Activity.java revision 529b60a3b16ac3dff24f2403d760ab8ebc9670ff
1/*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.app;
18
19import com.android.internal.app.ActionBarImpl;
20import com.android.internal.policy.PolicyManager;
21
22import android.content.ComponentCallbacks;
23import android.content.ComponentName;
24import android.content.ContentResolver;
25import android.content.Context;
26import android.content.IIntentSender;
27import android.content.Intent;
28import android.content.IntentSender;
29import android.content.SharedPreferences;
30import android.content.pm.ActivityInfo;
31import android.content.res.Configuration;
32import android.content.res.Resources;
33import android.content.res.TypedArray;
34import android.database.Cursor;
35import android.graphics.Bitmap;
36import android.graphics.Canvas;
37import android.graphics.drawable.Drawable;
38import android.media.AudioManager;
39import android.net.Uri;
40import android.os.Build;
41import android.os.Bundle;
42import android.os.Handler;
43import android.os.IBinder;
44import android.os.Parcelable;
45import android.os.RemoteException;
46import android.text.Selection;
47import android.text.SpannableStringBuilder;
48import android.text.TextUtils;
49import android.text.method.TextKeyListener;
50import android.util.AttributeSet;
51import android.util.Config;
52import android.util.EventLog;
53import android.util.Log;
54import android.util.SparseArray;
55import android.view.ActionMode;
56import android.view.ContextMenu;
57import android.view.ContextMenu.ContextMenuInfo;
58import android.view.ContextThemeWrapper;
59import android.view.InflateException;
60import android.view.KeyEvent;
61import android.view.LayoutInflater;
62import android.view.Menu;
63import android.view.MenuInflater;
64import android.view.MenuItem;
65import android.view.MotionEvent;
66import android.view.View;
67import android.view.View.OnCreateContextMenuListener;
68import android.view.ViewGroup;
69import android.view.ViewGroup.LayoutParams;
70import android.view.ViewManager;
71import android.view.Window;
72import android.view.WindowManager;
73import android.view.accessibility.AccessibilityEvent;
74import android.widget.AdapterView;
75import android.widget.FrameLayout;
76
77import java.util.ArrayList;
78import java.util.HashMap;
79
80/**
81 * An activity is a single, focused thing that the user can do.  Almost all
82 * activities interact with the user, so the Activity class takes care of
83 * creating a window for you in which you can place your UI with
84 * {@link #setContentView}.  While activities are often presented to the user
85 * as full-screen windows, they can also be used in other ways: as floating
86 * windows (via a theme with {@link android.R.attr#windowIsFloating} set)
87 * or embedded inside of another activity (using {@link ActivityGroup}).
88 *
89 * There are two methods almost all subclasses of Activity will implement:
90 *
91 * <ul>
92 *     <li> {@link #onCreate} is where you initialize your activity.  Most
93 *     importantly, here you will usually call {@link #setContentView(int)}
94 *     with a layout resource defining your UI, and using {@link #findViewById}
95 *     to retrieve the widgets in that UI that you need to interact with
96 *     programmatically.
97 *
98 *     <li> {@link #onPause} is where you deal with the user leaving your
99 *     activity.  Most importantly, any changes made by the user should at this
100 *     point be committed (usually to the
101 *     {@link android.content.ContentProvider} holding the data).
102 * </ul>
103 *
104 * <p>To be of use with {@link android.content.Context#startActivity Context.startActivity()}, all
105 * activity classes must have a corresponding
106 * {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
107 * declaration in their package's <code>AndroidManifest.xml</code>.</p>
108 *
109 * <p>The Activity class is an important part of an application's overall lifecycle,
110 * and the way activities are launched and put together is a fundamental
111 * part of the platform's application model. For a detailed perspective on the structure of
112 * Android applications and lifecycles, please read the <em>Dev Guide</em> document on
113 * <a href="{@docRoot}guide/topics/fundamentals.html">Application Fundamentals</a>.</p>
114 *
115 * <p>Topics covered here:
116 * <ol>
117 * <li><a href="#ActivityLifecycle">Activity Lifecycle</a>
118 * <li><a href="#ConfigurationChanges">Configuration Changes</a>
119 * <li><a href="#StartingActivities">Starting Activities and Getting Results</a>
120 * <li><a href="#SavingPersistentState">Saving Persistent State</a>
121 * <li><a href="#Permissions">Permissions</a>
122 * <li><a href="#ProcessLifecycle">Process Lifecycle</a>
123 * </ol>
124 *
125 * <a name="ActivityLifecycle"></a>
126 * <h3>Activity Lifecycle</h3>
127 *
128 * <p>Activities in the system are managed as an <em>activity stack</em>.
129 * When a new activity is started, it is placed on the top of the stack
130 * and becomes the running activity -- the previous activity always remains
131 * below it in the stack, and will not come to the foreground again until
132 * the new activity exits.</p>
133 *
134 * <p>An activity has essentially four states:</p>
135 * <ul>
136 *     <li> If an activity in the foreground of the screen (at the top of
137 *         the stack),
138 *         it is <em>active</em> or  <em>running</em>. </li>
139 *     <li>If an activity has lost focus but is still visible (that is, a new non-full-sized
140 *         or transparent activity has focus on top of your activity), it
141 *         is <em>paused</em>. A paused activity is completely alive (it
142 *         maintains all state and member information and remains attached to
143 *         the window manager), but can be killed by the system in extreme
144 *         low memory situations.
145 *     <li>If an activity is completely obscured by another activity,
146 *         it is <em>stopped</em>. It still retains all state and member information,
147 *         however, it is no longer visible to the user so its window is hidden
148 *         and it will often be killed by the system when memory is needed
149 *         elsewhere.</li>
150 *     <li>If an activity is paused or stopped, the system can drop the activity
151 *         from memory by either asking it to finish, or simply killing its
152 *         process.  When it is displayed again to the user, it must be
153 *         completely restarted and restored to its previous state.</li>
154 * </ul>
155 *
156 * <p>The following diagram shows the important state paths of an Activity.
157 * The square rectangles represent callback methods you can implement to
158 * perform operations when the Activity moves between states.  The colored
159 * ovals are major states the Activity can be in.</p>
160 *
161 * <p><img src="../../../images/activity_lifecycle.png"
162 *      alt="State diagram for an Android Activity Lifecycle." border="0" /></p>
163 *
164 * <p>There are three key loops you may be interested in monitoring within your
165 * activity:
166 *
167 * <ul>
168 * <li>The <b>entire lifetime</b> of an activity happens between the first call
169 * to {@link android.app.Activity#onCreate} through to a single final call
170 * to {@link android.app.Activity#onDestroy}.  An activity will do all setup
171 * of "global" state in onCreate(), and release all remaining resources in
172 * onDestroy().  For example, if it has a thread running in the background
173 * to download data from the network, it may create that thread in onCreate()
174 * and then stop the thread in onDestroy().
175 *
176 * <li>The <b>visible lifetime</b> of an activity happens between a call to
177 * {@link android.app.Activity#onStart} until a corresponding call to
178 * {@link android.app.Activity#onStop}.  During this time the user can see the
179 * activity on-screen, though it may not be in the foreground and interacting
180 * with the user.  Between these two methods you can maintain resources that
181 * are needed to show the activity to the user.  For example, you can register
182 * a {@link android.content.BroadcastReceiver} in onStart() to monitor for changes
183 * that impact your UI, and unregister it in onStop() when the user an no
184 * longer see what you are displaying.  The onStart() and onStop() methods
185 * can be called multiple times, as the activity becomes visible and hidden
186 * to the user.
187 *
188 * <li>The <b>foreground lifetime</b> of an activity happens between a call to
189 * {@link android.app.Activity#onResume} until a corresponding call to
190 * {@link android.app.Activity#onPause}.  During this time the activity is
191 * in front of all other activities and interacting with the user.  An activity
192 * can frequently go between the resumed and paused states -- for example when
193 * the device goes to sleep, when an activity result is delivered, when a new
194 * intent is delivered -- so the code in these methods should be fairly
195 * lightweight.
196 * </ul>
197 *
198 * <p>The entire lifecycle of an activity is defined by the following
199 * Activity methods.  All of these are hooks that you can override
200 * to do appropriate work when the activity changes state.  All
201 * activities will implement {@link android.app.Activity#onCreate}
202 * to do their initial setup; many will also implement
203 * {@link android.app.Activity#onPause} to commit changes to data and
204 * otherwise prepare to stop interacting with the user.  You should always
205 * call up to your superclass when implementing these methods.</p>
206 *
207 * </p>
208 * <pre class="prettyprint">
209 * public class Activity extends ApplicationContext {
210 *     protected void onCreate(Bundle savedInstanceState);
211 *
212 *     protected void onStart();
213 *
214 *     protected void onRestart();
215 *
216 *     protected void onResume();
217 *
218 *     protected void onPause();
219 *
220 *     protected void onStop();
221 *
222 *     protected void onDestroy();
223 * }
224 * </pre>
225 *
226 * <p>In general the movement through an activity's lifecycle looks like
227 * this:</p>
228 *
229 * <table border="2" width="85%" align="center" frame="hsides" rules="rows">
230 *     <colgroup align="left" span="3" />
231 *     <colgroup align="left" />
232 *     <colgroup align="center" />
233 *     <colgroup align="center" />
234 *
235 *     <thead>
236 *     <tr><th colspan="3">Method</th> <th>Description</th> <th>Killable?</th> <th>Next</th></tr>
237 *     </thead>
238 *
239 *     <tbody>
240 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onCreate onCreate()}</th>
241 *         <td>Called when the activity is first created.
242 *             This is where you should do all of your normal static set up:
243 *             create views, bind data to lists, etc.  This method also
244 *             provides you with a Bundle containing the activity's previously
245 *             frozen state, if there was one.
246 *             <p>Always followed by <code>onStart()</code>.</td>
247 *         <td align="center">No</td>
248 *         <td align="center"><code>onStart()</code></td>
249 *     </tr>
250 *
251 *     <tr><td rowspan="5" style="border-left: none; border-right: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
252 *         <th colspan="2" align="left" border="0">{@link android.app.Activity#onRestart onRestart()}</th>
253 *         <td>Called after your activity has been stopped, prior to it being
254 *             started again.
255 *             <p>Always followed by <code>onStart()</code></td>
256 *         <td align="center">No</td>
257 *         <td align="center"><code>onStart()</code></td>
258 *     </tr>
259 *
260 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStart onStart()}</th>
261 *         <td>Called when the activity is becoming visible to the user.
262 *             <p>Followed by <code>onResume()</code> if the activity comes
263 *             to the foreground, or <code>onStop()</code> if it becomes hidden.</td>
264 *         <td align="center">No</td>
265 *         <td align="center"><code>onResume()</code> or <code>onStop()</code></td>
266 *     </tr>
267 *
268 *     <tr><td rowspan="2" style="border-left: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
269 *         <th align="left" border="0">{@link android.app.Activity#onResume onResume()}</th>
270 *         <td>Called when the activity will start
271 *             interacting with the user.  At this point your activity is at
272 *             the top of the activity stack, with user input going to it.
273 *             <p>Always followed by <code>onPause()</code>.</td>
274 *         <td align="center">No</td>
275 *         <td align="center"><code>onPause()</code></td>
276 *     </tr>
277 *
278 *     <tr><th align="left" border="0">{@link android.app.Activity#onPause onPause()}</th>
279 *         <td>Called when the system is about to start resuming a previous
280 *             activity.  This is typically used to commit unsaved changes to
281 *             persistent data, stop animations and other things that may be consuming
282 *             CPU, etc.  Implementations of this method must be very quick because
283 *             the next activity will not be resumed until this method returns.
284 *             <p>Followed by either <code>onResume()</code> if the activity
285 *             returns back to the front, or <code>onStop()</code> if it becomes
286 *             invisible to the user.</td>
287 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
288 *         <td align="center"><code>onResume()</code> or<br>
289 *                 <code>onStop()</code></td>
290 *     </tr>
291 *
292 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStop onStop()}</th>
293 *         <td>Called when the activity is no longer visible to the user, because
294 *             another activity has been resumed and is covering this one.  This
295 *             may happen either because a new activity is being started, an existing
296 *             one is being brought in front of this one, or this one is being
297 *             destroyed.
298 *             <p>Followed by either <code>onRestart()</code> if
299 *             this activity is coming back to interact with the user, or
300 *             <code>onDestroy()</code> if this activity is going away.</td>
301 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
302 *         <td align="center"><code>onRestart()</code> or<br>
303 *                 <code>onDestroy()</code></td>
304 *     </tr>
305 *
306 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onDestroy onDestroy()}</th>
307 *         <td>The final call you receive before your
308 *             activity is destroyed.  This can happen either because the
309 *             activity is finishing (someone called {@link Activity#finish} on
310 *             it, or because the system is temporarily destroying this
311 *             instance of the activity to save space.  You can distinguish
312 *             between these two scenarios with the {@link
313 *             Activity#isFinishing} method.</td>
314 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
315 *         <td align="center"><em>nothing</em></td>
316 *     </tr>
317 *     </tbody>
318 * </table>
319 *
320 * <p>Note the "Killable" column in the above table -- for those methods that
321 * are marked as being killable, after that method returns the process hosting the
322 * activity may killed by the system <em>at any time</em> without another line
323 * of its code being executed.  Because of this, you should use the
324 * {@link #onPause} method to write any persistent data (such as user edits)
325 * to storage.  In addition, the method
326 * {@link #onSaveInstanceState(Bundle)} is called before placing the activity
327 * in such a background state, allowing you to save away any dynamic instance
328 * state in your activity into the given Bundle, to be later received in
329 * {@link #onCreate} if the activity needs to be re-created.
330 * See the <a href="#ProcessLifecycle">Process Lifecycle</a>
331 * section for more information on how the lifecycle of a process is tied
332 * to the activities it is hosting.  Note that it is important to save
333 * persistent data in {@link #onPause} instead of {@link #onSaveInstanceState}
334 * because the later is not part of the lifecycle callbacks, so will not
335 * be called in every situation as described in its documentation.</p>
336 *
337 * <p>For those methods that are not marked as being killable, the activity's
338 * process will not be killed by the system starting from the time the method
339 * is called and continuing after it returns.  Thus an activity is in the killable
340 * state, for example, between after <code>onPause()</code> to the start of
341 * <code>onResume()</code>.</p>
342 *
343 * <a name="ConfigurationChanges"></a>
344 * <h3>Configuration Changes</h3>
345 *
346 * <p>If the configuration of the device (as defined by the
347 * {@link Configuration Resources.Configuration} class) changes,
348 * then anything displaying a user interface will need to update to match that
349 * configuration.  Because Activity is the primary mechanism for interacting
350 * with the user, it includes special support for handling configuration
351 * changes.</p>
352 *
353 * <p>Unless you specify otherwise, a configuration change (such as a change
354 * in screen orientation, language, input devices, etc) will cause your
355 * current activity to be <em>destroyed</em>, going through the normal activity
356 * lifecycle process of {@link #onPause},
357 * {@link #onStop}, and {@link #onDestroy} as appropriate.  If the activity
358 * had been in the foreground or visible to the user, once {@link #onDestroy} is
359 * called in that instance then a new instance of the activity will be
360 * created, with whatever savedInstanceState the previous instance had generated
361 * from {@link #onSaveInstanceState}.</p>
362 *
363 * <p>This is done because any application resource,
364 * including layout files, can change based on any configuration value.  Thus
365 * the only safe way to handle a configuration change is to re-retrieve all
366 * resources, including layouts, drawables, and strings.  Because activities
367 * must already know how to save their state and re-create themselves from
368 * that state, this is a convenient way to have an activity restart itself
369 * with a new configuration.</p>
370 *
371 * <p>In some special cases, you may want to bypass restarting of your
372 * activity based on one or more types of configuration changes.  This is
373 * done with the {@link android.R.attr#configChanges android:configChanges}
374 * attribute in its manifest.  For any types of configuration changes you say
375 * that you handle there, you will receive a call to your current activity's
376 * {@link #onConfigurationChanged} method instead of being restarted.  If
377 * a configuration change involves any that you do not handle, however, the
378 * activity will still be restarted and {@link #onConfigurationChanged}
379 * will not be called.</p>
380 *
381 * <a name="StartingActivities"></a>
382 * <h3>Starting Activities and Getting Results</h3>
383 *
384 * <p>The {@link android.app.Activity#startActivity}
385 * method is used to start a
386 * new activity, which will be placed at the top of the activity stack.  It
387 * takes a single argument, an {@link android.content.Intent Intent},
388 * which describes the activity
389 * to be executed.</p>
390 *
391 * <p>Sometimes you want to get a result back from an activity when it
392 * ends.  For example, you may start an activity that lets the user pick
393 * a person in a list of contacts; when it ends, it returns the person
394 * that was selected.  To do this, you call the
395 * {@link android.app.Activity#startActivityForResult(Intent, int)}
396 * version with a second integer parameter identifying the call.  The result
397 * will come back through your {@link android.app.Activity#onActivityResult}
398 * method.</p>
399 *
400 * <p>When an activity exits, it can call
401 * {@link android.app.Activity#setResult(int)}
402 * to return data back to its parent.  It must always supply a result code,
403 * which can be the standard results RESULT_CANCELED, RESULT_OK, or any
404 * custom values starting at RESULT_FIRST_USER.  In addition, it can optionally
405 * return back an Intent containing any additional data it wants.  All of this
406 * information appears back on the
407 * parent's <code>Activity.onActivityResult()</code>, along with the integer
408 * identifier it originally supplied.</p>
409 *
410 * <p>If a child activity fails for any reason (such as crashing), the parent
411 * activity will receive a result with the code RESULT_CANCELED.</p>
412 *
413 * <pre class="prettyprint">
414 * public class MyActivity extends Activity {
415 *     ...
416 *
417 *     static final int PICK_CONTACT_REQUEST = 0;
418 *
419 *     protected boolean onKeyDown(int keyCode, KeyEvent event) {
420 *         if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
421 *             // When the user center presses, let them pick a contact.
422 *             startActivityForResult(
423 *                 new Intent(Intent.ACTION_PICK,
424 *                 new Uri("content://contacts")),
425 *                 PICK_CONTACT_REQUEST);
426 *            return true;
427 *         }
428 *         return false;
429 *     }
430 *
431 *     protected void onActivityResult(int requestCode, int resultCode,
432 *             Intent data) {
433 *         if (requestCode == PICK_CONTACT_REQUEST) {
434 *             if (resultCode == RESULT_OK) {
435 *                 // A contact was picked.  Here we will just display it
436 *                 // to the user.
437 *                 startActivity(new Intent(Intent.ACTION_VIEW, data));
438 *             }
439 *         }
440 *     }
441 * }
442 * </pre>
443 *
444 * <a name="SavingPersistentState"></a>
445 * <h3>Saving Persistent State</h3>
446 *
447 * <p>There are generally two kinds of persistent state than an activity
448 * will deal with: shared document-like data (typically stored in a SQLite
449 * database using a {@linkplain android.content.ContentProvider content provider})
450 * and internal state such as user preferences.</p>
451 *
452 * <p>For content provider data, we suggest that activities use a
453 * "edit in place" user model.  That is, any edits a user makes are effectively
454 * made immediately without requiring an additional confirmation step.
455 * Supporting this model is generally a simple matter of following two rules:</p>
456 *
457 * <ul>
458 *     <li> <p>When creating a new document, the backing database entry or file for
459 *             it is created immediately.  For example, if the user chooses to write
460 *             a new e-mail, a new entry for that e-mail is created as soon as they
461 *             start entering data, so that if they go to any other activity after
462 *             that point this e-mail will now appear in the list of drafts.</p>
463 *     <li> <p>When an activity's <code>onPause()</code> method is called, it should
464 *             commit to the backing content provider or file any changes the user
465 *             has made.  This ensures that those changes will be seen by any other
466 *             activity that is about to run.  You will probably want to commit
467 *             your data even more aggressively at key times during your
468 *             activity's lifecycle: for example before starting a new
469 *             activity, before finishing your own activity, when the user
470 *             switches between input fields, etc.</p>
471 * </ul>
472 *
473 * <p>This model is designed to prevent data loss when a user is navigating
474 * between activities, and allows the system to safely kill an activity (because
475 * system resources are needed somewhere else) at any time after it has been
476 * paused.  Note this implies
477 * that the user pressing BACK from your activity does <em>not</em>
478 * mean "cancel" -- it means to leave the activity with its current contents
479 * saved away.  Cancelling edits in an activity must be provided through
480 * some other mechanism, such as an explicit "revert" or "undo" option.</p>
481 *
482 * <p>See the {@linkplain android.content.ContentProvider content package} for
483 * more information about content providers.  These are a key aspect of how
484 * different activities invoke and propagate data between themselves.</p>
485 *
486 * <p>The Activity class also provides an API for managing internal persistent state
487 * associated with an activity.  This can be used, for example, to remember
488 * the user's preferred initial display in a calendar (day view or week view)
489 * or the user's default home page in a web browser.</p>
490 *
491 * <p>Activity persistent state is managed
492 * with the method {@link #getPreferences},
493 * allowing you to retrieve and
494 * modify a set of name/value pairs associated with the activity.  To use
495 * preferences that are shared across multiple application components
496 * (activities, receivers, services, providers), you can use the underlying
497 * {@link Context#getSharedPreferences Context.getSharedPreferences()} method
498 * to retrieve a preferences
499 * object stored under a specific name.
500 * (Note that it is not possible to share settings data across application
501 * packages -- for that you will need a content provider.)</p>
502 *
503 * <p>Here is an excerpt from a calendar activity that stores the user's
504 * preferred view mode in its persistent settings:</p>
505 *
506 * <pre class="prettyprint">
507 * public class CalendarActivity extends Activity {
508 *     ...
509 *
510 *     static final int DAY_VIEW_MODE = 0;
511 *     static final int WEEK_VIEW_MODE = 1;
512 *
513 *     private SharedPreferences mPrefs;
514 *     private int mCurViewMode;
515 *
516 *     protected void onCreate(Bundle savedInstanceState) {
517 *         super.onCreate(savedInstanceState);
518 *
519 *         SharedPreferences mPrefs = getSharedPreferences();
520 *         mCurViewMode = mPrefs.getInt("view_mode" DAY_VIEW_MODE);
521 *     }
522 *
523 *     protected void onPause() {
524 *         super.onPause();
525 *
526 *         SharedPreferences.Editor ed = mPrefs.edit();
527 *         ed.putInt("view_mode", mCurViewMode);
528 *         ed.commit();
529 *     }
530 * }
531 * </pre>
532 *
533 * <a name="Permissions"></a>
534 * <h3>Permissions</h3>
535 *
536 * <p>The ability to start a particular Activity can be enforced when it is
537 * declared in its
538 * manifest's {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
539 * tag.  By doing so, other applications will need to declare a corresponding
540 * {@link android.R.styleable#AndroidManifestUsesPermission &lt;uses-permission&gt;}
541 * element in their own manifest to be able to start that activity.
542 *
543 * <p>See the <a href="{@docRoot}guide/topics/security/security.html">Security and Permissions</a>
544 * document for more information on permissions and security in general.
545 *
546 * <a name="ProcessLifecycle"></a>
547 * <h3>Process Lifecycle</h3>
548 *
549 * <p>The Android system attempts to keep application process around for as
550 * long as possible, but eventually will need to remove old processes when
551 * memory runs low.  As described in <a href="#ActivityLifecycle">Activity
552 * Lifecycle</a>, the decision about which process to remove is intimately
553 * tied to the state of the user's interaction with it.  In general, there
554 * are four states a process can be in based on the activities running in it,
555 * listed here in order of importance.  The system will kill less important
556 * processes (the last ones) before it resorts to killing more important
557 * processes (the first ones).
558 *
559 * <ol>
560 * <li> <p>The <b>foreground activity</b> (the activity at the top of the screen
561 * that the user is currently interacting with) is considered the most important.
562 * Its process will only be killed as a last resort, if it uses more memory
563 * than is available on the device.  Generally at this point the device has
564 * reached a memory paging state, so this is required in order to keep the user
565 * interface responsive.
566 * <li> <p>A <b>visible activity</b> (an activity that is visible to the user
567 * but not in the foreground, such as one sitting behind a foreground dialog)
568 * is considered extremely important and will not be killed unless that is
569 * required to keep the foreground activity running.
570 * <li> <p>A <b>background activity</b> (an activity that is not visible to
571 * the user and has been paused) is no longer critical, so the system may
572 * safely kill its process to reclaim memory for other foreground or
573 * visible processes.  If its process needs to be killed, when the user navigates
574 * back to the activity (making it visible on the screen again), its
575 * {@link #onCreate} method will be called with the savedInstanceState it had previously
576 * supplied in {@link #onSaveInstanceState} so that it can restart itself in the same
577 * state as the user last left it.
578 * <li> <p>An <b>empty process</b> is one hosting no activities or other
579 * application components (such as {@link Service} or
580 * {@link android.content.BroadcastReceiver} classes).  These are killed very
581 * quickly by the system as memory becomes low.  For this reason, any
582 * background operation you do outside of an activity must be executed in the
583 * context of an activity BroadcastReceiver or Service to ensure that the system
584 * knows it needs to keep your process around.
585 * </ol>
586 *
587 * <p>Sometimes an Activity may need to do a long-running operation that exists
588 * independently of the activity lifecycle itself.  An example may be a camera
589 * application that allows you to upload a picture to a web site.  The upload
590 * may take a long time, and the application should allow the user to leave
591 * the application will it is executing.  To accomplish this, your Activity
592 * should start a {@link Service} in which the upload takes place.  This allows
593 * the system to properly prioritize your process (considering it to be more
594 * important than other non-visible applications) for the duration of the
595 * upload, independent of whether the original activity is paused, stopped,
596 * or finished.
597 */
598public class Activity extends ContextThemeWrapper
599        implements LayoutInflater.Factory,
600        Window.Callback, KeyEvent.Callback,
601        OnCreateContextMenuListener, ComponentCallbacks {
602    private static final String TAG = "Activity";
603
604    /** Standard activity result: operation canceled. */
605    public static final int RESULT_CANCELED    = 0;
606    /** Standard activity result: operation succeeded. */
607    public static final int RESULT_OK           = -1;
608    /** Start of user-defined activity results. */
609    public static final int RESULT_FIRST_USER   = 1;
610
611    private static long sInstanceCount = 0;
612
613    private static final String WINDOW_HIERARCHY_TAG = "android:viewHierarchyState";
614    private static final String FRAGMENTS_TAG = "android:fragments";
615    private static final String SAVED_DIALOG_IDS_KEY = "android:savedDialogIds";
616    private static final String SAVED_DIALOGS_TAG = "android:savedDialogs";
617    private static final String SAVED_DIALOG_KEY_PREFIX = "android:dialog_";
618    private static final String SAVED_DIALOG_ARGS_KEY_PREFIX = "android:dialog_args_";
619
620    private static class ManagedDialog {
621        Dialog mDialog;
622        Bundle mArgs;
623    }
624    private SparseArray<ManagedDialog> mManagedDialogs;
625
626    // set by the thread after the constructor and before onCreate(Bundle savedInstanceState) is called.
627    private Instrumentation mInstrumentation;
628    private IBinder mToken;
629    private int mIdent;
630    /*package*/ String mEmbeddedID;
631    private Application mApplication;
632    /*package*/ Intent mIntent;
633    private ComponentName mComponent;
634    /*package*/ ActivityInfo mActivityInfo;
635    /*package*/ ActivityThread mMainThread;
636    Activity mParent;
637    boolean mCalled;
638    boolean mStarted;
639    private boolean mResumed;
640    private boolean mStopped;
641    boolean mFinished;
642    boolean mStartedActivity;
643    /** true if the activity is being destroyed in order to recreate it with a new configuration */
644    /*package*/ boolean mChangingConfigurations = false;
645    /*package*/ int mConfigChangeFlags;
646    /*package*/ Configuration mCurrentConfig;
647    private SearchManager mSearchManager;
648
649    static final class NonConfigurationInstances {
650        Object activity;
651        HashMap<String, Object> children;
652        ArrayList<Fragment> fragments;
653        SparseArray<LoaderManagerImpl> loaders;
654    }
655    /* package */ NonConfigurationInstances mLastNonConfigurationInstances;
656
657    private Window mWindow;
658
659    private WindowManager mWindowManager;
660    /*package*/ View mDecor = null;
661    /*package*/ boolean mWindowAdded = false;
662    /*package*/ boolean mVisibleFromServer = false;
663    /*package*/ boolean mVisibleFromClient = true;
664    /*package*/ ActionBarImpl mActionBar = null;
665
666    private CharSequence mTitle;
667    private int mTitleColor = 0;
668
669    final FragmentManager mFragments = new FragmentManager();
670
671    SparseArray<LoaderManagerImpl> mAllLoaderManagers;
672    LoaderManagerImpl mLoaderManager;
673
674    private static final class ManagedCursor {
675        ManagedCursor(Cursor cursor) {
676            mCursor = cursor;
677            mReleased = false;
678            mUpdated = false;
679        }
680
681        private final Cursor mCursor;
682        private boolean mReleased;
683        private boolean mUpdated;
684    }
685    private final ArrayList<ManagedCursor> mManagedCursors =
686        new ArrayList<ManagedCursor>();
687
688    // protected by synchronized (this)
689    int mResultCode = RESULT_CANCELED;
690    Intent mResultData = null;
691
692    private boolean mTitleReady = false;
693
694    private int mDefaultKeyMode = DEFAULT_KEYS_DISABLE;
695    private SpannableStringBuilder mDefaultKeySsb = null;
696
697    protected static final int[] FOCUSED_STATE_SET = {com.android.internal.R.attr.state_focused};
698
699    private Thread mUiThread;
700    final Handler mHandler = new Handler();
701
702    // Used for debug only
703    /*
704    public Activity() {
705        ++sInstanceCount;
706    }
707
708    @Override
709    protected void finalize() throws Throwable {
710        super.finalize();
711        --sInstanceCount;
712    }
713    */
714
715    public static long getInstanceCount() {
716        return sInstanceCount;
717    }
718
719    /** Return the intent that started this activity. */
720    public Intent getIntent() {
721        return mIntent;
722    }
723
724    /**
725     * Change the intent returned by {@link #getIntent}.  This holds a
726     * reference to the given intent; it does not copy it.  Often used in
727     * conjunction with {@link #onNewIntent}.
728     *
729     * @param newIntent The new Intent object to return from getIntent
730     *
731     * @see #getIntent
732     * @see #onNewIntent
733     */
734    public void setIntent(Intent newIntent) {
735        mIntent = newIntent;
736    }
737
738    /** Return the application that owns this activity. */
739    public final Application getApplication() {
740        return mApplication;
741    }
742
743    /** Is this activity embedded inside of another activity? */
744    public final boolean isChild() {
745        return mParent != null;
746    }
747
748    /** Return the parent activity if this view is an embedded child. */
749    public final Activity getParent() {
750        return mParent;
751    }
752
753    /** Retrieve the window manager for showing custom windows. */
754    public WindowManager getWindowManager() {
755        return mWindowManager;
756    }
757
758    /**
759     * Retrieve the current {@link android.view.Window} for the activity.
760     * This can be used to directly access parts of the Window API that
761     * are not available through Activity/Screen.
762     *
763     * @return Window The current window, or null if the activity is not
764     *         visual.
765     */
766    public Window getWindow() {
767        return mWindow;
768    }
769
770    /**
771     * Return the LoaderManager for this fragment, creating it if needed.
772     */
773    public LoaderManager getLoaderManager() {
774        if (mLoaderManager != null) {
775            return mLoaderManager;
776        }
777        mLoaderManager = getLoaderManager(-1, mStarted);
778        return mLoaderManager;
779    }
780
781    LoaderManagerImpl getLoaderManager(int index, boolean started) {
782        if (mAllLoaderManagers == null) {
783            mAllLoaderManagers = new SparseArray<LoaderManagerImpl>();
784        }
785        LoaderManagerImpl lm = mAllLoaderManagers.get(index);
786        if (lm == null) {
787            lm = new LoaderManagerImpl(started);
788            mAllLoaderManagers.put(index, lm);
789        }
790        return lm;
791    }
792
793    /**
794     * Calls {@link android.view.Window#getCurrentFocus} on the
795     * Window of this Activity to return the currently focused view.
796     *
797     * @return View The current View with focus or null.
798     *
799     * @see #getWindow
800     * @see android.view.Window#getCurrentFocus
801     */
802    public View getCurrentFocus() {
803        return mWindow != null ? mWindow.getCurrentFocus() : null;
804    }
805
806    @Override
807    public int getWallpaperDesiredMinimumWidth() {
808        int width = super.getWallpaperDesiredMinimumWidth();
809        return width <= 0 ? getWindowManager().getDefaultDisplay().getWidth() : width;
810    }
811
812    @Override
813    public int getWallpaperDesiredMinimumHeight() {
814        int height = super.getWallpaperDesiredMinimumHeight();
815        return height <= 0 ? getWindowManager().getDefaultDisplay().getHeight() : height;
816    }
817
818    /**
819     * Called when the activity is starting.  This is where most initialization
820     * should go: calling {@link #setContentView(int)} to inflate the
821     * activity's UI, using {@link #findViewById} to programmatically interact
822     * with widgets in the UI, calling
823     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)} to retrieve
824     * cursors for data being displayed, etc.
825     *
826     * <p>You can call {@link #finish} from within this function, in
827     * which case onDestroy() will be immediately called without any of the rest
828     * of the activity lifecycle ({@link #onStart}, {@link #onResume},
829     * {@link #onPause}, etc) executing.
830     *
831     * <p><em>Derived classes must call through to the super class's
832     * implementation of this method.  If they do not, an exception will be
833     * thrown.</em></p>
834     *
835     * @param savedInstanceState If the activity is being re-initialized after
836     *     previously being shut down then this Bundle contains the data it most
837     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
838     *
839     * @see #onStart
840     * @see #onSaveInstanceState
841     * @see #onRestoreInstanceState
842     * @see #onPostCreate
843     */
844    protected void onCreate(Bundle savedInstanceState) {
845        mVisibleFromClient = !mWindow.getWindowStyle().getBoolean(
846                com.android.internal.R.styleable.Window_windowNoDisplay, false);
847        if (mLastNonConfigurationInstances != null) {
848            mAllLoaderManagers = mLastNonConfigurationInstances.loaders;
849        }
850        if (savedInstanceState != null) {
851            Parcelable p = savedInstanceState.getParcelable(FRAGMENTS_TAG);
852            mFragments.restoreAllState(p, mLastNonConfigurationInstances != null
853                    ? mLastNonConfigurationInstances.fragments : null);
854        }
855        mFragments.dispatchCreate();
856        mCalled = true;
857    }
858
859    /**
860     * The hook for {@link ActivityThread} to restore the state of this activity.
861     *
862     * Calls {@link #onSaveInstanceState(android.os.Bundle)} and
863     * {@link #restoreManagedDialogs(android.os.Bundle)}.
864     *
865     * @param savedInstanceState contains the saved state
866     */
867    final void performRestoreInstanceState(Bundle savedInstanceState) {
868        onRestoreInstanceState(savedInstanceState);
869        restoreManagedDialogs(savedInstanceState);
870    }
871
872    /**
873     * This method is called after {@link #onStart} when the activity is
874     * being re-initialized from a previously saved state, given here in
875     * <var>savedInstanceState</var>.  Most implementations will simply use {@link #onCreate}
876     * to restore their state, but it is sometimes convenient to do it here
877     * after all of the initialization has been done or to allow subclasses to
878     * decide whether to use your default implementation.  The default
879     * implementation of this method performs a restore of any view state that
880     * had previously been frozen by {@link #onSaveInstanceState}.
881     *
882     * <p>This method is called between {@link #onStart} and
883     * {@link #onPostCreate}.
884     *
885     * @param savedInstanceState the data most recently supplied in {@link #onSaveInstanceState}.
886     *
887     * @see #onCreate
888     * @see #onPostCreate
889     * @see #onResume
890     * @see #onSaveInstanceState
891     */
892    protected void onRestoreInstanceState(Bundle savedInstanceState) {
893        if (mWindow != null) {
894            Bundle windowState = savedInstanceState.getBundle(WINDOW_HIERARCHY_TAG);
895            if (windowState != null) {
896                mWindow.restoreHierarchyState(windowState);
897            }
898        }
899    }
900
901    /**
902     * Restore the state of any saved managed dialogs.
903     *
904     * @param savedInstanceState The bundle to restore from.
905     */
906    private void restoreManagedDialogs(Bundle savedInstanceState) {
907        final Bundle b = savedInstanceState.getBundle(SAVED_DIALOGS_TAG);
908        if (b == null) {
909            return;
910        }
911
912        final int[] ids = b.getIntArray(SAVED_DIALOG_IDS_KEY);
913        final int numDialogs = ids.length;
914        mManagedDialogs = new SparseArray<ManagedDialog>(numDialogs);
915        for (int i = 0; i < numDialogs; i++) {
916            final Integer dialogId = ids[i];
917            Bundle dialogState = b.getBundle(savedDialogKeyFor(dialogId));
918            if (dialogState != null) {
919                // Calling onRestoreInstanceState() below will invoke dispatchOnCreate
920                // so tell createDialog() not to do it, otherwise we get an exception
921                final ManagedDialog md = new ManagedDialog();
922                md.mArgs = b.getBundle(savedDialogArgsKeyFor(dialogId));
923                md.mDialog = createDialog(dialogId, dialogState, md.mArgs);
924                if (md.mDialog != null) {
925                    mManagedDialogs.put(dialogId, md);
926                    onPrepareDialog(dialogId, md.mDialog, md.mArgs);
927                    md.mDialog.onRestoreInstanceState(dialogState);
928                }
929            }
930        }
931    }
932
933    private Dialog createDialog(Integer dialogId, Bundle state, Bundle args) {
934        final Dialog dialog = onCreateDialog(dialogId, args);
935        if (dialog == null) {
936            return null;
937        }
938        dialog.dispatchOnCreate(state);
939        return dialog;
940    }
941
942    private static String savedDialogKeyFor(int key) {
943        return SAVED_DIALOG_KEY_PREFIX + key;
944    }
945
946    private static String savedDialogArgsKeyFor(int key) {
947        return SAVED_DIALOG_ARGS_KEY_PREFIX + key;
948    }
949
950    /**
951     * Called when activity start-up is complete (after {@link #onStart}
952     * and {@link #onRestoreInstanceState} have been called).  Applications will
953     * generally not implement this method; it is intended for system
954     * classes to do final initialization after application code has run.
955     *
956     * <p><em>Derived classes must call through to the super class's
957     * implementation of this method.  If they do not, an exception will be
958     * thrown.</em></p>
959     *
960     * @param savedInstanceState If the activity is being re-initialized after
961     *     previously being shut down then this Bundle contains the data it most
962     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
963     * @see #onCreate
964     */
965    protected void onPostCreate(Bundle savedInstanceState) {
966        if (!isChild()) {
967            mTitleReady = true;
968            onTitleChanged(getTitle(), getTitleColor());
969        }
970        if (mWindow != null && mWindow.hasFeature(Window.FEATURE_ACTION_BAR)) {
971            // Invalidate the action bar menu so that it can initialize properly.
972            mWindow.invalidatePanelMenu(Window.FEATURE_ACTION_BAR);
973        }
974        mCalled = true;
975    }
976
977    /**
978     * Called after {@link #onCreate} &mdash; or after {@link #onRestart} when
979     * the activity had been stopped, but is now again being displayed to the
980	 * user.  It will be followed by {@link #onResume}.
981     *
982     * <p><em>Derived classes must call through to the super class's
983     * implementation of this method.  If they do not, an exception will be
984     * thrown.</em></p>
985     *
986     * @see #onCreate
987     * @see #onStop
988     * @see #onResume
989     */
990    protected void onStart() {
991        mCalled = true;
992        mStarted = true;
993        if (mLoaderManager != null) {
994            mLoaderManager.doStart();
995        }
996    }
997
998    /**
999     * Called after {@link #onStop} when the current activity is being
1000     * re-displayed to the user (the user has navigated back to it).  It will
1001     * be followed by {@link #onStart} and then {@link #onResume}.
1002     *
1003     * <p>For activities that are using raw {@link Cursor} objects (instead of
1004     * creating them through
1005     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)},
1006     * this is usually the place
1007     * where the cursor should be requeried (because you had deactivated it in
1008     * {@link #onStop}.
1009     *
1010     * <p><em>Derived classes must call through to the super class's
1011     * implementation of this method.  If they do not, an exception will be
1012     * thrown.</em></p>
1013     *
1014     * @see #onStop
1015     * @see #onStart
1016     * @see #onResume
1017     */
1018    protected void onRestart() {
1019        mCalled = true;
1020    }
1021
1022    /**
1023     * Called after {@link #onRestoreInstanceState}, {@link #onRestart}, or
1024     * {@link #onPause}, for your activity to start interacting with the user.
1025     * This is a good place to begin animations, open exclusive-access devices
1026     * (such as the camera), etc.
1027     *
1028     * <p>Keep in mind that onResume is not the best indicator that your activity
1029     * is visible to the user; a system window such as the keyguard may be in
1030     * front.  Use {@link #onWindowFocusChanged} to know for certain that your
1031     * activity is visible to the user (for example, to resume a game).
1032     *
1033     * <p><em>Derived classes must call through to the super class's
1034     * implementation of this method.  If they do not, an exception will be
1035     * thrown.</em></p>
1036     *
1037     * @see #onRestoreInstanceState
1038     * @see #onRestart
1039     * @see #onPostResume
1040     * @see #onPause
1041     */
1042    protected void onResume() {
1043        mCalled = true;
1044    }
1045
1046    /**
1047     * Called when activity resume is complete (after {@link #onResume} has
1048     * been called). Applications will generally not implement this method;
1049     * it is intended for system classes to do final setup after application
1050     * resume code has run.
1051     *
1052     * <p><em>Derived classes must call through to the super class's
1053     * implementation of this method.  If they do not, an exception will be
1054     * thrown.</em></p>
1055     *
1056     * @see #onResume
1057     */
1058    protected void onPostResume() {
1059        final Window win = getWindow();
1060        if (win != null) win.makeActive();
1061        mCalled = true;
1062    }
1063
1064    /**
1065     * This is called for activities that set launchMode to "singleTop" in
1066     * their package, or if a client used the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP}
1067     * flag when calling {@link #startActivity}.  In either case, when the
1068     * activity is re-launched while at the top of the activity stack instead
1069     * of a new instance of the activity being started, onNewIntent() will be
1070     * called on the existing instance with the Intent that was used to
1071     * re-launch it.
1072     *
1073     * <p>An activity will always be paused before receiving a new intent, so
1074     * you can count on {@link #onResume} being called after this method.
1075     *
1076     * <p>Note that {@link #getIntent} still returns the original Intent.  You
1077     * can use {@link #setIntent} to update it to this new Intent.
1078     *
1079     * @param intent The new intent that was started for the activity.
1080     *
1081     * @see #getIntent
1082     * @see #setIntent
1083     * @see #onResume
1084     */
1085    protected void onNewIntent(Intent intent) {
1086    }
1087
1088    /**
1089     * The hook for {@link ActivityThread} to save the state of this activity.
1090     *
1091     * Calls {@link #onSaveInstanceState(android.os.Bundle)}
1092     * and {@link #saveManagedDialogs(android.os.Bundle)}.
1093     *
1094     * @param outState The bundle to save the state to.
1095     */
1096    final void performSaveInstanceState(Bundle outState) {
1097        onSaveInstanceState(outState);
1098        saveManagedDialogs(outState);
1099    }
1100
1101    /**
1102     * Called to retrieve per-instance state from an activity before being killed
1103     * so that the state can be restored in {@link #onCreate} or
1104     * {@link #onRestoreInstanceState} (the {@link Bundle} populated by this method
1105     * will be passed to both).
1106     *
1107     * <p>This method is called before an activity may be killed so that when it
1108     * comes back some time in the future it can restore its state.  For example,
1109     * if activity B is launched in front of activity A, and at some point activity
1110     * A is killed to reclaim resources, activity A will have a chance to save the
1111     * current state of its user interface via this method so that when the user
1112     * returns to activity A, the state of the user interface can be restored
1113     * via {@link #onCreate} or {@link #onRestoreInstanceState}.
1114     *
1115     * <p>Do not confuse this method with activity lifecycle callbacks such as
1116     * {@link #onPause}, which is always called when an activity is being placed
1117     * in the background or on its way to destruction, or {@link #onStop} which
1118     * is called before destruction.  One example of when {@link #onPause} and
1119     * {@link #onStop} is called and not this method is when a user navigates back
1120     * from activity B to activity A: there is no need to call {@link #onSaveInstanceState}
1121     * on B because that particular instance will never be restored, so the
1122     * system avoids calling it.  An example when {@link #onPause} is called and
1123     * not {@link #onSaveInstanceState} is when activity B is launched in front of activity A:
1124     * the system may avoid calling {@link #onSaveInstanceState} on activity A if it isn't
1125     * killed during the lifetime of B since the state of the user interface of
1126     * A will stay intact.
1127     *
1128     * <p>The default implementation takes care of most of the UI per-instance
1129     * state for you by calling {@link android.view.View#onSaveInstanceState()} on each
1130     * view in the hierarchy that has an id, and by saving the id of the currently
1131     * focused view (all of which is restored by the default implementation of
1132     * {@link #onRestoreInstanceState}).  If you override this method to save additional
1133     * information not captured by each individual view, you will likely want to
1134     * call through to the default implementation, otherwise be prepared to save
1135     * all of the state of each view yourself.
1136     *
1137     * <p>If called, this method will occur before {@link #onStop}.  There are
1138     * no guarantees about whether it will occur before or after {@link #onPause}.
1139     *
1140     * @param outState Bundle in which to place your saved state.
1141     *
1142     * @see #onCreate
1143     * @see #onRestoreInstanceState
1144     * @see #onPause
1145     */
1146    protected void onSaveInstanceState(Bundle outState) {
1147        outState.putBundle(WINDOW_HIERARCHY_TAG, mWindow.saveHierarchyState());
1148        Parcelable p = mFragments.saveAllState();
1149        if (p != null) {
1150            outState.putParcelable(FRAGMENTS_TAG, p);
1151        }
1152    }
1153
1154    /**
1155     * Save the state of any managed dialogs.
1156     *
1157     * @param outState place to store the saved state.
1158     */
1159    private void saveManagedDialogs(Bundle outState) {
1160        if (mManagedDialogs == null) {
1161            return;
1162        }
1163
1164        final int numDialogs = mManagedDialogs.size();
1165        if (numDialogs == 0) {
1166            return;
1167        }
1168
1169        Bundle dialogState = new Bundle();
1170
1171        int[] ids = new int[mManagedDialogs.size()];
1172
1173        // save each dialog's bundle, gather the ids
1174        for (int i = 0; i < numDialogs; i++) {
1175            final int key = mManagedDialogs.keyAt(i);
1176            ids[i] = key;
1177            final ManagedDialog md = mManagedDialogs.valueAt(i);
1178            dialogState.putBundle(savedDialogKeyFor(key), md.mDialog.onSaveInstanceState());
1179            if (md.mArgs != null) {
1180                dialogState.putBundle(savedDialogArgsKeyFor(key), md.mArgs);
1181            }
1182        }
1183
1184        dialogState.putIntArray(SAVED_DIALOG_IDS_KEY, ids);
1185        outState.putBundle(SAVED_DIALOGS_TAG, dialogState);
1186    }
1187
1188
1189    /**
1190     * Called as part of the activity lifecycle when an activity is going into
1191     * the background, but has not (yet) been killed.  The counterpart to
1192     * {@link #onResume}.
1193     *
1194     * <p>When activity B is launched in front of activity A, this callback will
1195     * be invoked on A.  B will not be created until A's {@link #onPause} returns,
1196     * so be sure to not do anything lengthy here.
1197     *
1198     * <p>This callback is mostly used for saving any persistent state the
1199     * activity is editing, to present a "edit in place" model to the user and
1200     * making sure nothing is lost if there are not enough resources to start
1201     * the new activity without first killing this one.  This is also a good
1202     * place to do things like stop animations and other things that consume a
1203     * noticeable mount of CPU in order to make the switch to the next activity
1204     * as fast as possible, or to close resources that are exclusive access
1205     * such as the camera.
1206     *
1207     * <p>In situations where the system needs more memory it may kill paused
1208     * processes to reclaim resources.  Because of this, you should be sure
1209     * that all of your state is saved by the time you return from
1210     * this function.  In general {@link #onSaveInstanceState} is used to save
1211     * per-instance state in the activity and this method is used to store
1212     * global persistent data (in content providers, files, etc.)
1213     *
1214     * <p>After receiving this call you will usually receive a following call
1215     * to {@link #onStop} (after the next activity has been resumed and
1216     * displayed), however in some cases there will be a direct call back to
1217     * {@link #onResume} without going through the stopped state.
1218     *
1219     * <p><em>Derived classes must call through to the super class's
1220     * implementation of this method.  If they do not, an exception will be
1221     * thrown.</em></p>
1222     *
1223     * @see #onResume
1224     * @see #onSaveInstanceState
1225     * @see #onStop
1226     */
1227    protected void onPause() {
1228        mCalled = true;
1229    }
1230
1231    /**
1232     * Called as part of the activity lifecycle when an activity is about to go
1233     * into the background as the result of user choice.  For example, when the
1234     * user presses the Home key, {@link #onUserLeaveHint} will be called, but
1235     * when an incoming phone call causes the in-call Activity to be automatically
1236     * brought to the foreground, {@link #onUserLeaveHint} will not be called on
1237     * the activity being interrupted.  In cases when it is invoked, this method
1238     * is called right before the activity's {@link #onPause} callback.
1239     *
1240     * <p>This callback and {@link #onUserInteraction} are intended to help
1241     * activities manage status bar notifications intelligently; specifically,
1242     * for helping activities determine the proper time to cancel a notfication.
1243     *
1244     * @see #onUserInteraction()
1245     */
1246    protected void onUserLeaveHint() {
1247    }
1248
1249    /**
1250     * Generate a new thumbnail for this activity.  This method is called before
1251     * pausing the activity, and should draw into <var>outBitmap</var> the
1252     * imagery for the desired thumbnail in the dimensions of that bitmap.  It
1253     * can use the given <var>canvas</var>, which is configured to draw into the
1254     * bitmap, for rendering if desired.
1255     *
1256     * <p>The default implementation renders the Screen's current view
1257     * hierarchy into the canvas to generate a thumbnail.
1258     *
1259     * <p>If you return false, the bitmap will be filled with a default
1260     * thumbnail.
1261     *
1262     * @param outBitmap The bitmap to contain the thumbnail.
1263     * @param canvas Can be used to render into the bitmap.
1264     *
1265     * @return Return true if you have drawn into the bitmap; otherwise after
1266     *         you return it will be filled with a default thumbnail.
1267     *
1268     * @see #onCreateDescription
1269     * @see #onSaveInstanceState
1270     * @see #onPause
1271     */
1272    public boolean onCreateThumbnail(Bitmap outBitmap, Canvas canvas) {
1273        if (mDecor == null) {
1274            return false;
1275        }
1276
1277        int paddingLeft = 0;
1278        int paddingRight = 0;
1279        int paddingTop = 0;
1280        int paddingBottom = 0;
1281
1282        // Find System window and use padding so we ignore space reserved for decorations
1283        // like the status bar and such.
1284        final FrameLayout top = (FrameLayout) mDecor;
1285        for (int i = 0; i < top.getChildCount(); i++) {
1286            View child = top.getChildAt(i);
1287            if (child.isFitsSystemWindowsFlagSet()) {
1288                paddingLeft = child.getPaddingLeft();
1289                paddingRight = child.getPaddingRight();
1290                paddingTop = child.getPaddingTop();
1291                paddingBottom = child.getPaddingBottom();
1292                break;
1293            }
1294        }
1295
1296        final int visibleWidth = mDecor.getWidth() - paddingLeft - paddingRight;
1297        final int visibleHeight = mDecor.getHeight() - paddingTop - paddingBottom;
1298
1299        canvas.save();
1300        canvas.scale( (float) outBitmap.getWidth() / visibleWidth,
1301                (float) outBitmap.getHeight() / visibleHeight);
1302        canvas.translate(-paddingLeft, -paddingTop);
1303        mDecor.draw(canvas);
1304        canvas.restore();
1305
1306        return true;
1307    }
1308
1309    /**
1310     * Generate a new description for this activity.  This method is called
1311     * before pausing the activity and can, if desired, return some textual
1312     * description of its current state to be displayed to the user.
1313     *
1314     * <p>The default implementation returns null, which will cause you to
1315     * inherit the description from the previous activity.  If all activities
1316     * return null, generally the label of the top activity will be used as the
1317     * description.
1318     *
1319     * @return A description of what the user is doing.  It should be short and
1320     *         sweet (only a few words).
1321     *
1322     * @see #onCreateThumbnail
1323     * @see #onSaveInstanceState
1324     * @see #onPause
1325     */
1326    public CharSequence onCreateDescription() {
1327        return null;
1328    }
1329
1330    /**
1331     * Called when you are no longer visible to the user.  You will next
1332     * receive either {@link #onRestart}, {@link #onDestroy}, or nothing,
1333     * depending on later user activity.
1334     *
1335     * <p>Note that this method may never be called, in low memory situations
1336     * where the system does not have enough memory to keep your activity's
1337     * process running after its {@link #onPause} method is called.
1338     *
1339     * <p><em>Derived classes must call through to the super class's
1340     * implementation of this method.  If they do not, an exception will be
1341     * thrown.</em></p>
1342     *
1343     * @see #onRestart
1344     * @see #onResume
1345     * @see #onSaveInstanceState
1346     * @see #onDestroy
1347     */
1348    protected void onStop() {
1349        mCalled = true;
1350    }
1351
1352    /**
1353     * Perform any final cleanup before an activity is destroyed.  This can
1354     * happen either because the activity is finishing (someone called
1355     * {@link #finish} on it, or because the system is temporarily destroying
1356     * this instance of the activity to save space.  You can distinguish
1357     * between these two scenarios with the {@link #isFinishing} method.
1358     *
1359     * <p><em>Note: do not count on this method being called as a place for
1360     * saving data! For example, if an activity is editing data in a content
1361     * provider, those edits should be committed in either {@link #onPause} or
1362     * {@link #onSaveInstanceState}, not here.</em> This method is usually implemented to
1363     * free resources like threads that are associated with an activity, so
1364     * that a destroyed activity does not leave such things around while the
1365     * rest of its application is still running.  There are situations where
1366     * the system will simply kill the activity's hosting process without
1367     * calling this method (or any others) in it, so it should not be used to
1368     * do things that are intended to remain around after the process goes
1369     * away.
1370     *
1371     * <p><em>Derived classes must call through to the super class's
1372     * implementation of this method.  If they do not, an exception will be
1373     * thrown.</em></p>
1374     *
1375     * @see #onPause
1376     * @see #onStop
1377     * @see #finish
1378     * @see #isFinishing
1379     */
1380    protected void onDestroy() {
1381        mCalled = true;
1382
1383        // dismiss any dialogs we are managing.
1384        if (mManagedDialogs != null) {
1385            final int numDialogs = mManagedDialogs.size();
1386            for (int i = 0; i < numDialogs; i++) {
1387                final ManagedDialog md = mManagedDialogs.valueAt(i);
1388                if (md.mDialog.isShowing()) {
1389                    md.mDialog.dismiss();
1390                }
1391            }
1392            mManagedDialogs = null;
1393        }
1394
1395        // close any cursors we are managing.
1396        synchronized (mManagedCursors) {
1397            int numCursors = mManagedCursors.size();
1398            for (int i = 0; i < numCursors; i++) {
1399                ManagedCursor c = mManagedCursors.get(i);
1400                if (c != null) {
1401                    c.mCursor.close();
1402                }
1403            }
1404            mManagedCursors.clear();
1405        }
1406
1407        // Close any open search dialog
1408        if (mSearchManager != null) {
1409            mSearchManager.stopSearch();
1410        }
1411    }
1412
1413    /**
1414     * Called by the system when the device configuration changes while your
1415     * activity is running.  Note that this will <em>only</em> be called if
1416     * you have selected configurations you would like to handle with the
1417     * {@link android.R.attr#configChanges} attribute in your manifest.  If
1418     * any configuration change occurs that is not selected to be reported
1419     * by that attribute, then instead of reporting it the system will stop
1420     * and restart the activity (to have it launched with the new
1421     * configuration).
1422     *
1423     * <p>At the time that this function has been called, your Resources
1424     * object will have been updated to return resource values matching the
1425     * new configuration.
1426     *
1427     * @param newConfig The new device configuration.
1428     */
1429    public void onConfigurationChanged(Configuration newConfig) {
1430        mCalled = true;
1431
1432        if (mWindow != null) {
1433            // Pass the configuration changed event to the window
1434            mWindow.onConfigurationChanged(newConfig);
1435        }
1436    }
1437
1438    /**
1439     * If this activity is being destroyed because it can not handle a
1440     * configuration parameter being changed (and thus its
1441     * {@link #onConfigurationChanged(Configuration)} method is
1442     * <em>not</em> being called), then you can use this method to discover
1443     * the set of changes that have occurred while in the process of being
1444     * destroyed.  Note that there is no guarantee that these will be
1445     * accurate (other changes could have happened at any time), so you should
1446     * only use this as an optimization hint.
1447     *
1448     * @return Returns a bit field of the configuration parameters that are
1449     * changing, as defined by the {@link android.content.res.Configuration}
1450     * class.
1451     */
1452    public int getChangingConfigurations() {
1453        return mConfigChangeFlags;
1454    }
1455
1456    /**
1457     * Retrieve the non-configuration instance data that was previously
1458     * returned by {@link #onRetainNonConfigurationInstance()}.  This will
1459     * be available from the initial {@link #onCreate} and
1460     * {@link #onStart} calls to the new instance, allowing you to extract
1461     * any useful dynamic state from the previous instance.
1462     *
1463     * <p>Note that the data you retrieve here should <em>only</em> be used
1464     * as an optimization for handling configuration changes.  You should always
1465     * be able to handle getting a null pointer back, and an activity must
1466     * still be able to restore itself to its previous state (through the
1467     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1468     * function returns null.
1469     *
1470     * @return Returns the object previously returned by
1471     * {@link #onRetainNonConfigurationInstance()}.
1472     */
1473    public Object getLastNonConfigurationInstance() {
1474        return mLastNonConfigurationInstances != null
1475                ? mLastNonConfigurationInstances.activity : null;
1476    }
1477
1478    /**
1479     * Called by the system, as part of destroying an
1480     * activity due to a configuration change, when it is known that a new
1481     * instance will immediately be created for the new configuration.  You
1482     * can return any object you like here, including the activity instance
1483     * itself, which can later be retrieved by calling
1484     * {@link #getLastNonConfigurationInstance()} in the new activity
1485     * instance.
1486     *
1487     * <p>This function is called purely as an optimization, and you must
1488     * not rely on it being called.  When it is called, a number of guarantees
1489     * will be made to help optimize configuration switching:
1490     * <ul>
1491     * <li> The function will be called between {@link #onStop} and
1492     * {@link #onDestroy}.
1493     * <li> A new instance of the activity will <em>always</em> be immediately
1494     * created after this one's {@link #onDestroy()} is called.
1495     * <li> The object you return here will <em>always</em> be available from
1496     * the {@link #getLastNonConfigurationInstance()} method of the following
1497     * activity instance as described there.
1498     * </ul>
1499     *
1500     * <p>These guarantees are designed so that an activity can use this API
1501     * to propagate extensive state from the old to new activity instance, from
1502     * loaded bitmaps, to network connections, to evenly actively running
1503     * threads.  Note that you should <em>not</em> propagate any data that
1504     * may change based on the configuration, including any data loaded from
1505     * resources such as strings, layouts, or drawables.
1506     *
1507     * @return Return any Object holding the desired state to propagate to the
1508     * next activity instance.
1509     */
1510    public Object onRetainNonConfigurationInstance() {
1511        return null;
1512    }
1513
1514    /**
1515     * Retrieve the non-configuration instance data that was previously
1516     * returned by {@link #onRetainNonConfigurationChildInstances()}.  This will
1517     * be available from the initial {@link #onCreate} and
1518     * {@link #onStart} calls to the new instance, allowing you to extract
1519     * any useful dynamic state from the previous instance.
1520     *
1521     * <p>Note that the data you retrieve here should <em>only</em> be used
1522     * as an optimization for handling configuration changes.  You should always
1523     * be able to handle getting a null pointer back, and an activity must
1524     * still be able to restore itself to its previous state (through the
1525     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1526     * function returns null.
1527     *
1528     * @return Returns the object previously returned by
1529     * {@link #onRetainNonConfigurationChildInstances()}
1530     */
1531    HashMap<String, Object> getLastNonConfigurationChildInstances() {
1532        return mLastNonConfigurationInstances != null
1533                ? mLastNonConfigurationInstances.children : null;
1534    }
1535
1536    /**
1537     * This method is similar to {@link #onRetainNonConfigurationInstance()} except that
1538     * it should return either a mapping from  child activity id strings to arbitrary objects,
1539     * or null.  This method is intended to be used by Activity framework subclasses that control a
1540     * set of child activities, such as ActivityGroup.  The same guarantees and restrictions apply
1541     * as for {@link #onRetainNonConfigurationInstance()}.  The default implementation returns null.
1542     */
1543    HashMap<String,Object> onRetainNonConfigurationChildInstances() {
1544        return null;
1545    }
1546
1547    NonConfigurationInstances retainNonConfigurationInstances() {
1548        Object activity = onRetainNonConfigurationInstance();
1549        HashMap<String, Object> children = onRetainNonConfigurationChildInstances();
1550        ArrayList<Fragment> fragments = mFragments.retainNonConfig();
1551        boolean retainLoaders = false;
1552        if (mAllLoaderManagers != null) {
1553            // prune out any loader managers that were already stopped, so
1554            // have nothing useful to retain.
1555            for (int i=mAllLoaderManagers.size()-1; i>=0; i--) {
1556                LoaderManagerImpl lm = mAllLoaderManagers.valueAt(i);
1557                if (lm.mRetaining) {
1558                    retainLoaders = true;
1559                } else {
1560                    mAllLoaderManagers.removeAt(i);
1561                }
1562            }
1563        }
1564        if (activity == null && children == null && fragments == null && !retainLoaders) {
1565            return null;
1566        }
1567
1568        NonConfigurationInstances nci = new NonConfigurationInstances();
1569        nci.activity = activity;
1570        nci.children = children;
1571        nci.fragments = fragments;
1572        nci.loaders = mAllLoaderManagers;
1573        return nci;
1574    }
1575
1576    public void onLowMemory() {
1577        mCalled = true;
1578    }
1579
1580    /**
1581     * Start a series of edit operations on the Fragments associated with
1582     * this activity.
1583     */
1584    public FragmentTransaction openFragmentTransaction() {
1585        return new BackStackEntry(mFragments);
1586    }
1587
1588    void invalidateFragmentIndex(int index) {
1589        if (mAllLoaderManagers != null) {
1590            mAllLoaderManagers.remove(index);
1591        }
1592    }
1593
1594    /**
1595     * Called when a Fragment is being attached to this activity, immediately
1596     * after the call to its {@link Fragment#onAttach Fragment.onAttach()}
1597     * method and before {@link Fragment#onCreate Fragment.onCreate()}.
1598     */
1599    public void onAttachFragment(Fragment fragment) {
1600    }
1601
1602    /**
1603     * Wrapper around
1604     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1605     * that gives the resulting {@link Cursor} to call
1606     * {@link #startManagingCursor} so that the activity will manage its
1607     * lifecycle for you.
1608     *
1609     * @param uri The URI of the content provider to query.
1610     * @param projection List of columns to return.
1611     * @param selection SQL WHERE clause.
1612     * @param sortOrder SQL ORDER BY clause.
1613     *
1614     * @return The Cursor that was returned by query().
1615     *
1616     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1617     * @see #startManagingCursor
1618     * @hide
1619     */
1620    public final Cursor managedQuery(Uri uri,
1621                                     String[] projection,
1622                                     String selection,
1623                                     String sortOrder)
1624    {
1625        Cursor c = getContentResolver().query(uri, projection, selection, null, sortOrder);
1626        if (c != null) {
1627            startManagingCursor(c);
1628        }
1629        return c;
1630    }
1631
1632    /**
1633     * Wrapper around
1634     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1635     * that gives the resulting {@link Cursor} to call
1636     * {@link #startManagingCursor} so that the activity will manage its
1637     * lifecycle for you.
1638     *
1639     * @param uri The URI of the content provider to query.
1640     * @param projection List of columns to return.
1641     * @param selection SQL WHERE clause.
1642     * @param selectionArgs The arguments to selection, if any ?s are pesent
1643     * @param sortOrder SQL ORDER BY clause.
1644     *
1645     * @return The Cursor that was returned by query().
1646     *
1647     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1648     * @see #startManagingCursor
1649     */
1650    public final Cursor managedQuery(Uri uri,
1651                                     String[] projection,
1652                                     String selection,
1653                                     String[] selectionArgs,
1654                                     String sortOrder)
1655    {
1656        Cursor c = getContentResolver().query(uri, projection, selection, selectionArgs, sortOrder);
1657        if (c != null) {
1658            startManagingCursor(c);
1659        }
1660        return c;
1661    }
1662
1663    /**
1664     * This method allows the activity to take care of managing the given
1665     * {@link Cursor}'s lifecycle for you based on the activity's lifecycle.
1666     * That is, when the activity is stopped it will automatically call
1667     * {@link Cursor#deactivate} on the given Cursor, and when it is later restarted
1668     * it will call {@link Cursor#requery} for you.  When the activity is
1669     * destroyed, all managed Cursors will be closed automatically.
1670     *
1671     * @param c The Cursor to be managed.
1672     *
1673     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
1674     * @see #stopManagingCursor
1675     */
1676    public void startManagingCursor(Cursor c) {
1677        synchronized (mManagedCursors) {
1678            mManagedCursors.add(new ManagedCursor(c));
1679        }
1680    }
1681
1682    /**
1683     * Given a Cursor that was previously given to
1684     * {@link #startManagingCursor}, stop the activity's management of that
1685     * cursor.
1686     *
1687     * @param c The Cursor that was being managed.
1688     *
1689     * @see #startManagingCursor
1690     */
1691    public void stopManagingCursor(Cursor c) {
1692        synchronized (mManagedCursors) {
1693            final int N = mManagedCursors.size();
1694            for (int i=0; i<N; i++) {
1695                ManagedCursor mc = mManagedCursors.get(i);
1696                if (mc.mCursor == c) {
1697                    mManagedCursors.remove(i);
1698                    break;
1699                }
1700            }
1701        }
1702    }
1703
1704    /**
1705     * Control whether this activity is required to be persistent.  By default
1706     * activities are not persistent; setting this to true will prevent the
1707     * system from stopping this activity or its process when running low on
1708     * resources.
1709     *
1710     * <p><em>You should avoid using this method</em>, it has severe negative
1711     * consequences on how well the system can manage its resources.  A better
1712     * approach is to implement an application service that you control with
1713     * {@link Context#startService} and {@link Context#stopService}.
1714     *
1715     * @param isPersistent Control whether the current activity must be
1716     *                     persistent, true if so, false for the normal
1717     *                     behavior.
1718     */
1719    public void setPersistent(boolean isPersistent) {
1720        if (mParent == null) {
1721            try {
1722                ActivityManagerNative.getDefault()
1723                    .setPersistent(mToken, isPersistent);
1724            } catch (RemoteException e) {
1725                // Empty
1726            }
1727        } else {
1728            throw new RuntimeException("setPersistent() not yet supported for embedded activities");
1729        }
1730    }
1731
1732    /**
1733     * Finds a view that was identified by the id attribute from the XML that
1734     * was processed in {@link #onCreate}.
1735     *
1736     * @return The view if found or null otherwise.
1737     */
1738    public View findViewById(int id) {
1739        return getWindow().findViewById(id);
1740    }
1741
1742    /**
1743     * Retrieve a reference to this activity's ActionBar.
1744     *
1745     * <p><em>Note:</em> The ActionBar is initialized when a content view
1746     * is set. This function will return null if called before {@link #setContentView}
1747     * or {@link #addContentView}.
1748     * @return The Activity's ActionBar, or null if it does not have one.
1749     */
1750    public ActionBar getActionBar() {
1751        return mActionBar;
1752    }
1753
1754    /**
1755     * Creates a new ActionBar, locates the inflated ActionBarView,
1756     * initializes the ActionBar with the view, and sets mActionBar.
1757     */
1758    private void initActionBar() {
1759        Window window = getWindow();
1760        if (!window.hasFeature(Window.FEATURE_ACTION_BAR) || mActionBar != null) {
1761            return;
1762        }
1763
1764        mActionBar = new ActionBarImpl(this);
1765    }
1766
1767    /**
1768     * Finds a fragment that was identified by the given id either when inflated
1769     * from XML or as the container ID when added in a transaction.  This only
1770     * returns fragments that are currently added to the activity's content.
1771     * @return The fragment if found or null otherwise.
1772     */
1773    public Fragment findFragmentById(int id) {
1774        return mFragments.findFragmentById(id);
1775    }
1776
1777    /**
1778     * Finds a fragment that was identified by the given tag either when inflated
1779     * from XML or as supplied when added in a transaction.  This only
1780     * returns fragments that are currently added to the activity's content.
1781     * @return The fragment if found or null otherwise.
1782     */
1783    public Fragment findFragmentByTag(String tag) {
1784        return mFragments.findFragmentByTag(tag);
1785    }
1786
1787    /**
1788     * Set the activity content from a layout resource.  The resource will be
1789     * inflated, adding all top-level views to the activity.
1790     *
1791     * @param layoutResID Resource ID to be inflated.
1792     */
1793    public void setContentView(int layoutResID) {
1794        getWindow().setContentView(layoutResID);
1795        initActionBar();
1796    }
1797
1798    /**
1799     * Set the activity content to an explicit view.  This view is placed
1800     * directly into the activity's view hierarchy.  It can itself be a complex
1801     * view hierarhcy.
1802     *
1803     * @param view The desired content to display.
1804     */
1805    public void setContentView(View view) {
1806        getWindow().setContentView(view);
1807        initActionBar();
1808    }
1809
1810    /**
1811     * Set the activity content to an explicit view.  This view is placed
1812     * directly into the activity's view hierarchy.  It can itself be a complex
1813     * view hierarhcy.
1814     *
1815     * @param view The desired content to display.
1816     * @param params Layout parameters for the view.
1817     */
1818    public void setContentView(View view, ViewGroup.LayoutParams params) {
1819        getWindow().setContentView(view, params);
1820        initActionBar();
1821    }
1822
1823    /**
1824     * Add an additional content view to the activity.  Added after any existing
1825     * ones in the activity -- existing views are NOT removed.
1826     *
1827     * @param view The desired content to display.
1828     * @param params Layout parameters for the view.
1829     */
1830    public void addContentView(View view, ViewGroup.LayoutParams params) {
1831        getWindow().addContentView(view, params);
1832        initActionBar();
1833    }
1834
1835    /**
1836     * Use with {@link #setDefaultKeyMode} to turn off default handling of
1837     * keys.
1838     *
1839     * @see #setDefaultKeyMode
1840     */
1841    static public final int DEFAULT_KEYS_DISABLE = 0;
1842    /**
1843     * Use with {@link #setDefaultKeyMode} to launch the dialer during default
1844     * key handling.
1845     *
1846     * @see #setDefaultKeyMode
1847     */
1848    static public final int DEFAULT_KEYS_DIALER = 1;
1849    /**
1850     * Use with {@link #setDefaultKeyMode} to execute a menu shortcut in
1851     * default key handling.
1852     *
1853     * <p>That is, the user does not need to hold down the menu key to execute menu shortcuts.
1854     *
1855     * @see #setDefaultKeyMode
1856     */
1857    static public final int DEFAULT_KEYS_SHORTCUT = 2;
1858    /**
1859     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1860     * will start an application-defined search.  (If the application or activity does not
1861     * actually define a search, the the keys will be ignored.)
1862     *
1863     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1864     *
1865     * @see #setDefaultKeyMode
1866     */
1867    static public final int DEFAULT_KEYS_SEARCH_LOCAL = 3;
1868
1869    /**
1870     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1871     * will start a global search (typically web search, but some platforms may define alternate
1872     * methods for global search)
1873     *
1874     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1875     *
1876     * @see #setDefaultKeyMode
1877     */
1878    static public final int DEFAULT_KEYS_SEARCH_GLOBAL = 4;
1879
1880    /**
1881     * Select the default key handling for this activity.  This controls what
1882     * will happen to key events that are not otherwise handled.  The default
1883     * mode ({@link #DEFAULT_KEYS_DISABLE}) will simply drop them on the
1884     * floor. Other modes allow you to launch the dialer
1885     * ({@link #DEFAULT_KEYS_DIALER}), execute a shortcut in your options
1886     * menu without requiring the menu key be held down
1887     * ({@link #DEFAULT_KEYS_SHORTCUT}), or launch a search ({@link #DEFAULT_KEYS_SEARCH_LOCAL}
1888     * and {@link #DEFAULT_KEYS_SEARCH_GLOBAL}).
1889     *
1890     * <p>Note that the mode selected here does not impact the default
1891     * handling of system keys, such as the "back" and "menu" keys, and your
1892     * activity and its views always get a first chance to receive and handle
1893     * all application keys.
1894     *
1895     * @param mode The desired default key mode constant.
1896     *
1897     * @see #DEFAULT_KEYS_DISABLE
1898     * @see #DEFAULT_KEYS_DIALER
1899     * @see #DEFAULT_KEYS_SHORTCUT
1900     * @see #DEFAULT_KEYS_SEARCH_LOCAL
1901     * @see #DEFAULT_KEYS_SEARCH_GLOBAL
1902     * @see #onKeyDown
1903     */
1904    public final void setDefaultKeyMode(int mode) {
1905        mDefaultKeyMode = mode;
1906
1907        // Some modes use a SpannableStringBuilder to track & dispatch input events
1908        // This list must remain in sync with the switch in onKeyDown()
1909        switch (mode) {
1910        case DEFAULT_KEYS_DISABLE:
1911        case DEFAULT_KEYS_SHORTCUT:
1912            mDefaultKeySsb = null;      // not used in these modes
1913            break;
1914        case DEFAULT_KEYS_DIALER:
1915        case DEFAULT_KEYS_SEARCH_LOCAL:
1916        case DEFAULT_KEYS_SEARCH_GLOBAL:
1917            mDefaultKeySsb = new SpannableStringBuilder();
1918            Selection.setSelection(mDefaultKeySsb,0);
1919            break;
1920        default:
1921            throw new IllegalArgumentException();
1922        }
1923    }
1924
1925    /**
1926     * Called when a key was pressed down and not handled by any of the views
1927     * inside of the activity. So, for example, key presses while the cursor
1928     * is inside a TextView will not trigger the event (unless it is a navigation
1929     * to another object) because TextView handles its own key presses.
1930     *
1931     * <p>If the focused view didn't want this event, this method is called.
1932     *
1933     * <p>The default implementation takes care of {@link KeyEvent#KEYCODE_BACK}
1934     * by calling {@link #onBackPressed()}, though the behavior varies based
1935     * on the application compatibility mode: for
1936     * {@link android.os.Build.VERSION_CODES#ECLAIR} or later applications,
1937     * it will set up the dispatch to call {@link #onKeyUp} where the action
1938     * will be performed; for earlier applications, it will perform the
1939     * action immediately in on-down, as those versions of the platform
1940     * behaved.
1941     *
1942     * <p>Other additional default key handling may be performed
1943     * if configured with {@link #setDefaultKeyMode}.
1944     *
1945     * @return Return <code>true</code> to prevent this event from being propagated
1946     * further, or <code>false</code> to indicate that you have not handled
1947     * this event and it should continue to be propagated.
1948     * @see #onKeyUp
1949     * @see android.view.KeyEvent
1950     */
1951    public boolean onKeyDown(int keyCode, KeyEvent event)  {
1952        if (keyCode == KeyEvent.KEYCODE_BACK) {
1953            if (getApplicationInfo().targetSdkVersion
1954                    >= Build.VERSION_CODES.ECLAIR) {
1955                event.startTracking();
1956            } else {
1957                onBackPressed();
1958            }
1959            return true;
1960        }
1961
1962        if (mDefaultKeyMode == DEFAULT_KEYS_DISABLE) {
1963            return false;
1964        } else if (mDefaultKeyMode == DEFAULT_KEYS_SHORTCUT) {
1965            if (getWindow().performPanelShortcut(Window.FEATURE_OPTIONS_PANEL,
1966                    keyCode, event, Menu.FLAG_ALWAYS_PERFORM_CLOSE)) {
1967                return true;
1968            }
1969            return false;
1970        } else {
1971            // Common code for DEFAULT_KEYS_DIALER & DEFAULT_KEYS_SEARCH_*
1972            boolean clearSpannable = false;
1973            boolean handled;
1974            if ((event.getRepeatCount() != 0) || event.isSystem()) {
1975                clearSpannable = true;
1976                handled = false;
1977            } else {
1978                handled = TextKeyListener.getInstance().onKeyDown(
1979                        null, mDefaultKeySsb, keyCode, event);
1980                if (handled && mDefaultKeySsb.length() > 0) {
1981                    // something useable has been typed - dispatch it now.
1982
1983                    final String str = mDefaultKeySsb.toString();
1984                    clearSpannable = true;
1985
1986                    switch (mDefaultKeyMode) {
1987                    case DEFAULT_KEYS_DIALER:
1988                        Intent intent = new Intent(Intent.ACTION_DIAL,  Uri.parse("tel:" + str));
1989                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
1990                        startActivity(intent);
1991                        break;
1992                    case DEFAULT_KEYS_SEARCH_LOCAL:
1993                        startSearch(str, false, null, false);
1994                        break;
1995                    case DEFAULT_KEYS_SEARCH_GLOBAL:
1996                        startSearch(str, false, null, true);
1997                        break;
1998                    }
1999                }
2000            }
2001            if (clearSpannable) {
2002                mDefaultKeySsb.clear();
2003                mDefaultKeySsb.clearSpans();
2004                Selection.setSelection(mDefaultKeySsb,0);
2005            }
2006            return handled;
2007        }
2008    }
2009
2010    /**
2011     * Default implementation of {@link KeyEvent.Callback#onKeyLongPress(int, KeyEvent)
2012     * KeyEvent.Callback.onKeyLongPress()}: always returns false (doesn't handle
2013     * the event).
2014     */
2015    public boolean onKeyLongPress(int keyCode, KeyEvent event) {
2016        return false;
2017    }
2018
2019    /**
2020     * Called when a key was released and not handled by any of the views
2021     * inside of the activity. So, for example, key presses while the cursor
2022     * is inside a TextView will not trigger the event (unless it is a navigation
2023     * to another object) because TextView handles its own key presses.
2024     *
2025     * <p>The default implementation handles KEYCODE_BACK to stop the activity
2026     * and go back.
2027     *
2028     * @return Return <code>true</code> to prevent this event from being propagated
2029     * further, or <code>false</code> to indicate that you have not handled
2030     * this event and it should continue to be propagated.
2031     * @see #onKeyDown
2032     * @see KeyEvent
2033     */
2034    public boolean onKeyUp(int keyCode, KeyEvent event) {
2035        if (getApplicationInfo().targetSdkVersion
2036                >= Build.VERSION_CODES.ECLAIR) {
2037            if (keyCode == KeyEvent.KEYCODE_BACK && event.isTracking()
2038                    && !event.isCanceled()) {
2039                onBackPressed();
2040                return true;
2041            }
2042        }
2043        return false;
2044    }
2045
2046    /**
2047     * Default implementation of {@link KeyEvent.Callback#onKeyMultiple(int, int, KeyEvent)
2048     * KeyEvent.Callback.onKeyMultiple()}: always returns false (doesn't handle
2049     * the event).
2050     */
2051    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
2052        return false;
2053    }
2054
2055    /**
2056     * Flag for {@link #popBackStack(String, int)}
2057     * and {@link #popBackStack(int, int)}: If set, and the name or ID of
2058     * a back stack entry has been supplied, then all matching entries will
2059     * be consumed until one that doesn't match is found or the bottom of
2060     * the stack is reached.  Otherwise, all entries up to but not including that entry
2061     * will be removed.
2062     */
2063    public static final int POP_BACK_STACK_INCLUSIVE = 1<<0;
2064
2065    /**
2066     * Pop the top state off the back stack.  Returns true if there was one
2067     * to pop, else false.
2068     */
2069    public boolean popBackStack() {
2070        return popBackStack(null, -1);
2071    }
2072
2073    /**
2074     * Pop the last fragment transition from the local activity's fragment
2075     * back stack.  If there is nothing to pop, false is returned.
2076     * @param name If non-null, this is the name of a previous back state
2077     * to look for; if found, all states up to that state will be popped.  The
2078     * {@link #POP_BACK_STACK_INCLUSIVE} flag can be used to control whether
2079     * the named state itself is popped. If null, only the top state is popped.
2080     * @param flags Either 0 or {@link #POP_BACK_STACK_INCLUSIVE}.
2081     */
2082    public boolean popBackStack(String name, int flags) {
2083        return mFragments.popBackStackState(mHandler, name, flags);
2084    }
2085
2086    /**
2087     * Pop all back stack states up to the one with the given identifier.
2088     * @param id Identifier of the stated to be popped. If no identifier exists,
2089     * false is returned.
2090     * The identifier is the number returned by
2091     * {@link FragmentTransaction#commit() FragmentTransaction.commit()}.  The
2092     * {@link #POP_BACK_STACK_INCLUSIVE} flag can be used to control whether
2093     * the named state itself is popped.
2094     * @param flags Either 0 or {@link #POP_BACK_STACK_INCLUSIVE}.
2095     */
2096    public boolean popBackStack(int id, int flags) {
2097        return mFragments.popBackStackState(mHandler, id, flags);
2098    }
2099
2100    /**
2101     * Called when the activity has detected the user's press of the back
2102     * key.  The default implementation simply finishes the current activity,
2103     * but you can override this to do whatever you want.
2104     */
2105    public void onBackPressed() {
2106        if (!popBackStack()) {
2107            finish();
2108        }
2109    }
2110
2111    /**
2112     * Called when a touch screen event was not handled by any of the views
2113     * under it.  This is most useful to process touch events that happen
2114     * outside of your window bounds, where there is no view to receive it.
2115     *
2116     * @param event The touch screen event being processed.
2117     *
2118     * @return Return true if you have consumed the event, false if you haven't.
2119     * The default implementation always returns false.
2120     */
2121    public boolean onTouchEvent(MotionEvent event) {
2122        return false;
2123    }
2124
2125    /**
2126     * Called when the trackball was moved and not handled by any of the
2127     * views inside of the activity.  So, for example, if the trackball moves
2128     * while focus is on a button, you will receive a call here because
2129     * buttons do not normally do anything with trackball events.  The call
2130     * here happens <em>before</em> trackball movements are converted to
2131     * DPAD key events, which then get sent back to the view hierarchy, and
2132     * will be processed at the point for things like focus navigation.
2133     *
2134     * @param event The trackball event being processed.
2135     *
2136     * @return Return true if you have consumed the event, false if you haven't.
2137     * The default implementation always returns false.
2138     */
2139    public boolean onTrackballEvent(MotionEvent event) {
2140        return false;
2141    }
2142
2143    /**
2144     * Called whenever a key, touch, or trackball event is dispatched to the
2145     * activity.  Implement this method if you wish to know that the user has
2146     * interacted with the device in some way while your activity is running.
2147     * This callback and {@link #onUserLeaveHint} are intended to help
2148     * activities manage status bar notifications intelligently; specifically,
2149     * for helping activities determine the proper time to cancel a notfication.
2150     *
2151     * <p>All calls to your activity's {@link #onUserLeaveHint} callback will
2152     * be accompanied by calls to {@link #onUserInteraction}.  This
2153     * ensures that your activity will be told of relevant user activity such
2154     * as pulling down the notification pane and touching an item there.
2155     *
2156     * <p>Note that this callback will be invoked for the touch down action
2157     * that begins a touch gesture, but may not be invoked for the touch-moved
2158     * and touch-up actions that follow.
2159     *
2160     * @see #onUserLeaveHint()
2161     */
2162    public void onUserInteraction() {
2163    }
2164
2165    public void onWindowAttributesChanged(WindowManager.LayoutParams params) {
2166        // Update window manager if: we have a view, that view is
2167        // attached to its parent (which will be a RootView), and
2168        // this activity is not embedded.
2169        if (mParent == null) {
2170            View decor = mDecor;
2171            if (decor != null && decor.getParent() != null) {
2172                getWindowManager().updateViewLayout(decor, params);
2173            }
2174        }
2175    }
2176
2177    public void onContentChanged() {
2178    }
2179
2180    /**
2181     * Called when the current {@link Window} of the activity gains or loses
2182     * focus.  This is the best indicator of whether this activity is visible
2183     * to the user.  The default implementation clears the key tracking
2184     * state, so should always be called.
2185     *
2186     * <p>Note that this provides information about global focus state, which
2187     * is managed independently of activity lifecycles.  As such, while focus
2188     * changes will generally have some relation to lifecycle changes (an
2189     * activity that is stopped will not generally get window focus), you
2190     * should not rely on any particular order between the callbacks here and
2191     * those in the other lifecycle methods such as {@link #onResume}.
2192     *
2193     * <p>As a general rule, however, a resumed activity will have window
2194     * focus...  unless it has displayed other dialogs or popups that take
2195     * input focus, in which case the activity itself will not have focus
2196     * when the other windows have it.  Likewise, the system may display
2197     * system-level windows (such as the status bar notification panel or
2198     * a system alert) which will temporarily take window input focus without
2199     * pausing the foreground activity.
2200     *
2201     * @param hasFocus Whether the window of this activity has focus.
2202     *
2203     * @see #hasWindowFocus()
2204     * @see #onResume
2205     * @see View#onWindowFocusChanged(boolean)
2206     */
2207    public void onWindowFocusChanged(boolean hasFocus) {
2208    }
2209
2210    /**
2211     * Called when the main window associated with the activity has been
2212     * attached to the window manager.
2213     * See {@link View#onAttachedToWindow() View.onAttachedToWindow()}
2214     * for more information.
2215     * @see View#onAttachedToWindow
2216     */
2217    public void onAttachedToWindow() {
2218    }
2219
2220    /**
2221     * Called when the main window associated with the activity has been
2222     * detached from the window manager.
2223     * See {@link View#onDetachedFromWindow() View.onDetachedFromWindow()}
2224     * for more information.
2225     * @see View#onDetachedFromWindow
2226     */
2227    public void onDetachedFromWindow() {
2228    }
2229
2230    /**
2231     * Returns true if this activity's <em>main</em> window currently has window focus.
2232     * Note that this is not the same as the view itself having focus.
2233     *
2234     * @return True if this activity's main window currently has window focus.
2235     *
2236     * @see #onWindowAttributesChanged(android.view.WindowManager.LayoutParams)
2237     */
2238    public boolean hasWindowFocus() {
2239        Window w = getWindow();
2240        if (w != null) {
2241            View d = w.getDecorView();
2242            if (d != null) {
2243                return d.hasWindowFocus();
2244            }
2245        }
2246        return false;
2247    }
2248
2249    /**
2250     * Called to process key events.  You can override this to intercept all
2251     * key events before they are dispatched to the window.  Be sure to call
2252     * this implementation for key events that should be handled normally.
2253     *
2254     * @param event The key event.
2255     *
2256     * @return boolean Return true if this event was consumed.
2257     */
2258    public boolean dispatchKeyEvent(KeyEvent event) {
2259        onUserInteraction();
2260        Window win = getWindow();
2261        if (win.superDispatchKeyEvent(event)) {
2262            return true;
2263        }
2264        View decor = mDecor;
2265        if (decor == null) decor = win.getDecorView();
2266        return event.dispatch(this, decor != null
2267                ? decor.getKeyDispatcherState() : null, this);
2268    }
2269
2270    /**
2271     * Called to process touch screen events.  You can override this to
2272     * intercept all touch screen events before they are dispatched to the
2273     * window.  Be sure to call this implementation for touch screen events
2274     * that should be handled normally.
2275     *
2276     * @param ev The touch screen event.
2277     *
2278     * @return boolean Return true if this event was consumed.
2279     */
2280    public boolean dispatchTouchEvent(MotionEvent ev) {
2281        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
2282            onUserInteraction();
2283        }
2284        if (getWindow().superDispatchTouchEvent(ev)) {
2285            return true;
2286        }
2287        return onTouchEvent(ev);
2288    }
2289
2290    /**
2291     * Called to process trackball events.  You can override this to
2292     * intercept all trackball events before they are dispatched to the
2293     * window.  Be sure to call this implementation for trackball events
2294     * that should be handled normally.
2295     *
2296     * @param ev The trackball event.
2297     *
2298     * @return boolean Return true if this event was consumed.
2299     */
2300    public boolean dispatchTrackballEvent(MotionEvent ev) {
2301        onUserInteraction();
2302        if (getWindow().superDispatchTrackballEvent(ev)) {
2303            return true;
2304        }
2305        return onTrackballEvent(ev);
2306    }
2307
2308    public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) {
2309        event.setClassName(getClass().getName());
2310        event.setPackageName(getPackageName());
2311
2312        LayoutParams params = getWindow().getAttributes();
2313        boolean isFullScreen = (params.width == LayoutParams.MATCH_PARENT) &&
2314            (params.height == LayoutParams.MATCH_PARENT);
2315        event.setFullScreen(isFullScreen);
2316
2317        CharSequence title = getTitle();
2318        if (!TextUtils.isEmpty(title)) {
2319           event.getText().add(title);
2320        }
2321
2322        return true;
2323    }
2324
2325    /**
2326     * Default implementation of
2327     * {@link android.view.Window.Callback#onCreatePanelView}
2328     * for activities. This
2329     * simply returns null so that all panel sub-windows will have the default
2330     * menu behavior.
2331     */
2332    public View onCreatePanelView(int featureId) {
2333        return null;
2334    }
2335
2336    /**
2337     * Default implementation of
2338     * {@link android.view.Window.Callback#onCreatePanelMenu}
2339     * for activities.  This calls through to the new
2340     * {@link #onCreateOptionsMenu} method for the
2341     * {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2342     * so that subclasses of Activity don't need to deal with feature codes.
2343     */
2344    public boolean onCreatePanelMenu(int featureId, Menu menu) {
2345        if (featureId == Window.FEATURE_OPTIONS_PANEL) {
2346            boolean show = onCreateOptionsMenu(menu);
2347            show |= mFragments.dispatchCreateOptionsMenu(menu, getMenuInflater());
2348            return show;
2349        }
2350        return false;
2351    }
2352
2353    /**
2354     * Default implementation of
2355     * {@link android.view.Window.Callback#onPreparePanel}
2356     * for activities.  This
2357     * calls through to the new {@link #onPrepareOptionsMenu} method for the
2358     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2359     * panel, so that subclasses of
2360     * Activity don't need to deal with feature codes.
2361     */
2362    public boolean onPreparePanel(int featureId, View view, Menu menu) {
2363        if (featureId == Window.FEATURE_OPTIONS_PANEL && menu != null) {
2364            boolean goforit = onPrepareOptionsMenu(menu);
2365            goforit |= mFragments.dispatchPrepareOptionsMenu(menu);
2366            return goforit && menu.hasVisibleItems();
2367        }
2368        return true;
2369    }
2370
2371    /**
2372     * {@inheritDoc}
2373     *
2374     * @return The default implementation returns true.
2375     */
2376    public boolean onMenuOpened(int featureId, Menu menu) {
2377        return true;
2378    }
2379
2380    /**
2381     * Default implementation of
2382     * {@link android.view.Window.Callback#onMenuItemSelected}
2383     * for activities.  This calls through to the new
2384     * {@link #onOptionsItemSelected} method for the
2385     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2386     * panel, so that subclasses of
2387     * Activity don't need to deal with feature codes.
2388     */
2389    public boolean onMenuItemSelected(int featureId, MenuItem item) {
2390        switch (featureId) {
2391            case Window.FEATURE_OPTIONS_PANEL:
2392                // Put event logging here so it gets called even if subclass
2393                // doesn't call through to superclass's implmeentation of each
2394                // of these methods below
2395                EventLog.writeEvent(50000, 0, item.getTitleCondensed());
2396                if (onOptionsItemSelected(item)) {
2397                    return true;
2398                }
2399                return mFragments.dispatchOptionsItemSelected(item);
2400
2401            case Window.FEATURE_CONTEXT_MENU:
2402                EventLog.writeEvent(50000, 1, item.getTitleCondensed());
2403                if (onContextItemSelected(item)) {
2404                    return true;
2405                }
2406                return mFragments.dispatchContextItemSelected(item);
2407
2408            default:
2409                return false;
2410        }
2411    }
2412
2413    /**
2414     * Default implementation of
2415     * {@link android.view.Window.Callback#onPanelClosed(int, Menu)} for
2416     * activities. This calls through to {@link #onOptionsMenuClosed(Menu)}
2417     * method for the {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2418     * so that subclasses of Activity don't need to deal with feature codes.
2419     * For context menus ({@link Window#FEATURE_CONTEXT_MENU}), the
2420     * {@link #onContextMenuClosed(Menu)} will be called.
2421     */
2422    public void onPanelClosed(int featureId, Menu menu) {
2423        switch (featureId) {
2424            case Window.FEATURE_OPTIONS_PANEL:
2425                mFragments.dispatchOptionsMenuClosed(menu);
2426                onOptionsMenuClosed(menu);
2427                break;
2428
2429            case Window.FEATURE_CONTEXT_MENU:
2430                onContextMenuClosed(menu);
2431                break;
2432        }
2433    }
2434
2435    /**
2436     * Declare that the options menu has changed, so should be recreated.
2437     * The {@link #onCreateOptionsMenu(Menu)} method will be called the next
2438     * time it needs to be displayed.
2439     */
2440    public void invalidateOptionsMenu() {
2441        mWindow.invalidatePanelMenu(Window.FEATURE_OPTIONS_PANEL);
2442    }
2443
2444    /**
2445     * Initialize the contents of the Activity's standard options menu.  You
2446     * should place your menu items in to <var>menu</var>.
2447     *
2448     * <p>This is only called once, the first time the options menu is
2449     * displayed.  To update the menu every time it is displayed, see
2450     * {@link #onPrepareOptionsMenu}.
2451     *
2452     * <p>The default implementation populates the menu with standard system
2453     * menu items.  These are placed in the {@link Menu#CATEGORY_SYSTEM} group so that
2454     * they will be correctly ordered with application-defined menu items.
2455     * Deriving classes should always call through to the base implementation.
2456     *
2457     * <p>You can safely hold on to <var>menu</var> (and any items created
2458     * from it), making modifications to it as desired, until the next
2459     * time onCreateOptionsMenu() is called.
2460     *
2461     * <p>When you add items to the menu, you can implement the Activity's
2462     * {@link #onOptionsItemSelected} method to handle them there.
2463     *
2464     * @param menu The options menu in which you place your items.
2465     *
2466     * @return You must return true for the menu to be displayed;
2467     *         if you return false it will not be shown.
2468     *
2469     * @see #onPrepareOptionsMenu
2470     * @see #onOptionsItemSelected
2471     */
2472    public boolean onCreateOptionsMenu(Menu menu) {
2473        if (mParent != null) {
2474            return mParent.onCreateOptionsMenu(menu);
2475        }
2476        return true;
2477    }
2478
2479    /**
2480     * Prepare the Screen's standard options menu to be displayed.  This is
2481     * called right before the menu is shown, every time it is shown.  You can
2482     * use this method to efficiently enable/disable items or otherwise
2483     * dynamically modify the contents.
2484     *
2485     * <p>The default implementation updates the system menu items based on the
2486     * activity's state.  Deriving classes should always call through to the
2487     * base class implementation.
2488     *
2489     * @param menu The options menu as last shown or first initialized by
2490     *             onCreateOptionsMenu().
2491     *
2492     * @return You must return true for the menu to be displayed;
2493     *         if you return false it will not be shown.
2494     *
2495     * @see #onCreateOptionsMenu
2496     */
2497    public boolean onPrepareOptionsMenu(Menu menu) {
2498        if (mParent != null) {
2499            return mParent.onPrepareOptionsMenu(menu);
2500        }
2501        return true;
2502    }
2503
2504    /**
2505     * This hook is called whenever an item in your options menu is selected.
2506     * The default implementation simply returns false to have the normal
2507     * processing happen (calling the item's Runnable or sending a message to
2508     * its Handler as appropriate).  You can use this method for any items
2509     * for which you would like to do processing without those other
2510     * facilities.
2511     *
2512     * <p>Derived classes should call through to the base class for it to
2513     * perform the default menu handling.
2514     *
2515     * @param item The menu item that was selected.
2516     *
2517     * @return boolean Return false to allow normal menu processing to
2518     *         proceed, true to consume it here.
2519     *
2520     * @see #onCreateOptionsMenu
2521     */
2522    public boolean onOptionsItemSelected(MenuItem item) {
2523        if (mParent != null) {
2524            return mParent.onOptionsItemSelected(item);
2525        }
2526        return false;
2527    }
2528
2529    /**
2530     * This hook is called whenever the options menu is being closed (either by the user canceling
2531     * the menu with the back/menu button, or when an item is selected).
2532     *
2533     * @param menu The options menu as last shown or first initialized by
2534     *             onCreateOptionsMenu().
2535     */
2536    public void onOptionsMenuClosed(Menu menu) {
2537        if (mParent != null) {
2538            mParent.onOptionsMenuClosed(menu);
2539        }
2540    }
2541
2542    /**
2543     * Programmatically opens the options menu. If the options menu is already
2544     * open, this method does nothing.
2545     */
2546    public void openOptionsMenu() {
2547        mWindow.openPanel(Window.FEATURE_OPTIONS_PANEL, null);
2548    }
2549
2550    /**
2551     * Progammatically closes the options menu. If the options menu is already
2552     * closed, this method does nothing.
2553     */
2554    public void closeOptionsMenu() {
2555        mWindow.closePanel(Window.FEATURE_OPTIONS_PANEL);
2556    }
2557
2558    /**
2559     * Called when a context menu for the {@code view} is about to be shown.
2560     * Unlike {@link #onCreateOptionsMenu(Menu)}, this will be called every
2561     * time the context menu is about to be shown and should be populated for
2562     * the view (or item inside the view for {@link AdapterView} subclasses,
2563     * this can be found in the {@code menuInfo})).
2564     * <p>
2565     * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an
2566     * item has been selected.
2567     * <p>
2568     * It is not safe to hold onto the context menu after this method returns.
2569     * {@inheritDoc}
2570     */
2571    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
2572    }
2573
2574    /**
2575     * Registers a context menu to be shown for the given view (multiple views
2576     * can show the context menu). This method will set the
2577     * {@link OnCreateContextMenuListener} on the view to this activity, so
2578     * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be
2579     * called when it is time to show the context menu.
2580     *
2581     * @see #unregisterForContextMenu(View)
2582     * @param view The view that should show a context menu.
2583     */
2584    public void registerForContextMenu(View view) {
2585        view.setOnCreateContextMenuListener(this);
2586    }
2587
2588    /**
2589     * Prevents a context menu to be shown for the given view. This method will remove the
2590     * {@link OnCreateContextMenuListener} on the view.
2591     *
2592     * @see #registerForContextMenu(View)
2593     * @param view The view that should stop showing a context menu.
2594     */
2595    public void unregisterForContextMenu(View view) {
2596        view.setOnCreateContextMenuListener(null);
2597    }
2598
2599    /**
2600     * Programmatically opens the context menu for a particular {@code view}.
2601     * The {@code view} should have been added via
2602     * {@link #registerForContextMenu(View)}.
2603     *
2604     * @param view The view to show the context menu for.
2605     */
2606    public void openContextMenu(View view) {
2607        view.showContextMenu();
2608    }
2609
2610    /**
2611     * Programmatically closes the most recently opened context menu, if showing.
2612     */
2613    public void closeContextMenu() {
2614        mWindow.closePanel(Window.FEATURE_CONTEXT_MENU);
2615    }
2616
2617    /**
2618     * This hook is called whenever an item in a context menu is selected. The
2619     * default implementation simply returns false to have the normal processing
2620     * happen (calling the item's Runnable or sending a message to its Handler
2621     * as appropriate). You can use this method for any items for which you
2622     * would like to do processing without those other facilities.
2623     * <p>
2624     * Use {@link MenuItem#getMenuInfo()} to get extra information set by the
2625     * View that added this menu item.
2626     * <p>
2627     * Derived classes should call through to the base class for it to perform
2628     * the default menu handling.
2629     *
2630     * @param item The context menu item that was selected.
2631     * @return boolean Return false to allow normal context menu processing to
2632     *         proceed, true to consume it here.
2633     */
2634    public boolean onContextItemSelected(MenuItem item) {
2635        if (mParent != null) {
2636            return mParent.onContextItemSelected(item);
2637        }
2638        return false;
2639    }
2640
2641    /**
2642     * This hook is called whenever the context menu is being closed (either by
2643     * the user canceling the menu with the back/menu button, or when an item is
2644     * selected).
2645     *
2646     * @param menu The context menu that is being closed.
2647     */
2648    public void onContextMenuClosed(Menu menu) {
2649        if (mParent != null) {
2650            mParent.onContextMenuClosed(menu);
2651        }
2652    }
2653
2654    /**
2655     * @deprecated Old no-arguments version of {@link #onCreateDialog(int, Bundle)}.
2656     */
2657    @Deprecated
2658    protected Dialog onCreateDialog(int id) {
2659        return null;
2660    }
2661
2662    /**
2663     * Callback for creating dialogs that are managed (saved and restored) for you
2664     * by the activity.  The default implementation calls through to
2665     * {@link #onCreateDialog(int)} for compatibility.
2666     *
2667     * <p>If you use {@link #showDialog(int)}, the activity will call through to
2668     * this method the first time, and hang onto it thereafter.  Any dialog
2669     * that is created by this method will automatically be saved and restored
2670     * for you, including whether it is showing.
2671     *
2672     * <p>If you would like the activity to manage saving and restoring dialogs
2673     * for you, you should override this method and handle any ids that are
2674     * passed to {@link #showDialog}.
2675     *
2676     * <p>If you would like an opportunity to prepare your dialog before it is shown,
2677     * override {@link #onPrepareDialog(int, Dialog, Bundle)}.
2678     *
2679     * @param id The id of the dialog.
2680     * @param args The dialog arguments provided to {@link #showDialog(int, Bundle)}.
2681     * @return The dialog.  If you return null, the dialog will not be created.
2682     *
2683     * @see #onPrepareDialog(int, Dialog, Bundle)
2684     * @see #showDialog(int, Bundle)
2685     * @see #dismissDialog(int)
2686     * @see #removeDialog(int)
2687     */
2688    protected Dialog onCreateDialog(int id, Bundle args) {
2689        return onCreateDialog(id);
2690    }
2691
2692    /**
2693     * @deprecated Old no-arguments version of
2694     * {@link #onPrepareDialog(int, Dialog, Bundle)}.
2695     */
2696    @Deprecated
2697    protected void onPrepareDialog(int id, Dialog dialog) {
2698        dialog.setOwnerActivity(this);
2699    }
2700
2701    /**
2702     * Provides an opportunity to prepare a managed dialog before it is being
2703     * shown.  The default implementation calls through to
2704     * {@link #onPrepareDialog(int, Dialog)} for compatibility.
2705     *
2706     * <p>
2707     * Override this if you need to update a managed dialog based on the state
2708     * of the application each time it is shown. For example, a time picker
2709     * dialog might want to be updated with the current time. You should call
2710     * through to the superclass's implementation. The default implementation
2711     * will set this Activity as the owner activity on the Dialog.
2712     *
2713     * @param id The id of the managed dialog.
2714     * @param dialog The dialog.
2715     * @param args The dialog arguments provided to {@link #showDialog(int, Bundle)}.
2716     * @see #onCreateDialog(int, Bundle)
2717     * @see #showDialog(int)
2718     * @see #dismissDialog(int)
2719     * @see #removeDialog(int)
2720     */
2721    protected void onPrepareDialog(int id, Dialog dialog, Bundle args) {
2722        onPrepareDialog(id, dialog);
2723    }
2724
2725    /**
2726     * Simple version of {@link #showDialog(int, Bundle)} that does not
2727     * take any arguments.  Simply calls {@link #showDialog(int, Bundle)}
2728     * with null arguments.
2729     */
2730    public final void showDialog(int id) {
2731        showDialog(id, null);
2732    }
2733
2734    /**
2735     * Show a dialog managed by this activity.  A call to {@link #onCreateDialog(int, Bundle)}
2736     * will be made with the same id the first time this is called for a given
2737     * id.  From thereafter, the dialog will be automatically saved and restored.
2738     *
2739     * <p>Each time a dialog is shown, {@link #onPrepareDialog(int, Dialog, Bundle)} will
2740     * be made to provide an opportunity to do any timely preparation.
2741     *
2742     * @param id The id of the managed dialog.
2743     * @param args Arguments to pass through to the dialog.  These will be saved
2744     * and restored for you.  Note that if the dialog is already created,
2745     * {@link #onCreateDialog(int, Bundle)} will not be called with the new
2746     * arguments but {@link #onPrepareDialog(int, Dialog, Bundle)} will be.
2747     * If you need to rebuild the dialog, call {@link #removeDialog(int)} first.
2748     * @return Returns true if the Dialog was created; false is returned if
2749     * it is not created because {@link #onCreateDialog(int, Bundle)} returns false.
2750     *
2751     * @see Dialog
2752     * @see #onCreateDialog(int, Bundle)
2753     * @see #onPrepareDialog(int, Dialog, Bundle)
2754     * @see #dismissDialog(int)
2755     * @see #removeDialog(int)
2756     */
2757    public final boolean showDialog(int id, Bundle args) {
2758        if (mManagedDialogs == null) {
2759            mManagedDialogs = new SparseArray<ManagedDialog>();
2760        }
2761        ManagedDialog md = mManagedDialogs.get(id);
2762        if (md == null) {
2763            md = new ManagedDialog();
2764            md.mDialog = createDialog(id, null, args);
2765            if (md.mDialog == null) {
2766                return false;
2767            }
2768            mManagedDialogs.put(id, md);
2769        }
2770
2771        md.mArgs = args;
2772        onPrepareDialog(id, md.mDialog, args);
2773        md.mDialog.show();
2774        return true;
2775    }
2776
2777    /**
2778     * Dismiss a dialog that was previously shown via {@link #showDialog(int)}.
2779     *
2780     * @param id The id of the managed dialog.
2781     *
2782     * @throws IllegalArgumentException if the id was not previously shown via
2783     *   {@link #showDialog(int)}.
2784     *
2785     * @see #onCreateDialog(int, Bundle)
2786     * @see #onPrepareDialog(int, Dialog, Bundle)
2787     * @see #showDialog(int)
2788     * @see #removeDialog(int)
2789     */
2790    public final void dismissDialog(int id) {
2791        if (mManagedDialogs == null) {
2792            throw missingDialog(id);
2793        }
2794
2795        final ManagedDialog md = mManagedDialogs.get(id);
2796        if (md == null) {
2797            throw missingDialog(id);
2798        }
2799        md.mDialog.dismiss();
2800    }
2801
2802    /**
2803     * Creates an exception to throw if a user passed in a dialog id that is
2804     * unexpected.
2805     */
2806    private IllegalArgumentException missingDialog(int id) {
2807        return new IllegalArgumentException("no dialog with id " + id + " was ever "
2808                + "shown via Activity#showDialog");
2809    }
2810
2811    /**
2812     * Removes any internal references to a dialog managed by this Activity.
2813     * If the dialog is showing, it will dismiss it as part of the clean up.
2814     *
2815     * <p>This can be useful if you know that you will never show a dialog again and
2816     * want to avoid the overhead of saving and restoring it in the future.
2817     *
2818     * @param id The id of the managed dialog.
2819     *
2820     * @see #onCreateDialog(int, Bundle)
2821     * @see #onPrepareDialog(int, Dialog, Bundle)
2822     * @see #showDialog(int)
2823     * @see #dismissDialog(int)
2824     */
2825    public final void removeDialog(int id) {
2826        if (mManagedDialogs == null) {
2827            return;
2828        }
2829
2830        final ManagedDialog md = mManagedDialogs.get(id);
2831        if (md == null) {
2832            return;
2833        }
2834
2835        md.mDialog.dismiss();
2836        mManagedDialogs.remove(id);
2837    }
2838
2839    /**
2840     * This hook is called when the user signals the desire to start a search.
2841     *
2842     * <p>You can use this function as a simple way to launch the search UI, in response to a
2843     * menu item, search button, or other widgets within your activity. Unless overidden,
2844     * calling this function is the same as calling
2845     * {@link #startSearch startSearch(null, false, null, false)}, which launches
2846     * search for the current activity as specified in its manifest, see {@link SearchManager}.
2847     *
2848     * <p>You can override this function to force global search, e.g. in response to a dedicated
2849     * search key, or to block search entirely (by simply returning false).
2850     *
2851     * @return Returns {@code true} if search launched, and {@code false} if activity blocks it.
2852     *         The default implementation always returns {@code true}.
2853     *
2854     * @see android.app.SearchManager
2855     */
2856    public boolean onSearchRequested() {
2857        startSearch(null, false, null, false);
2858        return true;
2859    }
2860
2861    /**
2862     * This hook is called to launch the search UI.
2863     *
2864     * <p>It is typically called from onSearchRequested(), either directly from
2865     * Activity.onSearchRequested() or from an overridden version in any given
2866     * Activity.  If your goal is simply to activate search, it is preferred to call
2867     * onSearchRequested(), which may have been overriden elsewhere in your Activity.  If your goal
2868     * is to inject specific data such as context data, it is preferred to <i>override</i>
2869     * onSearchRequested(), so that any callers to it will benefit from the override.
2870     *
2871     * @param initialQuery Any non-null non-empty string will be inserted as
2872     * pre-entered text in the search query box.
2873     * @param selectInitialQuery If true, the intial query will be preselected, which means that
2874     * any further typing will replace it.  This is useful for cases where an entire pre-formed
2875     * query is being inserted.  If false, the selection point will be placed at the end of the
2876     * inserted query.  This is useful when the inserted query is text that the user entered,
2877     * and the user would expect to be able to keep typing.  <i>This parameter is only meaningful
2878     * if initialQuery is a non-empty string.</i>
2879     * @param appSearchData An application can insert application-specific
2880     * context here, in order to improve quality or specificity of its own
2881     * searches.  This data will be returned with SEARCH intent(s).  Null if
2882     * no extra data is required.
2883     * @param globalSearch If false, this will only launch the search that has been specifically
2884     * defined by the application (which is usually defined as a local search).  If no default
2885     * search is defined in the current application or activity, global search will be launched.
2886     * If true, this will always launch a platform-global (e.g. web-based) search instead.
2887     *
2888     * @see android.app.SearchManager
2889     * @see #onSearchRequested
2890     */
2891    public void startSearch(String initialQuery, boolean selectInitialQuery,
2892            Bundle appSearchData, boolean globalSearch) {
2893        ensureSearchManager();
2894        mSearchManager.startSearch(initialQuery, selectInitialQuery, getComponentName(),
2895                        appSearchData, globalSearch);
2896    }
2897
2898    /**
2899     * Similar to {@link #startSearch}, but actually fires off the search query after invoking
2900     * the search dialog.  Made available for testing purposes.
2901     *
2902     * @param query The query to trigger.  If empty, the request will be ignored.
2903     * @param appSearchData An application can insert application-specific
2904     * context here, in order to improve quality or specificity of its own
2905     * searches.  This data will be returned with SEARCH intent(s).  Null if
2906     * no extra data is required.
2907     */
2908    public void triggerSearch(String query, Bundle appSearchData) {
2909        ensureSearchManager();
2910        mSearchManager.triggerSearch(query, getComponentName(), appSearchData);
2911    }
2912
2913    /**
2914     * Request that key events come to this activity. Use this if your
2915     * activity has no views with focus, but the activity still wants
2916     * a chance to process key events.
2917     *
2918     * @see android.view.Window#takeKeyEvents
2919     */
2920    public void takeKeyEvents(boolean get) {
2921        getWindow().takeKeyEvents(get);
2922    }
2923
2924    /**
2925     * Enable extended window features.  This is a convenience for calling
2926     * {@link android.view.Window#requestFeature getWindow().requestFeature()}.
2927     *
2928     * @param featureId The desired feature as defined in
2929     *                  {@link android.view.Window}.
2930     * @return Returns true if the requested feature is supported and now
2931     *         enabled.
2932     *
2933     * @see android.view.Window#requestFeature
2934     */
2935    public final boolean requestWindowFeature(int featureId) {
2936        return getWindow().requestFeature(featureId);
2937    }
2938
2939    /**
2940     * Convenience for calling
2941     * {@link android.view.Window#setFeatureDrawableResource}.
2942     */
2943    public final void setFeatureDrawableResource(int featureId, int resId) {
2944        getWindow().setFeatureDrawableResource(featureId, resId);
2945    }
2946
2947    /**
2948     * Convenience for calling
2949     * {@link android.view.Window#setFeatureDrawableUri}.
2950     */
2951    public final void setFeatureDrawableUri(int featureId, Uri uri) {
2952        getWindow().setFeatureDrawableUri(featureId, uri);
2953    }
2954
2955    /**
2956     * Convenience for calling
2957     * {@link android.view.Window#setFeatureDrawable(int, Drawable)}.
2958     */
2959    public final void setFeatureDrawable(int featureId, Drawable drawable) {
2960        getWindow().setFeatureDrawable(featureId, drawable);
2961    }
2962
2963    /**
2964     * Convenience for calling
2965     * {@link android.view.Window#setFeatureDrawableAlpha}.
2966     */
2967    public final void setFeatureDrawableAlpha(int featureId, int alpha) {
2968        getWindow().setFeatureDrawableAlpha(featureId, alpha);
2969    }
2970
2971    /**
2972     * Convenience for calling
2973     * {@link android.view.Window#getLayoutInflater}.
2974     */
2975    public LayoutInflater getLayoutInflater() {
2976        return getWindow().getLayoutInflater();
2977    }
2978
2979    /**
2980     * Returns a {@link MenuInflater} with this context.
2981     */
2982    public MenuInflater getMenuInflater() {
2983        return new MenuInflater(this);
2984    }
2985
2986    @Override
2987    protected void onApplyThemeResource(Resources.Theme theme, int resid,
2988            boolean first) {
2989        if (mParent == null) {
2990            super.onApplyThemeResource(theme, resid, first);
2991        } else {
2992            try {
2993                theme.setTo(mParent.getTheme());
2994            } catch (Exception e) {
2995                // Empty
2996            }
2997            theme.applyStyle(resid, false);
2998        }
2999    }
3000
3001    /**
3002     * Launch an activity for which you would like a result when it finished.
3003     * When this activity exits, your
3004     * onActivityResult() method will be called with the given requestCode.
3005     * Using a negative requestCode is the same as calling
3006     * {@link #startActivity} (the activity is not launched as a sub-activity).
3007     *
3008     * <p>Note that this method should only be used with Intent protocols
3009     * that are defined to return a result.  In other protocols (such as
3010     * {@link Intent#ACTION_MAIN} or {@link Intent#ACTION_VIEW}), you may
3011     * not get the result when you expect.  For example, if the activity you
3012     * are launching uses the singleTask launch mode, it will not run in your
3013     * task and thus you will immediately receive a cancel result.
3014     *
3015     * <p>As a special case, if you call startActivityForResult() with a requestCode
3016     * >= 0 during the initial onCreate(Bundle savedInstanceState)/onResume() of your
3017     * activity, then your window will not be displayed until a result is
3018     * returned back from the started activity.  This is to avoid visible
3019     * flickering when redirecting to another activity.
3020     *
3021     * <p>This method throws {@link android.content.ActivityNotFoundException}
3022     * if there was no Activity found to run the given Intent.
3023     *
3024     * @param intent The intent to start.
3025     * @param requestCode If >= 0, this code will be returned in
3026     *                    onActivityResult() when the activity exits.
3027     *
3028     * @throws android.content.ActivityNotFoundException
3029     *
3030     * @see #startActivity
3031     */
3032    public void startActivityForResult(Intent intent, int requestCode) {
3033        if (mParent == null) {
3034            Instrumentation.ActivityResult ar =
3035                mInstrumentation.execStartActivity(
3036                    this, mMainThread.getApplicationThread(), mToken, this,
3037                    intent, requestCode);
3038            if (ar != null) {
3039                mMainThread.sendActivityResult(
3040                    mToken, mEmbeddedID, requestCode, ar.getResultCode(),
3041                    ar.getResultData());
3042            }
3043            if (requestCode >= 0) {
3044                // If this start is requesting a result, we can avoid making
3045                // the activity visible until the result is received.  Setting
3046                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
3047                // activity hidden during this time, to avoid flickering.
3048                // This can only be done when a result is requested because
3049                // that guarantees we will get information back when the
3050                // activity is finished, no matter what happens to it.
3051                mStartedActivity = true;
3052            }
3053        } else {
3054            mParent.startActivityFromChild(this, intent, requestCode);
3055        }
3056    }
3057
3058    /**
3059     * Like {@link #startActivityForResult(Intent, int)}, but allowing you
3060     * to use a IntentSender to describe the activity to be started.  If
3061     * the IntentSender is for an activity, that activity will be started
3062     * as if you had called the regular {@link #startActivityForResult(Intent, int)}
3063     * here; otherwise, its associated action will be executed (such as
3064     * sending a broadcast) as if you had called
3065     * {@link IntentSender#sendIntent IntentSender.sendIntent} on it.
3066     *
3067     * @param intent The IntentSender to launch.
3068     * @param requestCode If >= 0, this code will be returned in
3069     *                    onActivityResult() when the activity exits.
3070     * @param fillInIntent If non-null, this will be provided as the
3071     * intent parameter to {@link IntentSender#sendIntent}.
3072     * @param flagsMask Intent flags in the original IntentSender that you
3073     * would like to change.
3074     * @param flagsValues Desired values for any bits set in
3075     * <var>flagsMask</var>
3076     * @param extraFlags Always set to 0.
3077     */
3078    public void startIntentSenderForResult(IntentSender intent, int requestCode,
3079            Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags)
3080            throws IntentSender.SendIntentException {
3081        if (mParent == null) {
3082            startIntentSenderForResultInner(intent, requestCode, fillInIntent,
3083                    flagsMask, flagsValues, this);
3084        } else {
3085            mParent.startIntentSenderFromChild(this, intent, requestCode,
3086                    fillInIntent, flagsMask, flagsValues, extraFlags);
3087        }
3088    }
3089
3090    private void startIntentSenderForResultInner(IntentSender intent, int requestCode,
3091            Intent fillInIntent, int flagsMask, int flagsValues, Activity activity)
3092            throws IntentSender.SendIntentException {
3093        try {
3094            String resolvedType = null;
3095            if (fillInIntent != null) {
3096                resolvedType = fillInIntent.resolveTypeIfNeeded(getContentResolver());
3097            }
3098            int result = ActivityManagerNative.getDefault()
3099                .startActivityIntentSender(mMainThread.getApplicationThread(), intent,
3100                        fillInIntent, resolvedType, mToken, activity.mEmbeddedID,
3101                        requestCode, flagsMask, flagsValues);
3102            if (result == IActivityManager.START_CANCELED) {
3103                throw new IntentSender.SendIntentException();
3104            }
3105            Instrumentation.checkStartActivityResult(result, null);
3106        } catch (RemoteException e) {
3107        }
3108        if (requestCode >= 0) {
3109            // If this start is requesting a result, we can avoid making
3110            // the activity visible until the result is received.  Setting
3111            // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
3112            // activity hidden during this time, to avoid flickering.
3113            // This can only be done when a result is requested because
3114            // that guarantees we will get information back when the
3115            // activity is finished, no matter what happens to it.
3116            mStartedActivity = true;
3117        }
3118    }
3119
3120    /**
3121     * Launch a new activity.  You will not receive any information about when
3122     * the activity exits.  This implementation overrides the base version,
3123     * providing information about
3124     * the activity performing the launch.  Because of this additional
3125     * information, the {@link Intent#FLAG_ACTIVITY_NEW_TASK} launch flag is not
3126     * required; if not specified, the new activity will be added to the
3127     * task of the caller.
3128     *
3129     * <p>This method throws {@link android.content.ActivityNotFoundException}
3130     * if there was no Activity found to run the given Intent.
3131     *
3132     * @param intent The intent to start.
3133     *
3134     * @throws android.content.ActivityNotFoundException
3135     *
3136     * @see #startActivityForResult
3137     */
3138    @Override
3139    public void startActivity(Intent intent) {
3140        startActivityForResult(intent, -1);
3141    }
3142
3143    /**
3144     * Like {@link #startActivity(Intent)}, but taking a IntentSender
3145     * to start; see
3146     * {@link #startIntentSenderForResult(IntentSender, int, Intent, int, int, int)}
3147     * for more information.
3148     *
3149     * @param intent The IntentSender to launch.
3150     * @param fillInIntent If non-null, this will be provided as the
3151     * intent parameter to {@link IntentSender#sendIntent}.
3152     * @param flagsMask Intent flags in the original IntentSender that you
3153     * would like to change.
3154     * @param flagsValues Desired values for any bits set in
3155     * <var>flagsMask</var>
3156     * @param extraFlags Always set to 0.
3157     */
3158    public void startIntentSender(IntentSender intent,
3159            Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags)
3160            throws IntentSender.SendIntentException {
3161        startIntentSenderForResult(intent, -1, fillInIntent, flagsMask,
3162                flagsValues, extraFlags);
3163    }
3164
3165    /**
3166     * A special variation to launch an activity only if a new activity
3167     * instance is needed to handle the given Intent.  In other words, this is
3168     * just like {@link #startActivityForResult(Intent, int)} except: if you are
3169     * using the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP} flag, or
3170     * singleTask or singleTop
3171     * {@link android.R.styleable#AndroidManifestActivity_launchMode launchMode},
3172     * and the activity
3173     * that handles <var>intent</var> is the same as your currently running
3174     * activity, then a new instance is not needed.  In this case, instead of
3175     * the normal behavior of calling {@link #onNewIntent} this function will
3176     * return and you can handle the Intent yourself.
3177     *
3178     * <p>This function can only be called from a top-level activity; if it is
3179     * called from a child activity, a runtime exception will be thrown.
3180     *
3181     * @param intent The intent to start.
3182     * @param requestCode If >= 0, this code will be returned in
3183     *         onActivityResult() when the activity exits, as described in
3184     *         {@link #startActivityForResult}.
3185     *
3186     * @return If a new activity was launched then true is returned; otherwise
3187     *         false is returned and you must handle the Intent yourself.
3188     *
3189     * @see #startActivity
3190     * @see #startActivityForResult
3191     */
3192    public boolean startActivityIfNeeded(Intent intent, int requestCode) {
3193        if (mParent == null) {
3194            int result = IActivityManager.START_RETURN_INTENT_TO_CALLER;
3195            try {
3196                result = ActivityManagerNative.getDefault()
3197                    .startActivity(mMainThread.getApplicationThread(),
3198                            intent, intent.resolveTypeIfNeeded(
3199                                    getContentResolver()),
3200                            null, 0,
3201                            mToken, mEmbeddedID, requestCode, true, false);
3202            } catch (RemoteException e) {
3203                // Empty
3204            }
3205
3206            Instrumentation.checkStartActivityResult(result, intent);
3207
3208            if (requestCode >= 0) {
3209                // If this start is requesting a result, we can avoid making
3210                // the activity visible until the result is received.  Setting
3211                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
3212                // activity hidden during this time, to avoid flickering.
3213                // This can only be done when a result is requested because
3214                // that guarantees we will get information back when the
3215                // activity is finished, no matter what happens to it.
3216                mStartedActivity = true;
3217            }
3218            return result != IActivityManager.START_RETURN_INTENT_TO_CALLER;
3219        }
3220
3221        throw new UnsupportedOperationException(
3222            "startActivityIfNeeded can only be called from a top-level activity");
3223    }
3224
3225    /**
3226     * Special version of starting an activity, for use when you are replacing
3227     * other activity components.  You can use this to hand the Intent off
3228     * to the next Activity that can handle it.  You typically call this in
3229     * {@link #onCreate} with the Intent returned by {@link #getIntent}.
3230     *
3231     * @param intent The intent to dispatch to the next activity.  For
3232     * correct behavior, this must be the same as the Intent that started
3233     * your own activity; the only changes you can make are to the extras
3234     * inside of it.
3235     *
3236     * @return Returns a boolean indicating whether there was another Activity
3237     * to start: true if there was a next activity to start, false if there
3238     * wasn't.  In general, if true is returned you will then want to call
3239     * finish() on yourself.
3240     */
3241    public boolean startNextMatchingActivity(Intent intent) {
3242        if (mParent == null) {
3243            try {
3244                return ActivityManagerNative.getDefault()
3245                    .startNextMatchingActivity(mToken, intent);
3246            } catch (RemoteException e) {
3247                // Empty
3248            }
3249            return false;
3250        }
3251
3252        throw new UnsupportedOperationException(
3253            "startNextMatchingActivity can only be called from a top-level activity");
3254    }
3255
3256    /**
3257     * This is called when a child activity of this one calls its
3258     * {@link #startActivity} or {@link #startActivityForResult} method.
3259     *
3260     * <p>This method throws {@link android.content.ActivityNotFoundException}
3261     * if there was no Activity found to run the given Intent.
3262     *
3263     * @param child The activity making the call.
3264     * @param intent The intent to start.
3265     * @param requestCode Reply request code.  < 0 if reply is not requested.
3266     *
3267     * @throws android.content.ActivityNotFoundException
3268     *
3269     * @see #startActivity
3270     * @see #startActivityForResult
3271     */
3272    public void startActivityFromChild(Activity child, Intent intent,
3273            int requestCode) {
3274        Instrumentation.ActivityResult ar =
3275            mInstrumentation.execStartActivity(
3276                this, mMainThread.getApplicationThread(), mToken, child,
3277                intent, requestCode);
3278        if (ar != null) {
3279            mMainThread.sendActivityResult(
3280                mToken, child.mEmbeddedID, requestCode,
3281                ar.getResultCode(), ar.getResultData());
3282        }
3283    }
3284
3285    /**
3286     * This is called when a Fragment in this activity calls its
3287     * {@link Fragment#startActivity} or {@link Fragment#startActivityForResult}
3288     * method.
3289     *
3290     * <p>This method throws {@link android.content.ActivityNotFoundException}
3291     * if there was no Activity found to run the given Intent.
3292     *
3293     * @param fragment The fragment making the call.
3294     * @param intent The intent to start.
3295     * @param requestCode Reply request code.  < 0 if reply is not requested.
3296     *
3297     * @throws android.content.ActivityNotFoundException
3298     *
3299     * @see Fragment#startActivity
3300     * @see Fragment#startActivityForResult
3301     */
3302    public void startActivityFromFragment(Fragment fragment, Intent intent,
3303            int requestCode) {
3304        Instrumentation.ActivityResult ar =
3305            mInstrumentation.execStartActivity(
3306                this, mMainThread.getApplicationThread(), mToken, fragment,
3307                intent, requestCode);
3308        if (ar != null) {
3309            mMainThread.sendActivityResult(
3310                mToken, fragment.mWho, requestCode,
3311                ar.getResultCode(), ar.getResultData());
3312        }
3313    }
3314
3315    /**
3316     * Like {@link #startActivityFromChild(Activity, Intent, int)}, but
3317     * taking a IntentSender; see
3318     * {@link #startIntentSenderForResult(IntentSender, int, Intent, int, int, int)}
3319     * for more information.
3320     */
3321    public void startIntentSenderFromChild(Activity child, IntentSender intent,
3322            int requestCode, Intent fillInIntent, int flagsMask, int flagsValues,
3323            int extraFlags)
3324            throws IntentSender.SendIntentException {
3325        startIntentSenderForResultInner(intent, requestCode, fillInIntent,
3326                flagsMask, flagsValues, child);
3327    }
3328
3329    /**
3330     * Call immediately after one of the flavors of {@link #startActivity(Intent)}
3331     * or {@link #finish} to specify an explicit transition animation to
3332     * perform next.
3333     * @param enterAnim A resource ID of the animation resource to use for
3334     * the incoming activity.  Use 0 for no animation.
3335     * @param exitAnim A resource ID of the animation resource to use for
3336     * the outgoing activity.  Use 0 for no animation.
3337     */
3338    public void overridePendingTransition(int enterAnim, int exitAnim) {
3339        try {
3340            ActivityManagerNative.getDefault().overridePendingTransition(
3341                    mToken, getPackageName(), enterAnim, exitAnim);
3342        } catch (RemoteException e) {
3343        }
3344    }
3345
3346    /**
3347     * Call this to set the result that your activity will return to its
3348     * caller.
3349     *
3350     * @param resultCode The result code to propagate back to the originating
3351     *                   activity, often RESULT_CANCELED or RESULT_OK
3352     *
3353     * @see #RESULT_CANCELED
3354     * @see #RESULT_OK
3355     * @see #RESULT_FIRST_USER
3356     * @see #setResult(int, Intent)
3357     */
3358    public final void setResult(int resultCode) {
3359        synchronized (this) {
3360            mResultCode = resultCode;
3361            mResultData = null;
3362        }
3363    }
3364
3365    /**
3366     * Call this to set the result that your activity will return to its
3367     * caller.
3368     *
3369     * @param resultCode The result code to propagate back to the originating
3370     *                   activity, often RESULT_CANCELED or RESULT_OK
3371     * @param data The data to propagate back to the originating activity.
3372     *
3373     * @see #RESULT_CANCELED
3374     * @see #RESULT_OK
3375     * @see #RESULT_FIRST_USER
3376     * @see #setResult(int)
3377     */
3378    public final void setResult(int resultCode, Intent data) {
3379        synchronized (this) {
3380            mResultCode = resultCode;
3381            mResultData = data;
3382        }
3383    }
3384
3385    /**
3386     * Return the name of the package that invoked this activity.  This is who
3387     * the data in {@link #setResult setResult()} will be sent to.  You can
3388     * use this information to validate that the recipient is allowed to
3389     * receive the data.
3390     *
3391     * <p>Note: if the calling activity is not expecting a result (that is it
3392     * did not use the {@link #startActivityForResult}
3393     * form that includes a request code), then the calling package will be
3394     * null.
3395     *
3396     * @return The package of the activity that will receive your
3397     *         reply, or null if none.
3398     */
3399    public String getCallingPackage() {
3400        try {
3401            return ActivityManagerNative.getDefault().getCallingPackage(mToken);
3402        } catch (RemoteException e) {
3403            return null;
3404        }
3405    }
3406
3407    /**
3408     * Return the name of the activity that invoked this activity.  This is
3409     * who the data in {@link #setResult setResult()} will be sent to.  You
3410     * can use this information to validate that the recipient is allowed to
3411     * receive the data.
3412     *
3413     * <p>Note: if the calling activity is not expecting a result (that is it
3414     * did not use the {@link #startActivityForResult}
3415     * form that includes a request code), then the calling package will be
3416     * null.
3417     *
3418     * @return String The full name of the activity that will receive your
3419     *         reply, or null if none.
3420     */
3421    public ComponentName getCallingActivity() {
3422        try {
3423            return ActivityManagerNative.getDefault().getCallingActivity(mToken);
3424        } catch (RemoteException e) {
3425            return null;
3426        }
3427    }
3428
3429    /**
3430     * Control whether this activity's main window is visible.  This is intended
3431     * only for the special case of an activity that is not going to show a
3432     * UI itself, but can't just finish prior to onResume() because it needs
3433     * to wait for a service binding or such.  Setting this to false allows
3434     * you to prevent your UI from being shown during that time.
3435     *
3436     * <p>The default value for this is taken from the
3437     * {@link android.R.attr#windowNoDisplay} attribute of the activity's theme.
3438     */
3439    public void setVisible(boolean visible) {
3440        if (mVisibleFromClient != visible) {
3441            mVisibleFromClient = visible;
3442            if (mVisibleFromServer) {
3443                if (visible) makeVisible();
3444                else mDecor.setVisibility(View.INVISIBLE);
3445            }
3446        }
3447    }
3448
3449    void makeVisible() {
3450        if (!mWindowAdded) {
3451            ViewManager wm = getWindowManager();
3452            wm.addView(mDecor, getWindow().getAttributes());
3453            mWindowAdded = true;
3454        }
3455        mDecor.setVisibility(View.VISIBLE);
3456    }
3457
3458    /**
3459     * Check to see whether this activity is in the process of finishing,
3460     * either because you called {@link #finish} on it or someone else
3461     * has requested that it finished.  This is often used in
3462     * {@link #onPause} to determine whether the activity is simply pausing or
3463     * completely finishing.
3464     *
3465     * @return If the activity is finishing, returns true; else returns false.
3466     *
3467     * @see #finish
3468     */
3469    public boolean isFinishing() {
3470        return mFinished;
3471    }
3472
3473    /**
3474     * Check to see whether this activity is in the process of being destroyed in order to be
3475     * recreated with a new configuration. This is often used in
3476     * {@link #onStop} to determine whether the state needs to be cleaned up or will be passed
3477     * on to the next instance of the activity via {@link #onRetainNonConfigurationInstance()}.
3478     *
3479     * @return If the activity is being torn down in order to be recreated with a new configuration,
3480     * returns true; else returns false.
3481     */
3482    public boolean isChangingConfigurations() {
3483        return mChangingConfigurations;
3484    }
3485
3486    /**
3487     * Call this when your activity is done and should be closed.  The
3488     * ActivityResult is propagated back to whoever launched you via
3489     * onActivityResult().
3490     */
3491    public void finish() {
3492        if (mParent == null) {
3493            int resultCode;
3494            Intent resultData;
3495            synchronized (this) {
3496                resultCode = mResultCode;
3497                resultData = mResultData;
3498            }
3499            if (Config.LOGV) Log.v(TAG, "Finishing self: token=" + mToken);
3500            try {
3501                if (ActivityManagerNative.getDefault()
3502                    .finishActivity(mToken, resultCode, resultData)) {
3503                    mFinished = true;
3504                }
3505            } catch (RemoteException e) {
3506                // Empty
3507            }
3508        } else {
3509            mParent.finishFromChild(this);
3510        }
3511    }
3512
3513    /**
3514     * This is called when a child activity of this one calls its
3515     * {@link #finish} method.  The default implementation simply calls
3516     * finish() on this activity (the parent), finishing the entire group.
3517     *
3518     * @param child The activity making the call.
3519     *
3520     * @see #finish
3521     */
3522    public void finishFromChild(Activity child) {
3523        finish();
3524    }
3525
3526    /**
3527     * Force finish another activity that you had previously started with
3528     * {@link #startActivityForResult}.
3529     *
3530     * @param requestCode The request code of the activity that you had
3531     *                    given to startActivityForResult().  If there are multiple
3532     *                    activities started with this request code, they
3533     *                    will all be finished.
3534     */
3535    public void finishActivity(int requestCode) {
3536        if (mParent == null) {
3537            try {
3538                ActivityManagerNative.getDefault()
3539                    .finishSubActivity(mToken, mEmbeddedID, requestCode);
3540            } catch (RemoteException e) {
3541                // Empty
3542            }
3543        } else {
3544            mParent.finishActivityFromChild(this, requestCode);
3545        }
3546    }
3547
3548    /**
3549     * This is called when a child activity of this one calls its
3550     * finishActivity().
3551     *
3552     * @param child The activity making the call.
3553     * @param requestCode Request code that had been used to start the
3554     *                    activity.
3555     */
3556    public void finishActivityFromChild(Activity child, int requestCode) {
3557        try {
3558            ActivityManagerNative.getDefault()
3559                .finishSubActivity(mToken, child.mEmbeddedID, requestCode);
3560        } catch (RemoteException e) {
3561            // Empty
3562        }
3563    }
3564
3565    /**
3566     * Called when an activity you launched exits, giving you the requestCode
3567     * you started it with, the resultCode it returned, and any additional
3568     * data from it.  The <var>resultCode</var> will be
3569     * {@link #RESULT_CANCELED} if the activity explicitly returned that,
3570     * didn't return any result, or crashed during its operation.
3571     *
3572     * <p>You will receive this call immediately before onResume() when your
3573     * activity is re-starting.
3574     *
3575     * @param requestCode The integer request code originally supplied to
3576     *                    startActivityForResult(), allowing you to identify who this
3577     *                    result came from.
3578     * @param resultCode The integer result code returned by the child activity
3579     *                   through its setResult().
3580     * @param data An Intent, which can return result data to the caller
3581     *               (various data can be attached to Intent "extras").
3582     *
3583     * @see #startActivityForResult
3584     * @see #createPendingResult
3585     * @see #setResult(int)
3586     */
3587    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
3588    }
3589
3590    /**
3591     * Create a new PendingIntent object which you can hand to others
3592     * for them to use to send result data back to your
3593     * {@link #onActivityResult} callback.  The created object will be either
3594     * one-shot (becoming invalid after a result is sent back) or multiple
3595     * (allowing any number of results to be sent through it).
3596     *
3597     * @param requestCode Private request code for the sender that will be
3598     * associated with the result data when it is returned.  The sender can not
3599     * modify this value, allowing you to identify incoming results.
3600     * @param data Default data to supply in the result, which may be modified
3601     * by the sender.
3602     * @param flags May be {@link PendingIntent#FLAG_ONE_SHOT PendingIntent.FLAG_ONE_SHOT},
3603     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE},
3604     * {@link PendingIntent#FLAG_CANCEL_CURRENT PendingIntent.FLAG_CANCEL_CURRENT},
3605     * {@link PendingIntent#FLAG_UPDATE_CURRENT PendingIntent.FLAG_UPDATE_CURRENT},
3606     * or any of the flags as supported by
3607     * {@link Intent#fillIn Intent.fillIn()} to control which unspecified parts
3608     * of the intent that can be supplied when the actual send happens.
3609     *
3610     * @return Returns an existing or new PendingIntent matching the given
3611     * parameters.  May return null only if
3612     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE} has been
3613     * supplied.
3614     *
3615     * @see PendingIntent
3616     */
3617    public PendingIntent createPendingResult(int requestCode, Intent data,
3618            int flags) {
3619        String packageName = getPackageName();
3620        try {
3621            IIntentSender target =
3622                ActivityManagerNative.getDefault().getIntentSender(
3623                        IActivityManager.INTENT_SENDER_ACTIVITY_RESULT, packageName,
3624                        mParent == null ? mToken : mParent.mToken,
3625                        mEmbeddedID, requestCode, data, null, flags);
3626            return target != null ? new PendingIntent(target) : null;
3627        } catch (RemoteException e) {
3628            // Empty
3629        }
3630        return null;
3631    }
3632
3633    /**
3634     * Change the desired orientation of this activity.  If the activity
3635     * is currently in the foreground or otherwise impacting the screen
3636     * orientation, the screen will immediately be changed (possibly causing
3637     * the activity to be restarted). Otherwise, this will be used the next
3638     * time the activity is visible.
3639     *
3640     * @param requestedOrientation An orientation constant as used in
3641     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3642     */
3643    public void setRequestedOrientation(int requestedOrientation) {
3644        if (mParent == null) {
3645            try {
3646                ActivityManagerNative.getDefault().setRequestedOrientation(
3647                        mToken, requestedOrientation);
3648            } catch (RemoteException e) {
3649                // Empty
3650            }
3651        } else {
3652            mParent.setRequestedOrientation(requestedOrientation);
3653        }
3654    }
3655
3656    /**
3657     * Return the current requested orientation of the activity.  This will
3658     * either be the orientation requested in its component's manifest, or
3659     * the last requested orientation given to
3660     * {@link #setRequestedOrientation(int)}.
3661     *
3662     * @return Returns an orientation constant as used in
3663     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3664     */
3665    public int getRequestedOrientation() {
3666        if (mParent == null) {
3667            try {
3668                return ActivityManagerNative.getDefault()
3669                        .getRequestedOrientation(mToken);
3670            } catch (RemoteException e) {
3671                // Empty
3672            }
3673        } else {
3674            return mParent.getRequestedOrientation();
3675        }
3676        return ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
3677    }
3678
3679    /**
3680     * Return the identifier of the task this activity is in.  This identifier
3681     * will remain the same for the lifetime of the activity.
3682     *
3683     * @return Task identifier, an opaque integer.
3684     */
3685    public int getTaskId() {
3686        try {
3687            return ActivityManagerNative.getDefault()
3688                .getTaskForActivity(mToken, false);
3689        } catch (RemoteException e) {
3690            return -1;
3691        }
3692    }
3693
3694    /**
3695     * Return whether this activity is the root of a task.  The root is the
3696     * first activity in a task.
3697     *
3698     * @return True if this is the root activity, else false.
3699     */
3700    public boolean isTaskRoot() {
3701        try {
3702            return ActivityManagerNative.getDefault()
3703                .getTaskForActivity(mToken, true) >= 0;
3704        } catch (RemoteException e) {
3705            return false;
3706        }
3707    }
3708
3709    /**
3710     * Move the task containing this activity to the back of the activity
3711     * stack.  The activity's order within the task is unchanged.
3712     *
3713     * @param nonRoot If false then this only works if the activity is the root
3714     *                of a task; if true it will work for any activity in
3715     *                a task.
3716     *
3717     * @return If the task was moved (or it was already at the
3718     *         back) true is returned, else false.
3719     */
3720    public boolean moveTaskToBack(boolean nonRoot) {
3721        try {
3722            return ActivityManagerNative.getDefault().moveActivityTaskToBack(
3723                    mToken, nonRoot);
3724        } catch (RemoteException e) {
3725            // Empty
3726        }
3727        return false;
3728    }
3729
3730    /**
3731     * Returns class name for this activity with the package prefix removed.
3732     * This is the default name used to read and write settings.
3733     *
3734     * @return The local class name.
3735     */
3736    public String getLocalClassName() {
3737        final String pkg = getPackageName();
3738        final String cls = mComponent.getClassName();
3739        int packageLen = pkg.length();
3740        if (!cls.startsWith(pkg) || cls.length() <= packageLen
3741                || cls.charAt(packageLen) != '.') {
3742            return cls;
3743        }
3744        return cls.substring(packageLen+1);
3745    }
3746
3747    /**
3748     * Returns complete component name of this activity.
3749     *
3750     * @return Returns the complete component name for this activity
3751     */
3752    public ComponentName getComponentName()
3753    {
3754        return mComponent;
3755    }
3756
3757    /**
3758     * Retrieve a {@link SharedPreferences} object for accessing preferences
3759     * that are private to this activity.  This simply calls the underlying
3760     * {@link #getSharedPreferences(String, int)} method by passing in this activity's
3761     * class name as the preferences name.
3762     *
3763     * @param mode Operating mode.  Use {@link #MODE_PRIVATE} for the default
3764     *             operation, {@link #MODE_WORLD_READABLE} and
3765     *             {@link #MODE_WORLD_WRITEABLE} to control permissions.
3766     *
3767     * @return Returns the single SharedPreferences instance that can be used
3768     *         to retrieve and modify the preference values.
3769     */
3770    public SharedPreferences getPreferences(int mode) {
3771        return getSharedPreferences(getLocalClassName(), mode);
3772    }
3773
3774    private void ensureSearchManager() {
3775        if (mSearchManager != null) {
3776            return;
3777        }
3778
3779        mSearchManager = new SearchManager(this, null);
3780    }
3781
3782    @Override
3783    public Object getSystemService(String name) {
3784        if (getBaseContext() == null) {
3785            throw new IllegalStateException(
3786                    "System services not available to Activities before onCreate()");
3787        }
3788
3789        if (WINDOW_SERVICE.equals(name)) {
3790            return mWindowManager;
3791        } else if (SEARCH_SERVICE.equals(name)) {
3792            ensureSearchManager();
3793            return mSearchManager;
3794        }
3795        return super.getSystemService(name);
3796    }
3797
3798    /**
3799     * Change the title associated with this activity.  If this is a
3800     * top-level activity, the title for its window will change.  If it
3801     * is an embedded activity, the parent can do whatever it wants
3802     * with it.
3803     */
3804    public void setTitle(CharSequence title) {
3805        mTitle = title;
3806        onTitleChanged(title, mTitleColor);
3807
3808        if (mParent != null) {
3809            mParent.onChildTitleChanged(this, title);
3810        }
3811    }
3812
3813    /**
3814     * Change the title associated with this activity.  If this is a
3815     * top-level activity, the title for its window will change.  If it
3816     * is an embedded activity, the parent can do whatever it wants
3817     * with it.
3818     */
3819    public void setTitle(int titleId) {
3820        setTitle(getText(titleId));
3821    }
3822
3823    public void setTitleColor(int textColor) {
3824        mTitleColor = textColor;
3825        onTitleChanged(mTitle, textColor);
3826    }
3827
3828    public final CharSequence getTitle() {
3829        return mTitle;
3830    }
3831
3832    public final int getTitleColor() {
3833        return mTitleColor;
3834    }
3835
3836    protected void onTitleChanged(CharSequence title, int color) {
3837        if (mTitleReady) {
3838            final Window win = getWindow();
3839            if (win != null) {
3840                win.setTitle(title);
3841                if (color != 0) {
3842                    win.setTitleColor(color);
3843                }
3844            }
3845        }
3846    }
3847
3848    protected void onChildTitleChanged(Activity childActivity, CharSequence title) {
3849    }
3850
3851    /**
3852     * Sets the visibility of the progress bar in the title.
3853     * <p>
3854     * In order for the progress bar to be shown, the feature must be requested
3855     * via {@link #requestWindowFeature(int)}.
3856     *
3857     * @param visible Whether to show the progress bars in the title.
3858     */
3859    public final void setProgressBarVisibility(boolean visible) {
3860        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, visible ? Window.PROGRESS_VISIBILITY_ON :
3861            Window.PROGRESS_VISIBILITY_OFF);
3862    }
3863
3864    /**
3865     * Sets the visibility of the indeterminate progress bar in the title.
3866     * <p>
3867     * In order for the progress bar to be shown, the feature must be requested
3868     * via {@link #requestWindowFeature(int)}.
3869     *
3870     * @param visible Whether to show the progress bars in the title.
3871     */
3872    public final void setProgressBarIndeterminateVisibility(boolean visible) {
3873        getWindow().setFeatureInt(Window.FEATURE_INDETERMINATE_PROGRESS,
3874                visible ? Window.PROGRESS_VISIBILITY_ON : Window.PROGRESS_VISIBILITY_OFF);
3875    }
3876
3877    /**
3878     * Sets whether the horizontal progress bar in the title should be indeterminate (the circular
3879     * is always indeterminate).
3880     * <p>
3881     * In order for the progress bar to be shown, the feature must be requested
3882     * via {@link #requestWindowFeature(int)}.
3883     *
3884     * @param indeterminate Whether the horizontal progress bar should be indeterminate.
3885     */
3886    public final void setProgressBarIndeterminate(boolean indeterminate) {
3887        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3888                indeterminate ? Window.PROGRESS_INDETERMINATE_ON : Window.PROGRESS_INDETERMINATE_OFF);
3889    }
3890
3891    /**
3892     * Sets the progress for the progress bars in the title.
3893     * <p>
3894     * In order for the progress bar to be shown, the feature must be requested
3895     * via {@link #requestWindowFeature(int)}.
3896     *
3897     * @param progress The progress for the progress bar. Valid ranges are from
3898     *            0 to 10000 (both inclusive). If 10000 is given, the progress
3899     *            bar will be completely filled and will fade out.
3900     */
3901    public final void setProgress(int progress) {
3902        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, progress + Window.PROGRESS_START);
3903    }
3904
3905    /**
3906     * Sets the secondary progress for the progress bar in the title. This
3907     * progress is drawn between the primary progress (set via
3908     * {@link #setProgress(int)} and the background. It can be ideal for media
3909     * scenarios such as showing the buffering progress while the default
3910     * progress shows the play progress.
3911     * <p>
3912     * In order for the progress bar to be shown, the feature must be requested
3913     * via {@link #requestWindowFeature(int)}.
3914     *
3915     * @param secondaryProgress The secondary progress for the progress bar. Valid ranges are from
3916     *            0 to 10000 (both inclusive).
3917     */
3918    public final void setSecondaryProgress(int secondaryProgress) {
3919        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3920                secondaryProgress + Window.PROGRESS_SECONDARY_START);
3921    }
3922
3923    /**
3924     * Suggests an audio stream whose volume should be changed by the hardware
3925     * volume controls.
3926     * <p>
3927     * The suggested audio stream will be tied to the window of this Activity.
3928     * If the Activity is switched, the stream set here is no longer the
3929     * suggested stream. The client does not need to save and restore the old
3930     * suggested stream value in onPause and onResume.
3931     *
3932     * @param streamType The type of the audio stream whose volume should be
3933     *        changed by the hardware volume controls. It is not guaranteed that
3934     *        the hardware volume controls will always change this stream's
3935     *        volume (for example, if a call is in progress, its stream's volume
3936     *        may be changed instead). To reset back to the default, use
3937     *        {@link AudioManager#USE_DEFAULT_STREAM_TYPE}.
3938     */
3939    public final void setVolumeControlStream(int streamType) {
3940        getWindow().setVolumeControlStream(streamType);
3941    }
3942
3943    /**
3944     * Gets the suggested audio stream whose volume should be changed by the
3945     * harwdare volume controls.
3946     *
3947     * @return The suggested audio stream type whose volume should be changed by
3948     *         the hardware volume controls.
3949     * @see #setVolumeControlStream(int)
3950     */
3951    public final int getVolumeControlStream() {
3952        return getWindow().getVolumeControlStream();
3953    }
3954
3955    /**
3956     * Runs the specified action on the UI thread. If the current thread is the UI
3957     * thread, then the action is executed immediately. If the current thread is
3958     * not the UI thread, the action is posted to the event queue of the UI thread.
3959     *
3960     * @param action the action to run on the UI thread
3961     */
3962    public final void runOnUiThread(Runnable action) {
3963        if (Thread.currentThread() != mUiThread) {
3964            mHandler.post(action);
3965        } else {
3966            action.run();
3967        }
3968    }
3969
3970    /**
3971     * Standard implementation of
3972     * {@link android.view.LayoutInflater.Factory#onCreateView} used when
3973     * inflating with the LayoutInflater returned by {@link #getSystemService}.
3974     * This implementation handles <fragment> tags to embed fragments inside
3975     * of the activity.
3976     *
3977     * @see android.view.LayoutInflater#createView
3978     * @see android.view.Window#getLayoutInflater
3979     */
3980    public View onCreateView(String name, Context context, AttributeSet attrs) {
3981        if (!"fragment".equals(name)) {
3982            return null;
3983        }
3984
3985        TypedArray a =
3986            context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.Fragment);
3987        String fname = a.getString(com.android.internal.R.styleable.Fragment_name);
3988        int id = a.getResourceId(com.android.internal.R.styleable.Fragment_id, 0);
3989        String tag = a.getString(com.android.internal.R.styleable.Fragment_tag);
3990        a.recycle();
3991
3992        if (id == 0) {
3993            throw new IllegalArgumentException(attrs.getPositionDescription()
3994                    + ": Must specify unique android:id for " + fname);
3995        }
3996
3997        try {
3998            // If we restored from a previous state, we may already have
3999            // instantiated this fragment from the state and should use
4000            // that instance instead of making a new one.
4001            Fragment fragment = mFragments.findFragmentById(id);
4002            if (FragmentManager.DEBUG) Log.v(TAG, "onCreateView: id=0x"
4003                    + Integer.toHexString(id) + " fname=" + fname
4004                    + " existing=" + fragment);
4005            if (fragment == null) {
4006                fragment = Fragment.instantiate(this, fname);
4007                fragment.mFromLayout = true;
4008                fragment.mFragmentId = id;
4009                fragment.mTag = tag;
4010                fragment.mImmediateActivity = this;
4011                mFragments.addFragment(fragment, true);
4012            }
4013            // If this fragment is newly instantiated (either right now, or
4014            // from last saved state), then give it the attributes to
4015            // initialize itself.
4016            if (!fragment.mRetaining) {
4017                fragment.onInflate(this, attrs, fragment.mSavedFragmentState);
4018            }
4019            if (fragment.mView == null) {
4020                throw new IllegalStateException("Fragment " + fname
4021                        + " did not create a view.");
4022            }
4023            fragment.mView.setId(id);
4024            if (fragment.mView.getTag() == null) {
4025                fragment.mView.setTag(tag);
4026            }
4027            return fragment.mView;
4028        } catch (Exception e) {
4029            InflateException ie = new InflateException(attrs.getPositionDescription()
4030                    + ": Error inflating fragment " + fname);
4031            ie.initCause(e);
4032            throw ie;
4033        }
4034    }
4035
4036    /**
4037     * Bit indicating that this activity is "immersive" and should not be
4038     * interrupted by notifications if possible.
4039     *
4040     * This value is initially set by the manifest property
4041     * <code>android:immersive</code> but may be changed at runtime by
4042     * {@link #setImmersive}.
4043     *
4044     * @see android.content.pm.ActivityInfo#FLAG_IMMERSIVE
4045     */
4046    public boolean isImmersive() {
4047        try {
4048            return ActivityManagerNative.getDefault().isImmersive(mToken);
4049        } catch (RemoteException e) {
4050            return false;
4051        }
4052    }
4053
4054    /**
4055     * Adjust the current immersive mode setting.
4056     *
4057     * Note that changing this value will have no effect on the activity's
4058     * {@link android.content.pm.ActivityInfo} structure; that is, if
4059     * <code>android:immersive</code> is set to <code>true</code>
4060     * in the application's manifest entry for this activity, the {@link
4061     * android.content.pm.ActivityInfo#flags ActivityInfo.flags} member will
4062     * always have its {@link android.content.pm.ActivityInfo#FLAG_IMMERSIVE
4063     * FLAG_IMMERSIVE} bit set.
4064     *
4065     * @see #isImmersive
4066     * @see android.content.pm.ActivityInfo#FLAG_IMMERSIVE
4067     */
4068    public void setImmersive(boolean i) {
4069        try {
4070            ActivityManagerNative.getDefault().setImmersive(mToken, i);
4071        } catch (RemoteException e) {
4072            // pass
4073        }
4074    }
4075
4076    /**
4077     * Start a context mode.
4078     *
4079     * @param callback Callback that will manage lifecycle events for this context mode
4080     * @return The ContextMode that was started, or null if it was canceled
4081     *
4082     * @see ActionMode
4083     */
4084    public ActionMode startActionMode(ActionMode.Callback callback) {
4085        return mWindow.getDecorView().startActionMode(callback);
4086    }
4087
4088    public ActionMode onStartActionMode(ActionMode.Callback callback) {
4089        if (mActionBar != null) {
4090            return mActionBar.startActionMode(callback);
4091        }
4092        return null;
4093    }
4094
4095    // ------------------ Internal API ------------------
4096
4097    final void setParent(Activity parent) {
4098        mParent = parent;
4099    }
4100
4101    final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token,
4102            Application application, Intent intent, ActivityInfo info, CharSequence title,
4103            Activity parent, String id, NonConfigurationInstances lastNonConfigurationInstances,
4104            Configuration config) {
4105        attach(context, aThread, instr, token, 0, application, intent, info, title, parent, id,
4106            lastNonConfigurationInstances, config);
4107    }
4108
4109    final void attach(Context context, ActivityThread aThread,
4110            Instrumentation instr, IBinder token, int ident,
4111            Application application, Intent intent, ActivityInfo info,
4112            CharSequence title, Activity parent, String id,
4113            NonConfigurationInstances lastNonConfigurationInstances,
4114            Configuration config) {
4115        attachBaseContext(context);
4116
4117        mFragments.attachActivity(this);
4118
4119        mWindow = PolicyManager.makeNewWindow(this);
4120        mWindow.setCallback(this);
4121        mWindow.getLayoutInflater().setFactory(this);
4122        if (info.softInputMode != WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED) {
4123            mWindow.setSoftInputMode(info.softInputMode);
4124        }
4125        mUiThread = Thread.currentThread();
4126
4127        mMainThread = aThread;
4128        mInstrumentation = instr;
4129        mToken = token;
4130        mIdent = ident;
4131        mApplication = application;
4132        mIntent = intent;
4133        mComponent = intent.getComponent();
4134        mActivityInfo = info;
4135        mTitle = title;
4136        mParent = parent;
4137        mEmbeddedID = id;
4138        mLastNonConfigurationInstances = lastNonConfigurationInstances;
4139
4140        mWindow.setWindowManager(null, mToken, mComponent.flattenToString(),
4141                (info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0);
4142        if (mParent != null) {
4143            mWindow.setContainer(mParent.getWindow());
4144        }
4145        mWindowManager = mWindow.getWindowManager();
4146        mCurrentConfig = config;
4147    }
4148
4149    final IBinder getActivityToken() {
4150        return mParent != null ? mParent.getActivityToken() : mToken;
4151    }
4152
4153    final void performCreate(Bundle icicle) {
4154        onCreate(icicle);
4155        mFragments.dispatchActivityCreated();
4156    }
4157
4158    final void performStart() {
4159        mCalled = false;
4160        mFragments.execPendingActions();
4161        mInstrumentation.callActivityOnStart(this);
4162        if (!mCalled) {
4163            throw new SuperNotCalledException(
4164                "Activity " + mComponent.toShortString() +
4165                " did not call through to super.onStart()");
4166        }
4167        mFragments.dispatchStart();
4168        if (mAllLoaderManagers != null) {
4169            for (int i=mAllLoaderManagers.size()-1; i>=0; i--) {
4170                mAllLoaderManagers.valueAt(i).finishRetain();
4171            }
4172        }
4173    }
4174
4175    final void performRestart() {
4176        synchronized (mManagedCursors) {
4177            final int N = mManagedCursors.size();
4178            for (int i=0; i<N; i++) {
4179                ManagedCursor mc = mManagedCursors.get(i);
4180                if (mc.mReleased || mc.mUpdated) {
4181                    mc.mCursor.requery();
4182                    mc.mReleased = false;
4183                    mc.mUpdated = false;
4184                }
4185            }
4186        }
4187
4188        if (mStopped) {
4189            mStopped = false;
4190            mCalled = false;
4191            mInstrumentation.callActivityOnRestart(this);
4192            if (!mCalled) {
4193                throw new SuperNotCalledException(
4194                    "Activity " + mComponent.toShortString() +
4195                    " did not call through to super.onRestart()");
4196            }
4197            performStart();
4198        }
4199    }
4200
4201    final void performResume() {
4202        performRestart();
4203
4204        mFragments.execPendingActions();
4205
4206        mLastNonConfigurationInstances = null;
4207
4208        // First call onResume() -before- setting mResumed, so we don't
4209        // send out any status bar / menu notifications the client makes.
4210        mCalled = false;
4211        mInstrumentation.callActivityOnResume(this);
4212        if (!mCalled) {
4213            throw new SuperNotCalledException(
4214                "Activity " + mComponent.toShortString() +
4215                " did not call through to super.onResume()");
4216        }
4217
4218        // Now really resume, and install the current status bar and menu.
4219        mResumed = true;
4220        mCalled = false;
4221
4222        mFragments.dispatchResume();
4223        mFragments.execPendingActions();
4224
4225        onPostResume();
4226        if (!mCalled) {
4227            throw new SuperNotCalledException(
4228                "Activity " + mComponent.toShortString() +
4229                " did not call through to super.onPostResume()");
4230        }
4231    }
4232
4233    final void performPause() {
4234        mFragments.dispatchPause();
4235        onPause();
4236    }
4237
4238    final void performUserLeaving() {
4239        onUserInteraction();
4240        onUserLeaveHint();
4241    }
4242
4243    final void performStop() {
4244        if (mStarted) {
4245            mStarted = false;
4246            if (mLoaderManager != null) {
4247                if (!mChangingConfigurations) {
4248                    mLoaderManager.doStop();
4249                } else {
4250                    mLoaderManager.doRetain();
4251                }
4252            }
4253        }
4254
4255        if (!mStopped) {
4256            if (mWindow != null) {
4257                mWindow.closeAllPanels();
4258            }
4259
4260            mFragments.dispatchStop();
4261
4262            mCalled = false;
4263            mInstrumentation.callActivityOnStop(this);
4264            if (!mCalled) {
4265                throw new SuperNotCalledException(
4266                    "Activity " + mComponent.toShortString() +
4267                    " did not call through to super.onStop()");
4268            }
4269
4270            synchronized (mManagedCursors) {
4271                final int N = mManagedCursors.size();
4272                for (int i=0; i<N; i++) {
4273                    ManagedCursor mc = mManagedCursors.get(i);
4274                    if (!mc.mReleased) {
4275                        mc.mCursor.deactivate();
4276                        mc.mReleased = true;
4277                    }
4278                }
4279            }
4280
4281            mStopped = true;
4282        }
4283        mResumed = false;
4284    }
4285
4286    final void performDestroy() {
4287        mFragments.dispatchDestroy();
4288        onDestroy();
4289    }
4290
4291    final boolean isResumed() {
4292        return mResumed;
4293    }
4294
4295    void dispatchActivityResult(String who, int requestCode,
4296        int resultCode, Intent data) {
4297        if (Config.LOGV) Log.v(
4298            TAG, "Dispatching result: who=" + who + ", reqCode=" + requestCode
4299            + ", resCode=" + resultCode + ", data=" + data);
4300        if (who == null) {
4301            onActivityResult(requestCode, resultCode, data);
4302        } else {
4303            Fragment frag = mFragments.findFragmentByWho(who);
4304            if (frag != null) {
4305                frag.onActivityResult(requestCode, resultCode, data);
4306            }
4307        }
4308    }
4309}
4310