a result");
        }
        try {
            if (ActivityManagerNative.getDefault().finishActivityAffinity(mToken)) {
                mFinished = true;
            }
        } catch (RemoteException e) {
            // Empty
        }
    }

    /**
     * This is called when a child activity of this one calls its
     * {@link #finish} method.  The default implementation simply calls
     * finish() on this activity (the parent), finishing the entire group.
     *
     * @param child The activity making the call.
     *
     * @see #finish
     */
    public void finishFromChild(Activity child) {
        finish();
    }

    /**
     * Reverses the Activity Scene entry Transition and triggers the calling Activity
     * to reverse its exit Transition. When the exit Transition completes,
     * {@link #finish()} is called. If no entry Transition was used, finish() is called
     * immediately and the Activity exit Transition is run.
     * @see android.app.ActivityOptions#makeSceneTransitionAnimation(Activity, android.util.Pair[])
     */
    public void finishAfterTransition() {
        if (!mActivityTransitionState.startExitBackTransition(this)) {
            finish();
        }
    }

    /**
     * Force finish another activity that you had previously started with
     * {@link #startActivityForResult}.
     *
     * @param requestCode The request code of the activity that you had
     *                    given to startActivityForResult().  If there are multiple
     *                    activities started with this request code, they
     *                    will all be finished.
     */
    public void finishActivity(int requestCode) {
        if (mParent == null) {
            try {
                ActivityManagerNative.getDefault()
                    .finishSubActivity(mToken, mEmbeddedID, requestCode);
            } catch (RemoteException e) {
                // Empty
            }
        } else {
            mParent.finishActivityFromChild(this, requestCode);
        }
    }

    /**
     * This is called when a child activity of this one calls its
     * finishActivity().
     *
     * @param child The activity making the call.
     * @param requestCode Request code that had been used to start the
     *                    activity.
     */
    public void finishActivityFromChild(@NonNull Activity child, int requestCode) {
        try {
            ActivityManagerNative.getDefault()
                .finishSubActivity(mToken, child.mEmbeddedID, requestCode);
        } catch (RemoteException e) {
            // Empty
        }
    }

    /**
     * Call this when your activity is done and should be closed and the task should be completely
     * removed as a part of finishing the Activity.
     */
    public void finishAndRemoveTask() {
        finish(true);
    }

    /**
     * Ask that the local app instance of this activity be released to free up its memory.
     * This is asking for the activity to be destroyed, but does <b>not</b> finish the activity --
     * a new instance of the activity will later be re-created if needed due to the user
     * navigating back to it.
     *
     * @return Returns true if the activity was in a state that it has started the process
     * of destroying its current instance; returns false if for any reason this could not
     * be done: it is currently visible to the user, it is already being destroyed, it is
     * being finished, it hasn't yet saved its state, etc.
     */
    public boolean releaseInstance() {
        try {
            return ActivityManagerNative.getDefault().releaseActivityInstance(mToken);
        } catch (RemoteException e) {
            // Empty
        }
        return false;
    }

    /**
     * Called when an activity you launched exits, giving you the requestCode
     * you started it with, the resultCode it returned, and any additional
     * data from it.  The <var>resultCode</var> will be
     * {@link #RESULT_CANCELED} if the activity explicitly returned that,
     * didn't return any result, or crashed during its operation.
     *
     * <p>You will receive this call immediately before onResume() when your
     * activity is re-starting.
     *
     * @param requestCode The integer request code originally supplied to
     *                    startActivityForResult(), allowing you to identify who this
     *                    result came from.
     * @param resultCode The integer result code returned by the child activity
     *                   through its setResult().
     * @param data An Intent, which can return result data to the caller
     *               (various data can be attached to Intent "extras").
     *
     * @see #startActivityForResult
     * @see #createPendingResult
     * @see #setResult(int)
     */
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    }

    /**
     * Called when an activity you launched with an activity transition exposes this
     * Activity through a returning activity transition, giving you the resultCode
     * and any additional data from it. This method will only be called if the activity
     * set a result code other than {@link #RESULT_CANCELED} and it supports activity
     * transitions with {@link Window#FEATURE_ACTIVITY_TRANSITIONS}.
     *
     * <p>The purpose of this function is to let the called Activity send a hint about
     * its state so that this underlying Activity can prepare to be exposed. A call to
     * this method does not guarantee that the called Activity has or will be exiting soon.
     * It only indicates that it will expose this Activity's Window and it has
     * some data to pass to prepare it.</p>
     *
     * @param resultCode The integer result code returned by the child activity
     *                   through its setResult().
     * @param data An Intent, which can return result data to the caller
     *               (various data can be attached to Intent "extras").
     */
    public void onActivityReenter(int resultCode, Intent data) {
    }

    /**
     * Create a new PendingIntent object which you can hand to others
     * for them to use to send result data back to your
     * {@link #onActivityResult} callback.  The created object will be either
     * one-shot (becoming invalid after a result is sent back) or multiple
     * (allowing any number of results to be sent through it).
     *
     * @param requestCode Private request code for the sender that will be
     * associated with the result data when it is returned.  The sender can not
     * modify this value, allowing you to identify incoming results.
     * @param data Default data to supply in the result, which may be modified
     * by the sender.
     * @param flags May be {@link PendingIntent#FLAG_ONE_SHOT PendingIntent.FLAG_ONE_SHOT},
     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE},
     * {@link PendingIntent#FLAG_CANCEL_CURRENT PendingIntent.FLAG_CANCEL_CURRENT},
     * {@link PendingIntent#FLAG_UPDATE_CURRENT PendingIntent.FLAG_UPDATE_CURRENT},
     * or any of the flags as supported by
     * {@link Intent#fillIn Intent.fillIn()} to control which unspecified parts
     * of the intent that can be supplied when the actual send happens.
     *
     * @return Returns an existing or new PendingIntent matching the given
     * parameters.  May return null only if
     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE} has been
     * supplied.
     *
     * @see PendingIntent
     */
    public PendingIntent createPendingResult(int requestCode, @NonNull Intent data,
            @PendingIntent.Flags int flags) {
        String packageName = getPackageName();
        try {
            data.prepareToLeaveProcess();
            IIntentSender target =
                ActivityManagerNative.getDefault().getIntentSender(
                        ActivityManager.INTENT_SENDER_ACTIVITY_RESULT, packageName,
                        mParent == null ? mToken : mParent.mToken,
                        mEmbeddedID, requestCode, new Intent[] { data }, null, flags, null,
                        UserHandle.myUserId());
            return target != null ? new PendingIntent(target) : null;
        } catch (RemoteException e) {
            // Empty
        }
        return null;
    }

    /**
     * Change the desired orientation of this activity.  If the activity
     * is currently in the foreground or otherwise impacting the screen
     * orientation, the screen will immediately be changed (possibly causing
     * the activity to be restarted). Otherwise, this will be used the next
     * time the activity is visible.
     *
     * @param requestedOrientation An orientation constant as used in
     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
     */
    public void setRequestedOrientation(@ActivityInfo.ScreenOrientation int requestedOrientation) {
        if (mParent == null) {
            try {
                ActivityManagerNative.getDefault().setRequestedOrientation(
                        mToken, requestedOrientation);
            } catch (RemoteException e) {
                // Empty
            }
        } else {
            mParent.setRequestedOrientation(requestedOrientation);
        }
    }

    /**
     * Return the current requested orientation of the activity.  This will
     * either be the orientation requested in its component's manifest, or
     * the last requested orientation given to
     * {@link #setRequestedOrientation(int)}.
     *
     * @return Returns an orientation constant as used in
     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
     */
    @ActivityInfo.ScreenOrientation
    public int getRequestedOrientation() {
        if (mParent == null) {
            try {
                return ActivityManagerNative.getDefault()
                        .getRequestedOrientation(mToken);
            } catch (RemoteException e) {
                // Empty
            }
        } else {
            return mParent.getRequestedOrientation();
        }
        return ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
    }

    /**
     * Return the identifier of the task this activity is in.  This identifier
     * will remain the same for the lifetime of the activity.
     *
     * @return Task identifier, an opaque integer.
     */
    public int getTaskId() {
        try {
            return ActivityManagerNative.getDefault()
                .getTaskForActivity(mToken, false);
        } catch (RemoteException e) {
            return -1;
        }
    }

    /**
     * Return whether this activity is the root of a task.  The root is the
     * first activity in a task.
     *
     * @return True if this is the root activity, else false.
     */
    public boolean isTaskRoot() {
        try {
            return ActivityManagerNative.getDefault()
                .getTaskForActivity(mToken, true) >= 0;
        } catch (RemoteException e) {
            return false;
        }
    }

    /**
     * Move the task containing this activity to the back of the activity
     * stack.  The activity's order within the task is unchanged.
     *
     * @param nonRoot If false then this only works if the activity is the root
     *                of a task; if true it will work for any activity in
     *                a task.
     *
     * @return If the task was moved (or it was already at the
     *         back) true is returned, else false.
     */
    public boolean moveTaskToBack(boolean nonRoot) {
        try {
            return ActivityManagerNative.getDefault().moveActivityTaskToBack(
                    mToken, nonRoot);
        } catch (RemoteException e) {
            // Empty
        }
        return false;
    }

    /**
     * Returns class name for this activity with the package prefix removed.
     * This is the default name used to read and write settings.
     *
     * @return The local class name.
     */
    @NonNull
    public String getLocalClassName() {
        final String pkg = getPackageName();
        final String cls = mComponent.getClassName();
        int packageLen = pkg.length();
        if (!cls.startsWith(pkg) || cls.length() <= packageLen
                || cls.charAt(packageLen) != '.') {
            return cls;
        }
        return cls.substring(packageLen+1);
    }

    /**
     * Returns complete component name of this activity.
     *
     * @return Returns the complete component name for this activity
     */
    public ComponentName getComponentName()
    {
        return mComponent;
    }

    /**
     * Retrieve a {@link SharedPreferences} object for accessing preferences
     * that are private to this activity.  This simply calls the underlying
     * {@link #getSharedPreferences(String, int)} method by passing in this activity's
     * class name as the preferences name.
     *
     * @param mode Operating mode.  Use {@link #MODE_PRIVATE} for the default
     *             operation, {@link #MODE_WORLD_READABLE} and
     *             {@link #MODE_WORLD_WRITEABLE} to control permissions.
     *
     * @return Returns the single SharedPreferences instance that can be used
     *         to retrieve and modify the preference values.
     */
    public SharedPreferences getPreferences(int mode) {
        return getSharedPreferences(getLocalClassName(), mode);
    }

    private void ensureSearchManager() {
        if (mSearchManager != null) {
            return;
        }

        mSearchManager = new SearchManager(this, null);
    }

    @Override
    public Object getSystemService(@ServiceName @NonNull String name) {
        if (getBaseContext() == null) {
            throw new IllegalStateException(
                    "System services not available to Activities before onCreate()");
        }

        if (WINDOW_SERVICE.equals(name)) {
            return mWindowManager;
        } else if (SEARCH_SERVICE.equals(name)) {
            ensureSearchManager();
            return mSearchManager;
        }
        return super.getSystemService(name);
    }

    /**
     * Change the title associated with this activity.  If this is a
     * top-level activity, the title for its window will change.  If it
     * is an embedded activity, the parent can do whatever it wants
     * with it.
     */
    public void setTitle(CharSequence title) {
        mTitle = title;
        onTitleChanged(title, mTitleColor);

        if (mParent != null) {
            mParent.onChildTitleChanged(this, title);
        }
    }

    /**
     * Change the title associated with this activity.  If this is a
     * top-level activity, the title for its window will change.  If it
     * is an embedded activity, the parent can do whatever it wants
     * with it.
     */
    public void setTitle(int titleId) {
        setTitle(getText(titleId));
    }

    /**
     * Change the color of the title associated with this activity.
     * <p>
     * This method is deprecated starting in API Level 11 and replaced by action
     * bar styles. For information on styling the Action Bar, read the <a
     * href="{@docRoot} guide/topics/ui/actionbar.html">Action Bar</a> developer
     * guide.
     *
     * @deprecated Use action bar styles instead.
     */
    @Deprecated
    public void setTitleColor(int textColor) {
        mTitleColor = textColor;
        onTitleChanged(mTitle, textColor);
    }

    public final CharSequence getTitle() {
        return mTitle;
    }

    public final int getTitleColor() {
        return mTitleColor;
    }

    protected void onTitleChanged(CharSequence title, int color) {
        if (mTitleReady) {
            final Window win = getWindow();
            if (win != null) {
                win.setTitle(title);
                if (color != 0) {
                    win.setTitleColor(color);
                }
            }
            if (mActionBar != null) {
                mActionBar.setWindowTitle(title);
            }
        }
    }

    protected void onChildTitleChanged(Activity childActivity, CharSequence title) {
    }

    /**
     * Sets information describing the task with this activity for presentation inside the Recents
     * System UI. When {@link ActivityManager#getRecentTasks} is called, the activities of each task
     * are traversed in order from the topmost activity to the bottommost. The traversal continues
     * for each property until a suitable value is found. For each task the taskDescription will be
     * returned in {@link android.app.ActivityManager.TaskDescription}.
     *
     * @see ActivityManager#getRecentTasks
     * @see android.app.ActivityManager.TaskDescription
     *
     * @param taskDescription The TaskDescription properties that describe the task with this activity
     */
    public void setTaskDescription(ActivityManager.TaskDescription taskDescription) {
        ActivityManager.TaskDescription td;
        // Scale the icon down to something reasonable if it is provided
        if (taskDescription.getIconFilename() == null && taskDescription.getIcon() != null) {
            final int size = ActivityManager.getLauncherLargeIconSizeInner(this);
            final Bitmap icon = Bitmap.createScaledBitmap(taskDescription.getIcon(), size, size, true);
            td = new ActivityManager.TaskDescription(taskDescription.getLabel(), icon,
                    taskDescription.getPrimaryColor());
        } else {
            td = taskDescription;
        }
        try {
            ActivityManagerNative.getDefault().setTaskDescription(mToken, td);
        } catch (RemoteException e) {
        }
    }

    /**
     * Sets the visibility of the progress bar in the title.
     * <p>
     * In order for the progress bar to be shown, the feature must be requested
     * via {@link #requestWindowFeature(int)}.
     *
     * @param visible Whether to show the progress bars in the title.
     */
    public final void setProgressBarVisibility(boolean visible) {
        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, visible ? Window.PROGRESS_VISIBILITY_ON :
            Window.PROGRESS_VISIBILITY_OFF);
    }

    /**
     * Sets the visibility of the indeterminate progress bar in the title.
     * <p>
     * In order for the progress bar to be shown, the feature must be requested
     * via {@link #requestWindowFeature(int)}.
     *
     * @param visible Whether to show the progress bars in the title.
     */
    public final void setProgressBarIndeterminateVisibility(boolean visible) {
        getWindow().setFeatureInt(Window.FEATURE_INDETERMINATE_PROGRESS,
                visible ? Window.PROGRESS_VISIBILITY_ON : Window.PROGRESS_VISIBILITY_OFF);
    }

    /**
     * Sets whether the horizontal progress bar in the title should be indeterminate (the circular
     * is always indeterminate).
     * <p>
     * In order for the progress bar to be shown, the feature must be requested
     * via {@link #requestWindowFeature(int)}.
     *
     * @param indeterminate Whether the horizontal progress bar should be indeterminate.
     */
    public final void setProgressBarIndeterminate(boolean indeterminate) {
        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
                indeterminate ? Window.PROGRESS_INDETERMINATE_ON
                        : Window.PROGRESS_INDETERMINATE_OFF);
    }

    /**
     * Sets the progress for the progress bars in the title.
     * <p>
     * In order for the progress bar to be shown, the feature must be requested
     * via {@link #requestWindowFeature(int)}.
     *
     * @param progress The progress for the progress bar. Valid ranges are from
     *            0 to 10000 (both inclusive). If 10000 is given, the progress
     *            bar will be completely filled and will fade out.
     */
    public final void setProgress(int progress) {
        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, progress + Window.PROGRESS_START);
    }

    /**
     * Sets the secondary progress for the progress bar in the title. This
     * progress is drawn between the primary progress (set via
     * {@link #setProgress(int)} and the background. It can be ideal for media
     * scenarios such as showing the buffering progress while the default
     * progress shows the play progress.
     * <p>
     * In order for the progress bar to be shown, the feature must be requested
     * via {@link #requestWindowFeature(int)}.
     *
     * @param secondaryProgress The secondary progress for the progress bar. Valid ranges are from
     *            0 to 10000 (both inclusive).
     */
    public final void setSecondaryProgress(int secondaryProgress) {
        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
                secondaryProgress + Window.PROGRESS_SECONDARY_START);
    }

    /**
     * Suggests an audio stream whose volume should be changed by the hardware
     * volume controls.
     * <p>
     * The suggested audio stream will be tied to the window of this Activity.
     * Volume requests which are received while the Activity is in the
     * foreground will affect this stream.
     * <p>
     * It is not guaranteed that the hardware volume controls will always change
     * this stream's volume (for example, if a call is in progress, its stream's
     * volume may be changed instead). To reset back to the default, use
     * {@link AudioManager#USE_DEFAULT_STREAM_TYPE}.
     *
     * @param streamType The type of the audio stream whose volume should be
     *            changed by the hardware volume controls.
     */
    public final void setVolumeControlStream(int streamType) {
        getWindow().setVolumeControlStream(streamType);
    }

    /**
     * Gets the suggested audio stream whose volume should be changed by the
     * hardware volume controls.
     *
     * @return The suggested audio stream type whose volume should be changed by
     *         the hardware volume controls.
     * @see #setVolumeControlStream(int)
     */
    public final int getVolumeControlStream() {
        return getWindow().getVolumeControlStream();
    }

    /**
     * Sets a {@link MediaController} to send media keys and volume changes to.
     * <p>
     * The controller will be tied to the window of this Activity. Media key and
     * volume events which are received while the Activity is in the foreground
     * will be forwarded to the controller and used to invoke transport controls
     * or adjust the volume. This may be used instead of or in addition to
     * {@link #setVolumeControlStream} to affect a specific session instead of a
     * specific stream.
     * <p>
     * It is not guaranteed that the hardware volume controls will always change
     * this session's volume (for example, if a call is in progress, its
     * stream's volume may be changed instead). To reset back to the default use
     * null as the controller.
     *
     * @param controller The controller for the session which should receive
     *            media keys and volume changes.
     */
    public final void setMediaController(MediaController controller) {
        getWindow().setMediaController(controller);
    }

    /**
     * Gets the controller which should be receiving media key and volume events
     * while this activity is in the foreground.
     *
     * @return The controller which should receive events.
     * @see #setMediaController(android.media.session.MediaController)
     */
    public final MediaController getMediaController() {
        return getWindow().getMediaController();
    }

    /**
     * Runs the specified action on the UI thread. If the current thread is the UI
     * thread, then the action is executed immediately. If the current thread is
     * not the UI thread, the action is posted to the event queue of the UI thread.
     *
     * @param action the action to run on the UI thread
     */
    public final void runOnUiThread(Runnable action) {
        if (Thread.currentThread() != mUiThread) {
            mHandler.post(action);
        } else {
            action.run();
        }
    }

    /**
     * Standard implementation of
     * {@link android.view.LayoutInflater.Factory#onCreateView} used when
     * inflating with the LayoutInflater returned by {@link #getSystemService}.
     * This implementation does nothing and is for
     * pre-{@link android.os.Build.VERSION_CODES#HONEYCOMB} apps.  Newer apps
     * should use {@link #onCreateView(View, String, Context, AttributeSet)}.
     *
     * @see android.view.LayoutInflater#createView
     * @see android.view.Window#getLayoutInflater
     */
    @Nullable
    public View onCreateView(String name, Context context, AttributeSet attrs) {
        return null;
    }

    /**
     * Standard implementation of
     * {@link android.view.LayoutInflater.Factory2#onCreateView(View, String, Context, AttributeSet)}
     * used when inflating with the LayoutInflater returned by {@link #getSystemService}.
     * This implementation handles <fragment> tags to embed fragments inside
     * of the activity.
     *
     * @see android.view.LayoutInflater#createView
     * @see android.view.Window#getLayoutInflater
     */
    public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
        if (!"fragment".equals(name)) {
            return onCreateView(name, context, attrs);
        }

        return mFragments.onCreateView(parent, name, context, attrs);
    }

    /**
     * Print the Activity's state into the given stream.  This gets invoked if
     * you run "adb shell dumpsys activity &lt;activity_component_name&gt;".
     *
     * @param prefix Desired prefix to prepend at each line of output.
     * @param fd The raw file descriptor that the dump is being sent to.
     * @param writer The PrintWriter to which you should dump your state.  This will be
     * closed for you after you return.
     * @param args additional arguments to the dump request.
     */
    public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
        dumpInner(prefix, fd, writer, args);
    }

    void dumpInner(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
        writer.print(prefix); writer.print("Local Activity ");
                writer.print(Integer.toHexString(System.identityHashCode(this)));
                writer.println(" State:");
        String innerPrefix = prefix + "  ";
        writer.print(innerPrefix); writer.print("mResumed=");
                writer.print(mResumed); writer.print(" mStopped=");
                writer.print(mStopped); writer.print(" mFinished=");
                writer.println(mFinished);
        writer.print(innerPrefix); writer.print("mLoadersStarted=");
                writer.println(mLoadersStarted);
        writer.print(innerPrefix); writer.print("mChangingConfigurations=");
                writer.println(mChangingConfigurations);
        writer.print(innerPrefix); writer.print("mCurrentConfig=");
                writer.println(mCurrentConfig);

        if (mLoaderManager != null) {
            writer.print(prefix); writer.print("Loader Manager ");
                    writer.print(Integer.toHexString(System.identityHashCode(mLoaderManager)));
                    writer.println(":");
            mLoaderManager.dump(prefix + "  ", fd, writer, args);
        }

        mFragments.dump(prefix, fd, writer, args);

        if (getWindow() != null &&
                getWindow().peekDecorView() != null &&
                getWindow().peekDecorView().getViewRootImpl() != null) {
            getWindow().peekDecorView().getViewRootImpl().dump(prefix, fd, writer, args);
        }

        mHandler.getLooper().dump(new PrintWriterPrinter(writer), prefix);
    }

    /**
     * Bit indicating that this activity is "immersive" and should not be
     * interrupted by notifications if possible.
     *
     * This value is initially set by the manifest property
     * <code>android:immersive</code> but may be changed at runtime by
     * {@link #setImmersive}.
     *
     * @see #setImmersive(boolean)
     * @see android.content.pm.ActivityInfo#FLAG_IMMERSIVE
     */
    public boolean isImmersive() {
        try {
            return ActivityManagerNative.getDefault().isImmersive(mToken);
        } catch (RemoteException e) {
            return false;
        }
    }

    /**
     * Indication of whether this is the highest level activity in this task. Can be used to
     * determine whether an activity launched by this activity was placed in the same task or
     * another task.
     *
     * @return true if this is the topmost, non-finishing activity in its task.
     */
    private boolean isTopOfTask() {
        try {
            return ActivityManagerNative.getDefault().isTopOfTask(mToken);
        } catch (RemoteException e) {
            return false;
        }
    }

    /**
     * Convert a translucent themed Activity {@link android.R.attr#windowIsTranslucent} to a
     * fullscreen opaque Activity.
     * <p>
     * Call this whenever the background of a translucent Activity has changed to become opaque.
     * Doing so will allow the {@link android.view.Surface} of the Activity behind to be released.
     * <p>
     * This call has no effect on non-translucent activities or on activities with the
     * {@link android.R.attr#windowIsFloating} attribute.
     *
     * @see #convertToTranslucent(android.app.Activity.TranslucentConversionListener,
     * ActivityOptions)
     * @see TranslucentConversionListener
     *
     * @hide
     */
    @SystemApi
    public void convertFromTranslucent() {
        try {
            mTranslucentCallback = null;
            if (ActivityManagerNative.getDefault().convertFromTranslucent(mToken)) {
                WindowManagerGlobal.getInstance().changeCanvasOpacity(mToken, true);
            }
        } catch (RemoteException e) {
            // pass
        }
    }

    /**
     * Convert a translucent themed Activity {@link android.R.attr#windowIsTranslucent} back from
     * opaque to translucent following a call to {@link #convertFromTranslucent()}.
     * <p>
     * Calling this allows the Activity behind this one to be seen again. Once all such Activities
     * have been redrawn {@link TranslucentConversionListener#onTranslucentConversionComplete} will
     * be called indicating that it is safe to make this activity translucent again. Until
     * {@link TranslucentConversionListener#onTranslucentConversionComplete} is called the image
     * behind the frontmost Activity will be indeterminate.
     * <p>
     * This call has no effect on non-translucent activities or on activities with the
     * {@link android.R.attr#windowIsFloating} attribute.
     *
     * @param callback the method to call when all visible Activities behind this one have been
     * drawn and it is safe to make this Activity translucent again.
     * @param options activity options delivered to the activity below this one. The options
     * are retrieved using {@link #getActivityOptions}.
     * @return <code>true</code> if Window was opaque and will become translucent or
     * <code>false</code> if window was translucent and no change needed to be made.
     *
     * @see #convertFromTranslucent()
     * @see TranslucentConversionListener
     *
     * @hide
     */
    @SystemApi
    public boolean convertToTranslucent(TranslucentConversionListener callback,
            ActivityOptions options) {
        boolean drawComplete;
        try {
            mTranslucentCallback = callback;
            mChangeCanvasToTranslucent =
                    ActivityManagerNative.getDefault().convertToTranslucent(mToken, options);
            WindowManagerGlobal.getInstance().changeCanvasOpacity(mToken, false);
            drawComplete = true;
        } catch (RemoteException e) {
            // Make callback return as though it timed out.
            mChangeCanvasToTranslucent = false;
            drawComplete = false;
        }
        if (!mChangeCanvasToTranslucent && mTranslucentCallback != null) {
            // Window is already translucent.
            mTranslucentCallback.onTranslucentConversionComplete(drawComplete);
        }
        return mChangeCanvasToTranslucent;
    }

    /** @hide */
    void onTranslucentConversionComplete(boolean drawComplete) {
        if (mTranslucentCallback != null) {
            mTranslucentCallback.onTranslucentConversionComplete(drawComplete);
            mTranslucentCallback = null;
        }
        if (mChangeCanvasToTranslucent) {
            WindowManagerGlobal.getInstance().changeCanvasOpacity(mToken, false);
        }
    }

    /** @hide */
    public void onNewActivityOptions(ActivityOptions options) {
        mActivityTransitionState.setEnterActivityOptions(this, options);
        if (!mStopped) {
            mActivityTransitionState.enterReady(this);
        }
    }

    /**
     * Retrieve the ActivityOptions passed in from the launching activity or passed back
     * from an activity launched by this activity in its call to {@link
     * #convertToTranslucent(TranslucentConversionListener, ActivityOptions)}
     *
     * @return The ActivityOptions passed to {@link #convertToTranslucent}.
     * @hide
     */
    ActivityOptions getActivityOptions() {
        try {
            return ActivityManagerNative.getDefault().getActivityOptions(mToken);
        } catch (RemoteException e) {
        }
        return null;
    }

    /**
     * Activities that want to remain visible behind a translucent activity above them must call
     * this method anytime between the start of {@link #onResume()} and the return from
     * {@link #onPause()}. If this call is successful then the activity will remain visible after
     * {@link #onPause()} is called, and is allowed to continue playing media in the background.
     *
     * <p>The actions of this call are reset each time that this activity is brought to the
     * front. That is, every time {@link #onResume()} is called the activity will be assumed
     * to not have requested visible behind. Therefore, if you want this activity to continue to
     * be visible in the background you must call this method again.
     *
     * <p>Only fullscreen opaque activities may make this call. I.e. this call is a nop
     * for dialog and translucent activities.
     *
     * <p>Under all circumstances, the activity must stop playing and release resources prior to or
     * within a call to {@link #onVisibleBehindCanceled()} or if this call returns false.
     *
     * <p>False will be returned any time this method is called between the return of onPause and
     *      the next call to onResume.
     *
     * @param visible true to notify the system that the activity wishes to be visible behind other
     *                translucent activities, false to indicate otherwise. Resources must be
     *                released when passing false to this method.
     * @return the resulting visibiity state. If true the activity will remain visible beyond
     *      {@link #onPause()} if the next activity is translucent or not fullscreen. If false
     *      then the activity may not count on being visible behind other translucent activities,
     *      and must stop any media playback and release resources.
     *      Returning false may occur in lieu of a call to {@link #onVisibleBehindCanceled()} so
     *      the return value must be checked.
     *
     * @see #onVisibleBehindCanceled()
     * @see #onBackgroundVisibleBehindChanged(boolean)
     */
    public boolean requestVisibleBehind(boolean visible) {
        if (!mResumed) {
            // Do not permit paused or stopped activities to do this.
            visible = false;
        }
        try {
            mVisibleBehind = ActivityManagerNative.getDefault()
                    .requestVisibleBehind(mToken, visible) && visible;
        } catch (RemoteException e) {
            mVisibleBehind = false;
        }
        return mVisibleBehind;
    }

    /**
     * Called when a translucent activity over this activity is becoming opaque or another
     * activity is being launched. Activities that override this method must call
     * <code>super.onVisibleBehindCanceled()</code> or a SuperNotCalledException will be thrown.
     *
     * <p>When this method is called the activity has 500 msec to release any resources it may be
     * using while visible in the background.
     * If the activity has not returned from this method in 500 msec the system will destroy
     * the activity and kill the process in order to recover the resources for another
     * process. Otherwise {@link #onStop()} will be called following return.
     *
     * @see #requestVisibleBehind(boolean)
     * @see #onBackgroundVisibleBehindChanged(boolean)
     */
    public void onVisibleBehindCanceled() {
        mCalled = true;
    }

    /**
     * Translucent activities may call this to determine if there is an activity below them that
     * is currently set to be visible in the background.
     *
     * @return true if an activity below is set to visible according to the most recent call to
     * {@link #requestVisibleBehind(boolean)}, false otherwise.
     *
     * @see #requestVisibleBehind(boolean)
     * @see #onVisibleBehindCanceled()
     * @see #onBackgroundVisibleBehindChanged(boolean)
     * @hide
     */
    @SystemApi
    public boolean isBackgroundVisibleBehind() {
        try {
            return ActivityManagerNative.getDefault().isBackgroundVisibleBehind(mToken);
        } catch (RemoteException e) {
        }
        return false;
    }

    /**
     * The topmost foreground activity will receive this call when the background visibility state
     * of the activity below it changes.
     *
     * This call may be a consequence of {@link #requestVisibleBehind(boolean)} or might be
     * due to a background activity finishing itself.
     *
     * @param visible true if a background activity is visible, false otherwise.
     *
     * @see #requestVisibleBehind(boolean)
     * @see #onVisibleBehindCanceled()
     * @hide
     */
    @SystemApi
    public void onBackgroundVisibleBehindChanged(boolean visible) {
    }

    /**
     * Activities cannot draw during the period that their windows are animating in. In order
     * to know when it is safe to begin drawing they can override this method which will be
     * called when the entering animation has completed.
     */
    public void onEnterAnimationComplete() {
    }

    /**
     * Adjust the current immersive mode setting.
     *
     * Note that changing this value will have no effect on the activity's
     * {@link android.content.pm.ActivityInfo} structure; that is, if
     * <code>android:immersive</code> is set to <code>true</code>
     * in the application's manifest entry for this activity, the {@link
     * android.content.pm.ActivityInfo#flags ActivityInfo.flags} member will
     * always have its {@link android.content.pm.ActivityInfo#FLAG_IMMERSIVE
     * FLAG_IMMERSIVE} bit set.
     *
     * @see #isImmersive()
     * @see android.content.pm.ActivityInfo#FLAG_IMMERSIVE
     */
    public void setImmersive(boolean i) {
        try {
            ActivityManagerNative.getDefault().setImmersive(mToken, i);
        } catch (RemoteException e) {
            // pass
        }
    }

    /**
     * Start an action mode.
     *
     * @param callback Callback that will manage lifecycle events for this context mode
     * @return The ContextMode that was started, or null if it was canceled
     *
     * @see ActionMode
     */
    @Nullable
    public ActionMode startActionMode(ActionMode.Callback callback) {
        return mWindow.getDecorView().startActionMode(callback);
    }

    /**
     * Give the Activity a chance to control the UI for an action mode requested
     * by the system.
     *
     * <p>Note: If you are looking for a notification callback that an action mode
     * has been started for this activity, see {@link #onActionModeStarted(ActionMode)}.</p>
     *
     * @param callback The callback that should control the new action mode
     * @return The new action mode, or <code>null</code> if the activity does not want to
     *         provide special handling for this action mode. (It will be handled by the system.)
     */
    @Nullable
    @Override
    public ActionMode onWindowStartingActionMode(ActionMode.Callback callback) {
        initWindowDecorActionBar();
        if (mActionBar != null) {
            return mActionBar.startActionMode(callback);
        }
        return null;
    }

    /**
     * Notifies the Activity that an action mode has been started.
     * Activity subclasses overriding this method should call the superclass implementation.
     *
     * @param mode The new action mode.
     */
    @Override
    public void onActionModeStarted(ActionMode mode) {
    }

    /**
     * Notifies the activity that an action mode has finished.
     * Activity subclasses overriding this method should call the superclass implementation.
     *
     * @param mode The action mode that just finished.
     */
    @Override
    public void onActionModeFinished(ActionMode mode) {
    }

    /**
     * Returns true if the app should recreate the task when navigating 'up' from this activity
     * by using targetIntent.
     *
     * <p>If this method returns false the app can trivially call
     * {@link #navigateUpTo(Intent)} using the same parameters to correctly perform
     * up navigation. If this method returns false, the app should synthesize a new task stack
     * by using {@link TaskStackBuilder} or another similar mechanism to perform up navigation.</p>
     *
     * @param targetIntent An intent representing the target destination for up navigation
     * @return true if navigating up should recreate a new task stack, false if the same task
     *         should be used for the destination
     */
    public boolean shouldUpRecreateTask(Intent targetIntent) {
        try {
            PackageManager pm = getPackageManager();
            ComponentName cn = targetIntent.getComponent();
            if (cn == null) {
                cn = targetIntent.resolveActivity(pm);
            }
            ActivityInfo info = pm.getActivityInfo(cn, 0);
            if (info.taskAffinity == null) {
                return false;
            }
            return ActivityManagerNative.getDefault()
                    .shouldUpRecreateTask(mToken, info.taskAffinity);
        } catch (RemoteException e) {
            return false;
        } catch (NameNotFoundException e) {
            return false;
        }
    }

    /**
     * Navigate from this activity to the activity specified by upIntent, finishing this activity
     * in the process. If the activity indicated by upIntent already exists in the task's history,
     * this activity and all others before the indicated activity in the history stack will be
     * finished.
     *
     * <p>If the indicated activity does not appear in the history stack, this will finish
     * each activity in this task until the root activity of the task is reached, resulting in
     * an "in-app home" behavior. This can be useful in apps with a complex navigation hierarchy
     * when an activity may be reached by a path not passing through a canonical parent
     * activity.</p>
     *
     * <p>This method should be used when performing up navigation from within the same task
     * as the destination. If up navigation should cross tasks in some cases, see
     * {@link #shouldUpRecreateTask(Intent)}.</p>
     *
     * @param upIntent An intent representing the target destination for up navigation
     *
     * @return true if up navigation successfully reached the activity indicated by upIntent and
     *         upIntent was delivered to it. false if an instance of the indicated activity could
     *         not be found and this activity was simply finished normally.
     */
    public boolean navigateUpTo(Intent upIntent) {
        if (mParent == null) {
            ComponentName destInfo = upIntent.getComponent();
            if (destInfo == null) {
                destInfo = upIntent.resolveActivity(getPackageManager());
                if (destInfo == null) {
                    return false;
                }
                upIntent = new Intent(upIntent);
                upIntent.setComponent(destInfo);
            }
            int resultCode;
            Intent resultData;
            synchronized (this) {
                resultCode = mResultCode;
                resultData = mResultData;
            }
            if (resultData != null) {
                resultData.prepareToLeaveProcess();
            }
            try {
                upIntent.prepareToLeaveProcess();
                return ActivityManagerNative.getDefault().navigateUpTo(mToken, upIntent,
                        resultCode, resultData);
            } catch (RemoteException e) {
                return false;
            }
        } else {
            return mParent.navigateUpToFromChild(this, upIntent);
        }
    }

    /**
     * This is called when a child activity of this one calls its
     * {@link #navigateUpTo} method.  The default implementation simply calls
     * navigateUpTo(upIntent) on this activity (the parent).
     *
     * @param child The activity making the call.
     * @param upIntent An intent representing the target destination for up navigation
     *
     * @return true if up navigation successfully reached the activity indicated by upIntent and
     *         upIntent was delivered to it. false if an instance of the indicated activity could
     *         not be found and this activity was simply finished normally.
     */
    public boolean navigateUpToFromChild(Activity child, Intent upIntent) {
        return navigateUpTo(upIntent);
    }

    /**
     * Obtain an {@link Intent} that will launch an explicit target activity specified by
     * this activity's logical parent. The logical parent is named in the application's manifest
     * by the {@link android.R.attr#parentActivityName parentActivityName} attribute.
     * Activity subclasses may override this method to modify the Intent returned by
     * super.getParentActivityIntent() or to implement a different mechanism of retrieving
     * the parent intent entirely.
     *
     * @return a new Intent targeting the defined parent of this activity or null if
     *         there is no valid parent.
     */
    @Nullable
    public Intent getParentActivityIntent() {
        final String parentName = mActivityInfo.parentActivityName;
        if (TextUtils.isEmpty(parentName)) {
            return null;
        }

        // If the parent itself has no parent, generate a main activity intent.
        final ComponentName target = new ComponentName(this, parentName);
        try {
            final ActivityInfo parentInfo = getPackageManager().getActivityInfo(target, 0);
            final String parentActivity = parentInfo.parentActivityName;
            final Intent parentIntent = parentActivity == null
                    ? Intent.makeMainActivity(target)
                    : new Intent().setComponent(target);
            return parentIntent;
        } catch (NameNotFoundException e) {
            Log.e(TAG, "getParentActivityIntent: bad parentActivityName '" + parentName +
                    "' in manifest");
            return null;
        }
    }

    /**
     * When {@link android.app.ActivityOptions#makeSceneTransitionAnimation(Activity,
     * android.view.View, String)} was used to start an Activity, <var>callback</var>
     * will be called to handle shared elements on the <i>launched</i> Activity. This requires
     * {@link Window#FEATURE_ACTIVITY_TRANSITIONS}.
     *
     * @param callback Used to manipulate shared element transitions on the launched Activity.
     */
    public void setEnterSharedElementCallback(SharedElementCallback callback) {
        if (callback == null) {
            callback = SharedElementCallback.NULL_CALLBACK;
        }
        mEnterTransitionListener = callback;
    }

    /**
     * When {@link android.app.ActivityOptions#makeSceneTransitionAnimation(Activity,
     * android.view.View, String)} was used to start an Activity, <var>callback</var>
     * will be called to handle shared elements on the <i>launching</i> Activity. Most
     * calls will only come when returning from the started Activity.
     * This requires {@link Window#FEATURE_ACTIVITY_TRANSITIONS}.
     *
     * @param callback Used to manipulate shared element transitions on the launching Activity.
     */
    public void setExitSharedElementCallback(SharedElementCallback callback) {
        if (callback == null) {
            callback = SharedElementCallback.NULL_CALLBACK;
        }
        mExitTransitionListener = callback;
    }

    /**
     * Postpone the entering activity transition when Activity was started with
     * {@link android.app.ActivityOptions#makeSceneTransitionAnimation(Activity,
     * android.util.Pair[])}.
     * <p>This method gives the Activity the ability to delay starting the entering and
     * shared element transitions until all data is loaded. Until then, the Activity won't
     * draw into its window, leaving the window transparent. This may also cause the
     * returning animation to be delayed until data is ready. This method should be
     * called in {@link #onCreate(android.os.Bundle)} or in
     * {@link #onActivityReenter(int, android.content.Intent)}.
     * {@link #startPostponedEnterTransition()} must be called to allow the Activity to
     * start the transitions. If the Activity did not use
     * {@link android.app.ActivityOptions#makeSceneTransitionAnimation(Activity,
     * android.util.Pair[])}, then this method does nothing.</p>
     */
    public void postponeEnterTransition() {
        mActivityTransitionState.postponeEnterTransition();
    }

    /**
     * Begin postponed transitions after {@link #postponeEnterTransition()} was called.
     * If postponeEnterTransition() was called, you must call startPostponedEnterTransition()
     * to have your Activity start drawing.
     */
    public void startPostponedEnterTransition() {
        mActivityTransitionState.startPostponedEnterTransition();
    }

    // ------------------ Internal API ------------------

    final void setParent(Activity parent) {
        mParent = parent;
    }

    final void attach(Context context, ActivityThread aThread,
            Instrumentation instr, IBinder token, int ident,
            Application application, Intent intent, ActivityInfo info,
            CharSequence title, Activity parent, String id,
            NonConfigurationInstances lastNonConfigurationInstances,
            Configuration config, String referrer, IVoiceInteractor voiceInteractor) {
        attachBaseContext(context);

        mFragments.attachActivity(this, mContainer, null);

        mWindow = PolicyManager.makeNewWindow(this);
        mWindow.setCallback(this);
        mWindow.setOnWindowDismissedCallback(this);
        mWindow.getLayoutInflater().setPrivateFactory(this);
        if (info.softInputMode != WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED) {
            mWindow.setSoftInputMode(info.softInputMode);
        }
        if (info.uiOptions != 0) {
            mWindow.setUiOptions(info.uiOptions);
        }
        mUiThread = Thread.currentThread();

        mMainThread = aThread;
        mInstrumentation = instr;
        mToken = token;
        mIdent = ident;
        mApplication = application;
        mIntent = intent;
        mReferrer = referrer;
        mComponent = intent.getComponent();
        mActivityInfo = info;
        mTitle = title;
        mParent = parent;
        mEmbeddedID = id;
        mLastNonConfigurationInstances = lastNonConfigurationInstances;
        if (voiceInteractor != null) {
            if (lastNonConfigurationInstances != null) {
                mVoiceInteractor = lastNonConfigurationInstances.voiceInteractor;
            } else {
                mVoiceInteractor = new VoiceInteractor(voiceInteractor, this, this,
                        Looper.myLooper());
            }
        }

        mWindow.setWindowManager(
                (WindowManager)context.getSystemService(Context.WINDOW_SERVICE),
                mToken, mComponent.flattenToString(),
                (info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0);
        if (mParent != null) {
            mWindow.setContainer(mParent.getWindow());
        }
        mWindowManager = mWindow.getWindowManager();
        mCurrentConfig = config;
    }

    /** @hide */
    public final IBinder getActivityToken() {
        return mParent != null ? mParent.getActivityToken() : mToken;
    }

    final void performCreateCommon() {
        mVisibleFromClient = !mWindow.getWindowStyle().getBoolean(
                com.android.internal.R.styleable.Window_windowNoDisplay, false);
        mFragments.dispatchActivityCreated();
        mActivityTransitionState.setEnterActivityOptions(this, getActivityOptions());
    }

    final void performCreate(Bundle icicle) {
        onCreate(icicle);
        mActivityTransitionState.readState(icicle);
        performCreateCommon();
    }

    final void performCreate(Bundle icicle, PersistableBundle persistentState) {
        onCreate(icicle, persistentState);
        mActivityTransitionState.readState(icicle);
        performCreateCommon();
    }

    final void performStart() {
        mActivityTransitionState.setEnterActivityOptions(this, getActivityOptions());
        mFragments.noteStateNotSaved();
        mCalled = false;
        mFragments.execPendingActions();
        mInstrumentation.callActivityOnStart(this);
        if (!mCalled) {
            throw new SuperNotCalledException(
                "Activity " + mComponent.toShortString() +
                " did not call through to super.onStart()");
        }
        mFragments.dispatchStart();
        if (mAllLoaderManagers != null) {
            final int N = mAllLoaderManagers.size();
            LoaderManagerImpl loaders[] = new LoaderManagerImpl[N];
            for (int i=N-1; i>=0; i--) {
                loaders[i] = mAllLoaderManagers.valueAt(i);
            }
            for (int i=0; i<N; i++) {
                LoaderManagerImpl lm = loaders[i];
                lm.finishRetain();
                lm.doReportStart();
            }
        }
        mActivityTransitionState.enterReady(this);
    }

    final void performRestart() {
        mFragments.noteStateNotSaved();

        if (mStopped) {
            mStopped = false;
            if (mToken != null && mParent == null) {
                WindowManagerGlobal.getInstance().setStoppedState(mToken, false);
            }

            synchronized (mManagedCursors) {
                final int N = mManagedCursors.size();
                for (int i=0; i<N; i++) {
                    ManagedCursor mc = mManagedCursors.get(i);
                    if (mc.mReleased || mc.mUpdated) {
                        if (!mc.mCursor.requery()) {
                            if (getApplicationInfo().targetSdkVersion
                                    >= android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
                                throw new IllegalStateException(
                                        "trying to requery an already closed cursor  "
                                        + mc.mCursor);
                            }
                        }
                        mc.mReleased = false;
                        mc.mUpdated = false;
                    }
                }
            }

            mCalled = false;
            mInstrumentation.callActivityOnRestart(this);
            if (!mCalled) {
                throw new SuperNotCalledException(
                    "Activity " + mComponent.toShortString() +
                    " did not call through to super.onRestart()");
            }
            performStart();
        }
    }

    final void performResume() {
        performRestart();

        mFragments.execPendingActions();

        mLastNonConfigurationInstances = null;

        mCalled = false;
        // mResumed is set by the instrumentation
        mInstrumentation.callActivityOnResume(this);
        if (!mCalled) {
            throw new SuperNotCalledException(
                "Activity " + mComponent.toShortString() +
                " did not call through to super.onResume()");
        }

        // Now really resume, and install the current status bar and menu.
        mCalled = false;

        mFragments.dispatchResume();
        mFragments.execPendingActions();

        onPostResume();
        if (!mCalled) {
            throw new SuperNotCalledException(
                "Activity " + mComponent.toShortString() +
                " did not call through to super.onPostResume()");
        }
    }

    final void performPause() {
        mDoReportFullyDrawn = false;
        mFragments.dispatchPause();
        mCalled = false;
        onPause();
        mResumed = false;
        if (!mCalled && getApplicationInfo().targetSdkVersion
                >= android.os.Build.VERSION_CODES.GINGERBREAD) {
            throw new SuperNotCalledException(
                    "Activity " + mComponent.toShortString() +
                    " did not call through to super.onPause()");
        }
        mResumed = false;
    }

    final void performUserLeaving() {
        onUserInteraction();
        onUserLeaveHint();
    }

    final void performStop() {
        mDoReportFullyDrawn = false;
        if (mLoadersStarted) {
            mLoadersStarted = false;
            if (mLoaderManager != null) {
                if (!mChangingConfigurations) {
                    mLoaderManager.doStop();
                } else {
                    mLoaderManager.doRetain();
                }
            }
        }

        if (!mStopped) {
            if (mWindow != null) {
                mWindow.closeAllPanels();
            }

            if (mToken != null && mParent == null) {
                WindowManagerGlobal.getInstance().setStoppedState(mToken, true);
            }

            mFragments.dispatchStop();

            mCalled = false;
            mInstrumentation.callActivityOnStop(this);
            if (!mCalled) {
                throw new SuperNotCalledException(
                    "Activity " + mComponent.toShortString() +
                    " did not call through to super.onStop()");
            }

            synchronized (mManagedCursors) {
                final int N = mManagedCursors.size();
                for (int i=0; i<N; i++) {
                    ManagedCursor mc = mManagedCursors.get(i);
                    if (!mc.mReleased) {
                        mc.mCursor.deactivate();
                        mc.mReleased = true;
                    }
                }
            }

            mStopped = true;
        }
        mResumed = false;
    }

    final void performDestroy() {
        mDestroyed = true;
        mWindow.destroy();
        mFragments.dispatchDestroy();
        onDestroy();
        if (mLoaderManager != null) {
            mLoaderManager.doDestroy();
        }
        if (mVoiceInteractor != null) {
            mVoiceInteractor.detachActivity();
        }
    }

    /**
     * @hide
     */
    public final boolean isResumed() {
        return mResumed;
    }

    void dispatchActivityResult(String who, int requestCode,
        int resultCode, Intent data) {
        if (false) Log.v(
            TAG, "Dispatching result: who=" + who + ", reqCode=" + requestCode
            + ", resCode=" + resultCode + ", data=" + data);
        mFragments.noteStateNotSaved();
        if (who == null) {
            onActivityResult(requestCode, resultCode, data);
        } else {
            Fragment frag = mFragments.findFragmentByWho(who);
            if (frag != null) {
                frag.onActivityResult(requestCode, resultCode, data);
            }
        }
    }

    /**
     * Request to put this Activity in a mode where the user is locked to the
     * current task.
     *
     * This will prevent the user from launching other apps, going to settings,
     * or reaching the home screen.
     *
     * If {@link DevicePolicyManager#isLockTaskPermitted(String)} returns true
     * for this component then the app will go directly into Lock Task mode.  The user
     * will not be able to exit this mode until {@link Activity#stopLockTask()} is called.
     *
     * If {@link DevicePolicyManager#isLockTaskPermitted(String)} returns false
     * then the system will prompt the user with a dialog requesting permission to enter
     * this mode.  When entered through this method the user can exit at any time through
     * an action described by the request dialog.  Calling stopLockTask will also exit the
     * mode.
     */
    public void startLockTask() {
        try {
            ActivityManagerNative.getDefault().startLockTaskMode(mToken);
        } catch (RemoteException e) {
        }
    }

    /**
     * Allow the user to switch away from the current task.
     *
     * Called to end the mode started by {@link Activity#startLockTask}. This
     * can only be called by activities that have successfully called
     * startLockTask previously.
     *
     * This will allow the user to exit this app and move onto other activities.
     */
    public void stopLockTask() {
        try {
            ActivityManagerNative.getDefault().stopLockTaskMode();
        } catch (RemoteException e) {
        }
    }

    /**
     * Interface for informing a translucent {@link Activity} once all visible activities below it
     * have completed drawing. This is necessary only after an {@link Activity} has been made
     * opaque using {@link Activity#convertFromTranslucent()} and before it has been drawn
     * translucent again following a call to {@link
     * Activity#convertToTranslucent(android.app.Activity.TranslucentConversionListener,
     * ActivityOptions)}
     *
     * @hide
     */
    @SystemApi
    public interface TranslucentConversionListener {
        /**
         * Callback made following {@link Activity#convertToTranslucent} once all visible Activities
         * below the top one have been redrawn. Following this callback it is safe to make the top
         * Activity translucent because the underlying Activity has been drawn.
         *
         * @param drawComplete True if the background Activity has drawn itself. False if a timeout
         * occurred waiting for the Activity to complete drawing.
         *
         * @see Activity#convertFromTranslucent()
         * @see Activity#convertToTranslucent(TranslucentConversionListener, ActivityOptions)
         */
        public void onTranslucentConversionComplete(boolean drawComplete);
    }
}