Activity.java revision 764d5331d15c19162c938e617777b4bf15a6314d
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.policy.PolicyManager;
20
21import android.content.ComponentCallbacks;
22import android.content.ComponentName;
23import android.content.ContentResolver;
24import android.content.Context;
25import android.content.Intent;
26import android.content.IIntentSender;
27import android.content.SharedPreferences;
28import android.content.pm.ActivityInfo;
29import android.content.res.Configuration;
30import android.content.res.Resources;
31import android.database.Cursor;
32import android.graphics.Bitmap;
33import android.graphics.Canvas;
34import android.graphics.drawable.Drawable;
35import android.media.AudioManager;
36import android.net.Uri;
37import android.os.Bundle;
38import android.os.Handler;
39import android.os.IBinder;
40import android.os.RemoteException;
41import android.text.Selection;
42import android.text.SpannableStringBuilder;
43import android.text.TextUtils;
44import android.text.method.TextKeyListener;
45import android.util.AttributeSet;
46import android.util.Config;
47import android.util.EventLog;
48import android.util.Log;
49import android.util.SparseArray;
50import android.view.ContextMenu;
51import android.view.ContextThemeWrapper;
52import android.view.KeyEvent;
53import android.view.LayoutInflater;
54import android.view.Menu;
55import android.view.MenuInflater;
56import android.view.MenuItem;
57import android.view.MotionEvent;
58import android.view.View;
59import android.view.ViewGroup;
60import android.view.ViewManager;
61import android.view.Window;
62import android.view.WindowManager;
63import android.view.ContextMenu.ContextMenuInfo;
64import android.view.View.OnCreateContextMenuListener;
65import android.view.ViewGroup.LayoutParams;
66import android.view.accessibility.AccessibilityEvent;
67import android.widget.AdapterView;
68
69import java.util.ArrayList;
70import java.util.HashMap;
71
72/**
73 * An activity is a single, focused thing that the user can do.  Almost all
74 * activities interact with the user, so the Activity class takes care of
75 * creating a window for you in which you can place your UI with
76 * {@link #setContentView}.  While activities are often presented to the user
77 * as full-screen windows, they can also be used in other ways: as floating
78 * windows (via a theme with {@link android.R.attr#windowIsFloating} set)
79 * or embedded inside of another activity (using {@link ActivityGroup}).
80 *
81 * There are two methods almost all subclasses of Activity will implement:
82 *
83 * <ul>
84 *     <li> {@link #onCreate} is where you initialize your activity.  Most
85 *     importantly, here you will usually call {@link #setContentView(int)}
86 *     with a layout resource defining your UI, and using {@link #findViewById}
87 *     to retrieve the widgets in that UI that you need to interact with
88 *     programmatically.
89 *
90 *     <li> {@link #onPause} is where you deal with the user leaving your
91 *     activity.  Most importantly, any changes made by the user should at this
92 *     point be committed (usually to the
93 *     {@link android.content.ContentProvider} holding the data).
94 * </ul>
95 *
96 * <p>To be of use with {@link android.content.Context#startActivity Context.startActivity()}, all
97 * activity classes must have a corresponding
98 * {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
99 * declaration in their package's <code>AndroidManifest.xml</code>.</p>
100 *
101 * <p>The Activity class is an important part of an application's overall lifecycle,
102 * and the way activities are launched and put together is a fundamental
103 * part of the platform's application model. For a detailed perspective on the structure of
104 * Android applications and lifecycles, please read the <em>Dev Guide</em> document on
105 * <a href="{@docRoot}guide/topics/fundamentals.html">Application Fundamentals</a>.</p>
106 *
107 * <p>Topics covered here:
108 * <ol>
109 * <li><a href="#ActivityLifecycle">Activity Lifecycle</a>
110 * <li><a href="#ConfigurationChanges">Configuration Changes</a>
111 * <li><a href="#StartingActivities">Starting Activities and Getting Results</a>
112 * <li><a href="#SavingPersistentState">Saving Persistent State</a>
113 * <li><a href="#Permissions">Permissions</a>
114 * <li><a href="#ProcessLifecycle">Process Lifecycle</a>
115 * </ol>
116 *
117 * <a name="ActivityLifecycle"></a>
118 * <h3>Activity Lifecycle</h3>
119 *
120 * <p>Activities in the system are managed as an <em>activity stack</em>.
121 * When a new activity is started, it is placed on the top of the stack
122 * and becomes the running activity -- the previous activity always remains
123 * below it in the stack, and will not come to the foreground again until
124 * the new activity exits.</p>
125 *
126 * <p>An activity has essentially four states:</p>
127 * <ul>
128 *     <li> If an activity in the foreground of the screen (at the top of
129 *         the stack),
130 *         it is <em>active</em> or  <em>running</em>. </li>
131 *     <li>If an activity has lost focus but is still visible (that is, a new non-full-sized
132 *         or transparent activity has focus on top of your activity), it
133 *         is <em>paused</em>. A paused activity is completely alive (it
134 *         maintains all state and member information and remains attached to
135 *         the window manager), but can be killed by the system in extreme
136 *         low memory situations.
137 *     <li>If an activity is completely obscured by another activity,
138 *         it is <em>stopped</em>. It still retains all state and member information,
139 *         however, it is no longer visible to the user so its window is hidden
140 *         and it will often be killed by the system when memory is needed
141 *         elsewhere.</li>
142 *     <li>If an activity is paused or stopped, the system can drop the activity
143 *         from memory by either asking it to finish, or simply killing its
144 *         process.  When it is displayed again to the user, it must be
145 *         completely restarted and restored to its previous state.</li>
146 * </ul>
147 *
148 * <p>The following diagram shows the important state paths of an Activity.
149 * The square rectangles represent callback methods you can implement to
150 * perform operations when the Activity moves between states.  The colored
151 * ovals are major states the Activity can be in.</p>
152 *
153 * <p><img src="../../../images/activity_lifecycle.png"
154 *      alt="State diagram for an Android Activity Lifecycle." border="0" /></p>
155 *
156 * <p>There are three key loops you may be interested in monitoring within your
157 * activity:
158 *
159 * <ul>
160 * <li>The <b>entire lifetime</b> of an activity happens between the first call
161 * to {@link android.app.Activity#onCreate} through to a single final call
162 * to {@link android.app.Activity#onDestroy}.  An activity will do all setup
163 * of "global" state in onCreate(), and release all remaining resources in
164 * onDestroy().  For example, if it has a thread running in the background
165 * to download data from the network, it may create that thread in onCreate()
166 * and then stop the thread in onDestroy().
167 *
168 * <li>The <b>visible lifetime</b> of an activity happens between a call to
169 * {@link android.app.Activity#onStart} until a corresponding call to
170 * {@link android.app.Activity#onStop}.  During this time the user can see the
171 * activity on-screen, though it may not be in the foreground and interacting
172 * with the user.  Between these two methods you can maintain resources that
173 * are needed to show the activity to the user.  For example, you can register
174 * a {@link android.content.BroadcastReceiver} in onStart() to monitor for changes
175 * that impact your UI, and unregister it in onStop() when the user an no
176 * longer see what you are displaying.  The onStart() and onStop() methods
177 * can be called multiple times, as the activity becomes visible and hidden
178 * to the user.
179 *
180 * <li>The <b>foreground lifetime</b> of an activity happens between a call to
181 * {@link android.app.Activity#onResume} until a corresponding call to
182 * {@link android.app.Activity#onPause}.  During this time the activity is
183 * in front of all other activities and interacting with the user.  An activity
184 * can frequently go between the resumed and paused states -- for example when
185 * the device goes to sleep, when an activity result is delivered, when a new
186 * intent is delivered -- so the code in these methods should be fairly
187 * lightweight.
188 * </ul>
189 *
190 * <p>The entire lifecycle of an activity is defined by the following
191 * Activity methods.  All of these are hooks that you can override
192 * to do appropriate work when the activity changes state.  All
193 * activities will implement {@link android.app.Activity#onCreate}
194 * to do their initial setup; many will also implement
195 * {@link android.app.Activity#onPause} to commit changes to data and
196 * otherwise prepare to stop interacting with the user.  You should always
197 * call up to your superclass when implementing these methods.</p>
198 *
199 * </p>
200 * <pre class="prettyprint">
201 * public class Activity extends ApplicationContext {
202 *     protected void onCreate(Bundle savedInstanceState);
203 *
204 *     protected void onStart();
205 *
206 *     protected void onRestart();
207 *
208 *     protected void onResume();
209 *
210 *     protected void onPause();
211 *
212 *     protected void onStop();
213 *
214 *     protected void onDestroy();
215 * }
216 * </pre>
217 *
218 * <p>In general the movement through an activity's lifecycle looks like
219 * this:</p>
220 *
221 * <table border="2" width="85%" align="center" frame="hsides" rules="rows">
222 *     <colgroup align="left" span="3" />
223 *     <colgroup align="left" />
224 *     <colgroup align="center" />
225 *     <colgroup align="center" />
226 *
227 *     <thead>
228 *     <tr><th colspan="3">Method</th> <th>Description</th> <th>Killable?</th> <th>Next</th></tr>
229 *     </thead>
230 *
231 *     <tbody>
232 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onCreate onCreate()}</th>
233 *         <td>Called when the activity is first created.
234 *             This is where you should do all of your normal static set up:
235 *             create views, bind data to lists, etc.  This method also
236 *             provides you with a Bundle containing the activity's previously
237 *             frozen state, if there was one.
238 *             <p>Always followed by <code>onStart()</code>.</td>
239 *         <td align="center">No</td>
240 *         <td align="center"><code>onStart()</code></td>
241 *     </tr>
242 *
243 *     <tr><td rowspan="5" style="border-left: none; border-right: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
244 *         <th colspan="2" align="left" border="0">{@link android.app.Activity#onRestart onRestart()}</th>
245 *         <td>Called after your activity has been stopped, prior to it being
246 *             started again.
247 *             <p>Always followed by <code>onStart()</code></td>
248 *         <td align="center">No</td>
249 *         <td align="center"><code>onStart()</code></td>
250 *     </tr>
251 *
252 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStart onStart()}</th>
253 *         <td>Called when the activity is becoming visible to the user.
254 *             <p>Followed by <code>onResume()</code> if the activity comes
255 *             to the foreground, or <code>onStop()</code> if it becomes hidden.</td>
256 *         <td align="center">No</td>
257 *         <td align="center"><code>onResume()</code> or <code>onStop()</code></td>
258 *     </tr>
259 *
260 *     <tr><td rowspan="2" style="border-left: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
261 *         <th align="left" border="0">{@link android.app.Activity#onResume onResume()}</th>
262 *         <td>Called when the activity will start
263 *             interacting with the user.  At this point your activity is at
264 *             the top of the activity stack, with user input going to it.
265 *             <p>Always followed by <code>onPause()</code>.</td>
266 *         <td align="center">No</td>
267 *         <td align="center"><code>onPause()</code></td>
268 *     </tr>
269 *
270 *     <tr><th align="left" border="0">{@link android.app.Activity#onPause onPause()}</th>
271 *         <td>Called when the system is about to start resuming a previous
272 *             activity.  This is typically used to commit unsaved changes to
273 *             persistent data, stop animations and other things that may be consuming
274 *             CPU, etc.  Implementations of this method must be very quick because
275 *             the next activity will not be resumed until this method returns.
276 *             <p>Followed by either <code>onResume()</code> if the activity
277 *             returns back to the front, or <code>onStop()</code> if it becomes
278 *             invisible to the user.</td>
279 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
280 *         <td align="center"><code>onResume()</code> or<br>
281 *                 <code>onStop()</code></td>
282 *     </tr>
283 *
284 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStop onStop()}</th>
285 *         <td>Called when the activity is no longer visible to the user, because
286 *             another activity has been resumed and is covering this one.  This
287 *             may happen either because a new activity is being started, an existing
288 *             one is being brought in front of this one, or this one is being
289 *             destroyed.
290 *             <p>Followed by either <code>onRestart()</code> if
291 *             this activity is coming back to interact with the user, or
292 *             <code>onDestroy()</code> if this activity is going away.</td>
293 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
294 *         <td align="center"><code>onRestart()</code> or<br>
295 *                 <code>onDestroy()</code></td>
296 *     </tr>
297 *
298 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onDestroy onDestroy()}</th>
299 *         <td>The final call you receive before your
300 *             activity is destroyed.  This can happen either because the
301 *             activity is finishing (someone called {@link Activity#finish} on
302 *             it, or because the system is temporarily destroying this
303 *             instance of the activity to save space.  You can distinguish
304 *             between these two scenarios with the {@link
305 *             Activity#isFinishing} method.</td>
306 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
307 *         <td align="center"><em>nothing</em></td>
308 *     </tr>
309 *     </tbody>
310 * </table>
311 *
312 * <p>Note the "Killable" column in the above table -- for those methods that
313 * are marked as being killable, after that method returns the process hosting the
314 * activity may killed by the system <em>at any time</em> without another line
315 * of its code being executed.  Because of this, you should use the
316 * {@link #onPause} method to write any persistent data (such as user edits)
317 * to storage.  In addition, the method
318 * {@link #onSaveInstanceState(Bundle)} is called before placing the activity
319 * in such a background state, allowing you to save away any dynamic instance
320 * state in your activity into the given Bundle, to be later received in
321 * {@link #onCreate} if the activity needs to be re-created.
322 * See the <a href="#ProcessLifecycle">Process Lifecycle</a>
323 * section for more information on how the lifecycle of a process is tied
324 * to the activities it is hosting.  Note that it is important to save
325 * persistent data in {@link #onPause} instead of {@link #onSaveInstanceState}
326 * because the later is not part of the lifecycle callbacks, so will not
327 * be called in every situation as described in its documentation.</p>
328 *
329 * <p>For those methods that are not marked as being killable, the activity's
330 * process will not be killed by the system starting from the time the method
331 * is called and continuing after it returns.  Thus an activity is in the killable
332 * state, for example, between after <code>onPause()</code> to the start of
333 * <code>onResume()</code>.</p>
334 *
335 * <a name="ConfigurationChanges"></a>
336 * <h3>Configuration Changes</h3>
337 *
338 * <p>If the configuration of the device (as defined by the
339 * {@link Configuration Resources.Configuration} class) changes,
340 * then anything displaying a user interface will need to update to match that
341 * configuration.  Because Activity is the primary mechanism for interacting
342 * with the user, it includes special support for handling configuration
343 * changes.</p>
344 *
345 * <p>Unless you specify otherwise, a configuration change (such as a change
346 * in screen orientation, language, input devices, etc) will cause your
347 * current activity to be <em>destroyed</em>, going through the normal activity
348 * lifecycle process of {@link #onPause},
349 * {@link #onStop}, and {@link #onDestroy} as appropriate.  If the activity
350 * had been in the foreground or visible to the user, once {@link #onDestroy} is
351 * called in that instance then a new instance of the activity will be
352 * created, with whatever savedInstanceState the previous instance had generated
353 * from {@link #onSaveInstanceState}.</p>
354 *
355 * <p>This is done because any application resource,
356 * including layout files, can change based on any configuration value.  Thus
357 * the only safe way to handle a configuration change is to re-retrieve all
358 * resources, including layouts, drawables, and strings.  Because activities
359 * must already know how to save their state and re-create themselves from
360 * that state, this is a convenient way to have an activity restart itself
361 * with a new configuration.</p>
362 *
363 * <p>In some special cases, you may want to bypass restarting of your
364 * activity based on one or more types of configuration changes.  This is
365 * done with the {@link android.R.attr#configChanges android:configChanges}
366 * attribute in its manifest.  For any types of configuration changes you say
367 * that you handle there, you will receive a call to your current activity's
368 * {@link #onConfigurationChanged} method instead of being restarted.  If
369 * a configuration change involves any that you do not handle, however, the
370 * activity will still be restarted and {@link #onConfigurationChanged}
371 * will not be called.</p>
372 *
373 * <a name="StartingActivities"></a>
374 * <h3>Starting Activities and Getting Results</h3>
375 *
376 * <p>The {@link android.app.Activity#startActivity}
377 * method is used to start a
378 * new activity, which will be placed at the top of the activity stack.  It
379 * takes a single argument, an {@link android.content.Intent Intent},
380 * which describes the activity
381 * to be executed.</p>
382 *
383 * <p>Sometimes you want to get a result back from an activity when it
384 * ends.  For example, you may start an activity that lets the user pick
385 * a person in a list of contacts; when it ends, it returns the person
386 * that was selected.  To do this, you call the
387 * {@link android.app.Activity#startActivityForResult(Intent, int)}
388 * version with a second integer parameter identifying the call.  The result
389 * will come back through your {@link android.app.Activity#onActivityResult}
390 * method.</p>
391 *
392 * <p>When an activity exits, it can call
393 * {@link android.app.Activity#setResult(int)}
394 * to return data back to its parent.  It must always supply a result code,
395 * which can be the standard results RESULT_CANCELED, RESULT_OK, or any
396 * custom values starting at RESULT_FIRST_USER.  In addition, it can optionally
397 * return back an Intent containing any additional data it wants.  All of this
398 * information appears back on the
399 * parent's <code>Activity.onActivityResult()</code>, along with the integer
400 * identifier it originally supplied.</p>
401 *
402 * <p>If a child activity fails for any reason (such as crashing), the parent
403 * activity will receive a result with the code RESULT_CANCELED.</p>
404 *
405 * <pre class="prettyprint">
406 * public class MyActivity extends Activity {
407 *     ...
408 *
409 *     static final int PICK_CONTACT_REQUEST = 0;
410 *
411 *     protected boolean onKeyDown(int keyCode, KeyEvent event) {
412 *         if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
413 *             // When the user center presses, let them pick a contact.
414 *             startActivityForResult(
415 *                 new Intent(Intent.ACTION_PICK,
416 *                 new Uri("content://contacts")),
417 *                 PICK_CONTACT_REQUEST);
418 *            return true;
419 *         }
420 *         return false;
421 *     }
422 *
423 *     protected void onActivityResult(int requestCode, int resultCode,
424 *             Intent data) {
425 *         if (requestCode == PICK_CONTACT_REQUEST) {
426 *             if (resultCode == RESULT_OK) {
427 *                 // A contact was picked.  Here we will just display it
428 *                 // to the user.
429 *                 startActivity(new Intent(Intent.ACTION_VIEW, data));
430 *             }
431 *         }
432 *     }
433 * }
434 * </pre>
435 *
436 * <a name="SavingPersistentState"></a>
437 * <h3>Saving Persistent State</h3>
438 *
439 * <p>There are generally two kinds of persistent state than an activity
440 * will deal with: shared document-like data (typically stored in a SQLite
441 * database using a {@linkplain android.content.ContentProvider content provider})
442 * and internal state such as user preferences.</p>
443 *
444 * <p>For content provider data, we suggest that activities use a
445 * "edit in place" user model.  That is, any edits a user makes are effectively
446 * made immediately without requiring an additional confirmation step.
447 * Supporting this model is generally a simple matter of following two rules:</p>
448 *
449 * <ul>
450 *     <li> <p>When creating a new document, the backing database entry or file for
451 *             it is created immediately.  For example, if the user chooses to write
452 *             a new e-mail, a new entry for that e-mail is created as soon as they
453 *             start entering data, so that if they go to any other activity after
454 *             that point this e-mail will now appear in the list of drafts.</p>
455 *     <li> <p>When an activity's <code>onPause()</code> method is called, it should
456 *             commit to the backing content provider or file any changes the user
457 *             has made.  This ensures that those changes will be seen by any other
458 *             activity that is about to run.  You will probably want to commit
459 *             your data even more aggressively at key times during your
460 *             activity's lifecycle: for example before starting a new
461 *             activity, before finishing your own activity, when the user
462 *             switches between input fields, etc.</p>
463 * </ul>
464 *
465 * <p>This model is designed to prevent data loss when a user is navigating
466 * between activities, and allows the system to safely kill an activity (because
467 * system resources are needed somewhere else) at any time after it has been
468 * paused.  Note this implies
469 * that the user pressing BACK from your activity does <em>not</em>
470 * mean "cancel" -- it means to leave the activity with its current contents
471 * saved away.  Cancelling edits in an activity must be provided through
472 * some other mechanism, such as an explicit "revert" or "undo" option.</p>
473 *
474 * <p>See the {@linkplain android.content.ContentProvider content package} for
475 * more information about content providers.  These are a key aspect of how
476 * different activities invoke and propagate data between themselves.</p>
477 *
478 * <p>The Activity class also provides an API for managing internal persistent state
479 * associated with an activity.  This can be used, for example, to remember
480 * the user's preferred initial display in a calendar (day view or week view)
481 * or the user's default home page in a web browser.</p>
482 *
483 * <p>Activity persistent state is managed
484 * with the method {@link #getPreferences},
485 * allowing you to retrieve and
486 * modify a set of name/value pairs associated with the activity.  To use
487 * preferences that are shared across multiple application components
488 * (activities, receivers, services, providers), you can use the underlying
489 * {@link Context#getSharedPreferences Context.getSharedPreferences()} method
490 * to retrieve a preferences
491 * object stored under a specific name.
492 * (Note that it is not possible to share settings data across application
493 * packages -- for that you will need a content provider.)</p>
494 *
495 * <p>Here is an excerpt from a calendar activity that stores the user's
496 * preferred view mode in its persistent settings:</p>
497 *
498 * <pre class="prettyprint">
499 * public class CalendarActivity extends Activity {
500 *     ...
501 *
502 *     static final int DAY_VIEW_MODE = 0;
503 *     static final int WEEK_VIEW_MODE = 1;
504 *
505 *     private SharedPreferences mPrefs;
506 *     private int mCurViewMode;
507 *
508 *     protected void onCreate(Bundle savedInstanceState) {
509 *         super.onCreate(savedInstanceState);
510 *
511 *         SharedPreferences mPrefs = getSharedPreferences();
512 *         mCurViewMode = mPrefs.getInt("view_mode" DAY_VIEW_MODE);
513 *     }
514 *
515 *     protected void onPause() {
516 *         super.onPause();
517 *
518 *         SharedPreferences.Editor ed = mPrefs.edit();
519 *         ed.putInt("view_mode", mCurViewMode);
520 *         ed.commit();
521 *     }
522 * }
523 * </pre>
524 *
525 * <a name="Permissions"></a>
526 * <h3>Permissions</h3>
527 *
528 * <p>The ability to start a particular Activity can be enforced when it is
529 * declared in its
530 * manifest's {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
531 * tag.  By doing so, other applications will need to declare a corresponding
532 * {@link android.R.styleable#AndroidManifestUsesPermission &lt;uses-permission&gt;}
533 * element in their own manifest to be able to start that activity.
534 *
535 * <p>See the <a href="{@docRoot}guide/topics/security/security.html">Security and Permissions</a>
536 * document for more information on permissions and security in general.
537 *
538 * <a name="ProcessLifecycle"></a>
539 * <h3>Process Lifecycle</h3>
540 *
541 * <p>The Android system attempts to keep application process around for as
542 * long as possible, but eventually will need to remove old processes when
543 * memory runs low.  As described in <a href="#ActivityLifecycle">Activity
544 * Lifecycle</a>, the decision about which process to remove is intimately
545 * tied to the state of the user's interaction with it.  In general, there
546 * are four states a process can be in based on the activities running in it,
547 * listed here in order of importance.  The system will kill less important
548 * processes (the last ones) before it resorts to killing more important
549 * processes (the first ones).
550 *
551 * <ol>
552 * <li> <p>The <b>foreground activity</b> (the activity at the top of the screen
553 * that the user is currently interacting with) is considered the most important.
554 * Its process will only be killed as a last resort, if it uses more memory
555 * than is available on the device.  Generally at this point the device has
556 * reached a memory paging state, so this is required in order to keep the user
557 * interface responsive.
558 * <li> <p>A <b>visible activity</b> (an activity that is visible to the user
559 * but not in the foreground, such as one sitting behind a foreground dialog)
560 * is considered extremely important and will not be killed unless that is
561 * required to keep the foreground activity running.
562 * <li> <p>A <b>background activity</b> (an activity that is not visible to
563 * the user and has been paused) is no longer critical, so the system may
564 * safely kill its process to reclaim memory for other foreground or
565 * visible processes.  If its process needs to be killed, when the user navigates
566 * back to the activity (making it visible on the screen again), its
567 * {@link #onCreate} method will be called with the savedInstanceState it had previously
568 * supplied in {@link #onSaveInstanceState} so that it can restart itself in the same
569 * state as the user last left it.
570 * <li> <p>An <b>empty process</b> is one hosting no activities or other
571 * application components (such as {@link Service} or
572 * {@link android.content.BroadcastReceiver} classes).  These are killed very
573 * quickly by the system as memory becomes low.  For this reason, any
574 * background operation you do outside of an activity must be executed in the
575 * context of an activity BroadcastReceiver or Service to ensure that the system
576 * knows it needs to keep your process around.
577 * </ol>
578 *
579 * <p>Sometimes an Activity may need to do a long-running operation that exists
580 * independently of the activity lifecycle itself.  An example may be a camera
581 * application that allows you to upload a picture to a web site.  The upload
582 * may take a long time, and the application should allow the user to leave
583 * the application will it is executing.  To accomplish this, your Activity
584 * should start a {@link Service} in which the upload takes place.  This allows
585 * the system to properly prioritize your process (considering it to be more
586 * important than other non-visible applications) for the duration of the
587 * upload, independent of whether the original activity is paused, stopped,
588 * or finished.
589 */
590public class Activity extends ContextThemeWrapper
591        implements LayoutInflater.Factory,
592        Window.Callback, KeyEvent.Callback,
593        OnCreateContextMenuListener, ComponentCallbacks {
594    private static final String TAG = "Activity";
595
596    /** Standard activity result: operation canceled. */
597    public static final int RESULT_CANCELED    = 0;
598    /** Standard activity result: operation succeeded. */
599    public static final int RESULT_OK           = -1;
600    /** Start of user-defined activity results. */
601    public static final int RESULT_FIRST_USER   = 1;
602
603    private static long sInstanceCount = 0;
604
605    private static final String WINDOW_HIERARCHY_TAG = "android:viewHierarchyState";
606    private static final String SAVED_DIALOG_IDS_KEY = "android:savedDialogIds";
607    private static final String SAVED_DIALOGS_TAG = "android:savedDialogs";
608    private static final String SAVED_DIALOG_KEY_PREFIX = "android:dialog_";
609    private static final String SAVED_SEARCH_DIALOG_KEY = "android:search_dialog";
610
611    private SparseArray<Dialog> mManagedDialogs;
612
613    // set by the thread after the constructor and before onCreate(Bundle savedInstanceState) is called.
614    private Instrumentation mInstrumentation;
615    private IBinder mToken;
616    /*package*/ String mEmbeddedID;
617    private Application mApplication;
618    /*package*/ Intent mIntent;
619    private ComponentName mComponent;
620    /*package*/ ActivityInfo mActivityInfo;
621    /*package*/ ActivityThread mMainThread;
622    /*package*/ Object mLastNonConfigurationInstance;
623    /*package*/ HashMap<String,Object> mLastNonConfigurationChildInstances;
624    Activity mParent;
625    boolean mCalled;
626    private boolean mResumed;
627    private boolean mStopped;
628    boolean mFinished;
629    boolean mStartedActivity;
630    /*package*/ int mConfigChangeFlags;
631    /*package*/ Configuration mCurrentConfig;
632    private SearchManager mSearchManager;
633    private Bundle mSearchDialogState = null;
634
635    private Window mWindow;
636
637    private WindowManager mWindowManager;
638    /*package*/ View mDecor = null;
639    /*package*/ boolean mWindowAdded = false;
640    /*package*/ boolean mVisibleFromServer = false;
641    /*package*/ boolean mVisibleFromClient = true;
642
643    private CharSequence mTitle;
644    private int mTitleColor = 0;
645
646    private static final class ManagedCursor {
647        ManagedCursor(Cursor cursor) {
648            mCursor = cursor;
649            mReleased = false;
650            mUpdated = false;
651        }
652
653        private final Cursor mCursor;
654        private boolean mReleased;
655        private boolean mUpdated;
656    }
657    private final ArrayList<ManagedCursor> mManagedCursors =
658        new ArrayList<ManagedCursor>();
659
660    // protected by synchronized (this)
661    int mResultCode = RESULT_CANCELED;
662    Intent mResultData = null;
663
664    private boolean mTitleReady = false;
665
666    private int mDefaultKeyMode = DEFAULT_KEYS_DISABLE;
667    private SpannableStringBuilder mDefaultKeySsb = null;
668
669    protected static final int[] FOCUSED_STATE_SET = {com.android.internal.R.attr.state_focused};
670
671    private Thread mUiThread;
672    private final Handler mHandler = new Handler();
673
674    public Activity() {
675        ++sInstanceCount;
676    }
677
678
679    @Override
680    protected void finalize() throws Throwable {
681        super.finalize();
682        --sInstanceCount;
683    }
684
685    public static long getInstanceCount() {
686        return sInstanceCount;
687    }
688
689    /** Return the intent that started this activity. */
690    public Intent getIntent() {
691        return mIntent;
692    }
693
694    /**
695     * Change the intent returned by {@link #getIntent}.  This holds a
696     * reference to the given intent; it does not copy it.  Often used in
697     * conjunction with {@link #onNewIntent}.
698     *
699     * @param newIntent The new Intent object to return from getIntent
700     *
701     * @see #getIntent
702     * @see #onNewIntent
703     */
704    public void setIntent(Intent newIntent) {
705        mIntent = newIntent;
706    }
707
708    /** Return the application that owns this activity. */
709    public final Application getApplication() {
710        return mApplication;
711    }
712
713    /** Is this activity embedded inside of another activity? */
714    public final boolean isChild() {
715        return mParent != null;
716    }
717
718    /** Return the parent activity if this view is an embedded child. */
719    public final Activity getParent() {
720        return mParent;
721    }
722
723    /** Retrieve the window manager for showing custom windows. */
724    public WindowManager getWindowManager() {
725        return mWindowManager;
726    }
727
728    /**
729     * Retrieve the current {@link android.view.Window} for the activity.
730     * This can be used to directly access parts of the Window API that
731     * are not available through Activity/Screen.
732     *
733     * @return Window The current window, or null if the activity is not
734     *         visual.
735     */
736    public Window getWindow() {
737        return mWindow;
738    }
739
740    /**
741     * Calls {@link android.view.Window#getCurrentFocus} on the
742     * Window of this Activity to return the currently focused view.
743     *
744     * @return View The current View with focus or null.
745     *
746     * @see #getWindow
747     * @see android.view.Window#getCurrentFocus
748     */
749    public View getCurrentFocus() {
750        return mWindow != null ? mWindow.getCurrentFocus() : null;
751    }
752
753    @Override
754    public int getWallpaperDesiredMinimumWidth() {
755        int width = super.getWallpaperDesiredMinimumWidth();
756        return width <= 0 ? getWindowManager().getDefaultDisplay().getWidth() : width;
757    }
758
759    @Override
760    public int getWallpaperDesiredMinimumHeight() {
761        int height = super.getWallpaperDesiredMinimumHeight();
762        return height <= 0 ? getWindowManager().getDefaultDisplay().getHeight() : height;
763    }
764
765    /**
766     * Called when the activity is starting.  This is where most initialization
767     * should go: calling {@link #setContentView(int)} to inflate the
768     * activity's UI, using {@link #findViewById} to programmatically interact
769     * with widgets in the UI, calling
770     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)} to retrieve
771     * cursors for data being displayed, etc.
772     *
773     * <p>You can call {@link #finish} from within this function, in
774     * which case onDestroy() will be immediately called without any of the rest
775     * of the activity lifecycle ({@link #onStart}, {@link #onResume},
776     * {@link #onPause}, etc) executing.
777     *
778     * <p><em>Derived classes must call through to the super class's
779     * implementation of this method.  If they do not, an exception will be
780     * thrown.</em></p>
781     *
782     * @param savedInstanceState If the activity is being re-initialized after
783     *     previously being shut down then this Bundle contains the data it most
784     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
785     *
786     * @see #onStart
787     * @see #onSaveInstanceState
788     * @see #onRestoreInstanceState
789     * @see #onPostCreate
790     */
791    protected void onCreate(Bundle savedInstanceState) {
792        mVisibleFromClient = mWindow.getWindowStyle().getBoolean(
793                com.android.internal.R.styleable.Window_windowNoDisplay, true);
794        // uses super.getSystemService() since this.getSystemService() looks at the
795        // mSearchManager field.
796        mSearchManager = (SearchManager) super.getSystemService(Context.SEARCH_SERVICE);
797        mCalled = true;
798    }
799
800    /**
801     * The hook for {@link ActivityThread} to restore the state of this activity.
802     *
803     * Calls {@link #onSaveInstanceState(android.os.Bundle)} and
804     * {@link #restoreManagedDialogs(android.os.Bundle)}.
805     *
806     * @param savedInstanceState contains the saved state
807     */
808    final void performRestoreInstanceState(Bundle savedInstanceState) {
809        onRestoreInstanceState(savedInstanceState);
810        restoreManagedDialogs(savedInstanceState);
811
812        // Also restore the state of a search dialog (if any)
813        // TODO more generic than just this manager
814        Bundle searchState = savedInstanceState.getBundle(SAVED_SEARCH_DIALOG_KEY);
815        if (searchState != null) {
816            mSearchManager.restoreSearchDialog(searchState);
817        }
818    }
819
820    /**
821     * This method is called after {@link #onStart} when the activity is
822     * being re-initialized from a previously saved state, given here in
823     * <var>state</var>.  Most implementations will simply use {@link #onCreate}
824     * to restore their state, but it is sometimes convenient to do it here
825     * after all of the initialization has been done or to allow subclasses to
826     * decide whether to use your default implementation.  The default
827     * implementation of this method performs a restore of any view state that
828     * had previously been frozen by {@link #onSaveInstanceState}.
829     *
830     * <p>This method is called between {@link #onStart} and
831     * {@link #onPostCreate}.
832     *
833     * @param savedInstanceState the data most recently supplied in {@link #onSaveInstanceState}.
834     *
835     * @see #onCreate
836     * @see #onPostCreate
837     * @see #onResume
838     * @see #onSaveInstanceState
839     */
840    protected void onRestoreInstanceState(Bundle savedInstanceState) {
841        if (mWindow != null) {
842            Bundle windowState = savedInstanceState.getBundle(WINDOW_HIERARCHY_TAG);
843            if (windowState != null) {
844                mWindow.restoreHierarchyState(windowState);
845            }
846        }
847    }
848
849    /**
850     * Restore the state of any saved managed dialogs.
851     *
852     * @param savedInstanceState The bundle to restore from.
853     */
854    private void restoreManagedDialogs(Bundle savedInstanceState) {
855        final Bundle b = savedInstanceState.getBundle(SAVED_DIALOGS_TAG);
856        if (b == null) {
857            return;
858        }
859
860        final int[] ids = b.getIntArray(SAVED_DIALOG_IDS_KEY);
861        final int numDialogs = ids.length;
862        mManagedDialogs = new SparseArray<Dialog>(numDialogs);
863        for (int i = 0; i < numDialogs; i++) {
864            final Integer dialogId = ids[i];
865            Bundle dialogState = b.getBundle(savedDialogKeyFor(dialogId));
866            if (dialogState != null) {
867                final Dialog dialog = createDialog(dialogId);
868                mManagedDialogs.put(dialogId, dialog);
869                onPrepareDialog(dialogId, dialog);
870                dialog.onRestoreInstanceState(dialogState);
871            }
872        }
873    }
874
875    private Dialog createDialog(Integer dialogId) {
876        final Dialog dialog = onCreateDialog(dialogId);
877        if (dialog == null) {
878            throw new IllegalArgumentException("Activity#onCreateDialog did "
879                    + "not create a dialog for id " + dialogId);
880        }
881        dialog.dispatchOnCreate(null);
882        return dialog;
883    }
884
885    private String savedDialogKeyFor(int key) {
886        return SAVED_DIALOG_KEY_PREFIX + key;
887    }
888
889
890    /**
891     * Called when activity start-up is complete (after {@link #onStart}
892     * and {@link #onRestoreInstanceState} have been called).  Applications will
893     * generally not implement this method; it is intended for system
894     * classes to do final initialization after application code has run.
895     *
896     * <p><em>Derived classes must call through to the super class's
897     * implementation of this method.  If they do not, an exception will be
898     * thrown.</em></p>
899     *
900     * @param savedInstanceState If the activity is being re-initialized after
901     *     previously being shut down then this Bundle contains the data it most
902     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
903     * @see #onCreate
904     */
905    protected void onPostCreate(Bundle savedInstanceState) {
906        if (!isChild()) {
907            mTitleReady = true;
908            onTitleChanged(getTitle(), getTitleColor());
909        }
910        mCalled = true;
911    }
912
913    /**
914     * Called after {@link #onCreate} &mdash; or after {@link #onRestart} when
915     * the activity had been stopped, but is now again being displayed to the
916	 * user.  It will be followed by {@link #onResume}.
917     *
918     * <p><em>Derived classes must call through to the super class's
919     * implementation of this method.  If they do not, an exception will be
920     * thrown.</em></p>
921     *
922     * @see #onCreate
923     * @see #onStop
924     * @see #onResume
925     */
926    protected void onStart() {
927        mCalled = true;
928    }
929
930    /**
931     * Called after {@link #onStop} when the current activity is being
932     * re-displayed to the user (the user has navigated back to it).  It will
933     * be followed by {@link #onStart} and then {@link #onResume}.
934     *
935     * <p>For activities that are using raw {@link Cursor} objects (instead of
936     * creating them through
937     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)},
938     * this is usually the place
939     * where the cursor should be requeried (because you had deactivated it in
940     * {@link #onStop}.
941     *
942     * <p><em>Derived classes must call through to the super class's
943     * implementation of this method.  If they do not, an exception will be
944     * thrown.</em></p>
945     *
946     * @see #onStop
947     * @see #onStart
948     * @see #onResume
949     */
950    protected void onRestart() {
951        mCalled = true;
952    }
953
954    /**
955     * Called after {@link #onRestoreInstanceState}, {@link #onRestart}, or
956     * {@link #onPause}, for your activity to start interacting with the user.
957     * This is a good place to begin animations, open exclusive-access devices
958     * (such as the camera), etc.
959     *
960     * <p>Keep in mind that onResume is not the best indicator that your activity
961     * is visible to the user; a system window such as the keyguard may be in
962     * front.  Use {@link #onWindowFocusChanged} to know for certain that your
963     * activity is visible to the user (for example, to resume a game).
964     *
965     * <p><em>Derived classes must call through to the super class's
966     * implementation of this method.  If they do not, an exception will be
967     * thrown.</em></p>
968     *
969     * @see #onRestoreInstanceState
970     * @see #onRestart
971     * @see #onPostResume
972     * @see #onPause
973     */
974    protected void onResume() {
975        mCalled = true;
976    }
977
978    /**
979     * Called when activity resume is complete (after {@link #onResume} has
980     * been called). Applications will generally not implement this method;
981     * it is intended for system classes to do final setup after application
982     * resume code has run.
983     *
984     * <p><em>Derived classes must call through to the super class's
985     * implementation of this method.  If they do not, an exception will be
986     * thrown.</em></p>
987     *
988     * @see #onResume
989     */
990    protected void onPostResume() {
991        final Window win = getWindow();
992        if (win != null) win.makeActive();
993        mCalled = true;
994    }
995
996    /**
997     * This is called for activities that set launchMode to "singleTop" in
998     * their package, or if a client used the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP}
999     * flag when calling {@link #startActivity}.  In either case, when the
1000     * activity is re-launched while at the top of the activity stack instead
1001     * of a new instance of the activity being started, onNewIntent() will be
1002     * called on the existing instance with the Intent that was used to
1003     * re-launch it.
1004     *
1005     * <p>An activity will always be paused before receiving a new intent, so
1006     * you can count on {@link #onResume} being called after this method.
1007     *
1008     * <p>Note that {@link #getIntent} still returns the original Intent.  You
1009     * can use {@link #setIntent} to update it to this new Intent.
1010     *
1011     * @param intent The new intent that was started for the activity.
1012     *
1013     * @see #getIntent
1014     * @see #setIntent
1015     * @see #onResume
1016     */
1017    protected void onNewIntent(Intent intent) {
1018    }
1019
1020    /**
1021     * The hook for {@link ActivityThread} to save the state of this activity.
1022     *
1023     * Calls {@link #onSaveInstanceState(android.os.Bundle)}
1024     * and {@link #saveManagedDialogs(android.os.Bundle)}.
1025     *
1026     * @param outState The bundle to save the state to.
1027     */
1028    final void performSaveInstanceState(Bundle outState) {
1029        onSaveInstanceState(outState);
1030        saveManagedDialogs(outState);
1031
1032        // Also save the state of a search dialog (if any)
1033        // TODO more generic than just this manager
1034        // onPause() should always be called before this method, so mSearchManagerState
1035        // should be up to date.
1036        if (mSearchDialogState != null) {
1037            outState.putBundle(SAVED_SEARCH_DIALOG_KEY, mSearchDialogState);
1038        }
1039    }
1040
1041    /**
1042     * Called to retrieve per-instance state from an activity before being killed
1043     * so that the state can be restored in {@link #onCreate} or
1044     * {@link #onRestoreInstanceState} (the {@link Bundle} populated by this method
1045     * will be passed to both).
1046     *
1047     * <p>This method is called before an activity may be killed so that when it
1048     * comes back some time in the future it can restore its state.  For example,
1049     * if activity B is launched in front of activity A, and at some point activity
1050     * A is killed to reclaim resources, activity A will have a chance to save the
1051     * current state of its user interface via this method so that when the user
1052     * returns to activity A, the state of the user interface can be restored
1053     * via {@link #onCreate} or {@link #onRestoreInstanceState}.
1054     *
1055     * <p>Do not confuse this method with activity lifecycle callbacks such as
1056     * {@link #onPause}, which is always called when an activity is being placed
1057     * in the background or on its way to destruction, or {@link #onStop} which
1058     * is called before destruction.  One example of when {@link #onPause} and
1059     * {@link #onStop} is called and not this method is when a user navigates back
1060     * from activity B to activity A: there is no need to call {@link #onSaveInstanceState}
1061     * on B because that particular instance will never be restored, so the
1062     * system avoids calling it.  An example when {@link #onPause} is called and
1063     * not {@link #onSaveInstanceState} is when activity B is launched in front of activity A:
1064     * the system may avoid calling {@link #onSaveInstanceState} on activity A if it isn't
1065     * killed during the lifetime of B since the state of the user interface of
1066     * A will stay intact.
1067     *
1068     * <p>The default implementation takes care of most of the UI per-instance
1069     * state for you by calling {@link android.view.View#onSaveInstanceState()} on each
1070     * view in the hierarchy that has an id, and by saving the id of the currently
1071     * focused view (all of which is restored by the default implementation of
1072     * {@link #onRestoreInstanceState}).  If you override this method to save additional
1073     * information not captured by each individual view, you will likely want to
1074     * call through to the default implementation, otherwise be prepared to save
1075     * all of the state of each view yourself.
1076     *
1077     * <p>If called, this method will occur before {@link #onStop}.  There are
1078     * no guarantees about whether it will occur before or after {@link #onPause}.
1079     *
1080     * @param outState Bundle in which to place your saved state.
1081     *
1082     * @see #onCreate
1083     * @see #onRestoreInstanceState
1084     * @see #onPause
1085     */
1086    protected void onSaveInstanceState(Bundle outState) {
1087        outState.putBundle(WINDOW_HIERARCHY_TAG, mWindow.saveHierarchyState());
1088    }
1089
1090    /**
1091     * Save the state of any managed dialogs.
1092     *
1093     * @param outState place to store the saved state.
1094     */
1095    private void saveManagedDialogs(Bundle outState) {
1096        if (mManagedDialogs == null) {
1097            return;
1098        }
1099
1100        final int numDialogs = mManagedDialogs.size();
1101        if (numDialogs == 0) {
1102            return;
1103        }
1104
1105        Bundle dialogState = new Bundle();
1106
1107        int[] ids = new int[mManagedDialogs.size()];
1108
1109        // save each dialog's bundle, gather the ids
1110        for (int i = 0; i < numDialogs; i++) {
1111            final int key = mManagedDialogs.keyAt(i);
1112            ids[i] = key;
1113            final Dialog dialog = mManagedDialogs.valueAt(i);
1114            dialogState.putBundle(savedDialogKeyFor(key), dialog.onSaveInstanceState());
1115        }
1116
1117        dialogState.putIntArray(SAVED_DIALOG_IDS_KEY, ids);
1118        outState.putBundle(SAVED_DIALOGS_TAG, dialogState);
1119    }
1120
1121
1122    /**
1123     * Called as part of the activity lifecycle when an activity is going into
1124     * the background, but has not (yet) been killed.  The counterpart to
1125     * {@link #onResume}.
1126     *
1127     * <p>When activity B is launched in front of activity A, this callback will
1128     * be invoked on A.  B will not be created until A's {@link #onPause} returns,
1129     * so be sure to not do anything lengthy here.
1130     *
1131     * <p>This callback is mostly used for saving any persistent state the
1132     * activity is editing, to present a "edit in place" model to the user and
1133     * making sure nothing is lost if there are not enough resources to start
1134     * the new activity without first killing this one.  This is also a good
1135     * place to do things like stop animations and other things that consume a
1136     * noticeable mount of CPU in order to make the switch to the next activity
1137     * as fast as possible, or to close resources that are exclusive access
1138     * such as the camera.
1139     *
1140     * <p>In situations where the system needs more memory it may kill paused
1141     * processes to reclaim resources.  Because of this, you should be sure
1142     * that all of your state is saved by the time you return from
1143     * this function.  In general {@link #onSaveInstanceState} is used to save
1144     * per-instance state in the activity and this method is used to store
1145     * global persistent data (in content providers, files, etc.)
1146     *
1147     * <p>After receiving this call you will usually receive a following call
1148     * to {@link #onStop} (after the next activity has been resumed and
1149     * displayed), however in some cases there will be a direct call back to
1150     * {@link #onResume} without going through the stopped state.
1151     *
1152     * <p><em>Derived classes must call through to the super class's
1153     * implementation of this method.  If they do not, an exception will be
1154     * thrown.</em></p>
1155     *
1156     * @see #onResume
1157     * @see #onSaveInstanceState
1158     * @see #onStop
1159     */
1160    protected void onPause() {
1161        mCalled = true;
1162    }
1163
1164    /**
1165     * Called as part of the activity lifecycle when an activity is about to go
1166     * into the background as the result of user choice.  For example, when the
1167     * user presses the Home key, {@link #onUserLeaveHint} will be called, but
1168     * when an incoming phone call causes the in-call Activity to be automatically
1169     * brought to the foreground, {@link #onUserLeaveHint} will not be called on
1170     * the activity being interrupted.  In cases when it is invoked, this method
1171     * is called right before the activity's {@link #onPause} callback.
1172     *
1173     * <p>This callback and {@link #onUserInteraction} are intended to help
1174     * activities manage status bar notifications intelligently; specifically,
1175     * for helping activities determine the proper time to cancel a notfication.
1176     *
1177     * @see #onUserInteraction()
1178     */
1179    protected void onUserLeaveHint() {
1180    }
1181
1182    /**
1183     * Generate a new thumbnail for this activity.  This method is called before
1184     * pausing the activity, and should draw into <var>outBitmap</var> the
1185     * imagery for the desired thumbnail in the dimensions of that bitmap.  It
1186     * can use the given <var>canvas</var>, which is configured to draw into the
1187     * bitmap, for rendering if desired.
1188     *
1189     * <p>The default implementation renders the Screen's current view
1190     * hierarchy into the canvas to generate a thumbnail.
1191     *
1192     * <p>If you return false, the bitmap will be filled with a default
1193     * thumbnail.
1194     *
1195     * @param outBitmap The bitmap to contain the thumbnail.
1196     * @param canvas Can be used to render into the bitmap.
1197     *
1198     * @return Return true if you have drawn into the bitmap; otherwise after
1199     *         you return it will be filled with a default thumbnail.
1200     *
1201     * @see #onCreateDescription
1202     * @see #onSaveInstanceState
1203     * @see #onPause
1204     */
1205    public boolean onCreateThumbnail(Bitmap outBitmap, Canvas canvas) {
1206        final View view = mDecor;
1207        if (view == null) {
1208            return false;
1209        }
1210
1211        final int vw = view.getWidth();
1212        final int vh = view.getHeight();
1213        final int dw = outBitmap.getWidth();
1214        final int dh = outBitmap.getHeight();
1215
1216        canvas.save();
1217        canvas.scale(((float)dw)/vw, ((float)dh)/vh);
1218        view.draw(canvas);
1219        canvas.restore();
1220
1221        return true;
1222    }
1223
1224    /**
1225     * Generate a new description for this activity.  This method is called
1226     * before pausing the activity and can, if desired, return some textual
1227     * description of its current state to be displayed to the user.
1228     *
1229     * <p>The default implementation returns null, which will cause you to
1230     * inherit the description from the previous activity.  If all activities
1231     * return null, generally the label of the top activity will be used as the
1232     * description.
1233     *
1234     * @return A description of what the user is doing.  It should be short and
1235     *         sweet (only a few words).
1236     *
1237     * @see #onCreateThumbnail
1238     * @see #onSaveInstanceState
1239     * @see #onPause
1240     */
1241    public CharSequence onCreateDescription() {
1242        return null;
1243    }
1244
1245    /**
1246     * Called when you are no longer visible to the user.  You will next
1247     * receive either {@link #onRestart}, {@link #onDestroy}, or nothing,
1248     * depending on later user activity.
1249     *
1250     * <p>Note that this method may never be called, in low memory situations
1251     * where the system does not have enough memory to keep your activity's
1252     * process running after its {@link #onPause} method is called.
1253     *
1254     * <p><em>Derived classes must call through to the super class's
1255     * implementation of this method.  If they do not, an exception will be
1256     * thrown.</em></p>
1257     *
1258     * @see #onRestart
1259     * @see #onResume
1260     * @see #onSaveInstanceState
1261     * @see #onDestroy
1262     */
1263    protected void onStop() {
1264        mCalled = true;
1265    }
1266
1267    /**
1268     * Perform any final cleanup before an activity is destroyed.  This can
1269     * happen either because the activity is finishing (someone called
1270     * {@link #finish} on it, or because the system is temporarily destroying
1271     * this instance of the activity to save space.  You can distinguish
1272     * between these two scenarios with the {@link #isFinishing} method.
1273     *
1274     * <p><em>Note: do not count on this method being called as a place for
1275     * saving data! For example, if an activity is editing data in a content
1276     * provider, those edits should be committed in either {@link #onPause} or
1277     * {@link #onSaveInstanceState}, not here.</em> This method is usually implemented to
1278     * free resources like threads that are associated with an activity, so
1279     * that a destroyed activity does not leave such things around while the
1280     * rest of its application is still running.  There are situations where
1281     * the system will simply kill the activity's hosting process without
1282     * calling this method (or any others) in it, so it should not be used to
1283     * do things that are intended to remain around after the process goes
1284     * away.
1285     *
1286     * <p><em>Derived classes must call through to the super class's
1287     * implementation of this method.  If they do not, an exception will be
1288     * thrown.</em></p>
1289     *
1290     * @see #onPause
1291     * @see #onStop
1292     * @see #finish
1293     * @see #isFinishing
1294     */
1295    protected void onDestroy() {
1296        mCalled = true;
1297
1298        // dismiss any dialogs we are managing.
1299        if (mManagedDialogs != null) {
1300
1301            final int numDialogs = mManagedDialogs.size();
1302            for (int i = 0; i < numDialogs; i++) {
1303                final Dialog dialog = mManagedDialogs.valueAt(i);
1304                if (dialog.isShowing()) {
1305                    dialog.dismiss();
1306                }
1307            }
1308        }
1309
1310        // close any cursors we are managing.
1311        int numCursors = mManagedCursors.size();
1312        for (int i = 0; i < numCursors; i++) {
1313            ManagedCursor c = mManagedCursors.get(i);
1314            if (c != null) {
1315                c.mCursor.close();
1316            }
1317        }
1318
1319        // Clear any search state saved in performPause(). If the state may be needed in the
1320        // future, it will have been saved by performSaveInstanceState()
1321        mSearchDialogState = null;
1322    }
1323
1324    /**
1325     * Called by the system when the device configuration changes while your
1326     * activity is running.  Note that this will <em>only</em> be called if
1327     * you have selected configurations you would like to handle with the
1328     * {@link android.R.attr#configChanges} attribute in your manifest.  If
1329     * any configuration change occurs that is not selected to be reported
1330     * by that attribute, then instead of reporting it the system will stop
1331     * and restart the activity (to have it launched with the new
1332     * configuration).
1333     *
1334     * <p>At the time that this function has been called, your Resources
1335     * object will have been updated to return resource values matching the
1336     * new configuration.
1337     *
1338     * @param newConfig The new device configuration.
1339     */
1340    public void onConfigurationChanged(Configuration newConfig) {
1341        mCalled = true;
1342
1343        // also update search dialog if showing
1344        // TODO more generic than just this manager
1345        mSearchManager.onConfigurationChanged(newConfig);
1346
1347        if (mWindow != null) {
1348            // Pass the configuration changed event to the window
1349            mWindow.onConfigurationChanged(newConfig);
1350        }
1351    }
1352
1353    /**
1354     * If this activity is being destroyed because it can not handle a
1355     * configuration parameter being changed (and thus its
1356     * {@link #onConfigurationChanged(Configuration)} method is
1357     * <em>not</em> being called), then you can use this method to discover
1358     * the set of changes that have occurred while in the process of being
1359     * destroyed.  Note that there is no guarantee that these will be
1360     * accurate (other changes could have happened at any time), so you should
1361     * only use this as an optimization hint.
1362     *
1363     * @return Returns a bit field of the configuration parameters that are
1364     * changing, as defined by the {@link android.content.res.Configuration}
1365     * class.
1366     */
1367    public int getChangingConfigurations() {
1368        return mConfigChangeFlags;
1369    }
1370
1371    /**
1372     * Retrieve the non-configuration instance data that was previously
1373     * returned by {@link #onRetainNonConfigurationInstance()}.  This will
1374     * be available from the initial {@link #onCreate} and
1375     * {@link #onStart} calls to the new instance, allowing you to extract
1376     * any useful dynamic state from the previous instance.
1377     *
1378     * <p>Note that the data you retrieve here should <em>only</em> be used
1379     * as an optimization for handling configuration changes.  You should always
1380     * be able to handle getting a null pointer back, and an activity must
1381     * still be able to restore itself to its previous state (through the
1382     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1383     * function returns null.
1384     *
1385     * @return Returns the object previously returned by
1386     * {@link #onRetainNonConfigurationInstance()}.
1387     */
1388    public Object getLastNonConfigurationInstance() {
1389        return mLastNonConfigurationInstance;
1390    }
1391
1392    /**
1393     * Called by the system, as part of destroying an
1394     * activity due to a configuration change, when it is known that a new
1395     * instance will immediately be created for the new configuration.  You
1396     * can return any object you like here, including the activity instance
1397     * itself, which can later be retrieved by calling
1398     * {@link #getLastNonConfigurationInstance()} in the new activity
1399     * instance.
1400     *
1401     * <p>This function is called purely as an optimization, and you must
1402     * not rely on it being called.  When it is called, a number of guarantees
1403     * will be made to help optimize configuration switching:
1404     * <ul>
1405     * <li> The function will be called between {@link #onStop} and
1406     * {@link #onDestroy}.
1407     * <li> A new instance of the activity will <em>always</em> be immediately
1408     * created after this one's {@link #onDestroy()} is called.
1409     * <li> The object you return here will <em>always</em> be available from
1410     * the {@link #getLastNonConfigurationInstance()} method of the following
1411     * activity instance as described there.
1412     * </ul>
1413     *
1414     * <p>These guarantees are designed so that an activity can use this API
1415     * to propagate extensive state from the old to new activity instance, from
1416     * loaded bitmaps, to network connections, to evenly actively running
1417     * threads.  Note that you should <em>not</em> propagate any data that
1418     * may change based on the configuration, including any data loaded from
1419     * resources such as strings, layouts, or drawables.
1420     *
1421     * @return Return any Object holding the desired state to propagate to the
1422     * next activity instance.
1423     */
1424    public Object onRetainNonConfigurationInstance() {
1425        return null;
1426    }
1427
1428    /**
1429     * Retrieve the non-configuration instance data that was previously
1430     * returned by {@link #onRetainNonConfigurationChildInstances()}.  This will
1431     * be available from the initial {@link #onCreate} and
1432     * {@link #onStart} calls to the new instance, allowing you to extract
1433     * any useful dynamic state from the previous instance.
1434     *
1435     * <p>Note that the data you retrieve here should <em>only</em> be used
1436     * as an optimization for handling configuration changes.  You should always
1437     * be able to handle getting a null pointer back, and an activity must
1438     * still be able to restore itself to its previous state (through the
1439     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1440     * function returns null.
1441     *
1442     * @return Returns the object previously returned by
1443     * {@link #onRetainNonConfigurationChildInstances()}
1444     */
1445    HashMap<String,Object> getLastNonConfigurationChildInstances() {
1446        return mLastNonConfigurationChildInstances;
1447    }
1448
1449    /**
1450     * This method is similar to {@link #onRetainNonConfigurationInstance()} except that
1451     * it should return either a mapping from  child activity id strings to arbitrary objects,
1452     * or null.  This method is intended to be used by Activity framework subclasses that control a
1453     * set of child activities, such as ActivityGroup.  The same guarantees and restrictions apply
1454     * as for {@link #onRetainNonConfigurationInstance()}.  The default implementation returns null.
1455     */
1456    HashMap<String,Object> onRetainNonConfigurationChildInstances() {
1457        return null;
1458    }
1459
1460    public void onLowMemory() {
1461        mCalled = true;
1462    }
1463
1464    /**
1465     * Wrapper around
1466     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1467     * that gives the resulting {@link Cursor} to call
1468     * {@link #startManagingCursor} so that the activity will manage its
1469     * lifecycle for you.
1470     *
1471     * @param uri The URI of the content provider to query.
1472     * @param projection List of columns to return.
1473     * @param selection SQL WHERE clause.
1474     * @param sortOrder SQL ORDER BY clause.
1475     *
1476     * @return The Cursor that was returned by query().
1477     *
1478     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1479     * @see #startManagingCursor
1480     * @hide
1481     */
1482    public final Cursor managedQuery(Uri uri,
1483                                     String[] projection,
1484                                     String selection,
1485                                     String sortOrder)
1486    {
1487        Cursor c = getContentResolver().query(uri, projection, selection, null, sortOrder);
1488        if (c != null) {
1489            startManagingCursor(c);
1490        }
1491        return c;
1492    }
1493
1494    /**
1495     * Wrapper around
1496     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1497     * that gives the resulting {@link Cursor} to call
1498     * {@link #startManagingCursor} so that the activity will manage its
1499     * lifecycle for you.
1500     *
1501     * @param uri The URI of the content provider to query.
1502     * @param projection List of columns to return.
1503     * @param selection SQL WHERE clause.
1504     * @param selectionArgs The arguments to selection, if any ?s are pesent
1505     * @param sortOrder SQL ORDER BY clause.
1506     *
1507     * @return The Cursor that was returned by query().
1508     *
1509     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1510     * @see #startManagingCursor
1511     */
1512    public final Cursor managedQuery(Uri uri,
1513                                     String[] projection,
1514                                     String selection,
1515                                     String[] selectionArgs,
1516                                     String sortOrder)
1517    {
1518        Cursor c = getContentResolver().query(uri, projection, selection, selectionArgs, sortOrder);
1519        if (c != null) {
1520            startManagingCursor(c);
1521        }
1522        return c;
1523    }
1524
1525    /**
1526     * Wrapper around {@link Cursor#commitUpdates()} that takes care of noting
1527     * that the Cursor needs to be requeried.  You can call this method in
1528     * {@link #onPause} or {@link #onStop} to have the system call
1529     * {@link Cursor#requery} for you if the activity is later resumed.  This
1530     * allows you to avoid determing when to do the requery yourself (which is
1531     * required for the Cursor to see any data changes that were committed with
1532     * it).
1533     *
1534     * @param c The Cursor whose changes are to be committed.
1535     *
1536     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
1537     * @see #startManagingCursor
1538     * @see Cursor#commitUpdates()
1539     * @see Cursor#requery
1540     * @hide
1541     */
1542    @Deprecated
1543    public void managedCommitUpdates(Cursor c) {
1544        synchronized (mManagedCursors) {
1545            final int N = mManagedCursors.size();
1546            for (int i=0; i<N; i++) {
1547                ManagedCursor mc = mManagedCursors.get(i);
1548                if (mc.mCursor == c) {
1549                    c.commitUpdates();
1550                    mc.mUpdated = true;
1551                    return;
1552                }
1553            }
1554            throw new RuntimeException(
1555                "Cursor " + c + " is not currently managed");
1556        }
1557    }
1558
1559    /**
1560     * This method allows the activity to take care of managing the given
1561     * {@link Cursor}'s lifecycle for you based on the activity's lifecycle.
1562     * That is, when the activity is stopped it will automatically call
1563     * {@link Cursor#deactivate} on the given Cursor, and when it is later restarted
1564     * it will call {@link Cursor#requery} for you.  When the activity is
1565     * destroyed, all managed Cursors will be closed automatically.
1566     *
1567     * @param c The Cursor to be managed.
1568     *
1569     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
1570     * @see #stopManagingCursor
1571     */
1572    public void startManagingCursor(Cursor c) {
1573        synchronized (mManagedCursors) {
1574            mManagedCursors.add(new ManagedCursor(c));
1575        }
1576    }
1577
1578    /**
1579     * Given a Cursor that was previously given to
1580     * {@link #startManagingCursor}, stop the activity's management of that
1581     * cursor.
1582     *
1583     * @param c The Cursor that was being managed.
1584     *
1585     * @see #startManagingCursor
1586     */
1587    public void stopManagingCursor(Cursor c) {
1588        synchronized (mManagedCursors) {
1589            final int N = mManagedCursors.size();
1590            for (int i=0; i<N; i++) {
1591                ManagedCursor mc = mManagedCursors.get(i);
1592                if (mc.mCursor == c) {
1593                    mManagedCursors.remove(i);
1594                    break;
1595                }
1596            }
1597        }
1598    }
1599
1600    /**
1601     * Control whether this activity is required to be persistent.  By default
1602     * activities are not persistent; setting this to true will prevent the
1603     * system from stopping this activity or its process when running low on
1604     * resources.
1605     *
1606     * <p><em>You should avoid using this method</em>, it has severe negative
1607     * consequences on how well the system can manage its resources.  A better
1608     * approach is to implement an application service that you control with
1609     * {@link Context#startService} and {@link Context#stopService}.
1610     *
1611     * @param isPersistent Control whether the current activity must be
1612     *                     persistent, true if so, false for the normal
1613     *                     behavior.
1614     */
1615    public void setPersistent(boolean isPersistent) {
1616        if (mParent == null) {
1617            try {
1618                ActivityManagerNative.getDefault()
1619                    .setPersistent(mToken, isPersistent);
1620            } catch (RemoteException e) {
1621                // Empty
1622            }
1623        } else {
1624            throw new RuntimeException("setPersistent() not yet supported for embedded activities");
1625        }
1626    }
1627
1628    /**
1629     * Finds a view that was identified by the id attribute from the XML that
1630     * was processed in {@link #onCreate}.
1631     *
1632     * @return The view if found or null otherwise.
1633     */
1634    public View findViewById(int id) {
1635        return getWindow().findViewById(id);
1636    }
1637
1638    /**
1639     * Set the activity content from a layout resource.  The resource will be
1640     * inflated, adding all top-level views to the activity.
1641     *
1642     * @param layoutResID Resource ID to be inflated.
1643     */
1644    public void setContentView(int layoutResID) {
1645        getWindow().setContentView(layoutResID);
1646    }
1647
1648    /**
1649     * Set the activity content to an explicit view.  This view is placed
1650     * directly into the activity's view hierarchy.  It can itself be a complex
1651     * view hierarhcy.
1652     *
1653     * @param view The desired content to display.
1654     */
1655    public void setContentView(View view) {
1656        getWindow().setContentView(view);
1657    }
1658
1659    /**
1660     * Set the activity content to an explicit view.  This view is placed
1661     * directly into the activity's view hierarchy.  It can itself be a complex
1662     * view hierarhcy.
1663     *
1664     * @param view The desired content to display.
1665     * @param params Layout parameters for the view.
1666     */
1667    public void setContentView(View view, ViewGroup.LayoutParams params) {
1668        getWindow().setContentView(view, params);
1669    }
1670
1671    /**
1672     * Add an additional content view to the activity.  Added after any existing
1673     * ones in the activity -- existing views are NOT removed.
1674     *
1675     * @param view The desired content to display.
1676     * @param params Layout parameters for the view.
1677     */
1678    public void addContentView(View view, ViewGroup.LayoutParams params) {
1679        getWindow().addContentView(view, params);
1680    }
1681
1682    /**
1683     * Use with {@link #setDefaultKeyMode} to turn off default handling of
1684     * keys.
1685     *
1686     * @see #setDefaultKeyMode
1687     */
1688    static public final int DEFAULT_KEYS_DISABLE = 0;
1689    /**
1690     * Use with {@link #setDefaultKeyMode} to launch the dialer during default
1691     * key handling.
1692     *
1693     * @see #setDefaultKeyMode
1694     */
1695    static public final int DEFAULT_KEYS_DIALER = 1;
1696    /**
1697     * Use with {@link #setDefaultKeyMode} to execute a menu shortcut in
1698     * default key handling.
1699     *
1700     * <p>That is, the user does not need to hold down the menu key to execute menu shortcuts.
1701     *
1702     * @see #setDefaultKeyMode
1703     */
1704    static public final int DEFAULT_KEYS_SHORTCUT = 2;
1705    /**
1706     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1707     * will start an application-defined search.  (If the application or activity does not
1708     * actually define a search, the the keys will be ignored.)
1709     *
1710     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1711     *
1712     * @see #setDefaultKeyMode
1713     */
1714    static public final int DEFAULT_KEYS_SEARCH_LOCAL = 3;
1715
1716    /**
1717     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1718     * will start a global search (typically web search, but some platforms may define alternate
1719     * methods for global search)
1720     *
1721     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1722     *
1723     * @see #setDefaultKeyMode
1724     */
1725    static public final int DEFAULT_KEYS_SEARCH_GLOBAL = 4;
1726
1727    /**
1728     * Select the default key handling for this activity.  This controls what
1729     * will happen to key events that are not otherwise handled.  The default
1730     * mode ({@link #DEFAULT_KEYS_DISABLE}) will simply drop them on the
1731     * floor. Other modes allow you to launch the dialer
1732     * ({@link #DEFAULT_KEYS_DIALER}), execute a shortcut in your options
1733     * menu without requiring the menu key be held down
1734     * ({@link #DEFAULT_KEYS_SHORTCUT}), or launch a search ({@link #DEFAULT_KEYS_SEARCH_LOCAL}
1735     * and {@link #DEFAULT_KEYS_SEARCH_GLOBAL}).
1736     *
1737     * <p>Note that the mode selected here does not impact the default
1738     * handling of system keys, such as the "back" and "menu" keys, and your
1739     * activity and its views always get a first chance to receive and handle
1740     * all application keys.
1741     *
1742     * @param mode The desired default key mode constant.
1743     *
1744     * @see #DEFAULT_KEYS_DISABLE
1745     * @see #DEFAULT_KEYS_DIALER
1746     * @see #DEFAULT_KEYS_SHORTCUT
1747     * @see #DEFAULT_KEYS_SEARCH_LOCAL
1748     * @see #DEFAULT_KEYS_SEARCH_GLOBAL
1749     * @see #onKeyDown
1750     */
1751    public final void setDefaultKeyMode(int mode) {
1752        mDefaultKeyMode = mode;
1753
1754        // Some modes use a SpannableStringBuilder to track & dispatch input events
1755        // This list must remain in sync with the switch in onKeyDown()
1756        switch (mode) {
1757        case DEFAULT_KEYS_DISABLE:
1758        case DEFAULT_KEYS_SHORTCUT:
1759            mDefaultKeySsb = null;      // not used in these modes
1760            break;
1761        case DEFAULT_KEYS_DIALER:
1762        case DEFAULT_KEYS_SEARCH_LOCAL:
1763        case DEFAULT_KEYS_SEARCH_GLOBAL:
1764            mDefaultKeySsb = new SpannableStringBuilder();
1765            Selection.setSelection(mDefaultKeySsb,0);
1766            break;
1767        default:
1768            throw new IllegalArgumentException();
1769        }
1770    }
1771
1772    /**
1773     * Called when a key was pressed down and not handled by any of the views
1774     * inside of the activity. So, for example, key presses while the cursor
1775     * is inside a TextView will not trigger the event (unless it is a navigation
1776     * to another object) because TextView handles its own key presses.
1777     *
1778     * <p>If the focused view didn't want this event, this method is called.
1779     *
1780     * <p>The default implementation handles KEYCODE_BACK to stop the activity
1781     * and go back, and other default key handling if configured with {@link #setDefaultKeyMode}.
1782     *
1783     * @return Return <code>true</code> to prevent this event from being propagated
1784     * further, or <code>false</code> to indicate that you have not handled
1785     * this event and it should continue to be propagated.
1786     * @see #onKeyUp
1787     * @see android.view.KeyEvent
1788     */
1789    public boolean onKeyDown(int keyCode, KeyEvent event)  {
1790        if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
1791            finish();
1792            return true;
1793        }
1794
1795        if (mDefaultKeyMode == DEFAULT_KEYS_DISABLE) {
1796            return false;
1797        } else if (mDefaultKeyMode == DEFAULT_KEYS_SHORTCUT) {
1798            return getWindow().performPanelShortcut(Window.FEATURE_OPTIONS_PANEL,
1799                                                    keyCode, event, Menu.FLAG_ALWAYS_PERFORM_CLOSE);
1800        } else {
1801            // Common code for DEFAULT_KEYS_DIALER & DEFAULT_KEYS_SEARCH_*
1802            boolean clearSpannable = false;
1803            boolean handled;
1804            if ((event.getRepeatCount() != 0) || event.isSystem()) {
1805                clearSpannable = true;
1806                handled = false;
1807            } else {
1808                handled = TextKeyListener.getInstance().onKeyDown(null, mDefaultKeySsb,
1809                                                                  keyCode, event);
1810                if (handled && mDefaultKeySsb.length() > 0) {
1811                    // something useable has been typed - dispatch it now.
1812
1813                    final String str = mDefaultKeySsb.toString();
1814                    clearSpannable = true;
1815
1816                    switch (mDefaultKeyMode) {
1817                    case DEFAULT_KEYS_DIALER:
1818                        Intent intent = new Intent(Intent.ACTION_DIAL,  Uri.parse("tel:" + str));
1819                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
1820                        startActivity(intent);
1821                        break;
1822                    case DEFAULT_KEYS_SEARCH_LOCAL:
1823                        startSearch(str, false, null, false);
1824                        break;
1825                    case DEFAULT_KEYS_SEARCH_GLOBAL:
1826                        startSearch(str, false, null, true);
1827                        break;
1828                    }
1829                }
1830            }
1831            if (clearSpannable) {
1832                mDefaultKeySsb.clear();
1833                mDefaultKeySsb.clearSpans();
1834                Selection.setSelection(mDefaultKeySsb,0);
1835            }
1836            return handled;
1837        }
1838    }
1839
1840    /**
1841     * Called when a key was released and not handled by any of the views
1842     * inside of the activity. So, for example, key presses while the cursor
1843     * is inside a TextView will not trigger the event (unless it is a navigation
1844     * to another object) because TextView handles its own key presses.
1845     *
1846     * @return Return <code>true</code> to prevent this event from being propagated
1847     * further, or <code>false</code> to indicate that you have not handled
1848     * this event and it should continue to be propagated.
1849     * @see #onKeyDown
1850     * @see KeyEvent
1851     */
1852    public boolean onKeyUp(int keyCode, KeyEvent event) {
1853        return false;
1854    }
1855
1856    /**
1857     * Default implementation of {@link KeyEvent.Callback#onKeyMultiple(int, int, KeyEvent)
1858     * KeyEvent.Callback.onKeyMultiple()}: always returns false (doesn't handle
1859     * the event).
1860     */
1861    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
1862        return false;
1863    }
1864
1865    /**
1866     * Called when a touch screen event was not handled by any of the views
1867     * under it.  This is most useful to process touch events that happen
1868     * outside of your window bounds, where there is no view to receive it.
1869     *
1870     * @param event The touch screen event being processed.
1871     *
1872     * @return Return true if you have consumed the event, false if you haven't.
1873     * The default implementation always returns false.
1874     */
1875    public boolean onTouchEvent(MotionEvent event) {
1876        return false;
1877    }
1878
1879    /**
1880     * Called when the trackball was moved and not handled by any of the
1881     * views inside of the activity.  So, for example, if the trackball moves
1882     * while focus is on a button, you will receive a call here because
1883     * buttons do not normally do anything with trackball events.  The call
1884     * here happens <em>before</em> trackball movements are converted to
1885     * DPAD key events, which then get sent back to the view hierarchy, and
1886     * will be processed at the point for things like focus navigation.
1887     *
1888     * @param event The trackball event being processed.
1889     *
1890     * @return Return true if you have consumed the event, false if you haven't.
1891     * The default implementation always returns false.
1892     */
1893    public boolean onTrackballEvent(MotionEvent event) {
1894        return false;
1895    }
1896
1897    /**
1898     * Called whenever a key, touch, or trackball event is dispatched to the
1899     * activity.  Implement this method if you wish to know that the user has
1900     * interacted with the device in some way while your activity is running.
1901     * This callback and {@link #onUserLeaveHint} are intended to help
1902     * activities manage status bar notifications intelligently; specifically,
1903     * for helping activities determine the proper time to cancel a notfication.
1904     *
1905     * <p>All calls to your activity's {@link #onUserLeaveHint} callback will
1906     * be accompanied by calls to {@link #onUserInteraction}.  This
1907     * ensures that your activity will be told of relevant user activity such
1908     * as pulling down the notification pane and touching an item there.
1909     *
1910     * <p>Note that this callback will be invoked for the touch down action
1911     * that begins a touch gesture, but may not be invoked for the touch-moved
1912     * and touch-up actions that follow.
1913     *
1914     * @see #onUserLeaveHint()
1915     */
1916    public void onUserInteraction() {
1917    }
1918
1919    public void onWindowAttributesChanged(WindowManager.LayoutParams params) {
1920        // Update window manager if: we have a view, that view is
1921        // attached to its parent (which will be a RootView), and
1922        // this activity is not embedded.
1923        if (mParent == null) {
1924            View decor = mDecor;
1925            if (decor != null && decor.getParent() != null) {
1926                getWindowManager().updateViewLayout(decor, params);
1927            }
1928        }
1929    }
1930
1931    public void onContentChanged() {
1932    }
1933
1934    /**
1935     * Called when the current {@link Window} of the activity gains or loses
1936     * focus.  This is the best indicator of whether this activity is visible
1937     * to the user.
1938     *
1939     * <p>Note that this provides information what global focus state, which
1940     * is managed independently of activity lifecycles.  As such, while focus
1941     * changes will generally have some relation to lifecycle changes (an
1942     * activity that is stopped will not generally get window focus), you
1943     * should not rely on any particular order between the callbacks here and
1944     * those in the other lifecycle methods such as {@link #onResume}.
1945     *
1946     * <p>As a general rule, however, a resumed activity will have window
1947     * focus...  unless it has displayed other dialogs or popups that take
1948     * input focus, in which case the activity itself will not have focus
1949     * when the other windows have it.  Likewise, the system may display
1950     * system-level windows (such as the status bar notification panel or
1951     * a system alert) which will temporarily take window input focus without
1952     * pausing the foreground activity.
1953     *
1954     * @param hasFocus Whether the window of this activity has focus.
1955     *
1956     * @see #hasWindowFocus()
1957     * @see #onResume
1958     */
1959    public void onWindowFocusChanged(boolean hasFocus) {
1960    }
1961
1962    /**
1963     * Returns true if this activity's <em>main</em> window currently has window focus.
1964     * Note that this is not the same as the view itself having focus.
1965     *
1966     * @return True if this activity's main window currently has window focus.
1967     *
1968     * @see #onWindowAttributesChanged(android.view.WindowManager.LayoutParams)
1969     */
1970    public boolean hasWindowFocus() {
1971        Window w = getWindow();
1972        if (w != null) {
1973            View d = w.getDecorView();
1974            if (d != null) {
1975                return d.hasWindowFocus();
1976            }
1977        }
1978        return false;
1979    }
1980
1981    /**
1982     * Called to process key events.  You can override this to intercept all
1983     * key events before they are dispatched to the window.  Be sure to call
1984     * this implementation for key events that should be handled normally.
1985     *
1986     * @param event The key event.
1987     *
1988     * @return boolean Return true if this event was consumed.
1989     */
1990    public boolean dispatchKeyEvent(KeyEvent event) {
1991        onUserInteraction();
1992        if (getWindow().superDispatchKeyEvent(event)) {
1993            return true;
1994        }
1995        return event.dispatch(this);
1996    }
1997
1998    /**
1999     * Called to process touch screen events.  You can override this to
2000     * intercept all touch screen events before they are dispatched to the
2001     * window.  Be sure to call this implementation for touch screen events
2002     * that should be handled normally.
2003     *
2004     * @param ev The touch screen event.
2005     *
2006     * @return boolean Return true if this event was consumed.
2007     */
2008    public boolean dispatchTouchEvent(MotionEvent ev) {
2009        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
2010            onUserInteraction();
2011        }
2012        if (getWindow().superDispatchTouchEvent(ev)) {
2013            return true;
2014        }
2015        return onTouchEvent(ev);
2016    }
2017
2018    /**
2019     * Called to process trackball events.  You can override this to
2020     * intercept all trackball events before they are dispatched to the
2021     * window.  Be sure to call this implementation for trackball events
2022     * that should be handled normally.
2023     *
2024     * @param ev The trackball event.
2025     *
2026     * @return boolean Return true if this event was consumed.
2027     */
2028    public boolean dispatchTrackballEvent(MotionEvent ev) {
2029        onUserInteraction();
2030        if (getWindow().superDispatchTrackballEvent(ev)) {
2031            return true;
2032        }
2033        return onTrackballEvent(ev);
2034    }
2035
2036    public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) {
2037        event.setClassName(getClass().getName());
2038        event.setPackageName(getPackageName());
2039
2040        LayoutParams params = getWindow().getAttributes();
2041        boolean isFullScreen = (params.width == LayoutParams.FILL_PARENT) &&
2042            (params.height == LayoutParams.FILL_PARENT);
2043        event.setFullScreen(isFullScreen);
2044
2045        CharSequence title = getTitle();
2046        if (!TextUtils.isEmpty(title)) {
2047           event.getText().add(title);
2048        }
2049
2050        return true;
2051    }
2052
2053    /**
2054     * Default implementation of
2055     * {@link android.view.Window.Callback#onCreatePanelView}
2056     * for activities. This
2057     * simply returns null so that all panel sub-windows will have the default
2058     * menu behavior.
2059     */
2060    public View onCreatePanelView(int featureId) {
2061        return null;
2062    }
2063
2064    /**
2065     * Default implementation of
2066     * {@link android.view.Window.Callback#onCreatePanelMenu}
2067     * for activities.  This calls through to the new
2068     * {@link #onCreateOptionsMenu} method for the
2069     * {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2070     * so that subclasses of Activity don't need to deal with feature codes.
2071     */
2072    public boolean onCreatePanelMenu(int featureId, Menu menu) {
2073        if (featureId == Window.FEATURE_OPTIONS_PANEL) {
2074            return onCreateOptionsMenu(menu);
2075        }
2076        return false;
2077    }
2078
2079    /**
2080     * Default implementation of
2081     * {@link android.view.Window.Callback#onPreparePanel}
2082     * for activities.  This
2083     * calls through to the new {@link #onPrepareOptionsMenu} method for the
2084     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2085     * panel, so that subclasses of
2086     * Activity don't need to deal with feature codes.
2087     */
2088    public boolean onPreparePanel(int featureId, View view, Menu menu) {
2089        if (featureId == Window.FEATURE_OPTIONS_PANEL && menu != null) {
2090            boolean goforit = onPrepareOptionsMenu(menu);
2091            return goforit && menu.hasVisibleItems();
2092        }
2093        return true;
2094    }
2095
2096    /**
2097     * {@inheritDoc}
2098     *
2099     * @return The default implementation returns true.
2100     */
2101    public boolean onMenuOpened(int featureId, Menu menu) {
2102        return true;
2103    }
2104
2105    /**
2106     * Default implementation of
2107     * {@link android.view.Window.Callback#onMenuItemSelected}
2108     * for activities.  This calls through to the new
2109     * {@link #onOptionsItemSelected} method for the
2110     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2111     * panel, so that subclasses of
2112     * Activity don't need to deal with feature codes.
2113     */
2114    public boolean onMenuItemSelected(int featureId, MenuItem item) {
2115        switch (featureId) {
2116            case Window.FEATURE_OPTIONS_PANEL:
2117                // Put event logging here so it gets called even if subclass
2118                // doesn't call through to superclass's implmeentation of each
2119                // of these methods below
2120                EventLog.writeEvent(50000, 0, item.getTitleCondensed());
2121                return onOptionsItemSelected(item);
2122
2123            case Window.FEATURE_CONTEXT_MENU:
2124                EventLog.writeEvent(50000, 1, item.getTitleCondensed());
2125                return onContextItemSelected(item);
2126
2127            default:
2128                return false;
2129        }
2130    }
2131
2132    /**
2133     * Default implementation of
2134     * {@link android.view.Window.Callback#onPanelClosed(int, Menu)} for
2135     * activities. This calls through to {@link #onOptionsMenuClosed(Menu)}
2136     * method for the {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2137     * so that subclasses of Activity don't need to deal with feature codes.
2138     * For context menus ({@link Window#FEATURE_CONTEXT_MENU}), the
2139     * {@link #onContextMenuClosed(Menu)} will be called.
2140     */
2141    public void onPanelClosed(int featureId, Menu menu) {
2142        switch (featureId) {
2143            case Window.FEATURE_OPTIONS_PANEL:
2144                onOptionsMenuClosed(menu);
2145                break;
2146
2147            case Window.FEATURE_CONTEXT_MENU:
2148                onContextMenuClosed(menu);
2149                break;
2150        }
2151    }
2152
2153    /**
2154     * Initialize the contents of the Activity's standard options menu.  You
2155     * should place your menu items in to <var>menu</var>.
2156     *
2157     * <p>This is only called once, the first time the options menu is
2158     * displayed.  To update the menu every time it is displayed, see
2159     * {@link #onPrepareOptionsMenu}.
2160     *
2161     * <p>The default implementation populates the menu with standard system
2162     * menu items.  These are placed in the {@link Menu#CATEGORY_SYSTEM} group so that
2163     * they will be correctly ordered with application-defined menu items.
2164     * Deriving classes should always call through to the base implementation.
2165     *
2166     * <p>You can safely hold on to <var>menu</var> (and any items created
2167     * from it), making modifications to it as desired, until the next
2168     * time onCreateOptionsMenu() is called.
2169     *
2170     * <p>When you add items to the menu, you can implement the Activity's
2171     * {@link #onOptionsItemSelected} method to handle them there.
2172     *
2173     * @param menu The options menu in which you place your items.
2174     *
2175     * @return You must return true for the menu to be displayed;
2176     *         if you return false it will not be shown.
2177     *
2178     * @see #onPrepareOptionsMenu
2179     * @see #onOptionsItemSelected
2180     */
2181    public boolean onCreateOptionsMenu(Menu menu) {
2182        if (mParent != null) {
2183            return mParent.onCreateOptionsMenu(menu);
2184        }
2185        return true;
2186    }
2187
2188    /**
2189     * Prepare the Screen's standard options menu to be displayed.  This is
2190     * called right before the menu is shown, every time it is shown.  You can
2191     * use this method to efficiently enable/disable items or otherwise
2192     * dynamically modify the contents.
2193     *
2194     * <p>The default implementation updates the system menu items based on the
2195     * activity's state.  Deriving classes should always call through to the
2196     * base class implementation.
2197     *
2198     * @param menu The options menu as last shown or first initialized by
2199     *             onCreateOptionsMenu().
2200     *
2201     * @return You must return true for the menu to be displayed;
2202     *         if you return false it will not be shown.
2203     *
2204     * @see #onCreateOptionsMenu
2205     */
2206    public boolean onPrepareOptionsMenu(Menu menu) {
2207        if (mParent != null) {
2208            return mParent.onPrepareOptionsMenu(menu);
2209        }
2210        return true;
2211    }
2212
2213    /**
2214     * This hook is called whenever an item in your options menu is selected.
2215     * The default implementation simply returns false to have the normal
2216     * processing happen (calling the item's Runnable or sending a message to
2217     * its Handler as appropriate).  You can use this method for any items
2218     * for which you would like to do processing without those other
2219     * facilities.
2220     *
2221     * <p>Derived classes should call through to the base class for it to
2222     * perform the default menu handling.
2223     *
2224     * @param item The menu item that was selected.
2225     *
2226     * @return boolean Return false to allow normal menu processing to
2227     *         proceed, true to consume it here.
2228     *
2229     * @see #onCreateOptionsMenu
2230     */
2231    public boolean onOptionsItemSelected(MenuItem item) {
2232        if (mParent != null) {
2233            return mParent.onOptionsItemSelected(item);
2234        }
2235        return false;
2236    }
2237
2238    /**
2239     * This hook is called whenever the options menu is being closed (either by the user canceling
2240     * the menu with the back/menu button, or when an item is selected).
2241     *
2242     * @param menu The options menu as last shown or first initialized by
2243     *             onCreateOptionsMenu().
2244     */
2245    public void onOptionsMenuClosed(Menu menu) {
2246        if (mParent != null) {
2247            mParent.onOptionsMenuClosed(menu);
2248        }
2249    }
2250
2251    /**
2252     * Programmatically opens the options menu. If the options menu is already
2253     * open, this method does nothing.
2254     */
2255    public void openOptionsMenu() {
2256        mWindow.openPanel(Window.FEATURE_OPTIONS_PANEL, null);
2257    }
2258
2259    /**
2260     * Progammatically closes the options menu. If the options menu is already
2261     * closed, this method does nothing.
2262     */
2263    public void closeOptionsMenu() {
2264        mWindow.closePanel(Window.FEATURE_OPTIONS_PANEL);
2265    }
2266
2267    /**
2268     * Called when a context menu for the {@code view} is about to be shown.
2269     * Unlike {@link #onCreateOptionsMenu(Menu)}, this will be called every
2270     * time the context menu is about to be shown and should be populated for
2271     * the view (or item inside the view for {@link AdapterView} subclasses,
2272     * this can be found in the {@code menuInfo})).
2273     * <p>
2274     * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an
2275     * item has been selected.
2276     * <p>
2277     * It is not safe to hold onto the context menu after this method returns.
2278     * {@inheritDoc}
2279     */
2280    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
2281    }
2282
2283    /**
2284     * Registers a context menu to be shown for the given view (multiple views
2285     * can show the context menu). This method will set the
2286     * {@link OnCreateContextMenuListener} on the view to this activity, so
2287     * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be
2288     * called when it is time to show the context menu.
2289     *
2290     * @see #unregisterForContextMenu(View)
2291     * @param view The view that should show a context menu.
2292     */
2293    public void registerForContextMenu(View view) {
2294        view.setOnCreateContextMenuListener(this);
2295    }
2296
2297    /**
2298     * Prevents a context menu to be shown for the given view. This method will remove the
2299     * {@link OnCreateContextMenuListener} on the view.
2300     *
2301     * @see #registerForContextMenu(View)
2302     * @param view The view that should stop showing a context menu.
2303     */
2304    public void unregisterForContextMenu(View view) {
2305        view.setOnCreateContextMenuListener(null);
2306    }
2307
2308    /**
2309     * Programmatically opens the context menu for a particular {@code view}.
2310     * The {@code view} should have been added via
2311     * {@link #registerForContextMenu(View)}.
2312     *
2313     * @param view The view to show the context menu for.
2314     */
2315    public void openContextMenu(View view) {
2316        view.showContextMenu();
2317    }
2318
2319    /**
2320     * Programmatically closes the most recently opened context menu, if showing.
2321     */
2322    public void closeContextMenu() {
2323        mWindow.closePanel(Window.FEATURE_CONTEXT_MENU);
2324    }
2325
2326    /**
2327     * This hook is called whenever an item in a context menu is selected. The
2328     * default implementation simply returns false to have the normal processing
2329     * happen (calling the item's Runnable or sending a message to its Handler
2330     * as appropriate). You can use this method for any items for which you
2331     * would like to do processing without those other facilities.
2332     * <p>
2333     * Use {@link MenuItem#getMenuInfo()} to get extra information set by the
2334     * View that added this menu item.
2335     * <p>
2336     * Derived classes should call through to the base class for it to perform
2337     * the default menu handling.
2338     *
2339     * @param item The context menu item that was selected.
2340     * @return boolean Return false to allow normal context menu processing to
2341     *         proceed, true to consume it here.
2342     */
2343    public boolean onContextItemSelected(MenuItem item) {
2344        if (mParent != null) {
2345            return mParent.onContextItemSelected(item);
2346        }
2347        return false;
2348    }
2349
2350    /**
2351     * This hook is called whenever the context menu is being closed (either by
2352     * the user canceling the menu with the back/menu button, or when an item is
2353     * selected).
2354     *
2355     * @param menu The context menu that is being closed.
2356     */
2357    public void onContextMenuClosed(Menu menu) {
2358        if (mParent != null) {
2359            mParent.onContextMenuClosed(menu);
2360        }
2361    }
2362
2363    /**
2364     * Callback for creating dialogs that are managed (saved and restored) for you
2365     * by the activity.
2366     *
2367     * If you use {@link #showDialog(int)}, the activity will call through to
2368     * this method the first time, and hang onto it thereafter.  Any dialog
2369     * that is created by this method will automatically be saved and restored
2370     * for you, including whether it is showing.
2371     *
2372     * If you would like the activity to manage the saving and restoring dialogs
2373     * for you, you should override this method and handle any ids that are
2374     * passed to {@link #showDialog}.
2375     *
2376     * If you would like an opportunity to prepare your dialog before it is shown,
2377     * override {@link #onPrepareDialog(int, Dialog)}.
2378     *
2379     * @param id The id of the dialog.
2380     * @return The dialog
2381     *
2382     * @see #onPrepareDialog(int, Dialog)
2383     * @see #showDialog(int)
2384     * @see #dismissDialog(int)
2385     * @see #removeDialog(int)
2386     */
2387    protected Dialog onCreateDialog(int id) {
2388        return null;
2389    }
2390
2391    /**
2392     * Provides an opportunity to prepare a managed dialog before it is being
2393     * shown.
2394     * <p>
2395     * Override this if you need to update a managed dialog based on the state
2396     * of the application each time it is shown. For example, a time picker
2397     * dialog might want to be updated with the current time. You should call
2398     * through to the superclass's implementation. The default implementation
2399     * will set this Activity as the owner activity on the Dialog.
2400     *
2401     * @param id The id of the managed dialog.
2402     * @param dialog The dialog.
2403     * @see #onCreateDialog(int)
2404     * @see #showDialog(int)
2405     * @see #dismissDialog(int)
2406     * @see #removeDialog(int)
2407     */
2408    protected void onPrepareDialog(int id, Dialog dialog) {
2409        dialog.setOwnerActivity(this);
2410    }
2411
2412    /**
2413     * Show a dialog managed by this activity.  A call to {@link #onCreateDialog(int)}
2414     * will be made with the same id the first time this is called for a given
2415     * id.  From thereafter, the dialog will be automatically saved and restored.
2416     *
2417     * Each time a dialog is shown, {@link #onPrepareDialog(int, Dialog)} will
2418     * be made to provide an opportunity to do any timely preparation.
2419     *
2420     * @param id The id of the managed dialog.
2421     *
2422     * @see #onCreateDialog(int)
2423     * @see #onPrepareDialog(int, Dialog)
2424     * @see #dismissDialog(int)
2425     * @see #removeDialog(int)
2426     */
2427    public final void showDialog(int id) {
2428        if (mManagedDialogs == null) {
2429            mManagedDialogs = new SparseArray<Dialog>();
2430        }
2431        Dialog dialog = mManagedDialogs.get(id);
2432        if (dialog == null) {
2433            dialog = createDialog(id);
2434            mManagedDialogs.put(id, dialog);
2435        }
2436
2437        onPrepareDialog(id, dialog);
2438        dialog.show();
2439    }
2440
2441    /**
2442     * Dismiss a dialog that was previously shown via {@link #showDialog(int)}.
2443     *
2444     * @param id The id of the managed dialog.
2445     *
2446     * @throws IllegalArgumentException if the id was not previously shown via
2447     *   {@link #showDialog(int)}.
2448     *
2449     * @see #onCreateDialog(int)
2450     * @see #onPrepareDialog(int, Dialog)
2451     * @see #showDialog(int)
2452     * @see #removeDialog(int)
2453     */
2454    public final void dismissDialog(int id) {
2455        if (mManagedDialogs == null) {
2456            throw missingDialog(id);
2457
2458        }
2459        final Dialog dialog = mManagedDialogs.get(id);
2460        if (dialog == null) {
2461            throw missingDialog(id);
2462        }
2463        dialog.dismiss();
2464    }
2465
2466    /**
2467     * Creates an exception to throw if a user passed in a dialog id that is
2468     * unexpected.
2469     */
2470    private IllegalArgumentException missingDialog(int id) {
2471        return new IllegalArgumentException("no dialog with id " + id + " was ever "
2472                + "shown via Activity#showDialog");
2473    }
2474
2475    /**
2476     * Removes any internal references to a dialog managed by this Activity.
2477     * If the dialog is showing, it will dismiss it as part of the clean up.
2478     *
2479     * This can be useful if you know that you will never show a dialog again and
2480     * want to avoid the overhead of saving and restoring it in the future.
2481     *
2482     * @param id The id of the managed dialog.
2483     *
2484     * @see #onCreateDialog(int)
2485     * @see #onPrepareDialog(int, Dialog)
2486     * @see #showDialog(int)
2487     * @see #dismissDialog(int)
2488     */
2489    public final void removeDialog(int id) {
2490
2491        if (mManagedDialogs == null) {
2492            return;
2493        }
2494
2495        final Dialog dialog = mManagedDialogs.get(id);
2496        if (dialog == null) {
2497            return;
2498        }
2499
2500        dialog.dismiss();
2501        mManagedDialogs.remove(id);
2502    }
2503
2504    /**
2505     * This hook is called when the user signals the desire to start a search.
2506     *
2507     * <p>You can use this function as a simple way to launch the search UI, in response to a
2508     * menu item, search button, or other widgets within your activity.  Unless overidden,
2509     * calling this function is the same as calling:
2510     * <p>The default implementation simply calls
2511     * {@link #startSearch startSearch(null, false, null, false)}, launching a local search.
2512     *
2513     * <p>You can override this function to force global search, e.g. in response to a dedicated
2514     * search key, or to block search entirely (by simply returning false).
2515     *
2516     * @return Returns true if search launched, false if activity blocks it
2517     *
2518     * @see android.app.SearchManager
2519     */
2520    public boolean onSearchRequested() {
2521        startSearch(null, false, null, false);
2522        return true;
2523    }
2524
2525    /**
2526     * This hook is called to launch the search UI.
2527     *
2528     * <p>It is typically called from onSearchRequested(), either directly from
2529     * Activity.onSearchRequested() or from an overridden version in any given
2530     * Activity.  If your goal is simply to activate search, it is preferred to call
2531     * onSearchRequested(), which may have been overriden elsewhere in your Activity.  If your goal
2532     * is to inject specific data such as context data, it is preferred to <i>override</i>
2533     * onSearchRequested(), so that any callers to it will benefit from the override.
2534     *
2535     * @param initialQuery Any non-null non-empty string will be inserted as
2536     * pre-entered text in the search query box.
2537     * @param selectInitialQuery If true, the intial query will be preselected, which means that
2538     * any further typing will replace it.  This is useful for cases where an entire pre-formed
2539     * query is being inserted.  If false, the selection point will be placed at the end of the
2540     * inserted query.  This is useful when the inserted query is text that the user entered,
2541     * and the user would expect to be able to keep typing.  <i>This parameter is only meaningful
2542     * if initialQuery is a non-empty string.</i>
2543     * @param appSearchData An application can insert application-specific
2544     * context here, in order to improve quality or specificity of its own
2545     * searches.  This data will be returned with SEARCH intent(s).  Null if
2546     * no extra data is required.
2547     * @param globalSearch If false, this will only launch the search that has been specifically
2548     * defined by the application (which is usually defined as a local search).  If no default
2549     * search is defined in the current application or activity, no search will be launched.
2550     * If true, this will always launch a platform-global (e.g. web-based) search instead.
2551     *
2552     * @see android.app.SearchManager
2553     * @see #onSearchRequested
2554     */
2555    public void startSearch(String initialQuery, boolean selectInitialQuery,
2556            Bundle appSearchData, boolean globalSearch) {
2557        mSearchManager.startSearch(initialQuery, selectInitialQuery, getComponentName(),
2558                        appSearchData, globalSearch);
2559    }
2560
2561    /**
2562     * Request that key events come to this activity. Use this if your
2563     * activity has no views with focus, but the activity still wants
2564     * a chance to process key events.
2565     *
2566     * @see android.view.Window#takeKeyEvents
2567     */
2568    public void takeKeyEvents(boolean get) {
2569        getWindow().takeKeyEvents(get);
2570    }
2571
2572    /**
2573     * Enable extended window features.  This is a convenience for calling
2574     * {@link android.view.Window#requestFeature getWindow().requestFeature()}.
2575     *
2576     * @param featureId The desired feature as defined in
2577     *                  {@link android.view.Window}.
2578     * @return Returns true if the requested feature is supported and now
2579     *         enabled.
2580     *
2581     * @see android.view.Window#requestFeature
2582     */
2583    public final boolean requestWindowFeature(int featureId) {
2584        return getWindow().requestFeature(featureId);
2585    }
2586
2587    /**
2588     * Convenience for calling
2589     * {@link android.view.Window#setFeatureDrawableResource}.
2590     */
2591    public final void setFeatureDrawableResource(int featureId, int resId) {
2592        getWindow().setFeatureDrawableResource(featureId, resId);
2593    }
2594
2595    /**
2596     * Convenience for calling
2597     * {@link android.view.Window#setFeatureDrawableUri}.
2598     */
2599    public final void setFeatureDrawableUri(int featureId, Uri uri) {
2600        getWindow().setFeatureDrawableUri(featureId, uri);
2601    }
2602
2603    /**
2604     * Convenience for calling
2605     * {@link android.view.Window#setFeatureDrawable(int, Drawable)}.
2606     */
2607    public final void setFeatureDrawable(int featureId, Drawable drawable) {
2608        getWindow().setFeatureDrawable(featureId, drawable);
2609    }
2610
2611    /**
2612     * Convenience for calling
2613     * {@link android.view.Window#setFeatureDrawableAlpha}.
2614     */
2615    public final void setFeatureDrawableAlpha(int featureId, int alpha) {
2616        getWindow().setFeatureDrawableAlpha(featureId, alpha);
2617    }
2618
2619    /**
2620     * Convenience for calling
2621     * {@link android.view.Window#getLayoutInflater}.
2622     */
2623    public LayoutInflater getLayoutInflater() {
2624        return getWindow().getLayoutInflater();
2625    }
2626
2627    /**
2628     * Returns a {@link MenuInflater} with this context.
2629     */
2630    public MenuInflater getMenuInflater() {
2631        return new MenuInflater(this);
2632    }
2633
2634    @Override
2635    protected void onApplyThemeResource(Resources.Theme theme,
2636                                      int resid,
2637                                      boolean first)
2638    {
2639        if (mParent == null) {
2640            super.onApplyThemeResource(theme, resid, first);
2641        } else {
2642            try {
2643                theme.setTo(mParent.getTheme());
2644            } catch (Exception e) {
2645                // Empty
2646            }
2647            theme.applyStyle(resid, false);
2648        }
2649    }
2650
2651    /**
2652     * Launch an activity for which you would like a result when it finished.
2653     * When this activity exits, your
2654     * onActivityResult() method will be called with the given requestCode.
2655     * Using a negative requestCode is the same as calling
2656     * {@link #startActivity} (the activity is not launched as a sub-activity).
2657     *
2658     * <p>Note that this method should only be used with Intent protocols
2659     * that are defined to return a result.  In other protocols (such as
2660     * {@link Intent#ACTION_MAIN} or {@link Intent#ACTION_VIEW}), you may
2661     * not get the result when you expect.  For example, if the activity you
2662     * are launching uses the singleTask launch mode, it will not run in your
2663     * task and thus you will immediately receive a cancel result.
2664     *
2665     * <p>As a special case, if you call startActivityForResult() with a requestCode
2666     * >= 0 during the initial onCreate(Bundle savedInstanceState)/onResume() of your
2667     * activity, then your window will not be displayed until a result is
2668     * returned back from the started activity.  This is to avoid visible
2669     * flickering when redirecting to another activity.
2670     *
2671     * <p>This method throws {@link android.content.ActivityNotFoundException}
2672     * if there was no Activity found to run the given Intent.
2673     *
2674     * @param intent The intent to start.
2675     * @param requestCode If >= 0, this code will be returned in
2676     *                    onActivityResult() when the activity exits.
2677     *
2678     * @throws android.content.ActivityNotFoundException
2679     *
2680     * @see #startActivity
2681     */
2682    public void startActivityForResult(Intent intent, int requestCode) {
2683        if (mParent == null) {
2684            Instrumentation.ActivityResult ar =
2685                mInstrumentation.execStartActivity(
2686                    this, mMainThread.getApplicationThread(), mToken, this,
2687                    intent, requestCode);
2688            if (ar != null) {
2689                mMainThread.sendActivityResult(
2690                    mToken, mEmbeddedID, requestCode, ar.getResultCode(),
2691                    ar.getResultData());
2692            }
2693            if (requestCode >= 0) {
2694                // If this start is requesting a result, we can avoid making
2695                // the activity visible until the result is received.  Setting
2696                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
2697                // activity hidden during this time, to avoid flickering.
2698                // This can only be done when a result is requested because
2699                // that guarantees we will get information back when the
2700                // activity is finished, no matter what happens to it.
2701                mStartedActivity = true;
2702            }
2703        } else {
2704            mParent.startActivityFromChild(this, intent, requestCode);
2705        }
2706    }
2707
2708    /**
2709     * Launch a new activity.  You will not receive any information about when
2710     * the activity exits.  This implementation overrides the base version,
2711     * providing information about
2712     * the activity performing the launch.  Because of this additional
2713     * information, the {@link Intent#FLAG_ACTIVITY_NEW_TASK} launch flag is not
2714     * required; if not specified, the new activity will be added to the
2715     * task of the caller.
2716     *
2717     * <p>This method throws {@link android.content.ActivityNotFoundException}
2718     * if there was no Activity found to run the given Intent.
2719     *
2720     * @param intent The intent to start.
2721     *
2722     * @throws android.content.ActivityNotFoundException
2723     *
2724     * @see #startActivityForResult
2725     */
2726    @Override
2727    public void startActivity(Intent intent) {
2728        startActivityForResult(intent, -1);
2729    }
2730
2731    /**
2732     * A special variation to launch an activity only if a new activity
2733     * instance is needed to handle the given Intent.  In other words, this is
2734     * just like {@link #startActivityForResult(Intent, int)} except: if you are
2735     * using the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP} flag, or
2736     * singleTask or singleTop
2737     * {@link android.R.styleable#AndroidManifestActivity_launchMode launchMode},
2738     * and the activity
2739     * that handles <var>intent</var> is the same as your currently running
2740     * activity, then a new instance is not needed.  In this case, instead of
2741     * the normal behavior of calling {@link #onNewIntent} this function will
2742     * return and you can handle the Intent yourself.
2743     *
2744     * <p>This function can only be called from a top-level activity; if it is
2745     * called from a child activity, a runtime exception will be thrown.
2746     *
2747     * @param intent The intent to start.
2748     * @param requestCode If >= 0, this code will be returned in
2749     *         onActivityResult() when the activity exits, as described in
2750     *         {@link #startActivityForResult}.
2751     *
2752     * @return If a new activity was launched then true is returned; otherwise
2753     *         false is returned and you must handle the Intent yourself.
2754     *
2755     * @see #startActivity
2756     * @see #startActivityForResult
2757     */
2758    public boolean startActivityIfNeeded(Intent intent, int requestCode) {
2759        if (mParent == null) {
2760            int result = IActivityManager.START_RETURN_INTENT_TO_CALLER;
2761            try {
2762                result = ActivityManagerNative.getDefault()
2763                    .startActivity(mMainThread.getApplicationThread(),
2764                            intent, intent.resolveTypeIfNeeded(
2765                                    getContentResolver()),
2766                            null, 0,
2767                            mToken, mEmbeddedID, requestCode, true, false);
2768            } catch (RemoteException e) {
2769                // Empty
2770            }
2771
2772            Instrumentation.checkStartActivityResult(result, intent);
2773
2774            if (requestCode >= 0) {
2775                // If this start is requesting a result, we can avoid making
2776                // the activity visible until the result is received.  Setting
2777                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
2778                // activity hidden during this time, to avoid flickering.
2779                // This can only be done when a result is requested because
2780                // that guarantees we will get information back when the
2781                // activity is finished, no matter what happens to it.
2782                mStartedActivity = true;
2783            }
2784            return result != IActivityManager.START_RETURN_INTENT_TO_CALLER;
2785        }
2786
2787        throw new UnsupportedOperationException(
2788            "startActivityIfNeeded can only be called from a top-level activity");
2789    }
2790
2791    /**
2792     * Special version of starting an activity, for use when you are replacing
2793     * other activity components.  You can use this to hand the Intent off
2794     * to the next Activity that can handle it.  You typically call this in
2795     * {@link #onCreate} with the Intent returned by {@link #getIntent}.
2796     *
2797     * @param intent The intent to dispatch to the next activity.  For
2798     * correct behavior, this must be the same as the Intent that started
2799     * your own activity; the only changes you can make are to the extras
2800     * inside of it.
2801     *
2802     * @return Returns a boolean indicating whether there was another Activity
2803     * to start: true if there was a next activity to start, false if there
2804     * wasn't.  In general, if true is returned you will then want to call
2805     * finish() on yourself.
2806     */
2807    public boolean startNextMatchingActivity(Intent intent) {
2808        if (mParent == null) {
2809            try {
2810                return ActivityManagerNative.getDefault()
2811                    .startNextMatchingActivity(mToken, intent);
2812            } catch (RemoteException e) {
2813                // Empty
2814            }
2815            return false;
2816        }
2817
2818        throw new UnsupportedOperationException(
2819            "startNextMatchingActivity can only be called from a top-level activity");
2820    }
2821
2822    /**
2823     * This is called when a child activity of this one calls its
2824     * {@link #startActivity} or {@link #startActivityForResult} method.
2825     *
2826     * <p>This method throws {@link android.content.ActivityNotFoundException}
2827     * if there was no Activity found to run the given Intent.
2828     *
2829     * @param child The activity making the call.
2830     * @param intent The intent to start.
2831     * @param requestCode Reply request code.  < 0 if reply is not requested.
2832     *
2833     * @throws android.content.ActivityNotFoundException
2834     *
2835     * @see #startActivity
2836     * @see #startActivityForResult
2837     */
2838    public void startActivityFromChild(Activity child, Intent intent,
2839            int requestCode) {
2840        Instrumentation.ActivityResult ar =
2841            mInstrumentation.execStartActivity(
2842                this, mMainThread.getApplicationThread(), mToken, child,
2843                intent, requestCode);
2844        if (ar != null) {
2845            mMainThread.sendActivityResult(
2846                mToken, child.mEmbeddedID, requestCode,
2847                ar.getResultCode(), ar.getResultData());
2848        }
2849    }
2850
2851    /**
2852     * Call this to set the result that your activity will return to its
2853     * caller.
2854     *
2855     * @param resultCode The result code to propagate back to the originating
2856     *                   activity, often RESULT_CANCELED or RESULT_OK
2857     *
2858     * @see #RESULT_CANCELED
2859     * @see #RESULT_OK
2860     * @see #RESULT_FIRST_USER
2861     * @see #setResult(int, Intent)
2862     */
2863    public final void setResult(int resultCode) {
2864        synchronized (this) {
2865            mResultCode = resultCode;
2866            mResultData = null;
2867        }
2868    }
2869
2870    /**
2871     * Call this to set the result that your activity will return to its
2872     * caller.
2873     *
2874     * @param resultCode The result code to propagate back to the originating
2875     *                   activity, often RESULT_CANCELED or RESULT_OK
2876     * @param data The data to propagate back to the originating activity.
2877     *
2878     * @see #RESULT_CANCELED
2879     * @see #RESULT_OK
2880     * @see #RESULT_FIRST_USER
2881     * @see #setResult(int)
2882     */
2883    public final void setResult(int resultCode, Intent data) {
2884        synchronized (this) {
2885            mResultCode = resultCode;
2886            mResultData = data;
2887        }
2888    }
2889
2890    /**
2891     * Return the name of the package that invoked this activity.  This is who
2892     * the data in {@link #setResult setResult()} will be sent to.  You can
2893     * use this information to validate that the recipient is allowed to
2894     * receive the data.
2895     *
2896     * <p>Note: if the calling activity is not expecting a result (that is it
2897     * did not use the {@link #startActivityForResult}
2898     * form that includes a request code), then the calling package will be
2899     * null.
2900     *
2901     * @return The package of the activity that will receive your
2902     *         reply, or null if none.
2903     */
2904    public String getCallingPackage() {
2905        try {
2906            return ActivityManagerNative.getDefault().getCallingPackage(mToken);
2907        } catch (RemoteException e) {
2908            return null;
2909        }
2910    }
2911
2912    /**
2913     * Return the name of the activity that invoked this activity.  This is
2914     * who the data in {@link #setResult setResult()} will be sent to.  You
2915     * can use this information to validate that the recipient is allowed to
2916     * receive the data.
2917     *
2918     * <p>Note: if the calling activity is not expecting a result (that is it
2919     * did not use the {@link #startActivityForResult}
2920     * form that includes a request code), then the calling package will be
2921     * null.
2922     *
2923     * @return String The full name of the activity that will receive your
2924     *         reply, or null if none.
2925     */
2926    public ComponentName getCallingActivity() {
2927        try {
2928            return ActivityManagerNative.getDefault().getCallingActivity(mToken);
2929        } catch (RemoteException e) {
2930            return null;
2931        }
2932    }
2933
2934    /**
2935     * Control whether this activity's main window is visible.  This is intended
2936     * only for the special case of an activity that is not going to show a
2937     * UI itself, but can't just finish prior to onResume() because it needs
2938     * to wait for a service binding or such.  Setting this to false allows
2939     * you to prevent your UI from being shown during that time.
2940     *
2941     * <p>The default value for this is taken from the
2942     * {@link android.R.attr#windowNoDisplay} attribute of the activity's theme.
2943     */
2944    public void setVisible(boolean visible) {
2945        if (mVisibleFromClient != visible) {
2946            mVisibleFromClient = visible;
2947            if (mVisibleFromServer) {
2948                if (visible) makeVisible();
2949                else mDecor.setVisibility(View.INVISIBLE);
2950            }
2951        }
2952    }
2953
2954    void makeVisible() {
2955        if (!mWindowAdded) {
2956            ViewManager wm = getWindowManager();
2957            wm.addView(mDecor, getWindow().getAttributes());
2958            mWindowAdded = true;
2959        }
2960        mDecor.setVisibility(View.VISIBLE);
2961    }
2962
2963    /**
2964     * Check to see whether this activity is in the process of finishing,
2965     * either because you called {@link #finish} on it or someone else
2966     * has requested that it finished.  This is often used in
2967     * {@link #onPause} to determine whether the activity is simply pausing or
2968     * completely finishing.
2969     *
2970     * @return If the activity is finishing, returns true; else returns false.
2971     *
2972     * @see #finish
2973     */
2974    public boolean isFinishing() {
2975        return mFinished;
2976    }
2977
2978    /**
2979     * Call this when your activity is done and should be closed.  The
2980     * ActivityResult is propagated back to whoever launched you via
2981     * onActivityResult().
2982     */
2983    public void finish() {
2984        if (mParent == null) {
2985            int resultCode;
2986            Intent resultData;
2987            synchronized (this) {
2988                resultCode = mResultCode;
2989                resultData = mResultData;
2990            }
2991            if (Config.LOGV) Log.v(TAG, "Finishing self: token=" + mToken);
2992            try {
2993                if (ActivityManagerNative.getDefault()
2994                    .finishActivity(mToken, resultCode, resultData)) {
2995                    mFinished = true;
2996                }
2997            } catch (RemoteException e) {
2998                // Empty
2999            }
3000        } else {
3001            mParent.finishFromChild(this);
3002        }
3003    }
3004
3005    /**
3006     * This is called when a child activity of this one calls its
3007     * {@link #finish} method.  The default implementation simply calls
3008     * finish() on this activity (the parent), finishing the entire group.
3009     *
3010     * @param child The activity making the call.
3011     *
3012     * @see #finish
3013     */
3014    public void finishFromChild(Activity child) {
3015        finish();
3016    }
3017
3018    /**
3019     * Force finish another activity that you had previously started with
3020     * {@link #startActivityForResult}.
3021     *
3022     * @param requestCode The request code of the activity that you had
3023     *                    given to startActivityForResult().  If there are multiple
3024     *                    activities started with this request code, they
3025     *                    will all be finished.
3026     */
3027    public void finishActivity(int requestCode) {
3028        if (mParent == null) {
3029            try {
3030                ActivityManagerNative.getDefault()
3031                    .finishSubActivity(mToken, mEmbeddedID, requestCode);
3032            } catch (RemoteException e) {
3033                // Empty
3034            }
3035        } else {
3036            mParent.finishActivityFromChild(this, requestCode);
3037        }
3038    }
3039
3040    /**
3041     * This is called when a child activity of this one calls its
3042     * finishActivity().
3043     *
3044     * @param child The activity making the call.
3045     * @param requestCode Request code that had been used to start the
3046     *                    activity.
3047     */
3048    public void finishActivityFromChild(Activity child, int requestCode) {
3049        try {
3050            ActivityManagerNative.getDefault()
3051                .finishSubActivity(mToken, child.mEmbeddedID, requestCode);
3052        } catch (RemoteException e) {
3053            // Empty
3054        }
3055    }
3056
3057    /**
3058     * Called when an activity you launched exits, giving you the requestCode
3059     * you started it with, the resultCode it returned, and any additional
3060     * data from it.  The <var>resultCode</var> will be
3061     * {@link #RESULT_CANCELED} if the activity explicitly returned that,
3062     * didn't return any result, or crashed during its operation.
3063     *
3064     * <p>You will receive this call immediately before onResume() when your
3065     * activity is re-starting.
3066     *
3067     * @param requestCode The integer request code originally supplied to
3068     *                    startActivityForResult(), allowing you to identify who this
3069     *                    result came from.
3070     * @param resultCode The integer result code returned by the child activity
3071     *                   through its setResult().
3072     * @param data An Intent, which can return result data to the caller
3073     *               (various data can be attached to Intent "extras").
3074     *
3075     * @see #startActivityForResult
3076     * @see #createPendingResult
3077     * @see #setResult(int)
3078     */
3079    protected void onActivityResult(int requestCode, int resultCode,
3080            Intent data) {
3081    }
3082
3083    /**
3084     * Create a new PendingIntent object which you can hand to others
3085     * for them to use to send result data back to your
3086     * {@link #onActivityResult} callback.  The created object will be either
3087     * one-shot (becoming invalid after a result is sent back) or multiple
3088     * (allowing any number of results to be sent through it).
3089     *
3090     * @param requestCode Private request code for the sender that will be
3091     * associated with the result data when it is returned.  The sender can not
3092     * modify this value, allowing you to identify incoming results.
3093     * @param data Default data to supply in the result, which may be modified
3094     * by the sender.
3095     * @param flags May be {@link PendingIntent#FLAG_ONE_SHOT PendingIntent.FLAG_ONE_SHOT},
3096     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE},
3097     * {@link PendingIntent#FLAG_CANCEL_CURRENT PendingIntent.FLAG_CANCEL_CURRENT},
3098     * {@link PendingIntent#FLAG_UPDATE_CURRENT PendingIntent.FLAG_UPDATE_CURRENT},
3099     * or any of the flags as supported by
3100     * {@link Intent#fillIn Intent.fillIn()} to control which unspecified parts
3101     * of the intent that can be supplied when the actual send happens.
3102     *
3103     * @return Returns an existing or new PendingIntent matching the given
3104     * parameters.  May return null only if
3105     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE} has been
3106     * supplied.
3107     *
3108     * @see PendingIntent
3109     */
3110    public PendingIntent createPendingResult(int requestCode, Intent data,
3111            int flags) {
3112        String packageName = getPackageName();
3113        try {
3114            IIntentSender target =
3115                ActivityManagerNative.getDefault().getIntentSender(
3116                        IActivityManager.INTENT_SENDER_ACTIVITY_RESULT, packageName,
3117                        mParent == null ? mToken : mParent.mToken,
3118                        mEmbeddedID, requestCode, data, null, flags);
3119            return target != null ? new PendingIntent(target) : null;
3120        } catch (RemoteException e) {
3121            // Empty
3122        }
3123        return null;
3124    }
3125
3126    /**
3127     * Change the desired orientation of this activity.  If the activity
3128     * is currently in the foreground or otherwise impacting the screen
3129     * orientation, the screen will immediately be changed (possibly causing
3130     * the activity to be restarted). Otherwise, this will be used the next
3131     * time the activity is visible.
3132     *
3133     * @param requestedOrientation An orientation constant as used in
3134     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3135     */
3136    public void setRequestedOrientation(int requestedOrientation) {
3137        if (mParent == null) {
3138            try {
3139                ActivityManagerNative.getDefault().setRequestedOrientation(
3140                        mToken, requestedOrientation);
3141            } catch (RemoteException e) {
3142                // Empty
3143            }
3144        } else {
3145            mParent.setRequestedOrientation(requestedOrientation);
3146        }
3147    }
3148
3149    /**
3150     * Return the current requested orientation of the activity.  This will
3151     * either be the orientation requested in its component's manifest, or
3152     * the last requested orientation given to
3153     * {@link #setRequestedOrientation(int)}.
3154     *
3155     * @return Returns an orientation constant as used in
3156     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3157     */
3158    public int getRequestedOrientation() {
3159        if (mParent == null) {
3160            try {
3161                return ActivityManagerNative.getDefault()
3162                        .getRequestedOrientation(mToken);
3163            } catch (RemoteException e) {
3164                // Empty
3165            }
3166        } else {
3167            return mParent.getRequestedOrientation();
3168        }
3169        return ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
3170    }
3171
3172    /**
3173     * Return the identifier of the task this activity is in.  This identifier
3174     * will remain the same for the lifetime of the activity.
3175     *
3176     * @return Task identifier, an opaque integer.
3177     */
3178    public int getTaskId() {
3179        try {
3180            return ActivityManagerNative.getDefault()
3181                .getTaskForActivity(mToken, false);
3182        } catch (RemoteException e) {
3183            return -1;
3184        }
3185    }
3186
3187    /**
3188     * Return whether this activity is the root of a task.  The root is the
3189     * first activity in a task.
3190     *
3191     * @return True if this is the root activity, else false.
3192     */
3193    public boolean isTaskRoot() {
3194        try {
3195            return ActivityManagerNative.getDefault()
3196                .getTaskForActivity(mToken, true) >= 0;
3197        } catch (RemoteException e) {
3198            return false;
3199        }
3200    }
3201
3202    /**
3203     * Move the task containing this activity to the back of the activity
3204     * stack.  The activity's order within the task is unchanged.
3205     *
3206     * @param nonRoot If false then this only works if the activity is the root
3207     *                of a task; if true it will work for any activity in
3208     *                a task.
3209     *
3210     * @return If the task was moved (or it was already at the
3211     *         back) true is returned, else false.
3212     */
3213    public boolean moveTaskToBack(boolean nonRoot) {
3214        try {
3215            return ActivityManagerNative.getDefault().moveActivityTaskToBack(
3216                    mToken, nonRoot);
3217        } catch (RemoteException e) {
3218            // Empty
3219        }
3220        return false;
3221    }
3222
3223    /**
3224     * Returns class name for this activity with the package prefix removed.
3225     * This is the default name used to read and write settings.
3226     *
3227     * @return The local class name.
3228     */
3229    public String getLocalClassName() {
3230        final String pkg = getPackageName();
3231        final String cls = mComponent.getClassName();
3232        int packageLen = pkg.length();
3233        if (!cls.startsWith(pkg) || cls.length() <= packageLen
3234                || cls.charAt(packageLen) != '.') {
3235            return cls;
3236        }
3237        return cls.substring(packageLen+1);
3238    }
3239
3240    /**
3241     * Returns complete component name of this activity.
3242     *
3243     * @return Returns the complete component name for this activity
3244     */
3245    public ComponentName getComponentName()
3246    {
3247        return mComponent;
3248    }
3249
3250    /**
3251     * Retrieve a {@link SharedPreferences} object for accessing preferences
3252     * that are private to this activity.  This simply calls the underlying
3253     * {@link #getSharedPreferences(String, int)} method by passing in this activity's
3254     * class name as the preferences name.
3255     *
3256     * @param mode Operating mode.  Use {@link #MODE_PRIVATE} for the default
3257     *             operation, {@link #MODE_WORLD_READABLE} and
3258     *             {@link #MODE_WORLD_WRITEABLE} to control permissions.
3259     *
3260     * @return Returns the single SharedPreferences instance that can be used
3261     *         to retrieve and modify the preference values.
3262     */
3263    public SharedPreferences getPreferences(int mode) {
3264        return getSharedPreferences(getLocalClassName(), mode);
3265    }
3266
3267    @Override
3268    public Object getSystemService(String name) {
3269        if (getBaseContext() == null) {
3270            throw new IllegalStateException(
3271                    "System services not available to Activities before onCreate()");
3272        }
3273
3274        if (WINDOW_SERVICE.equals(name)) {
3275            return mWindowManager;
3276        } else if (SEARCH_SERVICE.equals(name)) {
3277            return mSearchManager;
3278        }
3279        return super.getSystemService(name);
3280    }
3281
3282    /**
3283     * Change the title associated with this activity.  If this is a
3284     * top-level activity, the title for its window will change.  If it
3285     * is an embedded activity, the parent can do whatever it wants
3286     * with it.
3287     */
3288    public void setTitle(CharSequence title) {
3289        mTitle = title;
3290        onTitleChanged(title, mTitleColor);
3291
3292        if (mParent != null) {
3293            mParent.onChildTitleChanged(this, title);
3294        }
3295    }
3296
3297    /**
3298     * Change the title associated with this activity.  If this is a
3299     * top-level activity, the title for its window will change.  If it
3300     * is an embedded activity, the parent can do whatever it wants
3301     * with it.
3302     */
3303    public void setTitle(int titleId) {
3304        setTitle(getText(titleId));
3305    }
3306
3307    public void setTitleColor(int textColor) {
3308        mTitleColor = textColor;
3309        onTitleChanged(mTitle, textColor);
3310    }
3311
3312    public final CharSequence getTitle() {
3313        return mTitle;
3314    }
3315
3316    public final int getTitleColor() {
3317        return mTitleColor;
3318    }
3319
3320    protected void onTitleChanged(CharSequence title, int color) {
3321        if (mTitleReady) {
3322            final Window win = getWindow();
3323            if (win != null) {
3324                win.setTitle(title);
3325                if (color != 0) {
3326                    win.setTitleColor(color);
3327                }
3328            }
3329        }
3330    }
3331
3332    protected void onChildTitleChanged(Activity childActivity, CharSequence title) {
3333    }
3334
3335    /**
3336     * Sets the visibility of the progress bar in the title.
3337     * <p>
3338     * In order for the progress bar to be shown, the feature must be requested
3339     * via {@link #requestWindowFeature(int)}.
3340     *
3341     * @param visible Whether to show the progress bars in the title.
3342     */
3343    public final void setProgressBarVisibility(boolean visible) {
3344        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, visible ? Window.PROGRESS_VISIBILITY_ON :
3345            Window.PROGRESS_VISIBILITY_OFF);
3346    }
3347
3348    /**
3349     * Sets the visibility of the indeterminate progress bar in the title.
3350     * <p>
3351     * In order for the progress bar to be shown, the feature must be requested
3352     * via {@link #requestWindowFeature(int)}.
3353     *
3354     * @param visible Whether to show the progress bars in the title.
3355     */
3356    public final void setProgressBarIndeterminateVisibility(boolean visible) {
3357        getWindow().setFeatureInt(Window.FEATURE_INDETERMINATE_PROGRESS,
3358                visible ? Window.PROGRESS_VISIBILITY_ON : Window.PROGRESS_VISIBILITY_OFF);
3359    }
3360
3361    /**
3362     * Sets whether the horizontal progress bar in the title should be indeterminate (the circular
3363     * is always indeterminate).
3364     * <p>
3365     * In order for the progress bar to be shown, the feature must be requested
3366     * via {@link #requestWindowFeature(int)}.
3367     *
3368     * @param indeterminate Whether the horizontal progress bar should be indeterminate.
3369     */
3370    public final void setProgressBarIndeterminate(boolean indeterminate) {
3371        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3372                indeterminate ? Window.PROGRESS_INDETERMINATE_ON : Window.PROGRESS_INDETERMINATE_OFF);
3373    }
3374
3375    /**
3376     * Sets the progress for the progress bars in the title.
3377     * <p>
3378     * In order for the progress bar to be shown, the feature must be requested
3379     * via {@link #requestWindowFeature(int)}.
3380     *
3381     * @param progress The progress for the progress bar. Valid ranges are from
3382     *            0 to 10000 (both inclusive). If 10000 is given, the progress
3383     *            bar will be completely filled and will fade out.
3384     */
3385    public final void setProgress(int progress) {
3386        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, progress + Window.PROGRESS_START);
3387    }
3388
3389    /**
3390     * Sets the secondary progress for the progress bar in the title. This
3391     * progress is drawn between the primary progress (set via
3392     * {@link #setProgress(int)} and the background. It can be ideal for media
3393     * scenarios such as showing the buffering progress while the default
3394     * progress shows the play progress.
3395     * <p>
3396     * In order for the progress bar to be shown, the feature must be requested
3397     * via {@link #requestWindowFeature(int)}.
3398     *
3399     * @param secondaryProgress The secondary progress for the progress bar. Valid ranges are from
3400     *            0 to 10000 (both inclusive).
3401     */
3402    public final void setSecondaryProgress(int secondaryProgress) {
3403        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3404                secondaryProgress + Window.PROGRESS_SECONDARY_START);
3405    }
3406
3407    /**
3408     * Suggests an audio stream whose volume should be changed by the hardware
3409     * volume controls.
3410     * <p>
3411     * The suggested audio stream will be tied to the window of this Activity.
3412     * If the Activity is switched, the stream set here is no longer the
3413     * suggested stream. The client does not need to save and restore the old
3414     * suggested stream value in onPause and onResume.
3415     *
3416     * @param streamType The type of the audio stream whose volume should be
3417     *        changed by the hardware volume controls. It is not guaranteed that
3418     *        the hardware volume controls will always change this stream's
3419     *        volume (for example, if a call is in progress, its stream's volume
3420     *        may be changed instead). To reset back to the default, use
3421     *        {@link AudioManager#USE_DEFAULT_STREAM_TYPE}.
3422     */
3423    public final void setVolumeControlStream(int streamType) {
3424        getWindow().setVolumeControlStream(streamType);
3425    }
3426
3427    /**
3428     * Gets the suggested audio stream whose volume should be changed by the
3429     * harwdare volume controls.
3430     *
3431     * @return The suggested audio stream type whose volume should be changed by
3432     *         the hardware volume controls.
3433     * @see #setVolumeControlStream(int)
3434     */
3435    public final int getVolumeControlStream() {
3436        return getWindow().getVolumeControlStream();
3437    }
3438
3439    /**
3440     * Runs the specified action on the UI thread. If the current thread is the UI
3441     * thread, then the action is executed immediately. If the current thread is
3442     * not the UI thread, the action is posted to the event queue of the UI thread.
3443     *
3444     * @param action the action to run on the UI thread
3445     */
3446    public final void runOnUiThread(Runnable action) {
3447        if (Thread.currentThread() != mUiThread) {
3448            mHandler.post(action);
3449        } else {
3450            action.run();
3451        }
3452    }
3453
3454    /**
3455     * Stub implementation of {@link android.view.LayoutInflater.Factory#onCreateView} used when
3456     * inflating with the LayoutInflater returned by {@link #getSystemService}.  This
3457     * implementation simply returns null for all view names.
3458     *
3459     * @see android.view.LayoutInflater#createView
3460     * @see android.view.Window#getLayoutInflater
3461     */
3462    public View onCreateView(String name, Context context, AttributeSet attrs) {
3463        return null;
3464    }
3465
3466    // ------------------ Internal API ------------------
3467
3468    final void setParent(Activity parent) {
3469        mParent = parent;
3470    }
3471
3472    final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token,
3473            Application application, Intent intent, ActivityInfo info, CharSequence title,
3474            Activity parent, String id, Object lastNonConfigurationInstance,
3475            Configuration config) {
3476        attach(context, aThread, instr, token, application, intent, info, title, parent, id,
3477            lastNonConfigurationInstance, null, config);
3478    }
3479
3480    final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token,
3481        Application application, Intent intent, ActivityInfo info, CharSequence title,
3482        Activity parent, String id, Object lastNonConfigurationInstance,
3483        HashMap<String,Object> lastNonConfigurationChildInstances, Configuration config) {
3484        attachBaseContext(context);
3485
3486        mWindow = PolicyManager.makeNewWindow(this);
3487        mWindow.setCallback(this);
3488        if (info.softInputMode != WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED) {
3489            mWindow.setSoftInputMode(info.softInputMode);
3490        }
3491        mUiThread = Thread.currentThread();
3492
3493        mMainThread = aThread;
3494        mInstrumentation = instr;
3495        mToken = token;
3496        mApplication = application;
3497        mIntent = intent;
3498        mComponent = intent.getComponent();
3499        mActivityInfo = info;
3500        mTitle = title;
3501        mParent = parent;
3502        mEmbeddedID = id;
3503        mLastNonConfigurationInstance = lastNonConfigurationInstance;
3504        mLastNonConfigurationChildInstances = lastNonConfigurationChildInstances;
3505
3506        mWindow.setWindowManager(null, mToken, mComponent.flattenToString());
3507        if (mParent != null) {
3508            mWindow.setContainer(mParent.getWindow());
3509        }
3510        mWindowManager = mWindow.getWindowManager();
3511        mCurrentConfig = config;
3512    }
3513
3514    final IBinder getActivityToken() {
3515        return mParent != null ? mParent.getActivityToken() : mToken;
3516    }
3517
3518    final void performStart() {
3519        mCalled = false;
3520        mInstrumentation.callActivityOnStart(this);
3521        if (!mCalled) {
3522            throw new SuperNotCalledException(
3523                "Activity " + mComponent.toShortString() +
3524                " did not call through to super.onStart()");
3525        }
3526    }
3527
3528    final void performRestart() {
3529        final int N = mManagedCursors.size();
3530        for (int i=0; i<N; i++) {
3531            ManagedCursor mc = mManagedCursors.get(i);
3532            if (mc.mReleased || mc.mUpdated) {
3533                mc.mCursor.requery();
3534                mc.mReleased = false;
3535                mc.mUpdated = false;
3536            }
3537        }
3538
3539        if (mStopped) {
3540            mStopped = false;
3541            mCalled = false;
3542            mInstrumentation.callActivityOnRestart(this);
3543            if (!mCalled) {
3544                throw new SuperNotCalledException(
3545                    "Activity " + mComponent.toShortString() +
3546                    " did not call through to super.onRestart()");
3547            }
3548            performStart();
3549        }
3550    }
3551
3552    final void performResume() {
3553        performRestart();
3554
3555        mLastNonConfigurationInstance = null;
3556
3557        // First call onResume() -before- setting mResumed, so we don't
3558        // send out any status bar / menu notifications the client makes.
3559        mCalled = false;
3560        mInstrumentation.callActivityOnResume(this);
3561        if (!mCalled) {
3562            throw new SuperNotCalledException(
3563                "Activity " + mComponent.toShortString() +
3564                " did not call through to super.onResume()");
3565        }
3566
3567        // Now really resume, and install the current status bar and menu.
3568        mResumed = true;
3569        mCalled = false;
3570        onPostResume();
3571        if (!mCalled) {
3572            throw new SuperNotCalledException(
3573                "Activity " + mComponent.toShortString() +
3574                " did not call through to super.onPostResume()");
3575        }
3576
3577        // restore search dialog, if any
3578        if (mSearchDialogState != null) {
3579            mSearchManager.restoreSearchDialog(mSearchDialogState);
3580        }
3581        mSearchDialogState = null;
3582    }
3583
3584    final void performPause() {
3585        onPause();
3586
3587        // save search dialog state if the search dialog is open,
3588        // and then dismiss the search dialog
3589        mSearchDialogState = mSearchManager.saveSearchDialog();
3590        mSearchManager.stopSearch();
3591    }
3592
3593    final void performUserLeaving() {
3594        onUserInteraction();
3595        onUserLeaveHint();
3596    }
3597
3598    final void performStop() {
3599        if (!mStopped) {
3600            if (mWindow != null) {
3601                mWindow.closeAllPanels();
3602            }
3603
3604            mCalled = false;
3605            mInstrumentation.callActivityOnStop(this);
3606            if (!mCalled) {
3607                throw new SuperNotCalledException(
3608                    "Activity " + mComponent.toShortString() +
3609                    " did not call through to super.onStop()");
3610            }
3611
3612            final int N = mManagedCursors.size();
3613            for (int i=0; i<N; i++) {
3614                ManagedCursor mc = mManagedCursors.get(i);
3615                if (!mc.mReleased) {
3616                    mc.mCursor.deactivate();
3617                    mc.mReleased = true;
3618                }
3619            }
3620
3621            mStopped = true;
3622        }
3623        mResumed = false;
3624    }
3625
3626    final boolean isResumed() {
3627        return mResumed;
3628    }
3629
3630    void dispatchActivityResult(String who, int requestCode,
3631        int resultCode, Intent data) {
3632        if (Config.LOGV) Log.v(
3633            TAG, "Dispatching result: who=" + who + ", reqCode=" + requestCode
3634            + ", resCode=" + resultCode + ", data=" + data);
3635        if (who == null) {
3636            onActivityResult(requestCode, resultCode, data);
3637        }
3638    }
3639}
3640