Activity.java revision e35c23514592efe07d54fdbed7e7ec0b717e8bbe
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                // Calling onRestoreInstanceState() below will invoke dispatchOnCreate
868                // so tell createDialog() not to do it, otherwise we get an exception
869                final Dialog dialog = createDialog(dialogId, false);
870                mManagedDialogs.put(dialogId, dialog);
871                onPrepareDialog(dialogId, dialog);
872                dialog.onRestoreInstanceState(dialogState);
873            }
874        }
875    }
876
877    private Dialog createDialog(Integer dialogId, boolean dispatchOnCreate) {
878        final Dialog dialog = onCreateDialog(dialogId);
879        if (dialog == null) {
880            throw new IllegalArgumentException("Activity#onCreateDialog did "
881                    + "not create a dialog for id " + dialogId);
882        }
883        if (dispatchOnCreate) dialog.dispatchOnCreate(null);
884        return dialog;
885    }
886
887    private String savedDialogKeyFor(int key) {
888        return SAVED_DIALOG_KEY_PREFIX + key;
889    }
890
891
892    /**
893     * Called when activity start-up is complete (after {@link #onStart}
894     * and {@link #onRestoreInstanceState} have been called).  Applications will
895     * generally not implement this method; it is intended for system
896     * classes to do final initialization after application code has run.
897     *
898     * <p><em>Derived classes must call through to the super class's
899     * implementation of this method.  If they do not, an exception will be
900     * thrown.</em></p>
901     *
902     * @param savedInstanceState If the activity is being re-initialized after
903     *     previously being shut down then this Bundle contains the data it most
904     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
905     * @see #onCreate
906     */
907    protected void onPostCreate(Bundle savedInstanceState) {
908        if (!isChild()) {
909            mTitleReady = true;
910            onTitleChanged(getTitle(), getTitleColor());
911        }
912        mCalled = true;
913    }
914
915    /**
916     * Called after {@link #onCreate} &mdash; or after {@link #onRestart} when
917     * the activity had been stopped, but is now again being displayed to the
918	 * user.  It will be followed by {@link #onResume}.
919     *
920     * <p><em>Derived classes must call through to the super class's
921     * implementation of this method.  If they do not, an exception will be
922     * thrown.</em></p>
923     *
924     * @see #onCreate
925     * @see #onStop
926     * @see #onResume
927     */
928    protected void onStart() {
929        mCalled = true;
930    }
931
932    /**
933     * Called after {@link #onStop} when the current activity is being
934     * re-displayed to the user (the user has navigated back to it).  It will
935     * be followed by {@link #onStart} and then {@link #onResume}.
936     *
937     * <p>For activities that are using raw {@link Cursor} objects (instead of
938     * creating them through
939     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)},
940     * this is usually the place
941     * where the cursor should be requeried (because you had deactivated it in
942     * {@link #onStop}.
943     *
944     * <p><em>Derived classes must call through to the super class's
945     * implementation of this method.  If they do not, an exception will be
946     * thrown.</em></p>
947     *
948     * @see #onStop
949     * @see #onStart
950     * @see #onResume
951     */
952    protected void onRestart() {
953        mCalled = true;
954    }
955
956    /**
957     * Called after {@link #onRestoreInstanceState}, {@link #onRestart}, or
958     * {@link #onPause}, for your activity to start interacting with the user.
959     * This is a good place to begin animations, open exclusive-access devices
960     * (such as the camera), etc.
961     *
962     * <p>Keep in mind that onResume is not the best indicator that your activity
963     * is visible to the user; a system window such as the keyguard may be in
964     * front.  Use {@link #onWindowFocusChanged} to know for certain that your
965     * activity is visible to the user (for example, to resume a game).
966     *
967     * <p><em>Derived classes must call through to the super class's
968     * implementation of this method.  If they do not, an exception will be
969     * thrown.</em></p>
970     *
971     * @see #onRestoreInstanceState
972     * @see #onRestart
973     * @see #onPostResume
974     * @see #onPause
975     */
976    protected void onResume() {
977        mCalled = true;
978    }
979
980    /**
981     * Called when activity resume is complete (after {@link #onResume} has
982     * been called). Applications will generally not implement this method;
983     * it is intended for system classes to do final setup after application
984     * resume code has run.
985     *
986     * <p><em>Derived classes must call through to the super class's
987     * implementation of this method.  If they do not, an exception will be
988     * thrown.</em></p>
989     *
990     * @see #onResume
991     */
992    protected void onPostResume() {
993        final Window win = getWindow();
994        if (win != null) win.makeActive();
995        mCalled = true;
996    }
997
998    /**
999     * This is called for activities that set launchMode to "singleTop" in
1000     * their package, or if a client used the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP}
1001     * flag when calling {@link #startActivity}.  In either case, when the
1002     * activity is re-launched while at the top of the activity stack instead
1003     * of a new instance of the activity being started, onNewIntent() will be
1004     * called on the existing instance with the Intent that was used to
1005     * re-launch it.
1006     *
1007     * <p>An activity will always be paused before receiving a new intent, so
1008     * you can count on {@link #onResume} being called after this method.
1009     *
1010     * <p>Note that {@link #getIntent} still returns the original Intent.  You
1011     * can use {@link #setIntent} to update it to this new Intent.
1012     *
1013     * @param intent The new intent that was started for the activity.
1014     *
1015     * @see #getIntent
1016     * @see #setIntent
1017     * @see #onResume
1018     */
1019    protected void onNewIntent(Intent intent) {
1020    }
1021
1022    /**
1023     * The hook for {@link ActivityThread} to save the state of this activity.
1024     *
1025     * Calls {@link #onSaveInstanceState(android.os.Bundle)}
1026     * and {@link #saveManagedDialogs(android.os.Bundle)}.
1027     *
1028     * @param outState The bundle to save the state to.
1029     */
1030    final void performSaveInstanceState(Bundle outState) {
1031        onSaveInstanceState(outState);
1032        saveManagedDialogs(outState);
1033
1034        // Also save the state of a search dialog (if any)
1035        // TODO more generic than just this manager
1036        // onPause() should always be called before this method, so mSearchManagerState
1037        // should be up to date.
1038        if (mSearchDialogState != null) {
1039            outState.putBundle(SAVED_SEARCH_DIALOG_KEY, mSearchDialogState);
1040        }
1041    }
1042
1043    /**
1044     * Called to retrieve per-instance state from an activity before being killed
1045     * so that the state can be restored in {@link #onCreate} or
1046     * {@link #onRestoreInstanceState} (the {@link Bundle} populated by this method
1047     * will be passed to both).
1048     *
1049     * <p>This method is called before an activity may be killed so that when it
1050     * comes back some time in the future it can restore its state.  For example,
1051     * if activity B is launched in front of activity A, and at some point activity
1052     * A is killed to reclaim resources, activity A will have a chance to save the
1053     * current state of its user interface via this method so that when the user
1054     * returns to activity A, the state of the user interface can be restored
1055     * via {@link #onCreate} or {@link #onRestoreInstanceState}.
1056     *
1057     * <p>Do not confuse this method with activity lifecycle callbacks such as
1058     * {@link #onPause}, which is always called when an activity is being placed
1059     * in the background or on its way to destruction, or {@link #onStop} which
1060     * is called before destruction.  One example of when {@link #onPause} and
1061     * {@link #onStop} is called and not this method is when a user navigates back
1062     * from activity B to activity A: there is no need to call {@link #onSaveInstanceState}
1063     * on B because that particular instance will never be restored, so the
1064     * system avoids calling it.  An example when {@link #onPause} is called and
1065     * not {@link #onSaveInstanceState} is when activity B is launched in front of activity A:
1066     * the system may avoid calling {@link #onSaveInstanceState} on activity A if it isn't
1067     * killed during the lifetime of B since the state of the user interface of
1068     * A will stay intact.
1069     *
1070     * <p>The default implementation takes care of most of the UI per-instance
1071     * state for you by calling {@link android.view.View#onSaveInstanceState()} on each
1072     * view in the hierarchy that has an id, and by saving the id of the currently
1073     * focused view (all of which is restored by the default implementation of
1074     * {@link #onRestoreInstanceState}).  If you override this method to save additional
1075     * information not captured by each individual view, you will likely want to
1076     * call through to the default implementation, otherwise be prepared to save
1077     * all of the state of each view yourself.
1078     *
1079     * <p>If called, this method will occur before {@link #onStop}.  There are
1080     * no guarantees about whether it will occur before or after {@link #onPause}.
1081     *
1082     * @param outState Bundle in which to place your saved state.
1083     *
1084     * @see #onCreate
1085     * @see #onRestoreInstanceState
1086     * @see #onPause
1087     */
1088    protected void onSaveInstanceState(Bundle outState) {
1089        outState.putBundle(WINDOW_HIERARCHY_TAG, mWindow.saveHierarchyState());
1090    }
1091
1092    /**
1093     * Save the state of any managed dialogs.
1094     *
1095     * @param outState place to store the saved state.
1096     */
1097    private void saveManagedDialogs(Bundle outState) {
1098        if (mManagedDialogs == null) {
1099            return;
1100        }
1101
1102        final int numDialogs = mManagedDialogs.size();
1103        if (numDialogs == 0) {
1104            return;
1105        }
1106
1107        Bundle dialogState = new Bundle();
1108
1109        int[] ids = new int[mManagedDialogs.size()];
1110
1111        // save each dialog's bundle, gather the ids
1112        for (int i = 0; i < numDialogs; i++) {
1113            final int key = mManagedDialogs.keyAt(i);
1114            ids[i] = key;
1115            final Dialog dialog = mManagedDialogs.valueAt(i);
1116            dialogState.putBundle(savedDialogKeyFor(key), dialog.onSaveInstanceState());
1117        }
1118
1119        dialogState.putIntArray(SAVED_DIALOG_IDS_KEY, ids);
1120        outState.putBundle(SAVED_DIALOGS_TAG, dialogState);
1121    }
1122
1123
1124    /**
1125     * Called as part of the activity lifecycle when an activity is going into
1126     * the background, but has not (yet) been killed.  The counterpart to
1127     * {@link #onResume}.
1128     *
1129     * <p>When activity B is launched in front of activity A, this callback will
1130     * be invoked on A.  B will not be created until A's {@link #onPause} returns,
1131     * so be sure to not do anything lengthy here.
1132     *
1133     * <p>This callback is mostly used for saving any persistent state the
1134     * activity is editing, to present a "edit in place" model to the user and
1135     * making sure nothing is lost if there are not enough resources to start
1136     * the new activity without first killing this one.  This is also a good
1137     * place to do things like stop animations and other things that consume a
1138     * noticeable mount of CPU in order to make the switch to the next activity
1139     * as fast as possible, or to close resources that are exclusive access
1140     * such as the camera.
1141     *
1142     * <p>In situations where the system needs more memory it may kill paused
1143     * processes to reclaim resources.  Because of this, you should be sure
1144     * that all of your state is saved by the time you return from
1145     * this function.  In general {@link #onSaveInstanceState} is used to save
1146     * per-instance state in the activity and this method is used to store
1147     * global persistent data (in content providers, files, etc.)
1148     *
1149     * <p>After receiving this call you will usually receive a following call
1150     * to {@link #onStop} (after the next activity has been resumed and
1151     * displayed), however in some cases there will be a direct call back to
1152     * {@link #onResume} without going through the stopped state.
1153     *
1154     * <p><em>Derived classes must call through to the super class's
1155     * implementation of this method.  If they do not, an exception will be
1156     * thrown.</em></p>
1157     *
1158     * @see #onResume
1159     * @see #onSaveInstanceState
1160     * @see #onStop
1161     */
1162    protected void onPause() {
1163        mCalled = true;
1164    }
1165
1166    /**
1167     * Called as part of the activity lifecycle when an activity is about to go
1168     * into the background as the result of user choice.  For example, when the
1169     * user presses the Home key, {@link #onUserLeaveHint} will be called, but
1170     * when an incoming phone call causes the in-call Activity to be automatically
1171     * brought to the foreground, {@link #onUserLeaveHint} will not be called on
1172     * the activity being interrupted.  In cases when it is invoked, this method
1173     * is called right before the activity's {@link #onPause} callback.
1174     *
1175     * <p>This callback and {@link #onUserInteraction} are intended to help
1176     * activities manage status bar notifications intelligently; specifically,
1177     * for helping activities determine the proper time to cancel a notfication.
1178     *
1179     * @see #onUserInteraction()
1180     */
1181    protected void onUserLeaveHint() {
1182    }
1183
1184    /**
1185     * Generate a new thumbnail for this activity.  This method is called before
1186     * pausing the activity, and should draw into <var>outBitmap</var> the
1187     * imagery for the desired thumbnail in the dimensions of that bitmap.  It
1188     * can use the given <var>canvas</var>, which is configured to draw into the
1189     * bitmap, for rendering if desired.
1190     *
1191     * <p>The default implementation renders the Screen's current view
1192     * hierarchy into the canvas to generate a thumbnail.
1193     *
1194     * <p>If you return false, the bitmap will be filled with a default
1195     * thumbnail.
1196     *
1197     * @param outBitmap The bitmap to contain the thumbnail.
1198     * @param canvas Can be used to render into the bitmap.
1199     *
1200     * @return Return true if you have drawn into the bitmap; otherwise after
1201     *         you return it will be filled with a default thumbnail.
1202     *
1203     * @see #onCreateDescription
1204     * @see #onSaveInstanceState
1205     * @see #onPause
1206     */
1207    public boolean onCreateThumbnail(Bitmap outBitmap, Canvas canvas) {
1208        final View view = mDecor;
1209        if (view == null) {
1210            return false;
1211        }
1212
1213        final int vw = view.getWidth();
1214        final int vh = view.getHeight();
1215        final int dw = outBitmap.getWidth();
1216        final int dh = outBitmap.getHeight();
1217
1218        canvas.save();
1219        canvas.scale(((float)dw)/vw, ((float)dh)/vh);
1220        view.draw(canvas);
1221        canvas.restore();
1222
1223        return true;
1224    }
1225
1226    /**
1227     * Generate a new description for this activity.  This method is called
1228     * before pausing the activity and can, if desired, return some textual
1229     * description of its current state to be displayed to the user.
1230     *
1231     * <p>The default implementation returns null, which will cause you to
1232     * inherit the description from the previous activity.  If all activities
1233     * return null, generally the label of the top activity will be used as the
1234     * description.
1235     *
1236     * @return A description of what the user is doing.  It should be short and
1237     *         sweet (only a few words).
1238     *
1239     * @see #onCreateThumbnail
1240     * @see #onSaveInstanceState
1241     * @see #onPause
1242     */
1243    public CharSequence onCreateDescription() {
1244        return null;
1245    }
1246
1247    /**
1248     * Called when you are no longer visible to the user.  You will next
1249     * receive either {@link #onRestart}, {@link #onDestroy}, or nothing,
1250     * depending on later user activity.
1251     *
1252     * <p>Note that this method may never be called, in low memory situations
1253     * where the system does not have enough memory to keep your activity's
1254     * process running after its {@link #onPause} method is called.
1255     *
1256     * <p><em>Derived classes must call through to the super class's
1257     * implementation of this method.  If they do not, an exception will be
1258     * thrown.</em></p>
1259     *
1260     * @see #onRestart
1261     * @see #onResume
1262     * @see #onSaveInstanceState
1263     * @see #onDestroy
1264     */
1265    protected void onStop() {
1266        mCalled = true;
1267    }
1268
1269    /**
1270     * Perform any final cleanup before an activity is destroyed.  This can
1271     * happen either because the activity is finishing (someone called
1272     * {@link #finish} on it, or because the system is temporarily destroying
1273     * this instance of the activity to save space.  You can distinguish
1274     * between these two scenarios with the {@link #isFinishing} method.
1275     *
1276     * <p><em>Note: do not count on this method being called as a place for
1277     * saving data! For example, if an activity is editing data in a content
1278     * provider, those edits should be committed in either {@link #onPause} or
1279     * {@link #onSaveInstanceState}, not here.</em> This method is usually implemented to
1280     * free resources like threads that are associated with an activity, so
1281     * that a destroyed activity does not leave such things around while the
1282     * rest of its application is still running.  There are situations where
1283     * the system will simply kill the activity's hosting process without
1284     * calling this method (or any others) in it, so it should not be used to
1285     * do things that are intended to remain around after the process goes
1286     * away.
1287     *
1288     * <p><em>Derived classes must call through to the super class's
1289     * implementation of this method.  If they do not, an exception will be
1290     * thrown.</em></p>
1291     *
1292     * @see #onPause
1293     * @see #onStop
1294     * @see #finish
1295     * @see #isFinishing
1296     */
1297    protected void onDestroy() {
1298        mCalled = true;
1299
1300        // dismiss any dialogs we are managing.
1301        if (mManagedDialogs != null) {
1302
1303            final int numDialogs = mManagedDialogs.size();
1304            for (int i = 0; i < numDialogs; i++) {
1305                final Dialog dialog = mManagedDialogs.valueAt(i);
1306                if (dialog.isShowing()) {
1307                    dialog.dismiss();
1308                }
1309            }
1310        }
1311
1312        // close any cursors we are managing.
1313        int numCursors = mManagedCursors.size();
1314        for (int i = 0; i < numCursors; i++) {
1315            ManagedCursor c = mManagedCursors.get(i);
1316            if (c != null) {
1317                c.mCursor.close();
1318            }
1319        }
1320
1321        // Clear any search state saved in performPause(). If the state may be needed in the
1322        // future, it will have been saved by performSaveInstanceState()
1323        mSearchDialogState = null;
1324    }
1325
1326    /**
1327     * Called by the system when the device configuration changes while your
1328     * activity is running.  Note that this will <em>only</em> be called if
1329     * you have selected configurations you would like to handle with the
1330     * {@link android.R.attr#configChanges} attribute in your manifest.  If
1331     * any configuration change occurs that is not selected to be reported
1332     * by that attribute, then instead of reporting it the system will stop
1333     * and restart the activity (to have it launched with the new
1334     * configuration).
1335     *
1336     * <p>At the time that this function has been called, your Resources
1337     * object will have been updated to return resource values matching the
1338     * new configuration.
1339     *
1340     * @param newConfig The new device configuration.
1341     */
1342    public void onConfigurationChanged(Configuration newConfig) {
1343        mCalled = true;
1344
1345        // also update search dialog if showing
1346        // TODO more generic than just this manager
1347        mSearchManager.onConfigurationChanged(newConfig);
1348
1349        if (mWindow != null) {
1350            // Pass the configuration changed event to the window
1351            mWindow.onConfigurationChanged(newConfig);
1352        }
1353    }
1354
1355    /**
1356     * If this activity is being destroyed because it can not handle a
1357     * configuration parameter being changed (and thus its
1358     * {@link #onConfigurationChanged(Configuration)} method is
1359     * <em>not</em> being called), then you can use this method to discover
1360     * the set of changes that have occurred while in the process of being
1361     * destroyed.  Note that there is no guarantee that these will be
1362     * accurate (other changes could have happened at any time), so you should
1363     * only use this as an optimization hint.
1364     *
1365     * @return Returns a bit field of the configuration parameters that are
1366     * changing, as defined by the {@link android.content.res.Configuration}
1367     * class.
1368     */
1369    public int getChangingConfigurations() {
1370        return mConfigChangeFlags;
1371    }
1372
1373    /**
1374     * Retrieve the non-configuration instance data that was previously
1375     * returned by {@link #onRetainNonConfigurationInstance()}.  This will
1376     * be available from the initial {@link #onCreate} and
1377     * {@link #onStart} calls to the new instance, allowing you to extract
1378     * any useful dynamic state from the previous instance.
1379     *
1380     * <p>Note that the data you retrieve here should <em>only</em> be used
1381     * as an optimization for handling configuration changes.  You should always
1382     * be able to handle getting a null pointer back, and an activity must
1383     * still be able to restore itself to its previous state (through the
1384     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1385     * function returns null.
1386     *
1387     * @return Returns the object previously returned by
1388     * {@link #onRetainNonConfigurationInstance()}.
1389     */
1390    public Object getLastNonConfigurationInstance() {
1391        return mLastNonConfigurationInstance;
1392    }
1393
1394    /**
1395     * Called by the system, as part of destroying an
1396     * activity due to a configuration change, when it is known that a new
1397     * instance will immediately be created for the new configuration.  You
1398     * can return any object you like here, including the activity instance
1399     * itself, which can later be retrieved by calling
1400     * {@link #getLastNonConfigurationInstance()} in the new activity
1401     * instance.
1402     *
1403     * <p>This function is called purely as an optimization, and you must
1404     * not rely on it being called.  When it is called, a number of guarantees
1405     * will be made to help optimize configuration switching:
1406     * <ul>
1407     * <li> The function will be called between {@link #onStop} and
1408     * {@link #onDestroy}.
1409     * <li> A new instance of the activity will <em>always</em> be immediately
1410     * created after this one's {@link #onDestroy()} is called.
1411     * <li> The object you return here will <em>always</em> be available from
1412     * the {@link #getLastNonConfigurationInstance()} method of the following
1413     * activity instance as described there.
1414     * </ul>
1415     *
1416     * <p>These guarantees are designed so that an activity can use this API
1417     * to propagate extensive state from the old to new activity instance, from
1418     * loaded bitmaps, to network connections, to evenly actively running
1419     * threads.  Note that you should <em>not</em> propagate any data that
1420     * may change based on the configuration, including any data loaded from
1421     * resources such as strings, layouts, or drawables.
1422     *
1423     * @return Return any Object holding the desired state to propagate to the
1424     * next activity instance.
1425     */
1426    public Object onRetainNonConfigurationInstance() {
1427        return null;
1428    }
1429
1430    /**
1431     * Retrieve the non-configuration instance data that was previously
1432     * returned by {@link #onRetainNonConfigurationChildInstances()}.  This will
1433     * be available from the initial {@link #onCreate} and
1434     * {@link #onStart} calls to the new instance, allowing you to extract
1435     * any useful dynamic state from the previous instance.
1436     *
1437     * <p>Note that the data you retrieve here should <em>only</em> be used
1438     * as an optimization for handling configuration changes.  You should always
1439     * be able to handle getting a null pointer back, and an activity must
1440     * still be able to restore itself to its previous state (through the
1441     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1442     * function returns null.
1443     *
1444     * @return Returns the object previously returned by
1445     * {@link #onRetainNonConfigurationChildInstances()}
1446     */
1447    HashMap<String,Object> getLastNonConfigurationChildInstances() {
1448        return mLastNonConfigurationChildInstances;
1449    }
1450
1451    /**
1452     * This method is similar to {@link #onRetainNonConfigurationInstance()} except that
1453     * it should return either a mapping from  child activity id strings to arbitrary objects,
1454     * or null.  This method is intended to be used by Activity framework subclasses that control a
1455     * set of child activities, such as ActivityGroup.  The same guarantees and restrictions apply
1456     * as for {@link #onRetainNonConfigurationInstance()}.  The default implementation returns null.
1457     */
1458    HashMap<String,Object> onRetainNonConfigurationChildInstances() {
1459        return null;
1460    }
1461
1462    public void onLowMemory() {
1463        mCalled = true;
1464    }
1465
1466    /**
1467     * Wrapper around
1468     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1469     * that gives the resulting {@link Cursor} to call
1470     * {@link #startManagingCursor} so that the activity will manage its
1471     * lifecycle for you.
1472     *
1473     * @param uri The URI of the content provider to query.
1474     * @param projection List of columns to return.
1475     * @param selection SQL WHERE clause.
1476     * @param sortOrder SQL ORDER BY clause.
1477     *
1478     * @return The Cursor that was returned by query().
1479     *
1480     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1481     * @see #startManagingCursor
1482     * @hide
1483     */
1484    public final Cursor managedQuery(Uri uri,
1485                                     String[] projection,
1486                                     String selection,
1487                                     String sortOrder)
1488    {
1489        Cursor c = getContentResolver().query(uri, projection, selection, null, sortOrder);
1490        if (c != null) {
1491            startManagingCursor(c);
1492        }
1493        return c;
1494    }
1495
1496    /**
1497     * Wrapper around
1498     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1499     * that gives the resulting {@link Cursor} to call
1500     * {@link #startManagingCursor} so that the activity will manage its
1501     * lifecycle for you.
1502     *
1503     * @param uri The URI of the content provider to query.
1504     * @param projection List of columns to return.
1505     * @param selection SQL WHERE clause.
1506     * @param selectionArgs The arguments to selection, if any ?s are pesent
1507     * @param sortOrder SQL ORDER BY clause.
1508     *
1509     * @return The Cursor that was returned by query().
1510     *
1511     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1512     * @see #startManagingCursor
1513     */
1514    public final Cursor managedQuery(Uri uri,
1515                                     String[] projection,
1516                                     String selection,
1517                                     String[] selectionArgs,
1518                                     String sortOrder)
1519    {
1520        Cursor c = getContentResolver().query(uri, projection, selection, selectionArgs, sortOrder);
1521        if (c != null) {
1522            startManagingCursor(c);
1523        }
1524        return c;
1525    }
1526
1527    /**
1528     * Wrapper around {@link Cursor#commitUpdates()} that takes care of noting
1529     * that the Cursor needs to be requeried.  You can call this method in
1530     * {@link #onPause} or {@link #onStop} to have the system call
1531     * {@link Cursor#requery} for you if the activity is later resumed.  This
1532     * allows you to avoid determing when to do the requery yourself (which is
1533     * required for the Cursor to see any data changes that were committed with
1534     * it).
1535     *
1536     * @param c The Cursor whose changes are to be committed.
1537     *
1538     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
1539     * @see #startManagingCursor
1540     * @see Cursor#commitUpdates()
1541     * @see Cursor#requery
1542     * @hide
1543     */
1544    @Deprecated
1545    public void managedCommitUpdates(Cursor c) {
1546        synchronized (mManagedCursors) {
1547            final int N = mManagedCursors.size();
1548            for (int i=0; i<N; i++) {
1549                ManagedCursor mc = mManagedCursors.get(i);
1550                if (mc.mCursor == c) {
1551                    c.commitUpdates();
1552                    mc.mUpdated = true;
1553                    return;
1554                }
1555            }
1556            throw new RuntimeException(
1557                "Cursor " + c + " is not currently managed");
1558        }
1559    }
1560
1561    /**
1562     * This method allows the activity to take care of managing the given
1563     * {@link Cursor}'s lifecycle for you based on the activity's lifecycle.
1564     * That is, when the activity is stopped it will automatically call
1565     * {@link Cursor#deactivate} on the given Cursor, and when it is later restarted
1566     * it will call {@link Cursor#requery} for you.  When the activity is
1567     * destroyed, all managed Cursors will be closed automatically.
1568     *
1569     * @param c The Cursor to be managed.
1570     *
1571     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
1572     * @see #stopManagingCursor
1573     */
1574    public void startManagingCursor(Cursor c) {
1575        synchronized (mManagedCursors) {
1576            mManagedCursors.add(new ManagedCursor(c));
1577        }
1578    }
1579
1580    /**
1581     * Given a Cursor that was previously given to
1582     * {@link #startManagingCursor}, stop the activity's management of that
1583     * cursor.
1584     *
1585     * @param c The Cursor that was being managed.
1586     *
1587     * @see #startManagingCursor
1588     */
1589    public void stopManagingCursor(Cursor c) {
1590        synchronized (mManagedCursors) {
1591            final int N = mManagedCursors.size();
1592            for (int i=0; i<N; i++) {
1593                ManagedCursor mc = mManagedCursors.get(i);
1594                if (mc.mCursor == c) {
1595                    mManagedCursors.remove(i);
1596                    break;
1597                }
1598            }
1599        }
1600    }
1601
1602    /**
1603     * Control whether this activity is required to be persistent.  By default
1604     * activities are not persistent; setting this to true will prevent the
1605     * system from stopping this activity or its process when running low on
1606     * resources.
1607     *
1608     * <p><em>You should avoid using this method</em>, it has severe negative
1609     * consequences on how well the system can manage its resources.  A better
1610     * approach is to implement an application service that you control with
1611     * {@link Context#startService} and {@link Context#stopService}.
1612     *
1613     * @param isPersistent Control whether the current activity must be
1614     *                     persistent, true if so, false for the normal
1615     *                     behavior.
1616     */
1617    public void setPersistent(boolean isPersistent) {
1618        if (mParent == null) {
1619            try {
1620                ActivityManagerNative.getDefault()
1621                    .setPersistent(mToken, isPersistent);
1622            } catch (RemoteException e) {
1623                // Empty
1624            }
1625        } else {
1626            throw new RuntimeException("setPersistent() not yet supported for embedded activities");
1627        }
1628    }
1629
1630    /**
1631     * Finds a view that was identified by the id attribute from the XML that
1632     * was processed in {@link #onCreate}.
1633     *
1634     * @return The view if found or null otherwise.
1635     */
1636    public View findViewById(int id) {
1637        return getWindow().findViewById(id);
1638    }
1639
1640    /**
1641     * Set the activity content from a layout resource.  The resource will be
1642     * inflated, adding all top-level views to the activity.
1643     *
1644     * @param layoutResID Resource ID to be inflated.
1645     */
1646    public void setContentView(int layoutResID) {
1647        getWindow().setContentView(layoutResID);
1648    }
1649
1650    /**
1651     * Set the activity content to an explicit view.  This view is placed
1652     * directly into the activity's view hierarchy.  It can itself be a complex
1653     * view hierarhcy.
1654     *
1655     * @param view The desired content to display.
1656     */
1657    public void setContentView(View view) {
1658        getWindow().setContentView(view);
1659    }
1660
1661    /**
1662     * Set the activity content to an explicit view.  This view is placed
1663     * directly into the activity's view hierarchy.  It can itself be a complex
1664     * view hierarhcy.
1665     *
1666     * @param view The desired content to display.
1667     * @param params Layout parameters for the view.
1668     */
1669    public void setContentView(View view, ViewGroup.LayoutParams params) {
1670        getWindow().setContentView(view, params);
1671    }
1672
1673    /**
1674     * Add an additional content view to the activity.  Added after any existing
1675     * ones in the activity -- existing views are NOT removed.
1676     *
1677     * @param view The desired content to display.
1678     * @param params Layout parameters for the view.
1679     */
1680    public void addContentView(View view, ViewGroup.LayoutParams params) {
1681        getWindow().addContentView(view, params);
1682    }
1683
1684    /**
1685     * Use with {@link #setDefaultKeyMode} to turn off default handling of
1686     * keys.
1687     *
1688     * @see #setDefaultKeyMode
1689     */
1690    static public final int DEFAULT_KEYS_DISABLE = 0;
1691    /**
1692     * Use with {@link #setDefaultKeyMode} to launch the dialer during default
1693     * key handling.
1694     *
1695     * @see #setDefaultKeyMode
1696     */
1697    static public final int DEFAULT_KEYS_DIALER = 1;
1698    /**
1699     * Use with {@link #setDefaultKeyMode} to execute a menu shortcut in
1700     * default key handling.
1701     *
1702     * <p>That is, the user does not need to hold down the menu key to execute menu shortcuts.
1703     *
1704     * @see #setDefaultKeyMode
1705     */
1706    static public final int DEFAULT_KEYS_SHORTCUT = 2;
1707    /**
1708     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1709     * will start an application-defined search.  (If the application or activity does not
1710     * actually define a search, the the keys will be ignored.)
1711     *
1712     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1713     *
1714     * @see #setDefaultKeyMode
1715     */
1716    static public final int DEFAULT_KEYS_SEARCH_LOCAL = 3;
1717
1718    /**
1719     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1720     * will start a global search (typically web search, but some platforms may define alternate
1721     * methods for global search)
1722     *
1723     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1724     *
1725     * @see #setDefaultKeyMode
1726     */
1727    static public final int DEFAULT_KEYS_SEARCH_GLOBAL = 4;
1728
1729    /**
1730     * Select the default key handling for this activity.  This controls what
1731     * will happen to key events that are not otherwise handled.  The default
1732     * mode ({@link #DEFAULT_KEYS_DISABLE}) will simply drop them on the
1733     * floor. Other modes allow you to launch the dialer
1734     * ({@link #DEFAULT_KEYS_DIALER}), execute a shortcut in your options
1735     * menu without requiring the menu key be held down
1736     * ({@link #DEFAULT_KEYS_SHORTCUT}), or launch a search ({@link #DEFAULT_KEYS_SEARCH_LOCAL}
1737     * and {@link #DEFAULT_KEYS_SEARCH_GLOBAL}).
1738     *
1739     * <p>Note that the mode selected here does not impact the default
1740     * handling of system keys, such as the "back" and "menu" keys, and your
1741     * activity and its views always get a first chance to receive and handle
1742     * all application keys.
1743     *
1744     * @param mode The desired default key mode constant.
1745     *
1746     * @see #DEFAULT_KEYS_DISABLE
1747     * @see #DEFAULT_KEYS_DIALER
1748     * @see #DEFAULT_KEYS_SHORTCUT
1749     * @see #DEFAULT_KEYS_SEARCH_LOCAL
1750     * @see #DEFAULT_KEYS_SEARCH_GLOBAL
1751     * @see #onKeyDown
1752     */
1753    public final void setDefaultKeyMode(int mode) {
1754        mDefaultKeyMode = mode;
1755
1756        // Some modes use a SpannableStringBuilder to track & dispatch input events
1757        // This list must remain in sync with the switch in onKeyDown()
1758        switch (mode) {
1759        case DEFAULT_KEYS_DISABLE:
1760        case DEFAULT_KEYS_SHORTCUT:
1761            mDefaultKeySsb = null;      // not used in these modes
1762            break;
1763        case DEFAULT_KEYS_DIALER:
1764        case DEFAULT_KEYS_SEARCH_LOCAL:
1765        case DEFAULT_KEYS_SEARCH_GLOBAL:
1766            mDefaultKeySsb = new SpannableStringBuilder();
1767            Selection.setSelection(mDefaultKeySsb,0);
1768            break;
1769        default:
1770            throw new IllegalArgumentException();
1771        }
1772    }
1773
1774    /**
1775     * Called when a key was pressed down and not handled by any of the views
1776     * inside of the activity. So, for example, key presses while the cursor
1777     * is inside a TextView will not trigger the event (unless it is a navigation
1778     * to another object) because TextView handles its own key presses.
1779     *
1780     * <p>If the focused view didn't want this event, this method is called.
1781     *
1782     * <p>The default implementation handles KEYCODE_BACK to stop the activity
1783     * and go back, and other default key handling if configured with {@link #setDefaultKeyMode}.
1784     *
1785     * @return Return <code>true</code> to prevent this event from being propagated
1786     * further, or <code>false</code> to indicate that you have not handled
1787     * this event and it should continue to be propagated.
1788     * @see #onKeyUp
1789     * @see android.view.KeyEvent
1790     */
1791    public boolean onKeyDown(int keyCode, KeyEvent event)  {
1792        if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
1793            finish();
1794            return true;
1795        }
1796
1797        if (mDefaultKeyMode == DEFAULT_KEYS_DISABLE) {
1798            return false;
1799        } else if (mDefaultKeyMode == DEFAULT_KEYS_SHORTCUT) {
1800            return getWindow().performPanelShortcut(Window.FEATURE_OPTIONS_PANEL,
1801                                                    keyCode, event, Menu.FLAG_ALWAYS_PERFORM_CLOSE);
1802        } else {
1803            // Common code for DEFAULT_KEYS_DIALER & DEFAULT_KEYS_SEARCH_*
1804            boolean clearSpannable = false;
1805            boolean handled;
1806            if ((event.getRepeatCount() != 0) || event.isSystem()) {
1807                clearSpannable = true;
1808                handled = false;
1809            } else {
1810                handled = TextKeyListener.getInstance().onKeyDown(null, mDefaultKeySsb,
1811                                                                  keyCode, event);
1812                if (handled && mDefaultKeySsb.length() > 0) {
1813                    // something useable has been typed - dispatch it now.
1814
1815                    final String str = mDefaultKeySsb.toString();
1816                    clearSpannable = true;
1817
1818                    switch (mDefaultKeyMode) {
1819                    case DEFAULT_KEYS_DIALER:
1820                        Intent intent = new Intent(Intent.ACTION_DIAL,  Uri.parse("tel:" + str));
1821                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
1822                        startActivity(intent);
1823                        break;
1824                    case DEFAULT_KEYS_SEARCH_LOCAL:
1825                        startSearch(str, false, null, false);
1826                        break;
1827                    case DEFAULT_KEYS_SEARCH_GLOBAL:
1828                        startSearch(str, false, null, true);
1829                        break;
1830                    }
1831                }
1832            }
1833            if (clearSpannable) {
1834                mDefaultKeySsb.clear();
1835                mDefaultKeySsb.clearSpans();
1836                Selection.setSelection(mDefaultKeySsb,0);
1837            }
1838            return handled;
1839        }
1840    }
1841
1842    /**
1843     * Called when a key was released and not handled by any of the views
1844     * inside of the activity. So, for example, key presses while the cursor
1845     * is inside a TextView will not trigger the event (unless it is a navigation
1846     * to another object) because TextView handles its own key presses.
1847     *
1848     * @return Return <code>true</code> to prevent this event from being propagated
1849     * further, or <code>false</code> to indicate that you have not handled
1850     * this event and it should continue to be propagated.
1851     * @see #onKeyDown
1852     * @see KeyEvent
1853     */
1854    public boolean onKeyUp(int keyCode, KeyEvent event) {
1855        return false;
1856    }
1857
1858    /**
1859     * Default implementation of {@link KeyEvent.Callback#onKeyMultiple(int, int, KeyEvent)
1860     * KeyEvent.Callback.onKeyMultiple()}: always returns false (doesn't handle
1861     * the event).
1862     */
1863    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
1864        return false;
1865    }
1866
1867    /**
1868     * Called when a touch screen event was not handled by any of the views
1869     * under it.  This is most useful to process touch events that happen
1870     * outside of your window bounds, where there is no view to receive it.
1871     *
1872     * @param event The touch screen event being processed.
1873     *
1874     * @return Return true if you have consumed the event, false if you haven't.
1875     * The default implementation always returns false.
1876     */
1877    public boolean onTouchEvent(MotionEvent event) {
1878        return false;
1879    }
1880
1881    /**
1882     * Called when the trackball was moved and not handled by any of the
1883     * views inside of the activity.  So, for example, if the trackball moves
1884     * while focus is on a button, you will receive a call here because
1885     * buttons do not normally do anything with trackball events.  The call
1886     * here happens <em>before</em> trackball movements are converted to
1887     * DPAD key events, which then get sent back to the view hierarchy, and
1888     * will be processed at the point for things like focus navigation.
1889     *
1890     * @param event The trackball event being processed.
1891     *
1892     * @return Return true if you have consumed the event, false if you haven't.
1893     * The default implementation always returns false.
1894     */
1895    public boolean onTrackballEvent(MotionEvent event) {
1896        return false;
1897    }
1898
1899    /**
1900     * Called whenever a key, touch, or trackball event is dispatched to the
1901     * activity.  Implement this method if you wish to know that the user has
1902     * interacted with the device in some way while your activity is running.
1903     * This callback and {@link #onUserLeaveHint} are intended to help
1904     * activities manage status bar notifications intelligently; specifically,
1905     * for helping activities determine the proper time to cancel a notfication.
1906     *
1907     * <p>All calls to your activity's {@link #onUserLeaveHint} callback will
1908     * be accompanied by calls to {@link #onUserInteraction}.  This
1909     * ensures that your activity will be told of relevant user activity such
1910     * as pulling down the notification pane and touching an item there.
1911     *
1912     * <p>Note that this callback will be invoked for the touch down action
1913     * that begins a touch gesture, but may not be invoked for the touch-moved
1914     * and touch-up actions that follow.
1915     *
1916     * @see #onUserLeaveHint()
1917     */
1918    public void onUserInteraction() {
1919    }
1920
1921    public void onWindowAttributesChanged(WindowManager.LayoutParams params) {
1922        // Update window manager if: we have a view, that view is
1923        // attached to its parent (which will be a RootView), and
1924        // this activity is not embedded.
1925        if (mParent == null) {
1926            View decor = mDecor;
1927            if (decor != null && decor.getParent() != null) {
1928                getWindowManager().updateViewLayout(decor, params);
1929            }
1930        }
1931    }
1932
1933    public void onContentChanged() {
1934    }
1935
1936    /**
1937     * Called when the current {@link Window} of the activity gains or loses
1938     * focus.  This is the best indicator of whether this activity is visible
1939     * to the user.
1940     *
1941     * <p>Note that this provides information what global focus state, which
1942     * is managed independently of activity lifecycles.  As such, while focus
1943     * changes will generally have some relation to lifecycle changes (an
1944     * activity that is stopped will not generally get window focus), you
1945     * should not rely on any particular order between the callbacks here and
1946     * those in the other lifecycle methods such as {@link #onResume}.
1947     *
1948     * <p>As a general rule, however, a resumed activity will have window
1949     * focus...  unless it has displayed other dialogs or popups that take
1950     * input focus, in which case the activity itself will not have focus
1951     * when the other windows have it.  Likewise, the system may display
1952     * system-level windows (such as the status bar notification panel or
1953     * a system alert) which will temporarily take window input focus without
1954     * pausing the foreground activity.
1955     *
1956     * @param hasFocus Whether the window of this activity has focus.
1957     *
1958     * @see #hasWindowFocus()
1959     * @see #onResume
1960     */
1961    public void onWindowFocusChanged(boolean hasFocus) {
1962    }
1963
1964    /**
1965     * Returns true if this activity's <em>main</em> window currently has window focus.
1966     * Note that this is not the same as the view itself having focus.
1967     *
1968     * @return True if this activity's main window currently has window focus.
1969     *
1970     * @see #onWindowAttributesChanged(android.view.WindowManager.LayoutParams)
1971     */
1972    public boolean hasWindowFocus() {
1973        Window w = getWindow();
1974        if (w != null) {
1975            View d = w.getDecorView();
1976            if (d != null) {
1977                return d.hasWindowFocus();
1978            }
1979        }
1980        return false;
1981    }
1982
1983    /**
1984     * Called to process key events.  You can override this to intercept all
1985     * key events before they are dispatched to the window.  Be sure to call
1986     * this implementation for key events that should be handled normally.
1987     *
1988     * @param event The key event.
1989     *
1990     * @return boolean Return true if this event was consumed.
1991     */
1992    public boolean dispatchKeyEvent(KeyEvent event) {
1993        onUserInteraction();
1994        if (getWindow().superDispatchKeyEvent(event)) {
1995            return true;
1996        }
1997        return event.dispatch(this);
1998    }
1999
2000    /**
2001     * Called to process touch screen events.  You can override this to
2002     * intercept all touch screen events before they are dispatched to the
2003     * window.  Be sure to call this implementation for touch screen events
2004     * that should be handled normally.
2005     *
2006     * @param ev The touch screen event.
2007     *
2008     * @return boolean Return true if this event was consumed.
2009     */
2010    public boolean dispatchTouchEvent(MotionEvent ev) {
2011        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
2012            onUserInteraction();
2013        }
2014        if (getWindow().superDispatchTouchEvent(ev)) {
2015            return true;
2016        }
2017        return onTouchEvent(ev);
2018    }
2019
2020    /**
2021     * Called to process trackball events.  You can override this to
2022     * intercept all trackball events before they are dispatched to the
2023     * window.  Be sure to call this implementation for trackball events
2024     * that should be handled normally.
2025     *
2026     * @param ev The trackball event.
2027     *
2028     * @return boolean Return true if this event was consumed.
2029     */
2030    public boolean dispatchTrackballEvent(MotionEvent ev) {
2031        onUserInteraction();
2032        if (getWindow().superDispatchTrackballEvent(ev)) {
2033            return true;
2034        }
2035        return onTrackballEvent(ev);
2036    }
2037
2038    public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) {
2039        event.setClassName(getClass().getName());
2040        event.setPackageName(getPackageName());
2041
2042        LayoutParams params = getWindow().getAttributes();
2043        boolean isFullScreen = (params.width == LayoutParams.FILL_PARENT) &&
2044            (params.height == LayoutParams.FILL_PARENT);
2045        event.setFullScreen(isFullScreen);
2046
2047        CharSequence title = getTitle();
2048        if (!TextUtils.isEmpty(title)) {
2049           event.getText().add(title);
2050        }
2051
2052        return true;
2053    }
2054
2055    /**
2056     * Default implementation of
2057     * {@link android.view.Window.Callback#onCreatePanelView}
2058     * for activities. This
2059     * simply returns null so that all panel sub-windows will have the default
2060     * menu behavior.
2061     */
2062    public View onCreatePanelView(int featureId) {
2063        return null;
2064    }
2065
2066    /**
2067     * Default implementation of
2068     * {@link android.view.Window.Callback#onCreatePanelMenu}
2069     * for activities.  This calls through to the new
2070     * {@link #onCreateOptionsMenu} method for the
2071     * {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2072     * so that subclasses of Activity don't need to deal with feature codes.
2073     */
2074    public boolean onCreatePanelMenu(int featureId, Menu menu) {
2075        if (featureId == Window.FEATURE_OPTIONS_PANEL) {
2076            return onCreateOptionsMenu(menu);
2077        }
2078        return false;
2079    }
2080
2081    /**
2082     * Default implementation of
2083     * {@link android.view.Window.Callback#onPreparePanel}
2084     * for activities.  This
2085     * calls through to the new {@link #onPrepareOptionsMenu} method for the
2086     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2087     * panel, so that subclasses of
2088     * Activity don't need to deal with feature codes.
2089     */
2090    public boolean onPreparePanel(int featureId, View view, Menu menu) {
2091        if (featureId == Window.FEATURE_OPTIONS_PANEL && menu != null) {
2092            boolean goforit = onPrepareOptionsMenu(menu);
2093            return goforit && menu.hasVisibleItems();
2094        }
2095        return true;
2096    }
2097
2098    /**
2099     * {@inheritDoc}
2100     *
2101     * @return The default implementation returns true.
2102     */
2103    public boolean onMenuOpened(int featureId, Menu menu) {
2104        return true;
2105    }
2106
2107    /**
2108     * Default implementation of
2109     * {@link android.view.Window.Callback#onMenuItemSelected}
2110     * for activities.  This calls through to the new
2111     * {@link #onOptionsItemSelected} method for the
2112     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2113     * panel, so that subclasses of
2114     * Activity don't need to deal with feature codes.
2115     */
2116    public boolean onMenuItemSelected(int featureId, MenuItem item) {
2117        switch (featureId) {
2118            case Window.FEATURE_OPTIONS_PANEL:
2119                // Put event logging here so it gets called even if subclass
2120                // doesn't call through to superclass's implmeentation of each
2121                // of these methods below
2122                EventLog.writeEvent(50000, 0, item.getTitleCondensed());
2123                return onOptionsItemSelected(item);
2124
2125            case Window.FEATURE_CONTEXT_MENU:
2126                EventLog.writeEvent(50000, 1, item.getTitleCondensed());
2127                return onContextItemSelected(item);
2128
2129            default:
2130                return false;
2131        }
2132    }
2133
2134    /**
2135     * Default implementation of
2136     * {@link android.view.Window.Callback#onPanelClosed(int, Menu)} for
2137     * activities. This calls through to {@link #onOptionsMenuClosed(Menu)}
2138     * method for the {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2139     * so that subclasses of Activity don't need to deal with feature codes.
2140     * For context menus ({@link Window#FEATURE_CONTEXT_MENU}), the
2141     * {@link #onContextMenuClosed(Menu)} will be called.
2142     */
2143    public void onPanelClosed(int featureId, Menu menu) {
2144        switch (featureId) {
2145            case Window.FEATURE_OPTIONS_PANEL:
2146                onOptionsMenuClosed(menu);
2147                break;
2148
2149            case Window.FEATURE_CONTEXT_MENU:
2150                onContextMenuClosed(menu);
2151                break;
2152        }
2153    }
2154
2155    /**
2156     * Initialize the contents of the Activity's standard options menu.  You
2157     * should place your menu items in to <var>menu</var>.
2158     *
2159     * <p>This is only called once, the first time the options menu is
2160     * displayed.  To update the menu every time it is displayed, see
2161     * {@link #onPrepareOptionsMenu}.
2162     *
2163     * <p>The default implementation populates the menu with standard system
2164     * menu items.  These are placed in the {@link Menu#CATEGORY_SYSTEM} group so that
2165     * they will be correctly ordered with application-defined menu items.
2166     * Deriving classes should always call through to the base implementation.
2167     *
2168     * <p>You can safely hold on to <var>menu</var> (and any items created
2169     * from it), making modifications to it as desired, until the next
2170     * time onCreateOptionsMenu() is called.
2171     *
2172     * <p>When you add items to the menu, you can implement the Activity's
2173     * {@link #onOptionsItemSelected} method to handle them there.
2174     *
2175     * @param menu The options menu in which you place your items.
2176     *
2177     * @return You must return true for the menu to be displayed;
2178     *         if you return false it will not be shown.
2179     *
2180     * @see #onPrepareOptionsMenu
2181     * @see #onOptionsItemSelected
2182     */
2183    public boolean onCreateOptionsMenu(Menu menu) {
2184        if (mParent != null) {
2185            return mParent.onCreateOptionsMenu(menu);
2186        }
2187        return true;
2188    }
2189
2190    /**
2191     * Prepare the Screen's standard options menu to be displayed.  This is
2192     * called right before the menu is shown, every time it is shown.  You can
2193     * use this method to efficiently enable/disable items or otherwise
2194     * dynamically modify the contents.
2195     *
2196     * <p>The default implementation updates the system menu items based on the
2197     * activity's state.  Deriving classes should always call through to the
2198     * base class implementation.
2199     *
2200     * @param menu The options menu as last shown or first initialized by
2201     *             onCreateOptionsMenu().
2202     *
2203     * @return You must return true for the menu to be displayed;
2204     *         if you return false it will not be shown.
2205     *
2206     * @see #onCreateOptionsMenu
2207     */
2208    public boolean onPrepareOptionsMenu(Menu menu) {
2209        if (mParent != null) {
2210            return mParent.onPrepareOptionsMenu(menu);
2211        }
2212        return true;
2213    }
2214
2215    /**
2216     * This hook is called whenever an item in your options menu is selected.
2217     * The default implementation simply returns false to have the normal
2218     * processing happen (calling the item's Runnable or sending a message to
2219     * its Handler as appropriate).  You can use this method for any items
2220     * for which you would like to do processing without those other
2221     * facilities.
2222     *
2223     * <p>Derived classes should call through to the base class for it to
2224     * perform the default menu handling.
2225     *
2226     * @param item The menu item that was selected.
2227     *
2228     * @return boolean Return false to allow normal menu processing to
2229     *         proceed, true to consume it here.
2230     *
2231     * @see #onCreateOptionsMenu
2232     */
2233    public boolean onOptionsItemSelected(MenuItem item) {
2234        if (mParent != null) {
2235            return mParent.onOptionsItemSelected(item);
2236        }
2237        return false;
2238    }
2239
2240    /**
2241     * This hook is called whenever the options menu is being closed (either by the user canceling
2242     * the menu with the back/menu button, or when an item is selected).
2243     *
2244     * @param menu The options menu as last shown or first initialized by
2245     *             onCreateOptionsMenu().
2246     */
2247    public void onOptionsMenuClosed(Menu menu) {
2248        if (mParent != null) {
2249            mParent.onOptionsMenuClosed(menu);
2250        }
2251    }
2252
2253    /**
2254     * Programmatically opens the options menu. If the options menu is already
2255     * open, this method does nothing.
2256     */
2257    public void openOptionsMenu() {
2258        mWindow.openPanel(Window.FEATURE_OPTIONS_PANEL, null);
2259    }
2260
2261    /**
2262     * Progammatically closes the options menu. If the options menu is already
2263     * closed, this method does nothing.
2264     */
2265    public void closeOptionsMenu() {
2266        mWindow.closePanel(Window.FEATURE_OPTIONS_PANEL);
2267    }
2268
2269    /**
2270     * Called when a context menu for the {@code view} is about to be shown.
2271     * Unlike {@link #onCreateOptionsMenu(Menu)}, this will be called every
2272     * time the context menu is about to be shown and should be populated for
2273     * the view (or item inside the view for {@link AdapterView} subclasses,
2274     * this can be found in the {@code menuInfo})).
2275     * <p>
2276     * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an
2277     * item has been selected.
2278     * <p>
2279     * It is not safe to hold onto the context menu after this method returns.
2280     * {@inheritDoc}
2281     */
2282    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
2283    }
2284
2285    /**
2286     * Registers a context menu to be shown for the given view (multiple views
2287     * can show the context menu). This method will set the
2288     * {@link OnCreateContextMenuListener} on the view to this activity, so
2289     * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be
2290     * called when it is time to show the context menu.
2291     *
2292     * @see #unregisterForContextMenu(View)
2293     * @param view The view that should show a context menu.
2294     */
2295    public void registerForContextMenu(View view) {
2296        view.setOnCreateContextMenuListener(this);
2297    }
2298
2299    /**
2300     * Prevents a context menu to be shown for the given view. This method will remove the
2301     * {@link OnCreateContextMenuListener} on the view.
2302     *
2303     * @see #registerForContextMenu(View)
2304     * @param view The view that should stop showing a context menu.
2305     */
2306    public void unregisterForContextMenu(View view) {
2307        view.setOnCreateContextMenuListener(null);
2308    }
2309
2310    /**
2311     * Programmatically opens the context menu for a particular {@code view}.
2312     * The {@code view} should have been added via
2313     * {@link #registerForContextMenu(View)}.
2314     *
2315     * @param view The view to show the context menu for.
2316     */
2317    public void openContextMenu(View view) {
2318        view.showContextMenu();
2319    }
2320
2321    /**
2322     * Programmatically closes the most recently opened context menu, if showing.
2323     */
2324    public void closeContextMenu() {
2325        mWindow.closePanel(Window.FEATURE_CONTEXT_MENU);
2326    }
2327
2328    /**
2329     * This hook is called whenever an item in a context menu is selected. The
2330     * default implementation simply returns false to have the normal processing
2331     * happen (calling the item's Runnable or sending a message to its Handler
2332     * as appropriate). You can use this method for any items for which you
2333     * would like to do processing without those other facilities.
2334     * <p>
2335     * Use {@link MenuItem#getMenuInfo()} to get extra information set by the
2336     * View that added this menu item.
2337     * <p>
2338     * Derived classes should call through to the base class for it to perform
2339     * the default menu handling.
2340     *
2341     * @param item The context menu item that was selected.
2342     * @return boolean Return false to allow normal context menu processing to
2343     *         proceed, true to consume it here.
2344     */
2345    public boolean onContextItemSelected(MenuItem item) {
2346        if (mParent != null) {
2347            return mParent.onContextItemSelected(item);
2348        }
2349        return false;
2350    }
2351
2352    /**
2353     * This hook is called whenever the context menu is being closed (either by
2354     * the user canceling the menu with the back/menu button, or when an item is
2355     * selected).
2356     *
2357     * @param menu The context menu that is being closed.
2358     */
2359    public void onContextMenuClosed(Menu menu) {
2360        if (mParent != null) {
2361            mParent.onContextMenuClosed(menu);
2362        }
2363    }
2364
2365    /**
2366     * Callback for creating dialogs that are managed (saved and restored) for you
2367     * by the activity.
2368     *
2369     * If you use {@link #showDialog(int)}, the activity will call through to
2370     * this method the first time, and hang onto it thereafter.  Any dialog
2371     * that is created by this method will automatically be saved and restored
2372     * for you, including whether it is showing.
2373     *
2374     * If you would like the activity to manage the saving and restoring dialogs
2375     * for you, you should override this method and handle any ids that are
2376     * passed to {@link #showDialog}.
2377     *
2378     * If you would like an opportunity to prepare your dialog before it is shown,
2379     * override {@link #onPrepareDialog(int, Dialog)}.
2380     *
2381     * @param id The id of the dialog.
2382     * @return The dialog
2383     *
2384     * @see #onPrepareDialog(int, Dialog)
2385     * @see #showDialog(int)
2386     * @see #dismissDialog(int)
2387     * @see #removeDialog(int)
2388     */
2389    protected Dialog onCreateDialog(int id) {
2390        return null;
2391    }
2392
2393    /**
2394     * Provides an opportunity to prepare a managed dialog before it is being
2395     * shown.
2396     * <p>
2397     * Override this if you need to update a managed dialog based on the state
2398     * of the application each time it is shown. For example, a time picker
2399     * dialog might want to be updated with the current time. You should call
2400     * through to the superclass's implementation. The default implementation
2401     * will set this Activity as the owner activity on the Dialog.
2402     *
2403     * @param id The id of the managed dialog.
2404     * @param dialog The dialog.
2405     * @see #onCreateDialog(int)
2406     * @see #showDialog(int)
2407     * @see #dismissDialog(int)
2408     * @see #removeDialog(int)
2409     */
2410    protected void onPrepareDialog(int id, Dialog dialog) {
2411        dialog.setOwnerActivity(this);
2412    }
2413
2414    /**
2415     * Show a dialog managed by this activity.  A call to {@link #onCreateDialog(int)}
2416     * will be made with the same id the first time this is called for a given
2417     * id.  From thereafter, the dialog will be automatically saved and restored.
2418     *
2419     * Each time a dialog is shown, {@link #onPrepareDialog(int, Dialog)} will
2420     * be made to provide an opportunity to do any timely preparation.
2421     *
2422     * @param id The id of the managed dialog.
2423     *
2424     * @see #onCreateDialog(int)
2425     * @see #onPrepareDialog(int, Dialog)
2426     * @see #dismissDialog(int)
2427     * @see #removeDialog(int)
2428     */
2429    public final void showDialog(int id) {
2430        if (mManagedDialogs == null) {
2431            mManagedDialogs = new SparseArray<Dialog>();
2432        }
2433        Dialog dialog = mManagedDialogs.get(id);
2434        if (dialog == null) {
2435            dialog = createDialog(id, true);
2436            mManagedDialogs.put(id, dialog);
2437        }
2438
2439        onPrepareDialog(id, dialog);
2440        dialog.show();
2441    }
2442
2443    /**
2444     * Dismiss a dialog that was previously shown via {@link #showDialog(int)}.
2445     *
2446     * @param id The id of the managed dialog.
2447     *
2448     * @throws IllegalArgumentException if the id was not previously shown via
2449     *   {@link #showDialog(int)}.
2450     *
2451     * @see #onCreateDialog(int)
2452     * @see #onPrepareDialog(int, Dialog)
2453     * @see #showDialog(int)
2454     * @see #removeDialog(int)
2455     */
2456    public final void dismissDialog(int id) {
2457        if (mManagedDialogs == null) {
2458            throw missingDialog(id);
2459
2460        }
2461        final Dialog dialog = mManagedDialogs.get(id);
2462        if (dialog == null) {
2463            throw missingDialog(id);
2464        }
2465        dialog.dismiss();
2466    }
2467
2468    /**
2469     * Creates an exception to throw if a user passed in a dialog id that is
2470     * unexpected.
2471     */
2472    private IllegalArgumentException missingDialog(int id) {
2473        return new IllegalArgumentException("no dialog with id " + id + " was ever "
2474                + "shown via Activity#showDialog");
2475    }
2476
2477    /**
2478     * Removes any internal references to a dialog managed by this Activity.
2479     * If the dialog is showing, it will dismiss it as part of the clean up.
2480     *
2481     * This can be useful if you know that you will never show a dialog again and
2482     * want to avoid the overhead of saving and restoring it in the future.
2483     *
2484     * @param id The id of the managed dialog.
2485     *
2486     * @see #onCreateDialog(int)
2487     * @see #onPrepareDialog(int, Dialog)
2488     * @see #showDialog(int)
2489     * @see #dismissDialog(int)
2490     */
2491    public final void removeDialog(int id) {
2492
2493        if (mManagedDialogs == null) {
2494            return;
2495        }
2496
2497        final Dialog dialog = mManagedDialogs.get(id);
2498        if (dialog == null) {
2499            return;
2500        }
2501
2502        dialog.dismiss();
2503        mManagedDialogs.remove(id);
2504    }
2505
2506    /**
2507     * This hook is called when the user signals the desire to start a search.
2508     *
2509     * <p>You can use this function as a simple way to launch the search UI, in response to a
2510     * menu item, search button, or other widgets within your activity.  Unless overidden,
2511     * calling this function is the same as calling:
2512     * <p>The default implementation simply calls
2513     * {@link #startSearch startSearch(null, false, null, false)}, launching a local search.
2514     *
2515     * <p>You can override this function to force global search, e.g. in response to a dedicated
2516     * search key, or to block search entirely (by simply returning false).
2517     *
2518     * @return Returns true if search launched, false if activity blocks it
2519     *
2520     * @see android.app.SearchManager
2521     */
2522    public boolean onSearchRequested() {
2523        startSearch(null, false, null, false);
2524        return true;
2525    }
2526
2527    /**
2528     * This hook is called to launch the search UI.
2529     *
2530     * <p>It is typically called from onSearchRequested(), either directly from
2531     * Activity.onSearchRequested() or from an overridden version in any given
2532     * Activity.  If your goal is simply to activate search, it is preferred to call
2533     * onSearchRequested(), which may have been overriden elsewhere in your Activity.  If your goal
2534     * is to inject specific data such as context data, it is preferred to <i>override</i>
2535     * onSearchRequested(), so that any callers to it will benefit from the override.
2536     *
2537     * @param initialQuery Any non-null non-empty string will be inserted as
2538     * pre-entered text in the search query box.
2539     * @param selectInitialQuery If true, the intial query will be preselected, which means that
2540     * any further typing will replace it.  This is useful for cases where an entire pre-formed
2541     * query is being inserted.  If false, the selection point will be placed at the end of the
2542     * inserted query.  This is useful when the inserted query is text that the user entered,
2543     * and the user would expect to be able to keep typing.  <i>This parameter is only meaningful
2544     * if initialQuery is a non-empty string.</i>
2545     * @param appSearchData An application can insert application-specific
2546     * context here, in order to improve quality or specificity of its own
2547     * searches.  This data will be returned with SEARCH intent(s).  Null if
2548     * no extra data is required.
2549     * @param globalSearch If false, this will only launch the search that has been specifically
2550     * defined by the application (which is usually defined as a local search).  If no default
2551     * search is defined in the current application or activity, no search will be launched.
2552     * If true, this will always launch a platform-global (e.g. web-based) search instead.
2553     *
2554     * @see android.app.SearchManager
2555     * @see #onSearchRequested
2556     */
2557    public void startSearch(String initialQuery, boolean selectInitialQuery,
2558            Bundle appSearchData, boolean globalSearch) {
2559        mSearchManager.startSearch(initialQuery, selectInitialQuery, getComponentName(),
2560                        appSearchData, globalSearch);
2561    }
2562
2563    /**
2564     * Request that key events come to this activity. Use this if your
2565     * activity has no views with focus, but the activity still wants
2566     * a chance to process key events.
2567     *
2568     * @see android.view.Window#takeKeyEvents
2569     */
2570    public void takeKeyEvents(boolean get) {
2571        getWindow().takeKeyEvents(get);
2572    }
2573
2574    /**
2575     * Enable extended window features.  This is a convenience for calling
2576     * {@link android.view.Window#requestFeature getWindow().requestFeature()}.
2577     *
2578     * @param featureId The desired feature as defined in
2579     *                  {@link android.view.Window}.
2580     * @return Returns true if the requested feature is supported and now
2581     *         enabled.
2582     *
2583     * @see android.view.Window#requestFeature
2584     */
2585    public final boolean requestWindowFeature(int featureId) {
2586        return getWindow().requestFeature(featureId);
2587    }
2588
2589    /**
2590     * Convenience for calling
2591     * {@link android.view.Window#setFeatureDrawableResource}.
2592     */
2593    public final void setFeatureDrawableResource(int featureId, int resId) {
2594        getWindow().setFeatureDrawableResource(featureId, resId);
2595    }
2596
2597    /**
2598     * Convenience for calling
2599     * {@link android.view.Window#setFeatureDrawableUri}.
2600     */
2601    public final void setFeatureDrawableUri(int featureId, Uri uri) {
2602        getWindow().setFeatureDrawableUri(featureId, uri);
2603    }
2604
2605    /**
2606     * Convenience for calling
2607     * {@link android.view.Window#setFeatureDrawable(int, Drawable)}.
2608     */
2609    public final void setFeatureDrawable(int featureId, Drawable drawable) {
2610        getWindow().setFeatureDrawable(featureId, drawable);
2611    }
2612
2613    /**
2614     * Convenience for calling
2615     * {@link android.view.Window#setFeatureDrawableAlpha}.
2616     */
2617    public final void setFeatureDrawableAlpha(int featureId, int alpha) {
2618        getWindow().setFeatureDrawableAlpha(featureId, alpha);
2619    }
2620
2621    /**
2622     * Convenience for calling
2623     * {@link android.view.Window#getLayoutInflater}.
2624     */
2625    public LayoutInflater getLayoutInflater() {
2626        return getWindow().getLayoutInflater();
2627    }
2628
2629    /**
2630     * Returns a {@link MenuInflater} with this context.
2631     */
2632    public MenuInflater getMenuInflater() {
2633        return new MenuInflater(this);
2634    }
2635
2636    @Override
2637    protected void onApplyThemeResource(Resources.Theme theme,
2638                                      int resid,
2639                                      boolean first)
2640    {
2641        if (mParent == null) {
2642            super.onApplyThemeResource(theme, resid, first);
2643        } else {
2644            try {
2645                theme.setTo(mParent.getTheme());
2646            } catch (Exception e) {
2647                // Empty
2648            }
2649            theme.applyStyle(resid, false);
2650        }
2651    }
2652
2653    /**
2654     * Launch an activity for which you would like a result when it finished.
2655     * When this activity exits, your
2656     * onActivityResult() method will be called with the given requestCode.
2657     * Using a negative requestCode is the same as calling
2658     * {@link #startActivity} (the activity is not launched as a sub-activity).
2659     *
2660     * <p>Note that this method should only be used with Intent protocols
2661     * that are defined to return a result.  In other protocols (such as
2662     * {@link Intent#ACTION_MAIN} or {@link Intent#ACTION_VIEW}), you may
2663     * not get the result when you expect.  For example, if the activity you
2664     * are launching uses the singleTask launch mode, it will not run in your
2665     * task and thus you will immediately receive a cancel result.
2666     *
2667     * <p>As a special case, if you call startActivityForResult() with a requestCode
2668     * >= 0 during the initial onCreate(Bundle savedInstanceState)/onResume() of your
2669     * activity, then your window will not be displayed until a result is
2670     * returned back from the started activity.  This is to avoid visible
2671     * flickering when redirecting to another activity.
2672     *
2673     * <p>This method throws {@link android.content.ActivityNotFoundException}
2674     * if there was no Activity found to run the given Intent.
2675     *
2676     * @param intent The intent to start.
2677     * @param requestCode If >= 0, this code will be returned in
2678     *                    onActivityResult() when the activity exits.
2679     *
2680     * @throws android.content.ActivityNotFoundException
2681     *
2682     * @see #startActivity
2683     */
2684    public void startActivityForResult(Intent intent, int requestCode) {
2685        if (mParent == null) {
2686            Instrumentation.ActivityResult ar =
2687                mInstrumentation.execStartActivity(
2688                    this, mMainThread.getApplicationThread(), mToken, this,
2689                    intent, requestCode);
2690            if (ar != null) {
2691                mMainThread.sendActivityResult(
2692                    mToken, mEmbeddedID, requestCode, ar.getResultCode(),
2693                    ar.getResultData());
2694            }
2695            if (requestCode >= 0) {
2696                // If this start is requesting a result, we can avoid making
2697                // the activity visible until the result is received.  Setting
2698                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
2699                // activity hidden during this time, to avoid flickering.
2700                // This can only be done when a result is requested because
2701                // that guarantees we will get information back when the
2702                // activity is finished, no matter what happens to it.
2703                mStartedActivity = true;
2704            }
2705        } else {
2706            mParent.startActivityFromChild(this, intent, requestCode);
2707        }
2708    }
2709
2710    /**
2711     * Launch a new activity.  You will not receive any information about when
2712     * the activity exits.  This implementation overrides the base version,
2713     * providing information about
2714     * the activity performing the launch.  Because of this additional
2715     * information, the {@link Intent#FLAG_ACTIVITY_NEW_TASK} launch flag is not
2716     * required; if not specified, the new activity will be added to the
2717     * task of the caller.
2718     *
2719     * <p>This method throws {@link android.content.ActivityNotFoundException}
2720     * if there was no Activity found to run the given Intent.
2721     *
2722     * @param intent The intent to start.
2723     *
2724     * @throws android.content.ActivityNotFoundException
2725     *
2726     * @see #startActivityForResult
2727     */
2728    @Override
2729    public void startActivity(Intent intent) {
2730        startActivityForResult(intent, -1);
2731    }
2732
2733    /**
2734     * A special variation to launch an activity only if a new activity
2735     * instance is needed to handle the given Intent.  In other words, this is
2736     * just like {@link #startActivityForResult(Intent, int)} except: if you are
2737     * using the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP} flag, or
2738     * singleTask or singleTop
2739     * {@link android.R.styleable#AndroidManifestActivity_launchMode launchMode},
2740     * and the activity
2741     * that handles <var>intent</var> is the same as your currently running
2742     * activity, then a new instance is not needed.  In this case, instead of
2743     * the normal behavior of calling {@link #onNewIntent} this function will
2744     * return and you can handle the Intent yourself.
2745     *
2746     * <p>This function can only be called from a top-level activity; if it is
2747     * called from a child activity, a runtime exception will be thrown.
2748     *
2749     * @param intent The intent to start.
2750     * @param requestCode If >= 0, this code will be returned in
2751     *         onActivityResult() when the activity exits, as described in
2752     *         {@link #startActivityForResult}.
2753     *
2754     * @return If a new activity was launched then true is returned; otherwise
2755     *         false is returned and you must handle the Intent yourself.
2756     *
2757     * @see #startActivity
2758     * @see #startActivityForResult
2759     */
2760    public boolean startActivityIfNeeded(Intent intent, int requestCode) {
2761        if (mParent == null) {
2762            int result = IActivityManager.START_RETURN_INTENT_TO_CALLER;
2763            try {
2764                result = ActivityManagerNative.getDefault()
2765                    .startActivity(mMainThread.getApplicationThread(),
2766                            intent, intent.resolveTypeIfNeeded(
2767                                    getContentResolver()),
2768                            null, 0,
2769                            mToken, mEmbeddedID, requestCode, true, false);
2770            } catch (RemoteException e) {
2771                // Empty
2772            }
2773
2774            Instrumentation.checkStartActivityResult(result, intent);
2775
2776            if (requestCode >= 0) {
2777                // If this start is requesting a result, we can avoid making
2778                // the activity visible until the result is received.  Setting
2779                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
2780                // activity hidden during this time, to avoid flickering.
2781                // This can only be done when a result is requested because
2782                // that guarantees we will get information back when the
2783                // activity is finished, no matter what happens to it.
2784                mStartedActivity = true;
2785            }
2786            return result != IActivityManager.START_RETURN_INTENT_TO_CALLER;
2787        }
2788
2789        throw new UnsupportedOperationException(
2790            "startActivityIfNeeded can only be called from a top-level activity");
2791    }
2792
2793    /**
2794     * Special version of starting an activity, for use when you are replacing
2795     * other activity components.  You can use this to hand the Intent off
2796     * to the next Activity that can handle it.  You typically call this in
2797     * {@link #onCreate} with the Intent returned by {@link #getIntent}.
2798     *
2799     * @param intent The intent to dispatch to the next activity.  For
2800     * correct behavior, this must be the same as the Intent that started
2801     * your own activity; the only changes you can make are to the extras
2802     * inside of it.
2803     *
2804     * @return Returns a boolean indicating whether there was another Activity
2805     * to start: true if there was a next activity to start, false if there
2806     * wasn't.  In general, if true is returned you will then want to call
2807     * finish() on yourself.
2808     */
2809    public boolean startNextMatchingActivity(Intent intent) {
2810        if (mParent == null) {
2811            try {
2812                return ActivityManagerNative.getDefault()
2813                    .startNextMatchingActivity(mToken, intent);
2814            } catch (RemoteException e) {
2815                // Empty
2816            }
2817            return false;
2818        }
2819
2820        throw new UnsupportedOperationException(
2821            "startNextMatchingActivity can only be called from a top-level activity");
2822    }
2823
2824    /**
2825     * This is called when a child activity of this one calls its
2826     * {@link #startActivity} or {@link #startActivityForResult} method.
2827     *
2828     * <p>This method throws {@link android.content.ActivityNotFoundException}
2829     * if there was no Activity found to run the given Intent.
2830     *
2831     * @param child The activity making the call.
2832     * @param intent The intent to start.
2833     * @param requestCode Reply request code.  < 0 if reply is not requested.
2834     *
2835     * @throws android.content.ActivityNotFoundException
2836     *
2837     * @see #startActivity
2838     * @see #startActivityForResult
2839     */
2840    public void startActivityFromChild(Activity child, Intent intent,
2841            int requestCode) {
2842        Instrumentation.ActivityResult ar =
2843            mInstrumentation.execStartActivity(
2844                this, mMainThread.getApplicationThread(), mToken, child,
2845                intent, requestCode);
2846        if (ar != null) {
2847            mMainThread.sendActivityResult(
2848                mToken, child.mEmbeddedID, requestCode,
2849                ar.getResultCode(), ar.getResultData());
2850        }
2851    }
2852
2853    /**
2854     * Call this to set the result that your activity will return to its
2855     * caller.
2856     *
2857     * @param resultCode The result code to propagate back to the originating
2858     *                   activity, often RESULT_CANCELED or RESULT_OK
2859     *
2860     * @see #RESULT_CANCELED
2861     * @see #RESULT_OK
2862     * @see #RESULT_FIRST_USER
2863     * @see #setResult(int, Intent)
2864     */
2865    public final void setResult(int resultCode) {
2866        synchronized (this) {
2867            mResultCode = resultCode;
2868            mResultData = null;
2869        }
2870    }
2871
2872    /**
2873     * Call this to set the result that your activity will return to its
2874     * caller.
2875     *
2876     * @param resultCode The result code to propagate back to the originating
2877     *                   activity, often RESULT_CANCELED or RESULT_OK
2878     * @param data The data to propagate back to the originating activity.
2879     *
2880     * @see #RESULT_CANCELED
2881     * @see #RESULT_OK
2882     * @see #RESULT_FIRST_USER
2883     * @see #setResult(int)
2884     */
2885    public final void setResult(int resultCode, Intent data) {
2886        synchronized (this) {
2887            mResultCode = resultCode;
2888            mResultData = data;
2889        }
2890    }
2891
2892    /**
2893     * Return the name of the package that invoked this activity.  This is who
2894     * the data in {@link #setResult setResult()} will be sent to.  You can
2895     * use this information to validate that the recipient is allowed to
2896     * receive the data.
2897     *
2898     * <p>Note: if the calling activity is not expecting a result (that is it
2899     * did not use the {@link #startActivityForResult}
2900     * form that includes a request code), then the calling package will be
2901     * null.
2902     *
2903     * @return The package of the activity that will receive your
2904     *         reply, or null if none.
2905     */
2906    public String getCallingPackage() {
2907        try {
2908            return ActivityManagerNative.getDefault().getCallingPackage(mToken);
2909        } catch (RemoteException e) {
2910            return null;
2911        }
2912    }
2913
2914    /**
2915     * Return the name of the activity that invoked this activity.  This is
2916     * who the data in {@link #setResult setResult()} will be sent to.  You
2917     * can use this information to validate that the recipient is allowed to
2918     * receive the data.
2919     *
2920     * <p>Note: if the calling activity is not expecting a result (that is it
2921     * did not use the {@link #startActivityForResult}
2922     * form that includes a request code), then the calling package will be
2923     * null.
2924     *
2925     * @return String The full name of the activity that will receive your
2926     *         reply, or null if none.
2927     */
2928    public ComponentName getCallingActivity() {
2929        try {
2930            return ActivityManagerNative.getDefault().getCallingActivity(mToken);
2931        } catch (RemoteException e) {
2932            return null;
2933        }
2934    }
2935
2936    /**
2937     * Control whether this activity's main window is visible.  This is intended
2938     * only for the special case of an activity that is not going to show a
2939     * UI itself, but can't just finish prior to onResume() because it needs
2940     * to wait for a service binding or such.  Setting this to false allows
2941     * you to prevent your UI from being shown during that time.
2942     *
2943     * <p>The default value for this is taken from the
2944     * {@link android.R.attr#windowNoDisplay} attribute of the activity's theme.
2945     */
2946    public void setVisible(boolean visible) {
2947        if (mVisibleFromClient != visible) {
2948            mVisibleFromClient = visible;
2949            if (mVisibleFromServer) {
2950                if (visible) makeVisible();
2951                else mDecor.setVisibility(View.INVISIBLE);
2952            }
2953        }
2954    }
2955
2956    void makeVisible() {
2957        if (!mWindowAdded) {
2958            ViewManager wm = getWindowManager();
2959            wm.addView(mDecor, getWindow().getAttributes());
2960            mWindowAdded = true;
2961        }
2962        mDecor.setVisibility(View.VISIBLE);
2963    }
2964
2965    /**
2966     * Check to see whether this activity is in the process of finishing,
2967     * either because you called {@link #finish} on it or someone else
2968     * has requested that it finished.  This is often used in
2969     * {@link #onPause} to determine whether the activity is simply pausing or
2970     * completely finishing.
2971     *
2972     * @return If the activity is finishing, returns true; else returns false.
2973     *
2974     * @see #finish
2975     */
2976    public boolean isFinishing() {
2977        return mFinished;
2978    }
2979
2980    /**
2981     * Call this when your activity is done and should be closed.  The
2982     * ActivityResult is propagated back to whoever launched you via
2983     * onActivityResult().
2984     */
2985    public void finish() {
2986        if (mParent == null) {
2987            int resultCode;
2988            Intent resultData;
2989            synchronized (this) {
2990                resultCode = mResultCode;
2991                resultData = mResultData;
2992            }
2993            if (Config.LOGV) Log.v(TAG, "Finishing self: token=" + mToken);
2994            try {
2995                if (ActivityManagerNative.getDefault()
2996                    .finishActivity(mToken, resultCode, resultData)) {
2997                    mFinished = true;
2998                }
2999            } catch (RemoteException e) {
3000                // Empty
3001            }
3002        } else {
3003            mParent.finishFromChild(this);
3004        }
3005    }
3006
3007    /**
3008     * This is called when a child activity of this one calls its
3009     * {@link #finish} method.  The default implementation simply calls
3010     * finish() on this activity (the parent), finishing the entire group.
3011     *
3012     * @param child The activity making the call.
3013     *
3014     * @see #finish
3015     */
3016    public void finishFromChild(Activity child) {
3017        finish();
3018    }
3019
3020    /**
3021     * Force finish another activity that you had previously started with
3022     * {@link #startActivityForResult}.
3023     *
3024     * @param requestCode The request code of the activity that you had
3025     *                    given to startActivityForResult().  If there are multiple
3026     *                    activities started with this request code, they
3027     *                    will all be finished.
3028     */
3029    public void finishActivity(int requestCode) {
3030        if (mParent == null) {
3031            try {
3032                ActivityManagerNative.getDefault()
3033                    .finishSubActivity(mToken, mEmbeddedID, requestCode);
3034            } catch (RemoteException e) {
3035                // Empty
3036            }
3037        } else {
3038            mParent.finishActivityFromChild(this, requestCode);
3039        }
3040    }
3041
3042    /**
3043     * This is called when a child activity of this one calls its
3044     * finishActivity().
3045     *
3046     * @param child The activity making the call.
3047     * @param requestCode Request code that had been used to start the
3048     *                    activity.
3049     */
3050    public void finishActivityFromChild(Activity child, int requestCode) {
3051        try {
3052            ActivityManagerNative.getDefault()
3053                .finishSubActivity(mToken, child.mEmbeddedID, requestCode);
3054        } catch (RemoteException e) {
3055            // Empty
3056        }
3057    }
3058
3059    /**
3060     * Called when an activity you launched exits, giving you the requestCode
3061     * you started it with, the resultCode it returned, and any additional
3062     * data from it.  The <var>resultCode</var> will be
3063     * {@link #RESULT_CANCELED} if the activity explicitly returned that,
3064     * didn't return any result, or crashed during its operation.
3065     *
3066     * <p>You will receive this call immediately before onResume() when your
3067     * activity is re-starting.
3068     *
3069     * @param requestCode The integer request code originally supplied to
3070     *                    startActivityForResult(), allowing you to identify who this
3071     *                    result came from.
3072     * @param resultCode The integer result code returned by the child activity
3073     *                   through its setResult().
3074     * @param data An Intent, which can return result data to the caller
3075     *               (various data can be attached to Intent "extras").
3076     *
3077     * @see #startActivityForResult
3078     * @see #createPendingResult
3079     * @see #setResult(int)
3080     */
3081    protected void onActivityResult(int requestCode, int resultCode,
3082            Intent data) {
3083    }
3084
3085    /**
3086     * Create a new PendingIntent object which you can hand to others
3087     * for them to use to send result data back to your
3088     * {@link #onActivityResult} callback.  The created object will be either
3089     * one-shot (becoming invalid after a result is sent back) or multiple
3090     * (allowing any number of results to be sent through it).
3091     *
3092     * @param requestCode Private request code for the sender that will be
3093     * associated with the result data when it is returned.  The sender can not
3094     * modify this value, allowing you to identify incoming results.
3095     * @param data Default data to supply in the result, which may be modified
3096     * by the sender.
3097     * @param flags May be {@link PendingIntent#FLAG_ONE_SHOT PendingIntent.FLAG_ONE_SHOT},
3098     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE},
3099     * {@link PendingIntent#FLAG_CANCEL_CURRENT PendingIntent.FLAG_CANCEL_CURRENT},
3100     * {@link PendingIntent#FLAG_UPDATE_CURRENT PendingIntent.FLAG_UPDATE_CURRENT},
3101     * or any of the flags as supported by
3102     * {@link Intent#fillIn Intent.fillIn()} to control which unspecified parts
3103     * of the intent that can be supplied when the actual send happens.
3104     *
3105     * @return Returns an existing or new PendingIntent matching the given
3106     * parameters.  May return null only if
3107     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE} has been
3108     * supplied.
3109     *
3110     * @see PendingIntent
3111     */
3112    public PendingIntent createPendingResult(int requestCode, Intent data,
3113            int flags) {
3114        String packageName = getPackageName();
3115        try {
3116            IIntentSender target =
3117                ActivityManagerNative.getDefault().getIntentSender(
3118                        IActivityManager.INTENT_SENDER_ACTIVITY_RESULT, packageName,
3119                        mParent == null ? mToken : mParent.mToken,
3120                        mEmbeddedID, requestCode, data, null, flags);
3121            return target != null ? new PendingIntent(target) : null;
3122        } catch (RemoteException e) {
3123            // Empty
3124        }
3125        return null;
3126    }
3127
3128    /**
3129     * Change the desired orientation of this activity.  If the activity
3130     * is currently in the foreground or otherwise impacting the screen
3131     * orientation, the screen will immediately be changed (possibly causing
3132     * the activity to be restarted). Otherwise, this will be used the next
3133     * time the activity is visible.
3134     *
3135     * @param requestedOrientation An orientation constant as used in
3136     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3137     */
3138    public void setRequestedOrientation(int requestedOrientation) {
3139        if (mParent == null) {
3140            try {
3141                ActivityManagerNative.getDefault().setRequestedOrientation(
3142                        mToken, requestedOrientation);
3143            } catch (RemoteException e) {
3144                // Empty
3145            }
3146        } else {
3147            mParent.setRequestedOrientation(requestedOrientation);
3148        }
3149    }
3150
3151    /**
3152     * Return the current requested orientation of the activity.  This will
3153     * either be the orientation requested in its component's manifest, or
3154     * the last requested orientation given to
3155     * {@link #setRequestedOrientation(int)}.
3156     *
3157     * @return Returns an orientation constant as used in
3158     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3159     */
3160    public int getRequestedOrientation() {
3161        if (mParent == null) {
3162            try {
3163                return ActivityManagerNative.getDefault()
3164                        .getRequestedOrientation(mToken);
3165            } catch (RemoteException e) {
3166                // Empty
3167            }
3168        } else {
3169            return mParent.getRequestedOrientation();
3170        }
3171        return ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
3172    }
3173
3174    /**
3175     * Return the identifier of the task this activity is in.  This identifier
3176     * will remain the same for the lifetime of the activity.
3177     *
3178     * @return Task identifier, an opaque integer.
3179     */
3180    public int getTaskId() {
3181        try {
3182            return ActivityManagerNative.getDefault()
3183                .getTaskForActivity(mToken, false);
3184        } catch (RemoteException e) {
3185            return -1;
3186        }
3187    }
3188
3189    /**
3190     * Return whether this activity is the root of a task.  The root is the
3191     * first activity in a task.
3192     *
3193     * @return True if this is the root activity, else false.
3194     */
3195    public boolean isTaskRoot() {
3196        try {
3197            return ActivityManagerNative.getDefault()
3198                .getTaskForActivity(mToken, true) >= 0;
3199        } catch (RemoteException e) {
3200            return false;
3201        }
3202    }
3203
3204    /**
3205     * Move the task containing this activity to the back of the activity
3206     * stack.  The activity's order within the task is unchanged.
3207     *
3208     * @param nonRoot If false then this only works if the activity is the root
3209     *                of a task; if true it will work for any activity in
3210     *                a task.
3211     *
3212     * @return If the task was moved (or it was already at the
3213     *         back) true is returned, else false.
3214     */
3215    public boolean moveTaskToBack(boolean nonRoot) {
3216        try {
3217            return ActivityManagerNative.getDefault().moveActivityTaskToBack(
3218                    mToken, nonRoot);
3219        } catch (RemoteException e) {
3220            // Empty
3221        }
3222        return false;
3223    }
3224
3225    /**
3226     * Returns class name for this activity with the package prefix removed.
3227     * This is the default name used to read and write settings.
3228     *
3229     * @return The local class name.
3230     */
3231    public String getLocalClassName() {
3232        final String pkg = getPackageName();
3233        final String cls = mComponent.getClassName();
3234        int packageLen = pkg.length();
3235        if (!cls.startsWith(pkg) || cls.length() <= packageLen
3236                || cls.charAt(packageLen) != '.') {
3237            return cls;
3238        }
3239        return cls.substring(packageLen+1);
3240    }
3241
3242    /**
3243     * Returns complete component name of this activity.
3244     *
3245     * @return Returns the complete component name for this activity
3246     */
3247    public ComponentName getComponentName()
3248    {
3249        return mComponent;
3250    }
3251
3252    /**
3253     * Retrieve a {@link SharedPreferences} object for accessing preferences
3254     * that are private to this activity.  This simply calls the underlying
3255     * {@link #getSharedPreferences(String, int)} method by passing in this activity's
3256     * class name as the preferences name.
3257     *
3258     * @param mode Operating mode.  Use {@link #MODE_PRIVATE} for the default
3259     *             operation, {@link #MODE_WORLD_READABLE} and
3260     *             {@link #MODE_WORLD_WRITEABLE} to control permissions.
3261     *
3262     * @return Returns the single SharedPreferences instance that can be used
3263     *         to retrieve and modify the preference values.
3264     */
3265    public SharedPreferences getPreferences(int mode) {
3266        return getSharedPreferences(getLocalClassName(), mode);
3267    }
3268
3269    @Override
3270    public Object getSystemService(String name) {
3271        if (getBaseContext() == null) {
3272            throw new IllegalStateException(
3273                    "System services not available to Activities before onCreate()");
3274        }
3275
3276        if (WINDOW_SERVICE.equals(name)) {
3277            return mWindowManager;
3278        } else if (SEARCH_SERVICE.equals(name)) {
3279            return mSearchManager;
3280        }
3281        return super.getSystemService(name);
3282    }
3283
3284    /**
3285     * Change the title associated with this activity.  If this is a
3286     * top-level activity, the title for its window will change.  If it
3287     * is an embedded activity, the parent can do whatever it wants
3288     * with it.
3289     */
3290    public void setTitle(CharSequence title) {
3291        mTitle = title;
3292        onTitleChanged(title, mTitleColor);
3293
3294        if (mParent != null) {
3295            mParent.onChildTitleChanged(this, title);
3296        }
3297    }
3298
3299    /**
3300     * Change the title associated with this activity.  If this is a
3301     * top-level activity, the title for its window will change.  If it
3302     * is an embedded activity, the parent can do whatever it wants
3303     * with it.
3304     */
3305    public void setTitle(int titleId) {
3306        setTitle(getText(titleId));
3307    }
3308
3309    public void setTitleColor(int textColor) {
3310        mTitleColor = textColor;
3311        onTitleChanged(mTitle, textColor);
3312    }
3313
3314    public final CharSequence getTitle() {
3315        return mTitle;
3316    }
3317
3318    public final int getTitleColor() {
3319        return mTitleColor;
3320    }
3321
3322    protected void onTitleChanged(CharSequence title, int color) {
3323        if (mTitleReady) {
3324            final Window win = getWindow();
3325            if (win != null) {
3326                win.setTitle(title);
3327                if (color != 0) {
3328                    win.setTitleColor(color);
3329                }
3330            }
3331        }
3332    }
3333
3334    protected void onChildTitleChanged(Activity childActivity, CharSequence title) {
3335    }
3336
3337    /**
3338     * Sets the visibility of the progress bar in the title.
3339     * <p>
3340     * In order for the progress bar to be shown, the feature must be requested
3341     * via {@link #requestWindowFeature(int)}.
3342     *
3343     * @param visible Whether to show the progress bars in the title.
3344     */
3345    public final void setProgressBarVisibility(boolean visible) {
3346        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, visible ? Window.PROGRESS_VISIBILITY_ON :
3347            Window.PROGRESS_VISIBILITY_OFF);
3348    }
3349
3350    /**
3351     * Sets the visibility of the indeterminate progress bar in the title.
3352     * <p>
3353     * In order for the progress bar to be shown, the feature must be requested
3354     * via {@link #requestWindowFeature(int)}.
3355     *
3356     * @param visible Whether to show the progress bars in the title.
3357     */
3358    public final void setProgressBarIndeterminateVisibility(boolean visible) {
3359        getWindow().setFeatureInt(Window.FEATURE_INDETERMINATE_PROGRESS,
3360                visible ? Window.PROGRESS_VISIBILITY_ON : Window.PROGRESS_VISIBILITY_OFF);
3361    }
3362
3363    /**
3364     * Sets whether the horizontal progress bar in the title should be indeterminate (the circular
3365     * is always indeterminate).
3366     * <p>
3367     * In order for the progress bar to be shown, the feature must be requested
3368     * via {@link #requestWindowFeature(int)}.
3369     *
3370     * @param indeterminate Whether the horizontal progress bar should be indeterminate.
3371     */
3372    public final void setProgressBarIndeterminate(boolean indeterminate) {
3373        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3374                indeterminate ? Window.PROGRESS_INDETERMINATE_ON : Window.PROGRESS_INDETERMINATE_OFF);
3375    }
3376
3377    /**
3378     * Sets the progress for the progress bars in the title.
3379     * <p>
3380     * In order for the progress bar to be shown, the feature must be requested
3381     * via {@link #requestWindowFeature(int)}.
3382     *
3383     * @param progress The progress for the progress bar. Valid ranges are from
3384     *            0 to 10000 (both inclusive). If 10000 is given, the progress
3385     *            bar will be completely filled and will fade out.
3386     */
3387    public final void setProgress(int progress) {
3388        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, progress + Window.PROGRESS_START);
3389    }
3390
3391    /**
3392     * Sets the secondary progress for the progress bar in the title. This
3393     * progress is drawn between the primary progress (set via
3394     * {@link #setProgress(int)} and the background. It can be ideal for media
3395     * scenarios such as showing the buffering progress while the default
3396     * progress shows the play progress.
3397     * <p>
3398     * In order for the progress bar to be shown, the feature must be requested
3399     * via {@link #requestWindowFeature(int)}.
3400     *
3401     * @param secondaryProgress The secondary progress for the progress bar. Valid ranges are from
3402     *            0 to 10000 (both inclusive).
3403     */
3404    public final void setSecondaryProgress(int secondaryProgress) {
3405        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3406                secondaryProgress + Window.PROGRESS_SECONDARY_START);
3407    }
3408
3409    /**
3410     * Suggests an audio stream whose volume should be changed by the hardware
3411     * volume controls.
3412     * <p>
3413     * The suggested audio stream will be tied to the window of this Activity.
3414     * If the Activity is switched, the stream set here is no longer the
3415     * suggested stream. The client does not need to save and restore the old
3416     * suggested stream value in onPause and onResume.
3417     *
3418     * @param streamType The type of the audio stream whose volume should be
3419     *        changed by the hardware volume controls. It is not guaranteed that
3420     *        the hardware volume controls will always change this stream's
3421     *        volume (for example, if a call is in progress, its stream's volume
3422     *        may be changed instead). To reset back to the default, use
3423     *        {@link AudioManager#USE_DEFAULT_STREAM_TYPE}.
3424     */
3425    public final void setVolumeControlStream(int streamType) {
3426        getWindow().setVolumeControlStream(streamType);
3427    }
3428
3429    /**
3430     * Gets the suggested audio stream whose volume should be changed by the
3431     * harwdare volume controls.
3432     *
3433     * @return The suggested audio stream type whose volume should be changed by
3434     *         the hardware volume controls.
3435     * @see #setVolumeControlStream(int)
3436     */
3437    public final int getVolumeControlStream() {
3438        return getWindow().getVolumeControlStream();
3439    }
3440
3441    /**
3442     * Runs the specified action on the UI thread. If the current thread is the UI
3443     * thread, then the action is executed immediately. If the current thread is
3444     * not the UI thread, the action is posted to the event queue of the UI thread.
3445     *
3446     * @param action the action to run on the UI thread
3447     */
3448    public final void runOnUiThread(Runnable action) {
3449        if (Thread.currentThread() != mUiThread) {
3450            mHandler.post(action);
3451        } else {
3452            action.run();
3453        }
3454    }
3455
3456    /**
3457     * Stub implementation of {@link android.view.LayoutInflater.Factory#onCreateView} used when
3458     * inflating with the LayoutInflater returned by {@link #getSystemService}.  This
3459     * implementation simply returns null for all view names.
3460     *
3461     * @see android.view.LayoutInflater#createView
3462     * @see android.view.Window#getLayoutInflater
3463     */
3464    public View onCreateView(String name, Context context, AttributeSet attrs) {
3465        return null;
3466    }
3467
3468    // ------------------ Internal API ------------------
3469
3470    final void setParent(Activity parent) {
3471        mParent = parent;
3472    }
3473
3474    final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token,
3475            Application application, Intent intent, ActivityInfo info, CharSequence title,
3476            Activity parent, String id, Object lastNonConfigurationInstance,
3477            Configuration config) {
3478        attach(context, aThread, instr, token, application, intent, info, title, parent, id,
3479            lastNonConfigurationInstance, null, config);
3480    }
3481
3482    final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token,
3483        Application application, Intent intent, ActivityInfo info, CharSequence title,
3484        Activity parent, String id, Object lastNonConfigurationInstance,
3485        HashMap<String,Object> lastNonConfigurationChildInstances, Configuration config) {
3486        attachBaseContext(context);
3487
3488        mWindow = PolicyManager.makeNewWindow(this);
3489        mWindow.setCallback(this);
3490        if (info.softInputMode != WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED) {
3491            mWindow.setSoftInputMode(info.softInputMode);
3492        }
3493        mUiThread = Thread.currentThread();
3494
3495        mMainThread = aThread;
3496        mInstrumentation = instr;
3497        mToken = token;
3498        mApplication = application;
3499        mIntent = intent;
3500        mComponent = intent.getComponent();
3501        mActivityInfo = info;
3502        mTitle = title;
3503        mParent = parent;
3504        mEmbeddedID = id;
3505        mLastNonConfigurationInstance = lastNonConfigurationInstance;
3506        mLastNonConfigurationChildInstances = lastNonConfigurationChildInstances;
3507
3508        mWindow.setWindowManager(null, mToken, mComponent.flattenToString());
3509        if (mParent != null) {
3510            mWindow.setContainer(mParent.getWindow());
3511        }
3512        mWindowManager = mWindow.getWindowManager();
3513        mCurrentConfig = config;
3514    }
3515
3516    final IBinder getActivityToken() {
3517        return mParent != null ? mParent.getActivityToken() : mToken;
3518    }
3519
3520    final void performStart() {
3521        mCalled = false;
3522        mInstrumentation.callActivityOnStart(this);
3523        if (!mCalled) {
3524            throw new SuperNotCalledException(
3525                "Activity " + mComponent.toShortString() +
3526                " did not call through to super.onStart()");
3527        }
3528    }
3529
3530    final void performRestart() {
3531        final int N = mManagedCursors.size();
3532        for (int i=0; i<N; i++) {
3533            ManagedCursor mc = mManagedCursors.get(i);
3534            if (mc.mReleased || mc.mUpdated) {
3535                mc.mCursor.requery();
3536                mc.mReleased = false;
3537                mc.mUpdated = false;
3538            }
3539        }
3540
3541        if (mStopped) {
3542            mStopped = false;
3543            mCalled = false;
3544            mInstrumentation.callActivityOnRestart(this);
3545            if (!mCalled) {
3546                throw new SuperNotCalledException(
3547                    "Activity " + mComponent.toShortString() +
3548                    " did not call through to super.onRestart()");
3549            }
3550            performStart();
3551        }
3552    }
3553
3554    final void performResume() {
3555        performRestart();
3556
3557        mLastNonConfigurationInstance = null;
3558
3559        // First call onResume() -before- setting mResumed, so we don't
3560        // send out any status bar / menu notifications the client makes.
3561        mCalled = false;
3562        mInstrumentation.callActivityOnResume(this);
3563        if (!mCalled) {
3564            throw new SuperNotCalledException(
3565                "Activity " + mComponent.toShortString() +
3566                " did not call through to super.onResume()");
3567        }
3568
3569        // Now really resume, and install the current status bar and menu.
3570        mResumed = true;
3571        mCalled = false;
3572        onPostResume();
3573        if (!mCalled) {
3574            throw new SuperNotCalledException(
3575                "Activity " + mComponent.toShortString() +
3576                " did not call through to super.onPostResume()");
3577        }
3578
3579        // restore search dialog, if any
3580        if (mSearchDialogState != null) {
3581            mSearchManager.restoreSearchDialog(mSearchDialogState);
3582        }
3583        mSearchDialogState = null;
3584    }
3585
3586    final void performPause() {
3587        onPause();
3588
3589        // save search dialog state if the search dialog is open,
3590        // and then dismiss the search dialog
3591        mSearchDialogState = mSearchManager.saveSearchDialog();
3592        mSearchManager.stopSearch();
3593    }
3594
3595    final void performUserLeaving() {
3596        onUserInteraction();
3597        onUserLeaveHint();
3598    }
3599
3600    final void performStop() {
3601        if (!mStopped) {
3602            if (mWindow != null) {
3603                mWindow.closeAllPanels();
3604            }
3605
3606            mCalled = false;
3607            mInstrumentation.callActivityOnStop(this);
3608            if (!mCalled) {
3609                throw new SuperNotCalledException(
3610                    "Activity " + mComponent.toShortString() +
3611                    " did not call through to super.onStop()");
3612            }
3613
3614            final int N = mManagedCursors.size();
3615            for (int i=0; i<N; i++) {
3616                ManagedCursor mc = mManagedCursors.get(i);
3617                if (!mc.mReleased) {
3618                    mc.mCursor.deactivate();
3619                    mc.mReleased = true;
3620                }
3621            }
3622
3623            mStopped = true;
3624        }
3625        mResumed = false;
3626    }
3627
3628    final boolean isResumed() {
3629        return mResumed;
3630    }
3631
3632    void dispatchActivityResult(String who, int requestCode,
3633        int resultCode, Intent data) {
3634        if (Config.LOGV) Log.v(
3635            TAG, "Dispatching result: who=" + who + ", reqCode=" + requestCode
3636            + ", resCode=" + resultCode + ", data=" + data);
3637        if (who == null) {
3638            onActivityResult(requestCode, resultCode, data);
3639        }
3640    }
3641}
3642