Activity.java revision e9ce3f01d42769f03f10e70c3244500e92d7eee1
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.IntentSender;
28import android.content.SharedPreferences;
29import android.content.pm.ActivityInfo;
30import android.content.res.Configuration;
31import android.content.res.Resources;
32import android.database.Cursor;
33import android.graphics.Bitmap;
34import android.graphics.Canvas;
35import android.graphics.drawable.Drawable;
36import android.media.AudioManager;
37import android.net.Uri;
38import android.os.Build;
39import android.os.Bundle;
40import android.os.Handler;
41import android.os.IBinder;
42import android.os.Looper;
43import android.os.RemoteException;
44import android.text.Selection;
45import android.text.SpannableStringBuilder;
46import android.text.TextUtils;
47import android.text.method.TextKeyListener;
48import android.util.AttributeSet;
49import android.util.Config;
50import android.util.EventLog;
51import android.util.Log;
52import android.util.SparseArray;
53import android.view.ContextMenu;
54import android.view.ContextThemeWrapper;
55import android.view.KeyEvent;
56import android.view.LayoutInflater;
57import android.view.Menu;
58import android.view.MenuInflater;
59import android.view.MenuItem;
60import android.view.MotionEvent;
61import android.view.View;
62import android.view.ViewGroup;
63import android.view.ViewManager;
64import android.view.Window;
65import android.view.WindowManager;
66import android.view.ContextMenu.ContextMenuInfo;
67import android.view.View.OnCreateContextMenuListener;
68import android.view.ViewGroup.LayoutParams;
69import android.view.accessibility.AccessibilityEvent;
70import android.widget.AdapterView;
71
72import java.util.ArrayList;
73import java.util.HashMap;
74
75/**
76 * An activity is a single, focused thing that the user can do.  Almost all
77 * activities interact with the user, so the Activity class takes care of
78 * creating a window for you in which you can place your UI with
79 * {@link #setContentView}.  While activities are often presented to the user
80 * as full-screen windows, they can also be used in other ways: as floating
81 * windows (via a theme with {@link android.R.attr#windowIsFloating} set)
82 * or embedded inside of another activity (using {@link ActivityGroup}).
83 *
84 * There are two methods almost all subclasses of Activity will implement:
85 *
86 * <ul>
87 *     <li> {@link #onCreate} is where you initialize your activity.  Most
88 *     importantly, here you will usually call {@link #setContentView(int)}
89 *     with a layout resource defining your UI, and using {@link #findViewById}
90 *     to retrieve the widgets in that UI that you need to interact with
91 *     programmatically.
92 *
93 *     <li> {@link #onPause} is where you deal with the user leaving your
94 *     activity.  Most importantly, any changes made by the user should at this
95 *     point be committed (usually to the
96 *     {@link android.content.ContentProvider} holding the data).
97 * </ul>
98 *
99 * <p>To be of use with {@link android.content.Context#startActivity Context.startActivity()}, all
100 * activity classes must have a corresponding
101 * {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
102 * declaration in their package's <code>AndroidManifest.xml</code>.</p>
103 *
104 * <p>The Activity class is an important part of an application's overall lifecycle,
105 * and the way activities are launched and put together is a fundamental
106 * part of the platform's application model. For a detailed perspective on the structure of
107 * Android applications and lifecycles, please read the <em>Dev Guide</em> document on
108 * <a href="{@docRoot}guide/topics/fundamentals.html">Application Fundamentals</a>.</p>
109 *
110 * <p>Topics covered here:
111 * <ol>
112 * <li><a href="#ActivityLifecycle">Activity Lifecycle</a>
113 * <li><a href="#ConfigurationChanges">Configuration Changes</a>
114 * <li><a href="#StartingActivities">Starting Activities and Getting Results</a>
115 * <li><a href="#SavingPersistentState">Saving Persistent State</a>
116 * <li><a href="#Permissions">Permissions</a>
117 * <li><a href="#ProcessLifecycle">Process Lifecycle</a>
118 * </ol>
119 *
120 * <a name="ActivityLifecycle"></a>
121 * <h3>Activity Lifecycle</h3>
122 *
123 * <p>Activities in the system are managed as an <em>activity stack</em>.
124 * When a new activity is started, it is placed on the top of the stack
125 * and becomes the running activity -- the previous activity always remains
126 * below it in the stack, and will not come to the foreground again until
127 * the new activity exits.</p>
128 *
129 * <p>An activity has essentially four states:</p>
130 * <ul>
131 *     <li> If an activity in the foreground of the screen (at the top of
132 *         the stack),
133 *         it is <em>active</em> or  <em>running</em>. </li>
134 *     <li>If an activity has lost focus but is still visible (that is, a new non-full-sized
135 *         or transparent activity has focus on top of your activity), it
136 *         is <em>paused</em>. A paused activity is completely alive (it
137 *         maintains all state and member information and remains attached to
138 *         the window manager), but can be killed by the system in extreme
139 *         low memory situations.
140 *     <li>If an activity is completely obscured by another activity,
141 *         it is <em>stopped</em>. It still retains all state and member information,
142 *         however, it is no longer visible to the user so its window is hidden
143 *         and it will often be killed by the system when memory is needed
144 *         elsewhere.</li>
145 *     <li>If an activity is paused or stopped, the system can drop the activity
146 *         from memory by either asking it to finish, or simply killing its
147 *         process.  When it is displayed again to the user, it must be
148 *         completely restarted and restored to its previous state.</li>
149 * </ul>
150 *
151 * <p>The following diagram shows the important state paths of an Activity.
152 * The square rectangles represent callback methods you can implement to
153 * perform operations when the Activity moves between states.  The colored
154 * ovals are major states the Activity can be in.</p>
155 *
156 * <p><img src="../../../images/activity_lifecycle.png"
157 *      alt="State diagram for an Android Activity Lifecycle." border="0" /></p>
158 *
159 * <p>There are three key loops you may be interested in monitoring within your
160 * activity:
161 *
162 * <ul>
163 * <li>The <b>entire lifetime</b> of an activity happens between the first call
164 * to {@link android.app.Activity#onCreate} through to a single final call
165 * to {@link android.app.Activity#onDestroy}.  An activity will do all setup
166 * of "global" state in onCreate(), and release all remaining resources in
167 * onDestroy().  For example, if it has a thread running in the background
168 * to download data from the network, it may create that thread in onCreate()
169 * and then stop the thread in onDestroy().
170 *
171 * <li>The <b>visible lifetime</b> of an activity happens between a call to
172 * {@link android.app.Activity#onStart} until a corresponding call to
173 * {@link android.app.Activity#onStop}.  During this time the user can see the
174 * activity on-screen, though it may not be in the foreground and interacting
175 * with the user.  Between these two methods you can maintain resources that
176 * are needed to show the activity to the user.  For example, you can register
177 * a {@link android.content.BroadcastReceiver} in onStart() to monitor for changes
178 * that impact your UI, and unregister it in onStop() when the user an no
179 * longer see what you are displaying.  The onStart() and onStop() methods
180 * can be called multiple times, as the activity becomes visible and hidden
181 * to the user.
182 *
183 * <li>The <b>foreground lifetime</b> of an activity happens between a call to
184 * {@link android.app.Activity#onResume} until a corresponding call to
185 * {@link android.app.Activity#onPause}.  During this time the activity is
186 * in front of all other activities and interacting with the user.  An activity
187 * can frequently go between the resumed and paused states -- for example when
188 * the device goes to sleep, when an activity result is delivered, when a new
189 * intent is delivered -- so the code in these methods should be fairly
190 * lightweight.
191 * </ul>
192 *
193 * <p>The entire lifecycle of an activity is defined by the following
194 * Activity methods.  All of these are hooks that you can override
195 * to do appropriate work when the activity changes state.  All
196 * activities will implement {@link android.app.Activity#onCreate}
197 * to do their initial setup; many will also implement
198 * {@link android.app.Activity#onPause} to commit changes to data and
199 * otherwise prepare to stop interacting with the user.  You should always
200 * call up to your superclass when implementing these methods.</p>
201 *
202 * </p>
203 * <pre class="prettyprint">
204 * public class Activity extends ApplicationContext {
205 *     protected void onCreate(Bundle savedInstanceState);
206 *
207 *     protected void onStart();
208 *
209 *     protected void onRestart();
210 *
211 *     protected void onResume();
212 *
213 *     protected void onPause();
214 *
215 *     protected void onStop();
216 *
217 *     protected void onDestroy();
218 * }
219 * </pre>
220 *
221 * <p>In general the movement through an activity's lifecycle looks like
222 * this:</p>
223 *
224 * <table border="2" width="85%" align="center" frame="hsides" rules="rows">
225 *     <colgroup align="left" span="3" />
226 *     <colgroup align="left" />
227 *     <colgroup align="center" />
228 *     <colgroup align="center" />
229 *
230 *     <thead>
231 *     <tr><th colspan="3">Method</th> <th>Description</th> <th>Killable?</th> <th>Next</th></tr>
232 *     </thead>
233 *
234 *     <tbody>
235 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onCreate onCreate()}</th>
236 *         <td>Called when the activity is first created.
237 *             This is where you should do all of your normal static set up:
238 *             create views, bind data to lists, etc.  This method also
239 *             provides you with a Bundle containing the activity's previously
240 *             frozen state, if there was one.
241 *             <p>Always followed by <code>onStart()</code>.</td>
242 *         <td align="center">No</td>
243 *         <td align="center"><code>onStart()</code></td>
244 *     </tr>
245 *
246 *     <tr><td rowspan="5" style="border-left: none; border-right: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
247 *         <th colspan="2" align="left" border="0">{@link android.app.Activity#onRestart onRestart()}</th>
248 *         <td>Called after your activity has been stopped, prior to it being
249 *             started again.
250 *             <p>Always followed by <code>onStart()</code></td>
251 *         <td align="center">No</td>
252 *         <td align="center"><code>onStart()</code></td>
253 *     </tr>
254 *
255 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStart onStart()}</th>
256 *         <td>Called when the activity is becoming visible to the user.
257 *             <p>Followed by <code>onResume()</code> if the activity comes
258 *             to the foreground, or <code>onStop()</code> if it becomes hidden.</td>
259 *         <td align="center">No</td>
260 *         <td align="center"><code>onResume()</code> or <code>onStop()</code></td>
261 *     </tr>
262 *
263 *     <tr><td rowspan="2" style="border-left: none;">&nbsp;&nbsp;&nbsp;&nbsp;</td>
264 *         <th align="left" border="0">{@link android.app.Activity#onResume onResume()}</th>
265 *         <td>Called when the activity will start
266 *             interacting with the user.  At this point your activity is at
267 *             the top of the activity stack, with user input going to it.
268 *             <p>Always followed by <code>onPause()</code>.</td>
269 *         <td align="center">No</td>
270 *         <td align="center"><code>onPause()</code></td>
271 *     </tr>
272 *
273 *     <tr><th align="left" border="0">{@link android.app.Activity#onPause onPause()}</th>
274 *         <td>Called when the system is about to start resuming a previous
275 *             activity.  This is typically used to commit unsaved changes to
276 *             persistent data, stop animations and other things that may be consuming
277 *             CPU, etc.  Implementations of this method must be very quick because
278 *             the next activity will not be resumed until this method returns.
279 *             <p>Followed by either <code>onResume()</code> if the activity
280 *             returns back to the front, or <code>onStop()</code> if it becomes
281 *             invisible to the user.</td>
282 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
283 *         <td align="center"><code>onResume()</code> or<br>
284 *                 <code>onStop()</code></td>
285 *     </tr>
286 *
287 *     <tr><th colspan="2" align="left" border="0">{@link android.app.Activity#onStop onStop()}</th>
288 *         <td>Called when the activity is no longer visible to the user, because
289 *             another activity has been resumed and is covering this one.  This
290 *             may happen either because a new activity is being started, an existing
291 *             one is being brought in front of this one, or this one is being
292 *             destroyed.
293 *             <p>Followed by either <code>onRestart()</code> if
294 *             this activity is coming back to interact with the user, or
295 *             <code>onDestroy()</code> if this activity is going away.</td>
296 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
297 *         <td align="center"><code>onRestart()</code> or<br>
298 *                 <code>onDestroy()</code></td>
299 *     </tr>
300 *
301 *     <tr><th colspan="3" align="left" border="0">{@link android.app.Activity#onDestroy onDestroy()}</th>
302 *         <td>The final call you receive before your
303 *             activity is destroyed.  This can happen either because the
304 *             activity is finishing (someone called {@link Activity#finish} on
305 *             it, or because the system is temporarily destroying this
306 *             instance of the activity to save space.  You can distinguish
307 *             between these two scenarios with the {@link
308 *             Activity#isFinishing} method.</td>
309 *         <td align="center"><font color="#800000"><strong>Yes</strong></font></td>
310 *         <td align="center"><em>nothing</em></td>
311 *     </tr>
312 *     </tbody>
313 * </table>
314 *
315 * <p>Note the "Killable" column in the above table -- for those methods that
316 * are marked as being killable, after that method returns the process hosting the
317 * activity may killed by the system <em>at any time</em> without another line
318 * of its code being executed.  Because of this, you should use the
319 * {@link #onPause} method to write any persistent data (such as user edits)
320 * to storage.  In addition, the method
321 * {@link #onSaveInstanceState(Bundle)} is called before placing the activity
322 * in such a background state, allowing you to save away any dynamic instance
323 * state in your activity into the given Bundle, to be later received in
324 * {@link #onCreate} if the activity needs to be re-created.
325 * See the <a href="#ProcessLifecycle">Process Lifecycle</a>
326 * section for more information on how the lifecycle of a process is tied
327 * to the activities it is hosting.  Note that it is important to save
328 * persistent data in {@link #onPause} instead of {@link #onSaveInstanceState}
329 * because the later is not part of the lifecycle callbacks, so will not
330 * be called in every situation as described in its documentation.</p>
331 *
332 * <p>For those methods that are not marked as being killable, the activity's
333 * process will not be killed by the system starting from the time the method
334 * is called and continuing after it returns.  Thus an activity is in the killable
335 * state, for example, between after <code>onPause()</code> to the start of
336 * <code>onResume()</code>.</p>
337 *
338 * <a name="ConfigurationChanges"></a>
339 * <h3>Configuration Changes</h3>
340 *
341 * <p>If the configuration of the device (as defined by the
342 * {@link Configuration Resources.Configuration} class) changes,
343 * then anything displaying a user interface will need to update to match that
344 * configuration.  Because Activity is the primary mechanism for interacting
345 * with the user, it includes special support for handling configuration
346 * changes.</p>
347 *
348 * <p>Unless you specify otherwise, a configuration change (such as a change
349 * in screen orientation, language, input devices, etc) will cause your
350 * current activity to be <em>destroyed</em>, going through the normal activity
351 * lifecycle process of {@link #onPause},
352 * {@link #onStop}, and {@link #onDestroy} as appropriate.  If the activity
353 * had been in the foreground or visible to the user, once {@link #onDestroy} is
354 * called in that instance then a new instance of the activity will be
355 * created, with whatever savedInstanceState the previous instance had generated
356 * from {@link #onSaveInstanceState}.</p>
357 *
358 * <p>This is done because any application resource,
359 * including layout files, can change based on any configuration value.  Thus
360 * the only safe way to handle a configuration change is to re-retrieve all
361 * resources, including layouts, drawables, and strings.  Because activities
362 * must already know how to save their state and re-create themselves from
363 * that state, this is a convenient way to have an activity restart itself
364 * with a new configuration.</p>
365 *
366 * <p>In some special cases, you may want to bypass restarting of your
367 * activity based on one or more types of configuration changes.  This is
368 * done with the {@link android.R.attr#configChanges android:configChanges}
369 * attribute in its manifest.  For any types of configuration changes you say
370 * that you handle there, you will receive a call to your current activity's
371 * {@link #onConfigurationChanged} method instead of being restarted.  If
372 * a configuration change involves any that you do not handle, however, the
373 * activity will still be restarted and {@link #onConfigurationChanged}
374 * will not be called.</p>
375 *
376 * <a name="StartingActivities"></a>
377 * <h3>Starting Activities and Getting Results</h3>
378 *
379 * <p>The {@link android.app.Activity#startActivity}
380 * method is used to start a
381 * new activity, which will be placed at the top of the activity stack.  It
382 * takes a single argument, an {@link android.content.Intent Intent},
383 * which describes the activity
384 * to be executed.</p>
385 *
386 * <p>Sometimes you want to get a result back from an activity when it
387 * ends.  For example, you may start an activity that lets the user pick
388 * a person in a list of contacts; when it ends, it returns the person
389 * that was selected.  To do this, you call the
390 * {@link android.app.Activity#startActivityForResult(Intent, int)}
391 * version with a second integer parameter identifying the call.  The result
392 * will come back through your {@link android.app.Activity#onActivityResult}
393 * method.</p>
394 *
395 * <p>When an activity exits, it can call
396 * {@link android.app.Activity#setResult(int)}
397 * to return data back to its parent.  It must always supply a result code,
398 * which can be the standard results RESULT_CANCELED, RESULT_OK, or any
399 * custom values starting at RESULT_FIRST_USER.  In addition, it can optionally
400 * return back an Intent containing any additional data it wants.  All of this
401 * information appears back on the
402 * parent's <code>Activity.onActivityResult()</code>, along with the integer
403 * identifier it originally supplied.</p>
404 *
405 * <p>If a child activity fails for any reason (such as crashing), the parent
406 * activity will receive a result with the code RESULT_CANCELED.</p>
407 *
408 * <pre class="prettyprint">
409 * public class MyActivity extends Activity {
410 *     ...
411 *
412 *     static final int PICK_CONTACT_REQUEST = 0;
413 *
414 *     protected boolean onKeyDown(int keyCode, KeyEvent event) {
415 *         if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
416 *             // When the user center presses, let them pick a contact.
417 *             startActivityForResult(
418 *                 new Intent(Intent.ACTION_PICK,
419 *                 new Uri("content://contacts")),
420 *                 PICK_CONTACT_REQUEST);
421 *            return true;
422 *         }
423 *         return false;
424 *     }
425 *
426 *     protected void onActivityResult(int requestCode, int resultCode,
427 *             Intent data) {
428 *         if (requestCode == PICK_CONTACT_REQUEST) {
429 *             if (resultCode == RESULT_OK) {
430 *                 // A contact was picked.  Here we will just display it
431 *                 // to the user.
432 *                 startActivity(new Intent(Intent.ACTION_VIEW, data));
433 *             }
434 *         }
435 *     }
436 * }
437 * </pre>
438 *
439 * <a name="SavingPersistentState"></a>
440 * <h3>Saving Persistent State</h3>
441 *
442 * <p>There are generally two kinds of persistent state than an activity
443 * will deal with: shared document-like data (typically stored in a SQLite
444 * database using a {@linkplain android.content.ContentProvider content provider})
445 * and internal state such as user preferences.</p>
446 *
447 * <p>For content provider data, we suggest that activities use a
448 * "edit in place" user model.  That is, any edits a user makes are effectively
449 * made immediately without requiring an additional confirmation step.
450 * Supporting this model is generally a simple matter of following two rules:</p>
451 *
452 * <ul>
453 *     <li> <p>When creating a new document, the backing database entry or file for
454 *             it is created immediately.  For example, if the user chooses to write
455 *             a new e-mail, a new entry for that e-mail is created as soon as they
456 *             start entering data, so that if they go to any other activity after
457 *             that point this e-mail will now appear in the list of drafts.</p>
458 *     <li> <p>When an activity's <code>onPause()</code> method is called, it should
459 *             commit to the backing content provider or file any changes the user
460 *             has made.  This ensures that those changes will be seen by any other
461 *             activity that is about to run.  You will probably want to commit
462 *             your data even more aggressively at key times during your
463 *             activity's lifecycle: for example before starting a new
464 *             activity, before finishing your own activity, when the user
465 *             switches between input fields, etc.</p>
466 * </ul>
467 *
468 * <p>This model is designed to prevent data loss when a user is navigating
469 * between activities, and allows the system to safely kill an activity (because
470 * system resources are needed somewhere else) at any time after it has been
471 * paused.  Note this implies
472 * that the user pressing BACK from your activity does <em>not</em>
473 * mean "cancel" -- it means to leave the activity with its current contents
474 * saved away.  Cancelling edits in an activity must be provided through
475 * some other mechanism, such as an explicit "revert" or "undo" option.</p>
476 *
477 * <p>See the {@linkplain android.content.ContentProvider content package} for
478 * more information about content providers.  These are a key aspect of how
479 * different activities invoke and propagate data between themselves.</p>
480 *
481 * <p>The Activity class also provides an API for managing internal persistent state
482 * associated with an activity.  This can be used, for example, to remember
483 * the user's preferred initial display in a calendar (day view or week view)
484 * or the user's default home page in a web browser.</p>
485 *
486 * <p>Activity persistent state is managed
487 * with the method {@link #getPreferences},
488 * allowing you to retrieve and
489 * modify a set of name/value pairs associated with the activity.  To use
490 * preferences that are shared across multiple application components
491 * (activities, receivers, services, providers), you can use the underlying
492 * {@link Context#getSharedPreferences Context.getSharedPreferences()} method
493 * to retrieve a preferences
494 * object stored under a specific name.
495 * (Note that it is not possible to share settings data across application
496 * packages -- for that you will need a content provider.)</p>
497 *
498 * <p>Here is an excerpt from a calendar activity that stores the user's
499 * preferred view mode in its persistent settings:</p>
500 *
501 * <pre class="prettyprint">
502 * public class CalendarActivity extends Activity {
503 *     ...
504 *
505 *     static final int DAY_VIEW_MODE = 0;
506 *     static final int WEEK_VIEW_MODE = 1;
507 *
508 *     private SharedPreferences mPrefs;
509 *     private int mCurViewMode;
510 *
511 *     protected void onCreate(Bundle savedInstanceState) {
512 *         super.onCreate(savedInstanceState);
513 *
514 *         SharedPreferences mPrefs = getSharedPreferences();
515 *         mCurViewMode = mPrefs.getInt("view_mode" DAY_VIEW_MODE);
516 *     }
517 *
518 *     protected void onPause() {
519 *         super.onPause();
520 *
521 *         SharedPreferences.Editor ed = mPrefs.edit();
522 *         ed.putInt("view_mode", mCurViewMode);
523 *         ed.commit();
524 *     }
525 * }
526 * </pre>
527 *
528 * <a name="Permissions"></a>
529 * <h3>Permissions</h3>
530 *
531 * <p>The ability to start a particular Activity can be enforced when it is
532 * declared in its
533 * manifest's {@link android.R.styleable#AndroidManifestActivity &lt;activity&gt;}
534 * tag.  By doing so, other applications will need to declare a corresponding
535 * {@link android.R.styleable#AndroidManifestUsesPermission &lt;uses-permission&gt;}
536 * element in their own manifest to be able to start that activity.
537 *
538 * <p>See the <a href="{@docRoot}guide/topics/security/security.html">Security and Permissions</a>
539 * document for more information on permissions and security in general.
540 *
541 * <a name="ProcessLifecycle"></a>
542 * <h3>Process Lifecycle</h3>
543 *
544 * <p>The Android system attempts to keep application process around for as
545 * long as possible, but eventually will need to remove old processes when
546 * memory runs low.  As described in <a href="#ActivityLifecycle">Activity
547 * Lifecycle</a>, the decision about which process to remove is intimately
548 * tied to the state of the user's interaction with it.  In general, there
549 * are four states a process can be in based on the activities running in it,
550 * listed here in order of importance.  The system will kill less important
551 * processes (the last ones) before it resorts to killing more important
552 * processes (the first ones).
553 *
554 * <ol>
555 * <li> <p>The <b>foreground activity</b> (the activity at the top of the screen
556 * that the user is currently interacting with) is considered the most important.
557 * Its process will only be killed as a last resort, if it uses more memory
558 * than is available on the device.  Generally at this point the device has
559 * reached a memory paging state, so this is required in order to keep the user
560 * interface responsive.
561 * <li> <p>A <b>visible activity</b> (an activity that is visible to the user
562 * but not in the foreground, such as one sitting behind a foreground dialog)
563 * is considered extremely important and will not be killed unless that is
564 * required to keep the foreground activity running.
565 * <li> <p>A <b>background activity</b> (an activity that is not visible to
566 * the user and has been paused) is no longer critical, so the system may
567 * safely kill its process to reclaim memory for other foreground or
568 * visible processes.  If its process needs to be killed, when the user navigates
569 * back to the activity (making it visible on the screen again), its
570 * {@link #onCreate} method will be called with the savedInstanceState it had previously
571 * supplied in {@link #onSaveInstanceState} so that it can restart itself in the same
572 * state as the user last left it.
573 * <li> <p>An <b>empty process</b> is one hosting no activities or other
574 * application components (such as {@link Service} or
575 * {@link android.content.BroadcastReceiver} classes).  These are killed very
576 * quickly by the system as memory becomes low.  For this reason, any
577 * background operation you do outside of an activity must be executed in the
578 * context of an activity BroadcastReceiver or Service to ensure that the system
579 * knows it needs to keep your process around.
580 * </ol>
581 *
582 * <p>Sometimes an Activity may need to do a long-running operation that exists
583 * independently of the activity lifecycle itself.  An example may be a camera
584 * application that allows you to upload a picture to a web site.  The upload
585 * may take a long time, and the application should allow the user to leave
586 * the application will it is executing.  To accomplish this, your Activity
587 * should start a {@link Service} in which the upload takes place.  This allows
588 * the system to properly prioritize your process (considering it to be more
589 * important than other non-visible applications) for the duration of the
590 * upload, independent of whether the original activity is paused, stopped,
591 * or finished.
592 */
593public class Activity extends ContextThemeWrapper
594        implements LayoutInflater.Factory,
595        Window.Callback, KeyEvent.Callback,
596        OnCreateContextMenuListener, ComponentCallbacks {
597    private static final String TAG = "Activity";
598
599    /** Standard activity result: operation canceled. */
600    public static final int RESULT_CANCELED    = 0;
601    /** Standard activity result: operation succeeded. */
602    public static final int RESULT_OK           = -1;
603    /** Start of user-defined activity results. */
604    public static final int RESULT_FIRST_USER   = 1;
605
606    private static long sInstanceCount = 0;
607
608    private static final String WINDOW_HIERARCHY_TAG = "android:viewHierarchyState";
609    private static final String SAVED_DIALOG_IDS_KEY = "android:savedDialogIds";
610    private static final String SAVED_DIALOGS_TAG = "android:savedDialogs";
611    private static final String SAVED_DIALOG_KEY_PREFIX = "android:dialog_";
612
613    private SparseArray<Dialog> mManagedDialogs;
614
615    // set by the thread after the constructor and before onCreate(Bundle savedInstanceState) is called.
616    private Instrumentation mInstrumentation;
617    private IBinder mToken;
618    private int mIdent;
619    /*package*/ String mEmbeddedID;
620    private Application mApplication;
621    /*package*/ Intent mIntent;
622    private ComponentName mComponent;
623    /*package*/ ActivityInfo mActivityInfo;
624    /*package*/ ActivityThread mMainThread;
625    /*package*/ Object mLastNonConfigurationInstance;
626    /*package*/ HashMap<String,Object> mLastNonConfigurationChildInstances;
627    Activity mParent;
628    boolean mCalled;
629    private boolean mResumed;
630    private boolean mStopped;
631    boolean mFinished;
632    boolean mStartedActivity;
633    /*package*/ int mConfigChangeFlags;
634    /*package*/ Configuration mCurrentConfig;
635    private SearchManager mSearchManager;
636
637    private Window mWindow;
638
639    private WindowManager mWindowManager;
640    /*package*/ View mDecor = null;
641    /*package*/ boolean mWindowAdded = false;
642    /*package*/ boolean mVisibleFromServer = false;
643    /*package*/ boolean mVisibleFromClient = true;
644
645    private CharSequence mTitle;
646    private int mTitleColor = 0;
647
648    private static final class ManagedCursor {
649        ManagedCursor(Cursor cursor) {
650            mCursor = cursor;
651            mReleased = false;
652            mUpdated = false;
653        }
654
655        private final Cursor mCursor;
656        private boolean mReleased;
657        private boolean mUpdated;
658    }
659    private final ArrayList<ManagedCursor> mManagedCursors =
660        new ArrayList<ManagedCursor>();
661
662    // protected by synchronized (this)
663    int mResultCode = RESULT_CANCELED;
664    Intent mResultData = null;
665
666    private boolean mTitleReady = false;
667
668    private int mDefaultKeyMode = DEFAULT_KEYS_DISABLE;
669    private SpannableStringBuilder mDefaultKeySsb = null;
670
671    protected static final int[] FOCUSED_STATE_SET = {com.android.internal.R.attr.state_focused};
672
673    private Thread mUiThread;
674    private final Handler mHandler = new Handler();
675
676    public Activity() {
677        ++sInstanceCount;
678    }
679
680
681    @Override
682    protected void finalize() throws Throwable {
683        super.finalize();
684        --sInstanceCount;
685    }
686
687    public static long getInstanceCount() {
688        return sInstanceCount;
689    }
690
691    /** Return the intent that started this activity. */
692    public Intent getIntent() {
693        return mIntent;
694    }
695
696    /**
697     * Change the intent returned by {@link #getIntent}.  This holds a
698     * reference to the given intent; it does not copy it.  Often used in
699     * conjunction with {@link #onNewIntent}.
700     *
701     * @param newIntent The new Intent object to return from getIntent
702     *
703     * @see #getIntent
704     * @see #onNewIntent
705     */
706    public void setIntent(Intent newIntent) {
707        mIntent = newIntent;
708    }
709
710    /** Return the application that owns this activity. */
711    public final Application getApplication() {
712        return mApplication;
713    }
714
715    /** Is this activity embedded inside of another activity? */
716    public final boolean isChild() {
717        return mParent != null;
718    }
719
720    /** Return the parent activity if this view is an embedded child. */
721    public final Activity getParent() {
722        return mParent;
723    }
724
725    /** Retrieve the window manager for showing custom windows. */
726    public WindowManager getWindowManager() {
727        return mWindowManager;
728    }
729
730    /**
731     * Retrieve the current {@link android.view.Window} for the activity.
732     * This can be used to directly access parts of the Window API that
733     * are not available through Activity/Screen.
734     *
735     * @return Window The current window, or null if the activity is not
736     *         visual.
737     */
738    public Window getWindow() {
739        return mWindow;
740    }
741
742    /**
743     * Calls {@link android.view.Window#getCurrentFocus} on the
744     * Window of this Activity to return the currently focused view.
745     *
746     * @return View The current View with focus or null.
747     *
748     * @see #getWindow
749     * @see android.view.Window#getCurrentFocus
750     */
751    public View getCurrentFocus() {
752        return mWindow != null ? mWindow.getCurrentFocus() : null;
753    }
754
755    @Override
756    public int getWallpaperDesiredMinimumWidth() {
757        int width = super.getWallpaperDesiredMinimumWidth();
758        return width <= 0 ? getWindowManager().getDefaultDisplay().getWidth() : width;
759    }
760
761    @Override
762    public int getWallpaperDesiredMinimumHeight() {
763        int height = super.getWallpaperDesiredMinimumHeight();
764        return height <= 0 ? getWindowManager().getDefaultDisplay().getHeight() : height;
765    }
766
767    /**
768     * Called when the activity is starting.  This is where most initialization
769     * should go: calling {@link #setContentView(int)} to inflate the
770     * activity's UI, using {@link #findViewById} to programmatically interact
771     * with widgets in the UI, calling
772     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)} to retrieve
773     * cursors for data being displayed, etc.
774     *
775     * <p>You can call {@link #finish} from within this function, in
776     * which case onDestroy() will be immediately called without any of the rest
777     * of the activity lifecycle ({@link #onStart}, {@link #onResume},
778     * {@link #onPause}, etc) executing.
779     *
780     * <p><em>Derived classes must call through to the super class's
781     * implementation of this method.  If they do not, an exception will be
782     * thrown.</em></p>
783     *
784     * @param savedInstanceState If the activity is being re-initialized after
785     *     previously being shut down then this Bundle contains the data it most
786     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
787     *
788     * @see #onStart
789     * @see #onSaveInstanceState
790     * @see #onRestoreInstanceState
791     * @see #onPostCreate
792     */
793    protected void onCreate(Bundle savedInstanceState) {
794        mVisibleFromClient = !mWindow.getWindowStyle().getBoolean(
795                com.android.internal.R.styleable.Window_windowNoDisplay, false);
796        mCalled = true;
797    }
798
799    /**
800     * The hook for {@link ActivityThread} to restore the state of this activity.
801     *
802     * Calls {@link #onSaveInstanceState(android.os.Bundle)} and
803     * {@link #restoreManagedDialogs(android.os.Bundle)}.
804     *
805     * @param savedInstanceState contains the saved state
806     */
807    final void performRestoreInstanceState(Bundle savedInstanceState) {
808        onRestoreInstanceState(savedInstanceState);
809        restoreManagedDialogs(savedInstanceState);
810    }
811
812    /**
813     * This method is called after {@link #onStart} when the activity is
814     * being re-initialized from a previously saved state, given here in
815     * <var>state</var>.  Most implementations will simply use {@link #onCreate}
816     * to restore their state, but it is sometimes convenient to do it here
817     * after all of the initialization has been done or to allow subclasses to
818     * decide whether to use your default implementation.  The default
819     * implementation of this method performs a restore of any view state that
820     * had previously been frozen by {@link #onSaveInstanceState}.
821     *
822     * <p>This method is called between {@link #onStart} and
823     * {@link #onPostCreate}.
824     *
825     * @param savedInstanceState the data most recently supplied in {@link #onSaveInstanceState}.
826     *
827     * @see #onCreate
828     * @see #onPostCreate
829     * @see #onResume
830     * @see #onSaveInstanceState
831     */
832    protected void onRestoreInstanceState(Bundle savedInstanceState) {
833        if (mWindow != null) {
834            Bundle windowState = savedInstanceState.getBundle(WINDOW_HIERARCHY_TAG);
835            if (windowState != null) {
836                mWindow.restoreHierarchyState(windowState);
837            }
838        }
839    }
840
841    /**
842     * Restore the state of any saved managed dialogs.
843     *
844     * @param savedInstanceState The bundle to restore from.
845     */
846    private void restoreManagedDialogs(Bundle savedInstanceState) {
847        final Bundle b = savedInstanceState.getBundle(SAVED_DIALOGS_TAG);
848        if (b == null) {
849            return;
850        }
851
852        final int[] ids = b.getIntArray(SAVED_DIALOG_IDS_KEY);
853        final int numDialogs = ids.length;
854        mManagedDialogs = new SparseArray<Dialog>(numDialogs);
855        for (int i = 0; i < numDialogs; i++) {
856            final Integer dialogId = ids[i];
857            Bundle dialogState = b.getBundle(savedDialogKeyFor(dialogId));
858            if (dialogState != null) {
859                // Calling onRestoreInstanceState() below will invoke dispatchOnCreate
860                // so tell createDialog() not to do it, otherwise we get an exception
861                final Dialog dialog = createDialog(dialogId, dialogState);
862                mManagedDialogs.put(dialogId, dialog);
863                onPrepareDialog(dialogId, dialog);
864                dialog.onRestoreInstanceState(dialogState);
865            }
866        }
867    }
868
869    private Dialog createDialog(Integer dialogId, Bundle state) {
870        final Dialog dialog = onCreateDialog(dialogId);
871        if (dialog == null) {
872            throw new IllegalArgumentException("Activity#onCreateDialog did "
873                    + "not create a dialog for id " + dialogId);
874        }
875        dialog.dispatchOnCreate(state);
876        return dialog;
877    }
878
879    private String savedDialogKeyFor(int key) {
880        return SAVED_DIALOG_KEY_PREFIX + key;
881    }
882
883
884    /**
885     * Called when activity start-up is complete (after {@link #onStart}
886     * and {@link #onRestoreInstanceState} have been called).  Applications will
887     * generally not implement this method; it is intended for system
888     * classes to do final initialization after application code has run.
889     *
890     * <p><em>Derived classes must call through to the super class's
891     * implementation of this method.  If they do not, an exception will be
892     * thrown.</em></p>
893     *
894     * @param savedInstanceState If the activity is being re-initialized after
895     *     previously being shut down then this Bundle contains the data it most
896     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>
897     * @see #onCreate
898     */
899    protected void onPostCreate(Bundle savedInstanceState) {
900        if (!isChild()) {
901            mTitleReady = true;
902            onTitleChanged(getTitle(), getTitleColor());
903        }
904        mCalled = true;
905    }
906
907    /**
908     * Called after {@link #onCreate} &mdash; or after {@link #onRestart} when
909     * the activity had been stopped, but is now again being displayed to the
910	 * user.  It will be followed by {@link #onResume}.
911     *
912     * <p><em>Derived classes must call through to the super class's
913     * implementation of this method.  If they do not, an exception will be
914     * thrown.</em></p>
915     *
916     * @see #onCreate
917     * @see #onStop
918     * @see #onResume
919     */
920    protected void onStart() {
921        mCalled = true;
922    }
923
924    /**
925     * Called after {@link #onStop} when the current activity is being
926     * re-displayed to the user (the user has navigated back to it).  It will
927     * be followed by {@link #onStart} and then {@link #onResume}.
928     *
929     * <p>For activities that are using raw {@link Cursor} objects (instead of
930     * creating them through
931     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)},
932     * this is usually the place
933     * where the cursor should be requeried (because you had deactivated it in
934     * {@link #onStop}.
935     *
936     * <p><em>Derived classes must call through to the super class's
937     * implementation of this method.  If they do not, an exception will be
938     * thrown.</em></p>
939     *
940     * @see #onStop
941     * @see #onStart
942     * @see #onResume
943     */
944    protected void onRestart() {
945        mCalled = true;
946    }
947
948    /**
949     * Called after {@link #onRestoreInstanceState}, {@link #onRestart}, or
950     * {@link #onPause}, for your activity to start interacting with the user.
951     * This is a good place to begin animations, open exclusive-access devices
952     * (such as the camera), etc.
953     *
954     * <p>Keep in mind that onResume is not the best indicator that your activity
955     * is visible to the user; a system window such as the keyguard may be in
956     * front.  Use {@link #onWindowFocusChanged} to know for certain that your
957     * activity is visible to the user (for example, to resume a game).
958     *
959     * <p><em>Derived classes must call through to the super class's
960     * implementation of this method.  If they do not, an exception will be
961     * thrown.</em></p>
962     *
963     * @see #onRestoreInstanceState
964     * @see #onRestart
965     * @see #onPostResume
966     * @see #onPause
967     */
968    protected void onResume() {
969        mCalled = true;
970    }
971
972    /**
973     * Called when activity resume is complete (after {@link #onResume} has
974     * been called). Applications will generally not implement this method;
975     * it is intended for system classes to do final setup after application
976     * resume code has run.
977     *
978     * <p><em>Derived classes must call through to the super class's
979     * implementation of this method.  If they do not, an exception will be
980     * thrown.</em></p>
981     *
982     * @see #onResume
983     */
984    protected void onPostResume() {
985        final Window win = getWindow();
986        if (win != null) win.makeActive();
987        mCalled = true;
988    }
989
990    /**
991     * This is called for activities that set launchMode to "singleTop" in
992     * their package, or if a client used the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP}
993     * flag when calling {@link #startActivity}.  In either case, when the
994     * activity is re-launched while at the top of the activity stack instead
995     * of a new instance of the activity being started, onNewIntent() will be
996     * called on the existing instance with the Intent that was used to
997     * re-launch it.
998     *
999     * <p>An activity will always be paused before receiving a new intent, so
1000     * you can count on {@link #onResume} being called after this method.
1001     *
1002     * <p>Note that {@link #getIntent} still returns the original Intent.  You
1003     * can use {@link #setIntent} to update it to this new Intent.
1004     *
1005     * @param intent The new intent that was started for the activity.
1006     *
1007     * @see #getIntent
1008     * @see #setIntent
1009     * @see #onResume
1010     */
1011    protected void onNewIntent(Intent intent) {
1012    }
1013
1014    /**
1015     * The hook for {@link ActivityThread} to save the state of this activity.
1016     *
1017     * Calls {@link #onSaveInstanceState(android.os.Bundle)}
1018     * and {@link #saveManagedDialogs(android.os.Bundle)}.
1019     *
1020     * @param outState The bundle to save the state to.
1021     */
1022    final void performSaveInstanceState(Bundle outState) {
1023        onSaveInstanceState(outState);
1024        saveManagedDialogs(outState);
1025    }
1026
1027    /**
1028     * Called to retrieve per-instance state from an activity before being killed
1029     * so that the state can be restored in {@link #onCreate} or
1030     * {@link #onRestoreInstanceState} (the {@link Bundle} populated by this method
1031     * will be passed to both).
1032     *
1033     * <p>This method is called before an activity may be killed so that when it
1034     * comes back some time in the future it can restore its state.  For example,
1035     * if activity B is launched in front of activity A, and at some point activity
1036     * A is killed to reclaim resources, activity A will have a chance to save the
1037     * current state of its user interface via this method so that when the user
1038     * returns to activity A, the state of the user interface can be restored
1039     * via {@link #onCreate} or {@link #onRestoreInstanceState}.
1040     *
1041     * <p>Do not confuse this method with activity lifecycle callbacks such as
1042     * {@link #onPause}, which is always called when an activity is being placed
1043     * in the background or on its way to destruction, or {@link #onStop} which
1044     * is called before destruction.  One example of when {@link #onPause} and
1045     * {@link #onStop} is called and not this method is when a user navigates back
1046     * from activity B to activity A: there is no need to call {@link #onSaveInstanceState}
1047     * on B because that particular instance will never be restored, so the
1048     * system avoids calling it.  An example when {@link #onPause} is called and
1049     * not {@link #onSaveInstanceState} is when activity B is launched in front of activity A:
1050     * the system may avoid calling {@link #onSaveInstanceState} on activity A if it isn't
1051     * killed during the lifetime of B since the state of the user interface of
1052     * A will stay intact.
1053     *
1054     * <p>The default implementation takes care of most of the UI per-instance
1055     * state for you by calling {@link android.view.View#onSaveInstanceState()} on each
1056     * view in the hierarchy that has an id, and by saving the id of the currently
1057     * focused view (all of which is restored by the default implementation of
1058     * {@link #onRestoreInstanceState}).  If you override this method to save additional
1059     * information not captured by each individual view, you will likely want to
1060     * call through to the default implementation, otherwise be prepared to save
1061     * all of the state of each view yourself.
1062     *
1063     * <p>If called, this method will occur before {@link #onStop}.  There are
1064     * no guarantees about whether it will occur before or after {@link #onPause}.
1065     *
1066     * @param outState Bundle in which to place your saved state.
1067     *
1068     * @see #onCreate
1069     * @see #onRestoreInstanceState
1070     * @see #onPause
1071     */
1072    protected void onSaveInstanceState(Bundle outState) {
1073        outState.putBundle(WINDOW_HIERARCHY_TAG, mWindow.saveHierarchyState());
1074    }
1075
1076    /**
1077     * Save the state of any managed dialogs.
1078     *
1079     * @param outState place to store the saved state.
1080     */
1081    private void saveManagedDialogs(Bundle outState) {
1082        if (mManagedDialogs == null) {
1083            return;
1084        }
1085
1086        final int numDialogs = mManagedDialogs.size();
1087        if (numDialogs == 0) {
1088            return;
1089        }
1090
1091        Bundle dialogState = new Bundle();
1092
1093        int[] ids = new int[mManagedDialogs.size()];
1094
1095        // save each dialog's bundle, gather the ids
1096        for (int i = 0; i < numDialogs; i++) {
1097            final int key = mManagedDialogs.keyAt(i);
1098            ids[i] = key;
1099            final Dialog dialog = mManagedDialogs.valueAt(i);
1100            dialogState.putBundle(savedDialogKeyFor(key), dialog.onSaveInstanceState());
1101        }
1102
1103        dialogState.putIntArray(SAVED_DIALOG_IDS_KEY, ids);
1104        outState.putBundle(SAVED_DIALOGS_TAG, dialogState);
1105    }
1106
1107
1108    /**
1109     * Called as part of the activity lifecycle when an activity is going into
1110     * the background, but has not (yet) been killed.  The counterpart to
1111     * {@link #onResume}.
1112     *
1113     * <p>When activity B is launched in front of activity A, this callback will
1114     * be invoked on A.  B will not be created until A's {@link #onPause} returns,
1115     * so be sure to not do anything lengthy here.
1116     *
1117     * <p>This callback is mostly used for saving any persistent state the
1118     * activity is editing, to present a "edit in place" model to the user and
1119     * making sure nothing is lost if there are not enough resources to start
1120     * the new activity without first killing this one.  This is also a good
1121     * place to do things like stop animations and other things that consume a
1122     * noticeable mount of CPU in order to make the switch to the next activity
1123     * as fast as possible, or to close resources that are exclusive access
1124     * such as the camera.
1125     *
1126     * <p>In situations where the system needs more memory it may kill paused
1127     * processes to reclaim resources.  Because of this, you should be sure
1128     * that all of your state is saved by the time you return from
1129     * this function.  In general {@link #onSaveInstanceState} is used to save
1130     * per-instance state in the activity and this method is used to store
1131     * global persistent data (in content providers, files, etc.)
1132     *
1133     * <p>After receiving this call you will usually receive a following call
1134     * to {@link #onStop} (after the next activity has been resumed and
1135     * displayed), however in some cases there will be a direct call back to
1136     * {@link #onResume} without going through the stopped state.
1137     *
1138     * <p><em>Derived classes must call through to the super class's
1139     * implementation of this method.  If they do not, an exception will be
1140     * thrown.</em></p>
1141     *
1142     * @see #onResume
1143     * @see #onSaveInstanceState
1144     * @see #onStop
1145     */
1146    protected void onPause() {
1147        mCalled = true;
1148    }
1149
1150    /**
1151     * Called as part of the activity lifecycle when an activity is about to go
1152     * into the background as the result of user choice.  For example, when the
1153     * user presses the Home key, {@link #onUserLeaveHint} will be called, but
1154     * when an incoming phone call causes the in-call Activity to be automatically
1155     * brought to the foreground, {@link #onUserLeaveHint} will not be called on
1156     * the activity being interrupted.  In cases when it is invoked, this method
1157     * is called right before the activity's {@link #onPause} callback.
1158     *
1159     * <p>This callback and {@link #onUserInteraction} are intended to help
1160     * activities manage status bar notifications intelligently; specifically,
1161     * for helping activities determine the proper time to cancel a notfication.
1162     *
1163     * @see #onUserInteraction()
1164     */
1165    protected void onUserLeaveHint() {
1166    }
1167
1168    /**
1169     * Generate a new thumbnail for this activity.  This method is called before
1170     * pausing the activity, and should draw into <var>outBitmap</var> the
1171     * imagery for the desired thumbnail in the dimensions of that bitmap.  It
1172     * can use the given <var>canvas</var>, which is configured to draw into the
1173     * bitmap, for rendering if desired.
1174     *
1175     * <p>The default implementation renders the Screen's current view
1176     * hierarchy into the canvas to generate a thumbnail.
1177     *
1178     * <p>If you return false, the bitmap will be filled with a default
1179     * thumbnail.
1180     *
1181     * @param outBitmap The bitmap to contain the thumbnail.
1182     * @param canvas Can be used to render into the bitmap.
1183     *
1184     * @return Return true if you have drawn into the bitmap; otherwise after
1185     *         you return it will be filled with a default thumbnail.
1186     *
1187     * @see #onCreateDescription
1188     * @see #onSaveInstanceState
1189     * @see #onPause
1190     */
1191    public boolean onCreateThumbnail(Bitmap outBitmap, Canvas canvas) {
1192        final View view = mDecor;
1193        if (view == null) {
1194            return false;
1195        }
1196
1197        final int vw = view.getWidth();
1198        final int vh = view.getHeight();
1199        final int dw = outBitmap.getWidth();
1200        final int dh = outBitmap.getHeight();
1201
1202        canvas.save();
1203        canvas.scale(((float)dw)/vw, ((float)dh)/vh);
1204        view.draw(canvas);
1205        canvas.restore();
1206
1207        return true;
1208    }
1209
1210    /**
1211     * Generate a new description for this activity.  This method is called
1212     * before pausing the activity and can, if desired, return some textual
1213     * description of its current state to be displayed to the user.
1214     *
1215     * <p>The default implementation returns null, which will cause you to
1216     * inherit the description from the previous activity.  If all activities
1217     * return null, generally the label of the top activity will be used as the
1218     * description.
1219     *
1220     * @return A description of what the user is doing.  It should be short and
1221     *         sweet (only a few words).
1222     *
1223     * @see #onCreateThumbnail
1224     * @see #onSaveInstanceState
1225     * @see #onPause
1226     */
1227    public CharSequence onCreateDescription() {
1228        return null;
1229    }
1230
1231    /**
1232     * Called when you are no longer visible to the user.  You will next
1233     * receive either {@link #onRestart}, {@link #onDestroy}, or nothing,
1234     * depending on later user activity.
1235     *
1236     * <p>Note that this method may never be called, in low memory situations
1237     * where the system does not have enough memory to keep your activity's
1238     * process running after its {@link #onPause} method is called.
1239     *
1240     * <p><em>Derived classes must call through to the super class's
1241     * implementation of this method.  If they do not, an exception will be
1242     * thrown.</em></p>
1243     *
1244     * @see #onRestart
1245     * @see #onResume
1246     * @see #onSaveInstanceState
1247     * @see #onDestroy
1248     */
1249    protected void onStop() {
1250        mCalled = true;
1251    }
1252
1253    /**
1254     * Perform any final cleanup before an activity is destroyed.  This can
1255     * happen either because the activity is finishing (someone called
1256     * {@link #finish} on it, or because the system is temporarily destroying
1257     * this instance of the activity to save space.  You can distinguish
1258     * between these two scenarios with the {@link #isFinishing} method.
1259     *
1260     * <p><em>Note: do not count on this method being called as a place for
1261     * saving data! For example, if an activity is editing data in a content
1262     * provider, those edits should be committed in either {@link #onPause} or
1263     * {@link #onSaveInstanceState}, not here.</em> This method is usually implemented to
1264     * free resources like threads that are associated with an activity, so
1265     * that a destroyed activity does not leave such things around while the
1266     * rest of its application is still running.  There are situations where
1267     * the system will simply kill the activity's hosting process without
1268     * calling this method (or any others) in it, so it should not be used to
1269     * do things that are intended to remain around after the process goes
1270     * away.
1271     *
1272     * <p><em>Derived classes must call through to the super class's
1273     * implementation of this method.  If they do not, an exception will be
1274     * thrown.</em></p>
1275     *
1276     * @see #onPause
1277     * @see #onStop
1278     * @see #finish
1279     * @see #isFinishing
1280     */
1281    protected void onDestroy() {
1282        mCalled = true;
1283
1284        // dismiss any dialogs we are managing.
1285        if (mManagedDialogs != null) {
1286
1287            final int numDialogs = mManagedDialogs.size();
1288            for (int i = 0; i < numDialogs; i++) {
1289                final Dialog dialog = mManagedDialogs.valueAt(i);
1290                if (dialog.isShowing()) {
1291                    dialog.dismiss();
1292                }
1293            }
1294        }
1295
1296        // close any cursors we are managing.
1297        int numCursors = mManagedCursors.size();
1298        for (int i = 0; i < numCursors; i++) {
1299            ManagedCursor c = mManagedCursors.get(i);
1300            if (c != null) {
1301                c.mCursor.close();
1302            }
1303        }
1304    }
1305
1306    /**
1307     * Called by the system when the device configuration changes while your
1308     * activity is running.  Note that this will <em>only</em> be called if
1309     * you have selected configurations you would like to handle with the
1310     * {@link android.R.attr#configChanges} attribute in your manifest.  If
1311     * any configuration change occurs that is not selected to be reported
1312     * by that attribute, then instead of reporting it the system will stop
1313     * and restart the activity (to have it launched with the new
1314     * configuration).
1315     *
1316     * <p>At the time that this function has been called, your Resources
1317     * object will have been updated to return resource values matching the
1318     * new configuration.
1319     *
1320     * @param newConfig The new device configuration.
1321     */
1322    public void onConfigurationChanged(Configuration newConfig) {
1323        mCalled = true;
1324
1325        if (mWindow != null) {
1326            // Pass the configuration changed event to the window
1327            mWindow.onConfigurationChanged(newConfig);
1328        }
1329    }
1330
1331    /**
1332     * If this activity is being destroyed because it can not handle a
1333     * configuration parameter being changed (and thus its
1334     * {@link #onConfigurationChanged(Configuration)} method is
1335     * <em>not</em> being called), then you can use this method to discover
1336     * the set of changes that have occurred while in the process of being
1337     * destroyed.  Note that there is no guarantee that these will be
1338     * accurate (other changes could have happened at any time), so you should
1339     * only use this as an optimization hint.
1340     *
1341     * @return Returns a bit field of the configuration parameters that are
1342     * changing, as defined by the {@link android.content.res.Configuration}
1343     * class.
1344     */
1345    public int getChangingConfigurations() {
1346        return mConfigChangeFlags;
1347    }
1348
1349    /**
1350     * Retrieve the non-configuration instance data that was previously
1351     * returned by {@link #onRetainNonConfigurationInstance()}.  This will
1352     * be available from the initial {@link #onCreate} and
1353     * {@link #onStart} calls to the new instance, allowing you to extract
1354     * any useful dynamic state from the previous instance.
1355     *
1356     * <p>Note that the data you retrieve here should <em>only</em> be used
1357     * as an optimization for handling configuration changes.  You should always
1358     * be able to handle getting a null pointer back, and an activity must
1359     * still be able to restore itself to its previous state (through the
1360     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1361     * function returns null.
1362     *
1363     * @return Returns the object previously returned by
1364     * {@link #onRetainNonConfigurationInstance()}.
1365     */
1366    public Object getLastNonConfigurationInstance() {
1367        return mLastNonConfigurationInstance;
1368    }
1369
1370    /**
1371     * Called by the system, as part of destroying an
1372     * activity due to a configuration change, when it is known that a new
1373     * instance will immediately be created for the new configuration.  You
1374     * can return any object you like here, including the activity instance
1375     * itself, which can later be retrieved by calling
1376     * {@link #getLastNonConfigurationInstance()} in the new activity
1377     * instance.
1378     *
1379     * <p>This function is called purely as an optimization, and you must
1380     * not rely on it being called.  When it is called, a number of guarantees
1381     * will be made to help optimize configuration switching:
1382     * <ul>
1383     * <li> The function will be called between {@link #onStop} and
1384     * {@link #onDestroy}.
1385     * <li> A new instance of the activity will <em>always</em> be immediately
1386     * created after this one's {@link #onDestroy()} is called.
1387     * <li> The object you return here will <em>always</em> be available from
1388     * the {@link #getLastNonConfigurationInstance()} method of the following
1389     * activity instance as described there.
1390     * </ul>
1391     *
1392     * <p>These guarantees are designed so that an activity can use this API
1393     * to propagate extensive state from the old to new activity instance, from
1394     * loaded bitmaps, to network connections, to evenly actively running
1395     * threads.  Note that you should <em>not</em> propagate any data that
1396     * may change based on the configuration, including any data loaded from
1397     * resources such as strings, layouts, or drawables.
1398     *
1399     * @return Return any Object holding the desired state to propagate to the
1400     * next activity instance.
1401     */
1402    public Object onRetainNonConfigurationInstance() {
1403        return null;
1404    }
1405
1406    /**
1407     * Retrieve the non-configuration instance data that was previously
1408     * returned by {@link #onRetainNonConfigurationChildInstances()}.  This will
1409     * be available from the initial {@link #onCreate} and
1410     * {@link #onStart} calls to the new instance, allowing you to extract
1411     * any useful dynamic state from the previous instance.
1412     *
1413     * <p>Note that the data you retrieve here should <em>only</em> be used
1414     * as an optimization for handling configuration changes.  You should always
1415     * be able to handle getting a null pointer back, and an activity must
1416     * still be able to restore itself to its previous state (through the
1417     * normal {@link #onSaveInstanceState(Bundle)} mechanism) even if this
1418     * function returns null.
1419     *
1420     * @return Returns the object previously returned by
1421     * {@link #onRetainNonConfigurationChildInstances()}
1422     */
1423    HashMap<String,Object> getLastNonConfigurationChildInstances() {
1424        return mLastNonConfigurationChildInstances;
1425    }
1426
1427    /**
1428     * This method is similar to {@link #onRetainNonConfigurationInstance()} except that
1429     * it should return either a mapping from  child activity id strings to arbitrary objects,
1430     * or null.  This method is intended to be used by Activity framework subclasses that control a
1431     * set of child activities, such as ActivityGroup.  The same guarantees and restrictions apply
1432     * as for {@link #onRetainNonConfigurationInstance()}.  The default implementation returns null.
1433     */
1434    HashMap<String,Object> onRetainNonConfigurationChildInstances() {
1435        return null;
1436    }
1437
1438    public void onLowMemory() {
1439        mCalled = true;
1440    }
1441
1442    /**
1443     * Wrapper around
1444     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1445     * that gives the resulting {@link Cursor} to call
1446     * {@link #startManagingCursor} so that the activity will manage its
1447     * lifecycle for you.
1448     *
1449     * @param uri The URI of the content provider to query.
1450     * @param projection List of columns to return.
1451     * @param selection SQL WHERE clause.
1452     * @param sortOrder SQL ORDER BY clause.
1453     *
1454     * @return The Cursor that was returned by query().
1455     *
1456     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1457     * @see #startManagingCursor
1458     * @hide
1459     */
1460    public final Cursor managedQuery(Uri uri,
1461                                     String[] projection,
1462                                     String selection,
1463                                     String sortOrder)
1464    {
1465        Cursor c = getContentResolver().query(uri, projection, selection, null, sortOrder);
1466        if (c != null) {
1467            startManagingCursor(c);
1468        }
1469        return c;
1470    }
1471
1472    /**
1473     * Wrapper around
1474     * {@link ContentResolver#query(android.net.Uri , String[], String, String[], String)}
1475     * that gives the resulting {@link Cursor} to call
1476     * {@link #startManagingCursor} so that the activity will manage its
1477     * lifecycle for you.
1478     *
1479     * @param uri The URI of the content provider to query.
1480     * @param projection List of columns to return.
1481     * @param selection SQL WHERE clause.
1482     * @param selectionArgs The arguments to selection, if any ?s are pesent
1483     * @param sortOrder SQL ORDER BY clause.
1484     *
1485     * @return The Cursor that was returned by query().
1486     *
1487     * @see ContentResolver#query(android.net.Uri , String[], String, String[], String)
1488     * @see #startManagingCursor
1489     */
1490    public final Cursor managedQuery(Uri uri,
1491                                     String[] projection,
1492                                     String selection,
1493                                     String[] selectionArgs,
1494                                     String sortOrder)
1495    {
1496        Cursor c = getContentResolver().query(uri, projection, selection, selectionArgs, sortOrder);
1497        if (c != null) {
1498            startManagingCursor(c);
1499        }
1500        return c;
1501    }
1502
1503    /**
1504     * Wrapper around {@link Cursor#commitUpdates()} that takes care of noting
1505     * that the Cursor needs to be requeried.  You can call this method in
1506     * {@link #onPause} or {@link #onStop} to have the system call
1507     * {@link Cursor#requery} for you if the activity is later resumed.  This
1508     * allows you to avoid determing when to do the requery yourself (which is
1509     * required for the Cursor to see any data changes that were committed with
1510     * it).
1511     *
1512     * @param c The Cursor whose changes are to be committed.
1513     *
1514     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
1515     * @see #startManagingCursor
1516     * @see Cursor#commitUpdates()
1517     * @see Cursor#requery
1518     * @hide
1519     */
1520    @Deprecated
1521    public void managedCommitUpdates(Cursor c) {
1522        synchronized (mManagedCursors) {
1523            final int N = mManagedCursors.size();
1524            for (int i=0; i<N; i++) {
1525                ManagedCursor mc = mManagedCursors.get(i);
1526                if (mc.mCursor == c) {
1527                    c.commitUpdates();
1528                    mc.mUpdated = true;
1529                    return;
1530                }
1531            }
1532            throw new RuntimeException(
1533                "Cursor " + c + " is not currently managed");
1534        }
1535    }
1536
1537    /**
1538     * This method allows the activity to take care of managing the given
1539     * {@link Cursor}'s lifecycle for you based on the activity's lifecycle.
1540     * That is, when the activity is stopped it will automatically call
1541     * {@link Cursor#deactivate} on the given Cursor, and when it is later restarted
1542     * it will call {@link Cursor#requery} for you.  When the activity is
1543     * destroyed, all managed Cursors will be closed automatically.
1544     *
1545     * @param c The Cursor to be managed.
1546     *
1547     * @see #managedQuery(android.net.Uri , String[], String, String[], String)
1548     * @see #stopManagingCursor
1549     */
1550    public void startManagingCursor(Cursor c) {
1551        synchronized (mManagedCursors) {
1552            mManagedCursors.add(new ManagedCursor(c));
1553        }
1554    }
1555
1556    /**
1557     * Given a Cursor that was previously given to
1558     * {@link #startManagingCursor}, stop the activity's management of that
1559     * cursor.
1560     *
1561     * @param c The Cursor that was being managed.
1562     *
1563     * @see #startManagingCursor
1564     */
1565    public void stopManagingCursor(Cursor c) {
1566        synchronized (mManagedCursors) {
1567            final int N = mManagedCursors.size();
1568            for (int i=0; i<N; i++) {
1569                ManagedCursor mc = mManagedCursors.get(i);
1570                if (mc.mCursor == c) {
1571                    mManagedCursors.remove(i);
1572                    break;
1573                }
1574            }
1575        }
1576    }
1577
1578    /**
1579     * Control whether this activity is required to be persistent.  By default
1580     * activities are not persistent; setting this to true will prevent the
1581     * system from stopping this activity or its process when running low on
1582     * resources.
1583     *
1584     * <p><em>You should avoid using this method</em>, it has severe negative
1585     * consequences on how well the system can manage its resources.  A better
1586     * approach is to implement an application service that you control with
1587     * {@link Context#startService} and {@link Context#stopService}.
1588     *
1589     * @param isPersistent Control whether the current activity must be
1590     *                     persistent, true if so, false for the normal
1591     *                     behavior.
1592     */
1593    public void setPersistent(boolean isPersistent) {
1594        if (mParent == null) {
1595            try {
1596                ActivityManagerNative.getDefault()
1597                    .setPersistent(mToken, isPersistent);
1598            } catch (RemoteException e) {
1599                // Empty
1600            }
1601        } else {
1602            throw new RuntimeException("setPersistent() not yet supported for embedded activities");
1603        }
1604    }
1605
1606    /**
1607     * Finds a view that was identified by the id attribute from the XML that
1608     * was processed in {@link #onCreate}.
1609     *
1610     * @return The view if found or null otherwise.
1611     */
1612    public View findViewById(int id) {
1613        return getWindow().findViewById(id);
1614    }
1615
1616    /**
1617     * Set the activity content from a layout resource.  The resource will be
1618     * inflated, adding all top-level views to the activity.
1619     *
1620     * @param layoutResID Resource ID to be inflated.
1621     */
1622    public void setContentView(int layoutResID) {
1623        getWindow().setContentView(layoutResID);
1624    }
1625
1626    /**
1627     * Set the activity content to an explicit view.  This view is placed
1628     * directly into the activity's view hierarchy.  It can itself be a complex
1629     * view hierarhcy.
1630     *
1631     * @param view The desired content to display.
1632     */
1633    public void setContentView(View view) {
1634        getWindow().setContentView(view);
1635    }
1636
1637    /**
1638     * Set the activity content to an explicit view.  This view is placed
1639     * directly into the activity's view hierarchy.  It can itself be a complex
1640     * view hierarhcy.
1641     *
1642     * @param view The desired content to display.
1643     * @param params Layout parameters for the view.
1644     */
1645    public void setContentView(View view, ViewGroup.LayoutParams params) {
1646        getWindow().setContentView(view, params);
1647    }
1648
1649    /**
1650     * Add an additional content view to the activity.  Added after any existing
1651     * ones in the activity -- existing views are NOT removed.
1652     *
1653     * @param view The desired content to display.
1654     * @param params Layout parameters for the view.
1655     */
1656    public void addContentView(View view, ViewGroup.LayoutParams params) {
1657        getWindow().addContentView(view, params);
1658    }
1659
1660    /**
1661     * Use with {@link #setDefaultKeyMode} to turn off default handling of
1662     * keys.
1663     *
1664     * @see #setDefaultKeyMode
1665     */
1666    static public final int DEFAULT_KEYS_DISABLE = 0;
1667    /**
1668     * Use with {@link #setDefaultKeyMode} to launch the dialer during default
1669     * key handling.
1670     *
1671     * @see #setDefaultKeyMode
1672     */
1673    static public final int DEFAULT_KEYS_DIALER = 1;
1674    /**
1675     * Use with {@link #setDefaultKeyMode} to execute a menu shortcut in
1676     * default key handling.
1677     *
1678     * <p>That is, the user does not need to hold down the menu key to execute menu shortcuts.
1679     *
1680     * @see #setDefaultKeyMode
1681     */
1682    static public final int DEFAULT_KEYS_SHORTCUT = 2;
1683    /**
1684     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1685     * will start an application-defined search.  (If the application or activity does not
1686     * actually define a search, the the keys will be ignored.)
1687     *
1688     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1689     *
1690     * @see #setDefaultKeyMode
1691     */
1692    static public final int DEFAULT_KEYS_SEARCH_LOCAL = 3;
1693
1694    /**
1695     * Use with {@link #setDefaultKeyMode} to specify that unhandled keystrokes
1696     * will start a global search (typically web search, but some platforms may define alternate
1697     * methods for global search)
1698     *
1699     * <p>See {@link android.app.SearchManager android.app.SearchManager} for more details.
1700     *
1701     * @see #setDefaultKeyMode
1702     */
1703    static public final int DEFAULT_KEYS_SEARCH_GLOBAL = 4;
1704
1705    /**
1706     * Select the default key handling for this activity.  This controls what
1707     * will happen to key events that are not otherwise handled.  The default
1708     * mode ({@link #DEFAULT_KEYS_DISABLE}) will simply drop them on the
1709     * floor. Other modes allow you to launch the dialer
1710     * ({@link #DEFAULT_KEYS_DIALER}), execute a shortcut in your options
1711     * menu without requiring the menu key be held down
1712     * ({@link #DEFAULT_KEYS_SHORTCUT}), or launch a search ({@link #DEFAULT_KEYS_SEARCH_LOCAL}
1713     * and {@link #DEFAULT_KEYS_SEARCH_GLOBAL}).
1714     *
1715     * <p>Note that the mode selected here does not impact the default
1716     * handling of system keys, such as the "back" and "menu" keys, and your
1717     * activity and its views always get a first chance to receive and handle
1718     * all application keys.
1719     *
1720     * @param mode The desired default key mode constant.
1721     *
1722     * @see #DEFAULT_KEYS_DISABLE
1723     * @see #DEFAULT_KEYS_DIALER
1724     * @see #DEFAULT_KEYS_SHORTCUT
1725     * @see #DEFAULT_KEYS_SEARCH_LOCAL
1726     * @see #DEFAULT_KEYS_SEARCH_GLOBAL
1727     * @see #onKeyDown
1728     */
1729    public final void setDefaultKeyMode(int mode) {
1730        mDefaultKeyMode = mode;
1731
1732        // Some modes use a SpannableStringBuilder to track & dispatch input events
1733        // This list must remain in sync with the switch in onKeyDown()
1734        switch (mode) {
1735        case DEFAULT_KEYS_DISABLE:
1736        case DEFAULT_KEYS_SHORTCUT:
1737            mDefaultKeySsb = null;      // not used in these modes
1738            break;
1739        case DEFAULT_KEYS_DIALER:
1740        case DEFAULT_KEYS_SEARCH_LOCAL:
1741        case DEFAULT_KEYS_SEARCH_GLOBAL:
1742            mDefaultKeySsb = new SpannableStringBuilder();
1743            Selection.setSelection(mDefaultKeySsb,0);
1744            break;
1745        default:
1746            throw new IllegalArgumentException();
1747        }
1748    }
1749
1750    /**
1751     * Called when a key was pressed down and not handled by any of the views
1752     * inside of the activity. So, for example, key presses while the cursor
1753     * is inside a TextView will not trigger the event (unless it is a navigation
1754     * to another object) because TextView handles its own key presses.
1755     *
1756     * <p>If the focused view didn't want this event, this method is called.
1757     *
1758     * <p>The default implementation takes care of {@link KeyEvent#KEYCODE_BACK}
1759     * by calling {@link #onBackPressed()}, though the behavior varies based
1760     * on the application compatibility mode: for
1761     * {@link android.os.Build.VERSION_CODES#ECLAIR} or later applications,
1762     * it will set up the dispatch to call {@link #onKeyUp} where the action
1763     * will be performed; for earlier applications, it will perform the
1764     * action immediately in on-down, as those versions of the platform
1765     * behaved.
1766     *
1767     * <p>Other additional default key handling may be performed
1768     * if configured with {@link #setDefaultKeyMode}.
1769     *
1770     * @return Return <code>true</code> to prevent this event from being propagated
1771     * further, or <code>false</code> to indicate that you have not handled
1772     * this event and it should continue to be propagated.
1773     * @see #onKeyUp
1774     * @see android.view.KeyEvent
1775     */
1776    public boolean onKeyDown(int keyCode, KeyEvent event)  {
1777        if (keyCode == KeyEvent.KEYCODE_BACK) {
1778            if (getApplicationInfo().targetSdkVersion
1779                    >= Build.VERSION_CODES.ECLAIR) {
1780                event.startTracking();
1781            } else {
1782                onBackPressed();
1783            }
1784            return true;
1785        }
1786
1787        if (mDefaultKeyMode == DEFAULT_KEYS_DISABLE) {
1788            return false;
1789        } else if (mDefaultKeyMode == DEFAULT_KEYS_SHORTCUT) {
1790            if (getWindow().performPanelShortcut(Window.FEATURE_OPTIONS_PANEL,
1791                    keyCode, event, Menu.FLAG_ALWAYS_PERFORM_CLOSE)) {
1792                return true;
1793            }
1794            return false;
1795        } else {
1796            // Common code for DEFAULT_KEYS_DIALER & DEFAULT_KEYS_SEARCH_*
1797            boolean clearSpannable = false;
1798            boolean handled;
1799            if ((event.getRepeatCount() != 0) || event.isSystem()) {
1800                clearSpannable = true;
1801                handled = false;
1802            } else {
1803                handled = TextKeyListener.getInstance().onKeyDown(
1804                        null, mDefaultKeySsb, keyCode, event);
1805                if (handled && mDefaultKeySsb.length() > 0) {
1806                    // something useable has been typed - dispatch it now.
1807
1808                    final String str = mDefaultKeySsb.toString();
1809                    clearSpannable = true;
1810
1811                    switch (mDefaultKeyMode) {
1812                    case DEFAULT_KEYS_DIALER:
1813                        Intent intent = new Intent(Intent.ACTION_DIAL,  Uri.parse("tel:" + str));
1814                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
1815                        startActivity(intent);
1816                        break;
1817                    case DEFAULT_KEYS_SEARCH_LOCAL:
1818                        startSearch(str, false, null, false);
1819                        break;
1820                    case DEFAULT_KEYS_SEARCH_GLOBAL:
1821                        startSearch(str, false, null, true);
1822                        break;
1823                    }
1824                }
1825            }
1826            if (clearSpannable) {
1827                mDefaultKeySsb.clear();
1828                mDefaultKeySsb.clearSpans();
1829                Selection.setSelection(mDefaultKeySsb,0);
1830            }
1831            return handled;
1832        }
1833    }
1834
1835    /**
1836     * Default implementation of {@link KeyEvent.Callback#onKeyLongPress(int, KeyEvent)
1837     * KeyEvent.Callback.onKeyLongPress()}: always returns false (doesn't handle
1838     * the event).
1839     */
1840    public boolean onKeyLongPress(int keyCode, KeyEvent event) {
1841        return false;
1842    }
1843
1844    /**
1845     * Called when a key was released and not handled by any of the views
1846     * inside of the activity. So, for example, key presses while the cursor
1847     * is inside a TextView will not trigger the event (unless it is a navigation
1848     * to another object) because TextView handles its own key presses.
1849     *
1850     * <p>The default implementation handles KEYCODE_BACK to stop the activity
1851     * and go back.
1852     *
1853     * @return Return <code>true</code> to prevent this event from being propagated
1854     * further, or <code>false</code> to indicate that you have not handled
1855     * this event and it should continue to be propagated.
1856     * @see #onKeyDown
1857     * @see KeyEvent
1858     */
1859    public boolean onKeyUp(int keyCode, KeyEvent event) {
1860        if (getApplicationInfo().targetSdkVersion
1861                >= Build.VERSION_CODES.ECLAIR) {
1862            if (keyCode == KeyEvent.KEYCODE_BACK && event.isTracking()
1863                    && !event.isCanceled()) {
1864                onBackPressed();
1865                return true;
1866            }
1867        }
1868        return false;
1869    }
1870
1871    /**
1872     * Default implementation of {@link KeyEvent.Callback#onKeyMultiple(int, int, KeyEvent)
1873     * KeyEvent.Callback.onKeyMultiple()}: always returns false (doesn't handle
1874     * the event).
1875     */
1876    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
1877        return false;
1878    }
1879
1880    /**
1881     * Called when the activity has detected the user's press of the back
1882     * key.  The default implementation simply finishes the current activity,
1883     * but you can override this to do whatever you want.
1884     */
1885    public void onBackPressed() {
1886        finish();
1887    }
1888
1889    /**
1890     * Called when a touch screen event was not handled by any of the views
1891     * under it.  This is most useful to process touch events that happen
1892     * outside of your window bounds, where there is no view to receive it.
1893     *
1894     * @param event The touch screen event being processed.
1895     *
1896     * @return Return true if you have consumed the event, false if you haven't.
1897     * The default implementation always returns false.
1898     */
1899    public boolean onTouchEvent(MotionEvent event) {
1900        return false;
1901    }
1902
1903    /**
1904     * Called when the trackball was moved and not handled by any of the
1905     * views inside of the activity.  So, for example, if the trackball moves
1906     * while focus is on a button, you will receive a call here because
1907     * buttons do not normally do anything with trackball events.  The call
1908     * here happens <em>before</em> trackball movements are converted to
1909     * DPAD key events, which then get sent back to the view hierarchy, and
1910     * will be processed at the point for things like focus navigation.
1911     *
1912     * @param event The trackball event being processed.
1913     *
1914     * @return Return true if you have consumed the event, false if you haven't.
1915     * The default implementation always returns false.
1916     */
1917    public boolean onTrackballEvent(MotionEvent event) {
1918        return false;
1919    }
1920
1921    /**
1922     * Called whenever a key, touch, or trackball event is dispatched to the
1923     * activity.  Implement this method if you wish to know that the user has
1924     * interacted with the device in some way while your activity is running.
1925     * This callback and {@link #onUserLeaveHint} are intended to help
1926     * activities manage status bar notifications intelligently; specifically,
1927     * for helping activities determine the proper time to cancel a notfication.
1928     *
1929     * <p>All calls to your activity's {@link #onUserLeaveHint} callback will
1930     * be accompanied by calls to {@link #onUserInteraction}.  This
1931     * ensures that your activity will be told of relevant user activity such
1932     * as pulling down the notification pane and touching an item there.
1933     *
1934     * <p>Note that this callback will be invoked for the touch down action
1935     * that begins a touch gesture, but may not be invoked for the touch-moved
1936     * and touch-up actions that follow.
1937     *
1938     * @see #onUserLeaveHint()
1939     */
1940    public void onUserInteraction() {
1941    }
1942
1943    public void onWindowAttributesChanged(WindowManager.LayoutParams params) {
1944        // Update window manager if: we have a view, that view is
1945        // attached to its parent (which will be a RootView), and
1946        // this activity is not embedded.
1947        if (mParent == null) {
1948            View decor = mDecor;
1949            if (decor != null && decor.getParent() != null) {
1950                getWindowManager().updateViewLayout(decor, params);
1951            }
1952        }
1953    }
1954
1955    public void onContentChanged() {
1956    }
1957
1958    /**
1959     * Called when the current {@link Window} of the activity gains or loses
1960     * focus.  This is the best indicator of whether this activity is visible
1961     * to the user.  The default implementation clears the key tracking
1962     * state, so should always be called.
1963     *
1964     * <p>Note that this provides information about global focus state, which
1965     * is managed independently of activity lifecycles.  As such, while focus
1966     * changes will generally have some relation to lifecycle changes (an
1967     * activity that is stopped will not generally get window focus), you
1968     * should not rely on any particular order between the callbacks here and
1969     * those in the other lifecycle methods such as {@link #onResume}.
1970     *
1971     * <p>As a general rule, however, a resumed activity will have window
1972     * focus...  unless it has displayed other dialogs or popups that take
1973     * input focus, in which case the activity itself will not have focus
1974     * when the other windows have it.  Likewise, the system may display
1975     * system-level windows (such as the status bar notification panel or
1976     * a system alert) which will temporarily take window input focus without
1977     * pausing the foreground activity.
1978     *
1979     * @param hasFocus Whether the window of this activity has focus.
1980     *
1981     * @see #hasWindowFocus()
1982     * @see #onResume
1983     * @see View#onWindowFocusChanged(boolean)
1984     */
1985    public void onWindowFocusChanged(boolean hasFocus) {
1986    }
1987
1988    /**
1989     * Called when the main window associated with the activity has been
1990     * attached to the window manager.
1991     * See {@link View#onAttachedToWindow() View.onAttachedToWindow()}
1992     * for more information.
1993     * @see View#onAttachedToWindow
1994     */
1995    public void onAttachedToWindow() {
1996    }
1997
1998    /**
1999     * Called when the main window associated with the activity has been
2000     * detached from the window manager.
2001     * See {@link View#onDetachedFromWindow() View.onDetachedFromWindow()}
2002     * for more information.
2003     * @see View#onDetachedFromWindow
2004     */
2005    public void onDetachedFromWindow() {
2006    }
2007
2008    /**
2009     * Returns true if this activity's <em>main</em> window currently has window focus.
2010     * Note that this is not the same as the view itself having focus.
2011     *
2012     * @return True if this activity's main window currently has window focus.
2013     *
2014     * @see #onWindowAttributesChanged(android.view.WindowManager.LayoutParams)
2015     */
2016    public boolean hasWindowFocus() {
2017        Window w = getWindow();
2018        if (w != null) {
2019            View d = w.getDecorView();
2020            if (d != null) {
2021                return d.hasWindowFocus();
2022            }
2023        }
2024        return false;
2025    }
2026
2027    /**
2028     * Called to process key events.  You can override this to intercept all
2029     * key events before they are dispatched to the window.  Be sure to call
2030     * this implementation for key events that should be handled normally.
2031     *
2032     * @param event The key event.
2033     *
2034     * @return boolean Return true if this event was consumed.
2035     */
2036    public boolean dispatchKeyEvent(KeyEvent event) {
2037        onUserInteraction();
2038        Window win = getWindow();
2039        if (win.superDispatchKeyEvent(event)) {
2040            return true;
2041        }
2042        View decor = mDecor;
2043        if (decor == null) decor = win.getDecorView();
2044        return event.dispatch(this, decor != null
2045                ? decor.getKeyDispatcherState() : null, this);
2046    }
2047
2048    /**
2049     * Called to process touch screen events.  You can override this to
2050     * intercept all touch screen events before they are dispatched to the
2051     * window.  Be sure to call this implementation for touch screen events
2052     * that should be handled normally.
2053     *
2054     * @param ev The touch screen event.
2055     *
2056     * @return boolean Return true if this event was consumed.
2057     */
2058    public boolean dispatchTouchEvent(MotionEvent ev) {
2059        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
2060            onUserInteraction();
2061        }
2062        if (getWindow().superDispatchTouchEvent(ev)) {
2063            return true;
2064        }
2065        return onTouchEvent(ev);
2066    }
2067
2068    /**
2069     * Called to process trackball events.  You can override this to
2070     * intercept all trackball events before they are dispatched to the
2071     * window.  Be sure to call this implementation for trackball events
2072     * that should be handled normally.
2073     *
2074     * @param ev The trackball event.
2075     *
2076     * @return boolean Return true if this event was consumed.
2077     */
2078    public boolean dispatchTrackballEvent(MotionEvent ev) {
2079        onUserInteraction();
2080        if (getWindow().superDispatchTrackballEvent(ev)) {
2081            return true;
2082        }
2083        return onTrackballEvent(ev);
2084    }
2085
2086    public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) {
2087        event.setClassName(getClass().getName());
2088        event.setPackageName(getPackageName());
2089
2090        LayoutParams params = getWindow().getAttributes();
2091        boolean isFullScreen = (params.width == LayoutParams.MATCH_PARENT) &&
2092            (params.height == LayoutParams.MATCH_PARENT);
2093        event.setFullScreen(isFullScreen);
2094
2095        CharSequence title = getTitle();
2096        if (!TextUtils.isEmpty(title)) {
2097           event.getText().add(title);
2098        }
2099
2100        return true;
2101    }
2102
2103    /**
2104     * Default implementation of
2105     * {@link android.view.Window.Callback#onCreatePanelView}
2106     * for activities. This
2107     * simply returns null so that all panel sub-windows will have the default
2108     * menu behavior.
2109     */
2110    public View onCreatePanelView(int featureId) {
2111        return null;
2112    }
2113
2114    /**
2115     * Default implementation of
2116     * {@link android.view.Window.Callback#onCreatePanelMenu}
2117     * for activities.  This calls through to the new
2118     * {@link #onCreateOptionsMenu} method for the
2119     * {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2120     * so that subclasses of Activity don't need to deal with feature codes.
2121     */
2122    public boolean onCreatePanelMenu(int featureId, Menu menu) {
2123        if (featureId == Window.FEATURE_OPTIONS_PANEL) {
2124            return onCreateOptionsMenu(menu);
2125        }
2126        return false;
2127    }
2128
2129    /**
2130     * Default implementation of
2131     * {@link android.view.Window.Callback#onPreparePanel}
2132     * for activities.  This
2133     * calls through to the new {@link #onPrepareOptionsMenu} method for the
2134     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2135     * panel, so that subclasses of
2136     * Activity don't need to deal with feature codes.
2137     */
2138    public boolean onPreparePanel(int featureId, View view, Menu menu) {
2139        if (featureId == Window.FEATURE_OPTIONS_PANEL && menu != null) {
2140            boolean goforit = onPrepareOptionsMenu(menu);
2141            return goforit && menu.hasVisibleItems();
2142        }
2143        return true;
2144    }
2145
2146    /**
2147     * {@inheritDoc}
2148     *
2149     * @return The default implementation returns true.
2150     */
2151    public boolean onMenuOpened(int featureId, Menu menu) {
2152        return true;
2153    }
2154
2155    /**
2156     * Default implementation of
2157     * {@link android.view.Window.Callback#onMenuItemSelected}
2158     * for activities.  This calls through to the new
2159     * {@link #onOptionsItemSelected} method for the
2160     * {@link android.view.Window#FEATURE_OPTIONS_PANEL}
2161     * panel, so that subclasses of
2162     * Activity don't need to deal with feature codes.
2163     */
2164    public boolean onMenuItemSelected(int featureId, MenuItem item) {
2165        switch (featureId) {
2166            case Window.FEATURE_OPTIONS_PANEL:
2167                // Put event logging here so it gets called even if subclass
2168                // doesn't call through to superclass's implmeentation of each
2169                // of these methods below
2170                EventLog.writeEvent(50000, 0, item.getTitleCondensed());
2171                return onOptionsItemSelected(item);
2172
2173            case Window.FEATURE_CONTEXT_MENU:
2174                EventLog.writeEvent(50000, 1, item.getTitleCondensed());
2175                return onContextItemSelected(item);
2176
2177            default:
2178                return false;
2179        }
2180    }
2181
2182    /**
2183     * Default implementation of
2184     * {@link android.view.Window.Callback#onPanelClosed(int, Menu)} for
2185     * activities. This calls through to {@link #onOptionsMenuClosed(Menu)}
2186     * method for the {@link android.view.Window#FEATURE_OPTIONS_PANEL} panel,
2187     * so that subclasses of Activity don't need to deal with feature codes.
2188     * For context menus ({@link Window#FEATURE_CONTEXT_MENU}), the
2189     * {@link #onContextMenuClosed(Menu)} will be called.
2190     */
2191    public void onPanelClosed(int featureId, Menu menu) {
2192        switch (featureId) {
2193            case Window.FEATURE_OPTIONS_PANEL:
2194                onOptionsMenuClosed(menu);
2195                break;
2196
2197            case Window.FEATURE_CONTEXT_MENU:
2198                onContextMenuClosed(menu);
2199                break;
2200        }
2201    }
2202
2203    /**
2204     * Initialize the contents of the Activity's standard options menu.  You
2205     * should place your menu items in to <var>menu</var>.
2206     *
2207     * <p>This is only called once, the first time the options menu is
2208     * displayed.  To update the menu every time it is displayed, see
2209     * {@link #onPrepareOptionsMenu}.
2210     *
2211     * <p>The default implementation populates the menu with standard system
2212     * menu items.  These are placed in the {@link Menu#CATEGORY_SYSTEM} group so that
2213     * they will be correctly ordered with application-defined menu items.
2214     * Deriving classes should always call through to the base implementation.
2215     *
2216     * <p>You can safely hold on to <var>menu</var> (and any items created
2217     * from it), making modifications to it as desired, until the next
2218     * time onCreateOptionsMenu() is called.
2219     *
2220     * <p>When you add items to the menu, you can implement the Activity's
2221     * {@link #onOptionsItemSelected} method to handle them there.
2222     *
2223     * @param menu The options menu in which you place your items.
2224     *
2225     * @return You must return true for the menu to be displayed;
2226     *         if you return false it will not be shown.
2227     *
2228     * @see #onPrepareOptionsMenu
2229     * @see #onOptionsItemSelected
2230     */
2231    public boolean onCreateOptionsMenu(Menu menu) {
2232        if (mParent != null) {
2233            return mParent.onCreateOptionsMenu(menu);
2234        }
2235        return true;
2236    }
2237
2238    /**
2239     * Prepare the Screen's standard options menu to be displayed.  This is
2240     * called right before the menu is shown, every time it is shown.  You can
2241     * use this method to efficiently enable/disable items or otherwise
2242     * dynamically modify the contents.
2243     *
2244     * <p>The default implementation updates the system menu items based on the
2245     * activity's state.  Deriving classes should always call through to the
2246     * base class implementation.
2247     *
2248     * @param menu The options menu as last shown or first initialized by
2249     *             onCreateOptionsMenu().
2250     *
2251     * @return You must return true for the menu to be displayed;
2252     *         if you return false it will not be shown.
2253     *
2254     * @see #onCreateOptionsMenu
2255     */
2256    public boolean onPrepareOptionsMenu(Menu menu) {
2257        if (mParent != null) {
2258            return mParent.onPrepareOptionsMenu(menu);
2259        }
2260        return true;
2261    }
2262
2263    /**
2264     * This hook is called whenever an item in your options menu is selected.
2265     * The default implementation simply returns false to have the normal
2266     * processing happen (calling the item's Runnable or sending a message to
2267     * its Handler as appropriate).  You can use this method for any items
2268     * for which you would like to do processing without those other
2269     * facilities.
2270     *
2271     * <p>Derived classes should call through to the base class for it to
2272     * perform the default menu handling.
2273     *
2274     * @param item The menu item that was selected.
2275     *
2276     * @return boolean Return false to allow normal menu processing to
2277     *         proceed, true to consume it here.
2278     *
2279     * @see #onCreateOptionsMenu
2280     */
2281    public boolean onOptionsItemSelected(MenuItem item) {
2282        if (mParent != null) {
2283            return mParent.onOptionsItemSelected(item);
2284        }
2285        return false;
2286    }
2287
2288    /**
2289     * This hook is called whenever the options menu is being closed (either by the user canceling
2290     * the menu with the back/menu button, or when an item is selected).
2291     *
2292     * @param menu The options menu as last shown or first initialized by
2293     *             onCreateOptionsMenu().
2294     */
2295    public void onOptionsMenuClosed(Menu menu) {
2296        if (mParent != null) {
2297            mParent.onOptionsMenuClosed(menu);
2298        }
2299    }
2300
2301    /**
2302     * Programmatically opens the options menu. If the options menu is already
2303     * open, this method does nothing.
2304     */
2305    public void openOptionsMenu() {
2306        mWindow.openPanel(Window.FEATURE_OPTIONS_PANEL, null);
2307    }
2308
2309    /**
2310     * Progammatically closes the options menu. If the options menu is already
2311     * closed, this method does nothing.
2312     */
2313    public void closeOptionsMenu() {
2314        mWindow.closePanel(Window.FEATURE_OPTIONS_PANEL);
2315    }
2316
2317    /**
2318     * Called when a context menu for the {@code view} is about to be shown.
2319     * Unlike {@link #onCreateOptionsMenu(Menu)}, this will be called every
2320     * time the context menu is about to be shown and should be populated for
2321     * the view (or item inside the view for {@link AdapterView} subclasses,
2322     * this can be found in the {@code menuInfo})).
2323     * <p>
2324     * Use {@link #onContextItemSelected(android.view.MenuItem)} to know when an
2325     * item has been selected.
2326     * <p>
2327     * It is not safe to hold onto the context menu after this method returns.
2328     * {@inheritDoc}
2329     */
2330    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
2331    }
2332
2333    /**
2334     * Registers a context menu to be shown for the given view (multiple views
2335     * can show the context menu). This method will set the
2336     * {@link OnCreateContextMenuListener} on the view to this activity, so
2337     * {@link #onCreateContextMenu(ContextMenu, View, ContextMenuInfo)} will be
2338     * called when it is time to show the context menu.
2339     *
2340     * @see #unregisterForContextMenu(View)
2341     * @param view The view that should show a context menu.
2342     */
2343    public void registerForContextMenu(View view) {
2344        view.setOnCreateContextMenuListener(this);
2345    }
2346
2347    /**
2348     * Prevents a context menu to be shown for the given view. This method will remove the
2349     * {@link OnCreateContextMenuListener} on the view.
2350     *
2351     * @see #registerForContextMenu(View)
2352     * @param view The view that should stop showing a context menu.
2353     */
2354    public void unregisterForContextMenu(View view) {
2355        view.setOnCreateContextMenuListener(null);
2356    }
2357
2358    /**
2359     * Programmatically opens the context menu for a particular {@code view}.
2360     * The {@code view} should have been added via
2361     * {@link #registerForContextMenu(View)}.
2362     *
2363     * @param view The view to show the context menu for.
2364     */
2365    public void openContextMenu(View view) {
2366        view.showContextMenu();
2367    }
2368
2369    /**
2370     * Programmatically closes the most recently opened context menu, if showing.
2371     */
2372    public void closeContextMenu() {
2373        mWindow.closePanel(Window.FEATURE_CONTEXT_MENU);
2374    }
2375
2376    /**
2377     * This hook is called whenever an item in a context menu is selected. The
2378     * default implementation simply returns false to have the normal processing
2379     * happen (calling the item's Runnable or sending a message to its Handler
2380     * as appropriate). You can use this method for any items for which you
2381     * would like to do processing without those other facilities.
2382     * <p>
2383     * Use {@link MenuItem#getMenuInfo()} to get extra information set by the
2384     * View that added this menu item.
2385     * <p>
2386     * Derived classes should call through to the base class for it to perform
2387     * the default menu handling.
2388     *
2389     * @param item The context menu item that was selected.
2390     * @return boolean Return false to allow normal context menu processing to
2391     *         proceed, true to consume it here.
2392     */
2393    public boolean onContextItemSelected(MenuItem item) {
2394        if (mParent != null) {
2395            return mParent.onContextItemSelected(item);
2396        }
2397        return false;
2398    }
2399
2400    /**
2401     * This hook is called whenever the context menu is being closed (either by
2402     * the user canceling the menu with the back/menu button, or when an item is
2403     * selected).
2404     *
2405     * @param menu The context menu that is being closed.
2406     */
2407    public void onContextMenuClosed(Menu menu) {
2408        if (mParent != null) {
2409            mParent.onContextMenuClosed(menu);
2410        }
2411    }
2412
2413    /**
2414     * Callback for creating dialogs that are managed (saved and restored) for you
2415     * by the activity.
2416     *
2417     * If you use {@link #showDialog(int)}, the activity will call through to
2418     * this method the first time, and hang onto it thereafter.  Any dialog
2419     * that is created by this method will automatically be saved and restored
2420     * for you, including whether it is showing.
2421     *
2422     * If you would like the activity to manage the saving and restoring dialogs
2423     * for you, you should override this method and handle any ids that are
2424     * passed to {@link #showDialog}.
2425     *
2426     * If you would like an opportunity to prepare your dialog before it is shown,
2427     * override {@link #onPrepareDialog(int, Dialog)}.
2428     *
2429     * @param id The id of the dialog.
2430     * @return The dialog
2431     *
2432     * @see #onPrepareDialog(int, Dialog)
2433     * @see #showDialog(int)
2434     * @see #dismissDialog(int)
2435     * @see #removeDialog(int)
2436     */
2437    protected Dialog onCreateDialog(int id) {
2438        return null;
2439    }
2440
2441    /**
2442     * Provides an opportunity to prepare a managed dialog before it is being
2443     * shown.
2444     * <p>
2445     * Override this if you need to update a managed dialog based on the state
2446     * of the application each time it is shown. For example, a time picker
2447     * dialog might want to be updated with the current time. You should call
2448     * through to the superclass's implementation. The default implementation
2449     * will set this Activity as the owner activity on the Dialog.
2450     *
2451     * @param id The id of the managed dialog.
2452     * @param dialog The dialog.
2453     * @see #onCreateDialog(int)
2454     * @see #showDialog(int)
2455     * @see #dismissDialog(int)
2456     * @see #removeDialog(int)
2457     */
2458    protected void onPrepareDialog(int id, Dialog dialog) {
2459        dialog.setOwnerActivity(this);
2460    }
2461
2462    /**
2463     * Show a dialog managed by this activity.  A call to {@link #onCreateDialog(int)}
2464     * will be made with the same id the first time this is called for a given
2465     * id.  From thereafter, the dialog will be automatically saved and restored.
2466     *
2467     * Each time a dialog is shown, {@link #onPrepareDialog(int, Dialog)} will
2468     * be made to provide an opportunity to do any timely preparation.
2469     *
2470     * @param id The id of the managed dialog.
2471     *
2472     * @see Dialog
2473     * @see #onCreateDialog(int)
2474     * @see #onPrepareDialog(int, Dialog)
2475     * @see #dismissDialog(int)
2476     * @see #removeDialog(int)
2477     */
2478    public final void showDialog(int id) {
2479        if (mManagedDialogs == null) {
2480            mManagedDialogs = new SparseArray<Dialog>();
2481        }
2482        Dialog dialog = mManagedDialogs.get(id);
2483        if (dialog == null) {
2484            dialog = createDialog(id, null);
2485            mManagedDialogs.put(id, dialog);
2486        }
2487
2488        onPrepareDialog(id, dialog);
2489        dialog.show();
2490    }
2491
2492    /**
2493     * Dismiss a dialog that was previously shown via {@link #showDialog(int)}.
2494     *
2495     * @param id The id of the managed dialog.
2496     *
2497     * @throws IllegalArgumentException if the id was not previously shown via
2498     *   {@link #showDialog(int)}.
2499     *
2500     * @see #onCreateDialog(int)
2501     * @see #onPrepareDialog(int, Dialog)
2502     * @see #showDialog(int)
2503     * @see #removeDialog(int)
2504     */
2505    public final void dismissDialog(int id) {
2506        if (mManagedDialogs == null) {
2507            throw missingDialog(id);
2508
2509        }
2510        final Dialog dialog = mManagedDialogs.get(id);
2511        if (dialog == null) {
2512            throw missingDialog(id);
2513        }
2514        dialog.dismiss();
2515    }
2516
2517    /**
2518     * Creates an exception to throw if a user passed in a dialog id that is
2519     * unexpected.
2520     */
2521    private IllegalArgumentException missingDialog(int id) {
2522        return new IllegalArgumentException("no dialog with id " + id + " was ever "
2523                + "shown via Activity#showDialog");
2524    }
2525
2526    /**
2527     * Removes any internal references to a dialog managed by this Activity.
2528     * If the dialog is showing, it will dismiss it as part of the clean up.
2529     *
2530     * This can be useful if you know that you will never show a dialog again and
2531     * want to avoid the overhead of saving and restoring it in the future.
2532     *
2533     * @param id The id of the managed dialog.
2534     *
2535     * @see #onCreateDialog(int)
2536     * @see #onPrepareDialog(int, Dialog)
2537     * @see #showDialog(int)
2538     * @see #dismissDialog(int)
2539     */
2540    public final void removeDialog(int id) {
2541
2542        if (mManagedDialogs == null) {
2543            return;
2544        }
2545
2546        final Dialog dialog = mManagedDialogs.get(id);
2547        if (dialog == null) {
2548            return;
2549        }
2550
2551        dialog.dismiss();
2552        mManagedDialogs.remove(id);
2553    }
2554
2555    /**
2556     * This hook is called when the user signals the desire to start a search.
2557     *
2558     * <p>You can use this function as a simple way to launch the search UI, in response to a
2559     * menu item, search button, or other widgets within your activity. Unless overidden,
2560     * calling this function is the same as calling
2561     * {@link #startSearch startSearch(null, false, null, false)}, which launches
2562     * search for the current activity as specified in its manifest, see {@link SearchManager}.
2563     *
2564     * <p>You can override this function to force global search, e.g. in response to a dedicated
2565     * search key, or to block search entirely (by simply returning false).
2566     *
2567     * @return Returns {@code true} if search launched, and {@code false} if activity blocks it.
2568     *         The default implementation always returns {@code true}.
2569     *
2570     * @see android.app.SearchManager
2571     */
2572    public boolean onSearchRequested() {
2573        startSearch(null, false, null, false);
2574        return true;
2575    }
2576
2577    /**
2578     * This hook is called to launch the search UI.
2579     *
2580     * <p>It is typically called from onSearchRequested(), either directly from
2581     * Activity.onSearchRequested() or from an overridden version in any given
2582     * Activity.  If your goal is simply to activate search, it is preferred to call
2583     * onSearchRequested(), which may have been overriden elsewhere in your Activity.  If your goal
2584     * is to inject specific data such as context data, it is preferred to <i>override</i>
2585     * onSearchRequested(), so that any callers to it will benefit from the override.
2586     *
2587     * @param initialQuery Any non-null non-empty string will be inserted as
2588     * pre-entered text in the search query box.
2589     * @param selectInitialQuery If true, the intial query will be preselected, which means that
2590     * any further typing will replace it.  This is useful for cases where an entire pre-formed
2591     * query is being inserted.  If false, the selection point will be placed at the end of the
2592     * inserted query.  This is useful when the inserted query is text that the user entered,
2593     * and the user would expect to be able to keep typing.  <i>This parameter is only meaningful
2594     * if initialQuery is a non-empty string.</i>
2595     * @param appSearchData An application can insert application-specific
2596     * context here, in order to improve quality or specificity of its own
2597     * searches.  This data will be returned with SEARCH intent(s).  Null if
2598     * no extra data is required.
2599     * @param globalSearch If false, this will only launch the search that has been specifically
2600     * defined by the application (which is usually defined as a local search).  If no default
2601     * search is defined in the current application or activity, global search will be launched.
2602     * If true, this will always launch a platform-global (e.g. web-based) search instead.
2603     *
2604     * @see android.app.SearchManager
2605     * @see #onSearchRequested
2606     */
2607    public void startSearch(String initialQuery, boolean selectInitialQuery,
2608            Bundle appSearchData, boolean globalSearch) {
2609        ensureSearchManager();
2610        mSearchManager.startSearch(initialQuery, selectInitialQuery, getComponentName(),
2611                        appSearchData, globalSearch);
2612    }
2613
2614    /**
2615     * Similar to {@link #startSearch}, but actually fires off the search query after invoking
2616     * the search dialog.  Made available for testing purposes.
2617     *
2618     * @param query The query to trigger.  If empty, the request will be ignored.
2619     * @param appSearchData An application can insert application-specific
2620     * context here, in order to improve quality or specificity of its own
2621     * searches.  This data will be returned with SEARCH intent(s).  Null if
2622     * no extra data is required.
2623     */
2624    public void triggerSearch(String query, Bundle appSearchData) {
2625        ensureSearchManager();
2626        mSearchManager.triggerSearch(query, getComponentName(), appSearchData);
2627    }
2628
2629    /**
2630     * Request that key events come to this activity. Use this if your
2631     * activity has no views with focus, but the activity still wants
2632     * a chance to process key events.
2633     *
2634     * @see android.view.Window#takeKeyEvents
2635     */
2636    public void takeKeyEvents(boolean get) {
2637        getWindow().takeKeyEvents(get);
2638    }
2639
2640    /**
2641     * Enable extended window features.  This is a convenience for calling
2642     * {@link android.view.Window#requestFeature getWindow().requestFeature()}.
2643     *
2644     * @param featureId The desired feature as defined in
2645     *                  {@link android.view.Window}.
2646     * @return Returns true if the requested feature is supported and now
2647     *         enabled.
2648     *
2649     * @see android.view.Window#requestFeature
2650     */
2651    public final boolean requestWindowFeature(int featureId) {
2652        return getWindow().requestFeature(featureId);
2653    }
2654
2655    /**
2656     * Convenience for calling
2657     * {@link android.view.Window#setFeatureDrawableResource}.
2658     */
2659    public final void setFeatureDrawableResource(int featureId, int resId) {
2660        getWindow().setFeatureDrawableResource(featureId, resId);
2661    }
2662
2663    /**
2664     * Convenience for calling
2665     * {@link android.view.Window#setFeatureDrawableUri}.
2666     */
2667    public final void setFeatureDrawableUri(int featureId, Uri uri) {
2668        getWindow().setFeatureDrawableUri(featureId, uri);
2669    }
2670
2671    /**
2672     * Convenience for calling
2673     * {@link android.view.Window#setFeatureDrawable(int, Drawable)}.
2674     */
2675    public final void setFeatureDrawable(int featureId, Drawable drawable) {
2676        getWindow().setFeatureDrawable(featureId, drawable);
2677    }
2678
2679    /**
2680     * Convenience for calling
2681     * {@link android.view.Window#setFeatureDrawableAlpha}.
2682     */
2683    public final void setFeatureDrawableAlpha(int featureId, int alpha) {
2684        getWindow().setFeatureDrawableAlpha(featureId, alpha);
2685    }
2686
2687    /**
2688     * Convenience for calling
2689     * {@link android.view.Window#getLayoutInflater}.
2690     */
2691    public LayoutInflater getLayoutInflater() {
2692        return getWindow().getLayoutInflater();
2693    }
2694
2695    /**
2696     * Returns a {@link MenuInflater} with this context.
2697     */
2698    public MenuInflater getMenuInflater() {
2699        return new MenuInflater(this);
2700    }
2701
2702    @Override
2703    protected void onApplyThemeResource(Resources.Theme theme, int resid,
2704            boolean first) {
2705        if (mParent == null) {
2706            super.onApplyThemeResource(theme, resid, first);
2707        } else {
2708            try {
2709                theme.setTo(mParent.getTheme());
2710            } catch (Exception e) {
2711                // Empty
2712            }
2713            theme.applyStyle(resid, false);
2714        }
2715    }
2716
2717    /**
2718     * Launch an activity for which you would like a result when it finished.
2719     * When this activity exits, your
2720     * onActivityResult() method will be called with the given requestCode.
2721     * Using a negative requestCode is the same as calling
2722     * {@link #startActivity} (the activity is not launched as a sub-activity).
2723     *
2724     * <p>Note that this method should only be used with Intent protocols
2725     * that are defined to return a result.  In other protocols (such as
2726     * {@link Intent#ACTION_MAIN} or {@link Intent#ACTION_VIEW}), you may
2727     * not get the result when you expect.  For example, if the activity you
2728     * are launching uses the singleTask launch mode, it will not run in your
2729     * task and thus you will immediately receive a cancel result.
2730     *
2731     * <p>As a special case, if you call startActivityForResult() with a requestCode
2732     * >= 0 during the initial onCreate(Bundle savedInstanceState)/onResume() of your
2733     * activity, then your window will not be displayed until a result is
2734     * returned back from the started activity.  This is to avoid visible
2735     * flickering when redirecting to another activity.
2736     *
2737     * <p>This method throws {@link android.content.ActivityNotFoundException}
2738     * if there was no Activity found to run the given Intent.
2739     *
2740     * @param intent The intent to start.
2741     * @param requestCode If >= 0, this code will be returned in
2742     *                    onActivityResult() when the activity exits.
2743     *
2744     * @throws android.content.ActivityNotFoundException
2745     *
2746     * @see #startActivity
2747     */
2748    public void startActivityForResult(Intent intent, int requestCode) {
2749        if (mParent == null) {
2750            Instrumentation.ActivityResult ar =
2751                mInstrumentation.execStartActivity(
2752                    this, mMainThread.getApplicationThread(), mToken, this,
2753                    intent, requestCode);
2754            if (ar != null) {
2755                mMainThread.sendActivityResult(
2756                    mToken, mEmbeddedID, requestCode, ar.getResultCode(),
2757                    ar.getResultData());
2758            }
2759            if (requestCode >= 0) {
2760                // If this start is requesting a result, we can avoid making
2761                // the activity visible until the result is received.  Setting
2762                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
2763                // activity hidden during this time, to avoid flickering.
2764                // This can only be done when a result is requested because
2765                // that guarantees we will get information back when the
2766                // activity is finished, no matter what happens to it.
2767                mStartedActivity = true;
2768            }
2769        } else {
2770            mParent.startActivityFromChild(this, intent, requestCode);
2771        }
2772    }
2773
2774    /**
2775     * Like {@link #startActivityForResult(Intent, int)}, but allowing you
2776     * to use a IntentSender to describe the activity to be started.  If
2777     * the IntentSender is for an activity, that activity will be started
2778     * as if you had called the regular {@link #startActivityForResult(Intent, int)}
2779     * here; otherwise, its associated action will be executed (such as
2780     * sending a broadcast) as if you had called
2781     * {@link IntentSender#sendIntent IntentSender.sendIntent} on it.
2782     *
2783     * @param intent The IntentSender to launch.
2784     * @param requestCode If >= 0, this code will be returned in
2785     *                    onActivityResult() when the activity exits.
2786     * @param fillInIntent If non-null, this will be provided as the
2787     * intent parameter to {@link IntentSender#sendIntent}.
2788     * @param flagsMask Intent flags in the original IntentSender that you
2789     * would like to change.
2790     * @param flagsValues Desired values for any bits set in
2791     * <var>flagsMask</var>
2792     * @param extraFlags Always set to 0.
2793     */
2794    public void startIntentSenderForResult(IntentSender intent, int requestCode,
2795            Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags)
2796            throws IntentSender.SendIntentException {
2797        if (mParent == null) {
2798            startIntentSenderForResultInner(intent, requestCode, fillInIntent,
2799                    flagsMask, flagsValues, this);
2800        } else {
2801            mParent.startIntentSenderFromChild(this, intent, requestCode,
2802                    fillInIntent, flagsMask, flagsValues, extraFlags);
2803        }
2804    }
2805
2806    private void startIntentSenderForResultInner(IntentSender intent, int requestCode,
2807            Intent fillInIntent, int flagsMask, int flagsValues, Activity activity)
2808            throws IntentSender.SendIntentException {
2809        try {
2810            String resolvedType = null;
2811            if (fillInIntent != null) {
2812                resolvedType = fillInIntent.resolveTypeIfNeeded(getContentResolver());
2813            }
2814            int result = ActivityManagerNative.getDefault()
2815                .startActivityIntentSender(mMainThread.getApplicationThread(), intent,
2816                        fillInIntent, resolvedType, mToken, activity.mEmbeddedID,
2817                        requestCode, flagsMask, flagsValues);
2818            if (result == IActivityManager.START_CANCELED) {
2819                throw new IntentSender.SendIntentException();
2820            }
2821            Instrumentation.checkStartActivityResult(result, null);
2822        } catch (RemoteException e) {
2823        }
2824        if (requestCode >= 0) {
2825            // If this start is requesting a result, we can avoid making
2826            // the activity visible until the result is received.  Setting
2827            // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
2828            // activity hidden during this time, to avoid flickering.
2829            // This can only be done when a result is requested because
2830            // that guarantees we will get information back when the
2831            // activity is finished, no matter what happens to it.
2832            mStartedActivity = true;
2833        }
2834    }
2835
2836    /**
2837     * Launch a new activity.  You will not receive any information about when
2838     * the activity exits.  This implementation overrides the base version,
2839     * providing information about
2840     * the activity performing the launch.  Because of this additional
2841     * information, the {@link Intent#FLAG_ACTIVITY_NEW_TASK} launch flag is not
2842     * required; if not specified, the new activity will be added to the
2843     * task of the caller.
2844     *
2845     * <p>This method throws {@link android.content.ActivityNotFoundException}
2846     * if there was no Activity found to run the given Intent.
2847     *
2848     * @param intent The intent to start.
2849     *
2850     * @throws android.content.ActivityNotFoundException
2851     *
2852     * @see #startActivityForResult
2853     */
2854    @Override
2855    public void startActivity(Intent intent) {
2856        startActivityForResult(intent, -1);
2857    }
2858
2859    /**
2860     * Like {@link #startActivity(Intent)}, but taking a IntentSender
2861     * to start; see
2862     * {@link #startIntentSenderForResult(IntentSender, int, Intent, int, int, int)}
2863     * for more information.
2864     *
2865     * @param intent The IntentSender to launch.
2866     * @param fillInIntent If non-null, this will be provided as the
2867     * intent parameter to {@link IntentSender#sendIntent}.
2868     * @param flagsMask Intent flags in the original IntentSender that you
2869     * would like to change.
2870     * @param flagsValues Desired values for any bits set in
2871     * <var>flagsMask</var>
2872     * @param extraFlags Always set to 0.
2873     */
2874    public void startIntentSender(IntentSender intent,
2875            Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags)
2876            throws IntentSender.SendIntentException {
2877        startIntentSenderForResult(intent, -1, fillInIntent, flagsMask,
2878                flagsValues, extraFlags);
2879    }
2880
2881    /**
2882     * A special variation to launch an activity only if a new activity
2883     * instance is needed to handle the given Intent.  In other words, this is
2884     * just like {@link #startActivityForResult(Intent, int)} except: if you are
2885     * using the {@link Intent#FLAG_ACTIVITY_SINGLE_TOP} flag, or
2886     * singleTask or singleTop
2887     * {@link android.R.styleable#AndroidManifestActivity_launchMode launchMode},
2888     * and the activity
2889     * that handles <var>intent</var> is the same as your currently running
2890     * activity, then a new instance is not needed.  In this case, instead of
2891     * the normal behavior of calling {@link #onNewIntent} this function will
2892     * return and you can handle the Intent yourself.
2893     *
2894     * <p>This function can only be called from a top-level activity; if it is
2895     * called from a child activity, a runtime exception will be thrown.
2896     *
2897     * @param intent The intent to start.
2898     * @param requestCode If >= 0, this code will be returned in
2899     *         onActivityResult() when the activity exits, as described in
2900     *         {@link #startActivityForResult}.
2901     *
2902     * @return If a new activity was launched then true is returned; otherwise
2903     *         false is returned and you must handle the Intent yourself.
2904     *
2905     * @see #startActivity
2906     * @see #startActivityForResult
2907     */
2908    public boolean startActivityIfNeeded(Intent intent, int requestCode) {
2909        if (mParent == null) {
2910            int result = IActivityManager.START_RETURN_INTENT_TO_CALLER;
2911            try {
2912                result = ActivityManagerNative.getDefault()
2913                    .startActivity(mMainThread.getApplicationThread(),
2914                            intent, intent.resolveTypeIfNeeded(
2915                                    getContentResolver()),
2916                            null, 0,
2917                            mToken, mEmbeddedID, requestCode, true, false);
2918            } catch (RemoteException e) {
2919                // Empty
2920            }
2921
2922            Instrumentation.checkStartActivityResult(result, intent);
2923
2924            if (requestCode >= 0) {
2925                // If this start is requesting a result, we can avoid making
2926                // the activity visible until the result is received.  Setting
2927                // this code during onCreate(Bundle savedInstanceState) or onResume() will keep the
2928                // activity hidden during this time, to avoid flickering.
2929                // This can only be done when a result is requested because
2930                // that guarantees we will get information back when the
2931                // activity is finished, no matter what happens to it.
2932                mStartedActivity = true;
2933            }
2934            return result != IActivityManager.START_RETURN_INTENT_TO_CALLER;
2935        }
2936
2937        throw new UnsupportedOperationException(
2938            "startActivityIfNeeded can only be called from a top-level activity");
2939    }
2940
2941    /**
2942     * Special version of starting an activity, for use when you are replacing
2943     * other activity components.  You can use this to hand the Intent off
2944     * to the next Activity that can handle it.  You typically call this in
2945     * {@link #onCreate} with the Intent returned by {@link #getIntent}.
2946     *
2947     * @param intent The intent to dispatch to the next activity.  For
2948     * correct behavior, this must be the same as the Intent that started
2949     * your own activity; the only changes you can make are to the extras
2950     * inside of it.
2951     *
2952     * @return Returns a boolean indicating whether there was another Activity
2953     * to start: true if there was a next activity to start, false if there
2954     * wasn't.  In general, if true is returned you will then want to call
2955     * finish() on yourself.
2956     */
2957    public boolean startNextMatchingActivity(Intent intent) {
2958        if (mParent == null) {
2959            try {
2960                return ActivityManagerNative.getDefault()
2961                    .startNextMatchingActivity(mToken, intent);
2962            } catch (RemoteException e) {
2963                // Empty
2964            }
2965            return false;
2966        }
2967
2968        throw new UnsupportedOperationException(
2969            "startNextMatchingActivity can only be called from a top-level activity");
2970    }
2971
2972    /**
2973     * This is called when a child activity of this one calls its
2974     * {@link #startActivity} or {@link #startActivityForResult} method.
2975     *
2976     * <p>This method throws {@link android.content.ActivityNotFoundException}
2977     * if there was no Activity found to run the given Intent.
2978     *
2979     * @param child The activity making the call.
2980     * @param intent The intent to start.
2981     * @param requestCode Reply request code.  < 0 if reply is not requested.
2982     *
2983     * @throws android.content.ActivityNotFoundException
2984     *
2985     * @see #startActivity
2986     * @see #startActivityForResult
2987     */
2988    public void startActivityFromChild(Activity child, Intent intent,
2989            int requestCode) {
2990        Instrumentation.ActivityResult ar =
2991            mInstrumentation.execStartActivity(
2992                this, mMainThread.getApplicationThread(), mToken, child,
2993                intent, requestCode);
2994        if (ar != null) {
2995            mMainThread.sendActivityResult(
2996                mToken, child.mEmbeddedID, requestCode,
2997                ar.getResultCode(), ar.getResultData());
2998        }
2999    }
3000
3001    /**
3002     * Like {@link #startActivityFromChild(Activity, Intent, int)}, but
3003     * taking a IntentSender; see
3004     * {@link #startIntentSenderForResult(IntentSender, int, Intent, int, int, int)}
3005     * for more information.
3006     */
3007    public void startIntentSenderFromChild(Activity child, IntentSender intent,
3008            int requestCode, Intent fillInIntent, int flagsMask, int flagsValues,
3009            int extraFlags)
3010            throws IntentSender.SendIntentException {
3011        startIntentSenderForResultInner(intent, requestCode, fillInIntent,
3012                flagsMask, flagsValues, child);
3013    }
3014
3015    /**
3016     * Call immediately after one of the flavors of {@link #startActivity(Intent)}
3017     * or {@link #finish} to specify an explicit transition animation to
3018     * perform next.
3019     * @param enterAnim A resource ID of the animation resource to use for
3020     * the incoming activity.  Use 0 for no animation.
3021     * @param exitAnim A resource ID of the animation resource to use for
3022     * the outgoing activity.  Use 0 for no animation.
3023     */
3024    public void overridePendingTransition(int enterAnim, int exitAnim) {
3025        try {
3026            ActivityManagerNative.getDefault().overridePendingTransition(
3027                    mToken, getPackageName(), enterAnim, exitAnim);
3028        } catch (RemoteException e) {
3029        }
3030    }
3031
3032    /**
3033     * Call this to set the result that your activity will return to its
3034     * caller.
3035     *
3036     * @param resultCode The result code to propagate back to the originating
3037     *                   activity, often RESULT_CANCELED or RESULT_OK
3038     *
3039     * @see #RESULT_CANCELED
3040     * @see #RESULT_OK
3041     * @see #RESULT_FIRST_USER
3042     * @see #setResult(int, Intent)
3043     */
3044    public final void setResult(int resultCode) {
3045        synchronized (this) {
3046            mResultCode = resultCode;
3047            mResultData = null;
3048        }
3049    }
3050
3051    /**
3052     * Call this to set the result that your activity will return to its
3053     * caller.
3054     *
3055     * @param resultCode The result code to propagate back to the originating
3056     *                   activity, often RESULT_CANCELED or RESULT_OK
3057     * @param data The data to propagate back to the originating activity.
3058     *
3059     * @see #RESULT_CANCELED
3060     * @see #RESULT_OK
3061     * @see #RESULT_FIRST_USER
3062     * @see #setResult(int)
3063     */
3064    public final void setResult(int resultCode, Intent data) {
3065        synchronized (this) {
3066            mResultCode = resultCode;
3067            mResultData = data;
3068        }
3069    }
3070
3071    /**
3072     * Return the name of the package that invoked this activity.  This is who
3073     * the data in {@link #setResult setResult()} will be sent to.  You can
3074     * use this information to validate that the recipient is allowed to
3075     * receive the data.
3076     *
3077     * <p>Note: if the calling activity is not expecting a result (that is it
3078     * did not use the {@link #startActivityForResult}
3079     * form that includes a request code), then the calling package will be
3080     * null.
3081     *
3082     * @return The package of the activity that will receive your
3083     *         reply, or null if none.
3084     */
3085    public String getCallingPackage() {
3086        try {
3087            return ActivityManagerNative.getDefault().getCallingPackage(mToken);
3088        } catch (RemoteException e) {
3089            return null;
3090        }
3091    }
3092
3093    /**
3094     * Return the name of the activity that invoked this activity.  This is
3095     * who the data in {@link #setResult setResult()} will be sent to.  You
3096     * can use this information to validate that the recipient is allowed to
3097     * receive the data.
3098     *
3099     * <p>Note: if the calling activity is not expecting a result (that is it
3100     * did not use the {@link #startActivityForResult}
3101     * form that includes a request code), then the calling package will be
3102     * null.
3103     *
3104     * @return String The full name of the activity that will receive your
3105     *         reply, or null if none.
3106     */
3107    public ComponentName getCallingActivity() {
3108        try {
3109            return ActivityManagerNative.getDefault().getCallingActivity(mToken);
3110        } catch (RemoteException e) {
3111            return null;
3112        }
3113    }
3114
3115    /**
3116     * Control whether this activity's main window is visible.  This is intended
3117     * only for the special case of an activity that is not going to show a
3118     * UI itself, but can't just finish prior to onResume() because it needs
3119     * to wait for a service binding or such.  Setting this to false allows
3120     * you to prevent your UI from being shown during that time.
3121     *
3122     * <p>The default value for this is taken from the
3123     * {@link android.R.attr#windowNoDisplay} attribute of the activity's theme.
3124     */
3125    public void setVisible(boolean visible) {
3126        if (mVisibleFromClient != visible) {
3127            mVisibleFromClient = visible;
3128            if (mVisibleFromServer) {
3129                if (visible) makeVisible();
3130                else mDecor.setVisibility(View.INVISIBLE);
3131            }
3132        }
3133    }
3134
3135    void makeVisible() {
3136        if (!mWindowAdded) {
3137            ViewManager wm = getWindowManager();
3138            wm.addView(mDecor, getWindow().getAttributes());
3139            mWindowAdded = true;
3140        }
3141        mDecor.setVisibility(View.VISIBLE);
3142    }
3143
3144    /**
3145     * Check to see whether this activity is in the process of finishing,
3146     * either because you called {@link #finish} on it or someone else
3147     * has requested that it finished.  This is often used in
3148     * {@link #onPause} to determine whether the activity is simply pausing or
3149     * completely finishing.
3150     *
3151     * @return If the activity is finishing, returns true; else returns false.
3152     *
3153     * @see #finish
3154     */
3155    public boolean isFinishing() {
3156        return mFinished;
3157    }
3158
3159    /**
3160     * Call this when your activity is done and should be closed.  The
3161     * ActivityResult is propagated back to whoever launched you via
3162     * onActivityResult().
3163     */
3164    public void finish() {
3165        if (mParent == null) {
3166            int resultCode;
3167            Intent resultData;
3168            synchronized (this) {
3169                resultCode = mResultCode;
3170                resultData = mResultData;
3171            }
3172            if (Config.LOGV) Log.v(TAG, "Finishing self: token=" + mToken);
3173            try {
3174                if (ActivityManagerNative.getDefault()
3175                    .finishActivity(mToken, resultCode, resultData)) {
3176                    mFinished = true;
3177                }
3178            } catch (RemoteException e) {
3179                // Empty
3180            }
3181        } else {
3182            mParent.finishFromChild(this);
3183        }
3184    }
3185
3186    /**
3187     * This is called when a child activity of this one calls its
3188     * {@link #finish} method.  The default implementation simply calls
3189     * finish() on this activity (the parent), finishing the entire group.
3190     *
3191     * @param child The activity making the call.
3192     *
3193     * @see #finish
3194     */
3195    public void finishFromChild(Activity child) {
3196        finish();
3197    }
3198
3199    /**
3200     * Force finish another activity that you had previously started with
3201     * {@link #startActivityForResult}.
3202     *
3203     * @param requestCode The request code of the activity that you had
3204     *                    given to startActivityForResult().  If there are multiple
3205     *                    activities started with this request code, they
3206     *                    will all be finished.
3207     */
3208    public void finishActivity(int requestCode) {
3209        if (mParent == null) {
3210            try {
3211                ActivityManagerNative.getDefault()
3212                    .finishSubActivity(mToken, mEmbeddedID, requestCode);
3213            } catch (RemoteException e) {
3214                // Empty
3215            }
3216        } else {
3217            mParent.finishActivityFromChild(this, requestCode);
3218        }
3219    }
3220
3221    /**
3222     * This is called when a child activity of this one calls its
3223     * finishActivity().
3224     *
3225     * @param child The activity making the call.
3226     * @param requestCode Request code that had been used to start the
3227     *                    activity.
3228     */
3229    public void finishActivityFromChild(Activity child, int requestCode) {
3230        try {
3231            ActivityManagerNative.getDefault()
3232                .finishSubActivity(mToken, child.mEmbeddedID, requestCode);
3233        } catch (RemoteException e) {
3234            // Empty
3235        }
3236    }
3237
3238    /**
3239     * Called when an activity you launched exits, giving you the requestCode
3240     * you started it with, the resultCode it returned, and any additional
3241     * data from it.  The <var>resultCode</var> will be
3242     * {@link #RESULT_CANCELED} if the activity explicitly returned that,
3243     * didn't return any result, or crashed during its operation.
3244     *
3245     * <p>You will receive this call immediately before onResume() when your
3246     * activity is re-starting.
3247     *
3248     * @param requestCode The integer request code originally supplied to
3249     *                    startActivityForResult(), allowing you to identify who this
3250     *                    result came from.
3251     * @param resultCode The integer result code returned by the child activity
3252     *                   through its setResult().
3253     * @param data An Intent, which can return result data to the caller
3254     *               (various data can be attached to Intent "extras").
3255     *
3256     * @see #startActivityForResult
3257     * @see #createPendingResult
3258     * @see #setResult(int)
3259     */
3260    protected void onActivityResult(int requestCode, int resultCode,
3261            Intent data) {
3262    }
3263
3264    /**
3265     * Create a new PendingIntent object which you can hand to others
3266     * for them to use to send result data back to your
3267     * {@link #onActivityResult} callback.  The created object will be either
3268     * one-shot (becoming invalid after a result is sent back) or multiple
3269     * (allowing any number of results to be sent through it).
3270     *
3271     * @param requestCode Private request code for the sender that will be
3272     * associated with the result data when it is returned.  The sender can not
3273     * modify this value, allowing you to identify incoming results.
3274     * @param data Default data to supply in the result, which may be modified
3275     * by the sender.
3276     * @param flags May be {@link PendingIntent#FLAG_ONE_SHOT PendingIntent.FLAG_ONE_SHOT},
3277     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE},
3278     * {@link PendingIntent#FLAG_CANCEL_CURRENT PendingIntent.FLAG_CANCEL_CURRENT},
3279     * {@link PendingIntent#FLAG_UPDATE_CURRENT PendingIntent.FLAG_UPDATE_CURRENT},
3280     * or any of the flags as supported by
3281     * {@link Intent#fillIn Intent.fillIn()} to control which unspecified parts
3282     * of the intent that can be supplied when the actual send happens.
3283     *
3284     * @return Returns an existing or new PendingIntent matching the given
3285     * parameters.  May return null only if
3286     * {@link PendingIntent#FLAG_NO_CREATE PendingIntent.FLAG_NO_CREATE} has been
3287     * supplied.
3288     *
3289     * @see PendingIntent
3290     */
3291    public PendingIntent createPendingResult(int requestCode, Intent data,
3292            int flags) {
3293        String packageName = getPackageName();
3294        try {
3295            IIntentSender target =
3296                ActivityManagerNative.getDefault().getIntentSender(
3297                        IActivityManager.INTENT_SENDER_ACTIVITY_RESULT, packageName,
3298                        mParent == null ? mToken : mParent.mToken,
3299                        mEmbeddedID, requestCode, data, null, flags);
3300            return target != null ? new PendingIntent(target) : null;
3301        } catch (RemoteException e) {
3302            // Empty
3303        }
3304        return null;
3305    }
3306
3307    /**
3308     * Change the desired orientation of this activity.  If the activity
3309     * is currently in the foreground or otherwise impacting the screen
3310     * orientation, the screen will immediately be changed (possibly causing
3311     * the activity to be restarted). Otherwise, this will be used the next
3312     * time the activity is visible.
3313     *
3314     * @param requestedOrientation An orientation constant as used in
3315     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3316     */
3317    public void setRequestedOrientation(int requestedOrientation) {
3318        if (mParent == null) {
3319            try {
3320                ActivityManagerNative.getDefault().setRequestedOrientation(
3321                        mToken, requestedOrientation);
3322            } catch (RemoteException e) {
3323                // Empty
3324            }
3325        } else {
3326            mParent.setRequestedOrientation(requestedOrientation);
3327        }
3328    }
3329
3330    /**
3331     * Return the current requested orientation of the activity.  This will
3332     * either be the orientation requested in its component's manifest, or
3333     * the last requested orientation given to
3334     * {@link #setRequestedOrientation(int)}.
3335     *
3336     * @return Returns an orientation constant as used in
3337     * {@link ActivityInfo#screenOrientation ActivityInfo.screenOrientation}.
3338     */
3339    public int getRequestedOrientation() {
3340        if (mParent == null) {
3341            try {
3342                return ActivityManagerNative.getDefault()
3343                        .getRequestedOrientation(mToken);
3344            } catch (RemoteException e) {
3345                // Empty
3346            }
3347        } else {
3348            return mParent.getRequestedOrientation();
3349        }
3350        return ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
3351    }
3352
3353    /**
3354     * Return the identifier of the task this activity is in.  This identifier
3355     * will remain the same for the lifetime of the activity.
3356     *
3357     * @return Task identifier, an opaque integer.
3358     */
3359    public int getTaskId() {
3360        try {
3361            return ActivityManagerNative.getDefault()
3362                .getTaskForActivity(mToken, false);
3363        } catch (RemoteException e) {
3364            return -1;
3365        }
3366    }
3367
3368    /**
3369     * Return whether this activity is the root of a task.  The root is the
3370     * first activity in a task.
3371     *
3372     * @return True if this is the root activity, else false.
3373     */
3374    public boolean isTaskRoot() {
3375        try {
3376            return ActivityManagerNative.getDefault()
3377                .getTaskForActivity(mToken, true) >= 0;
3378        } catch (RemoteException e) {
3379            return false;
3380        }
3381    }
3382
3383    /**
3384     * Move the task containing this activity to the back of the activity
3385     * stack.  The activity's order within the task is unchanged.
3386     *
3387     * @param nonRoot If false then this only works if the activity is the root
3388     *                of a task; if true it will work for any activity in
3389     *                a task.
3390     *
3391     * @return If the task was moved (or it was already at the
3392     *         back) true is returned, else false.
3393     */
3394    public boolean moveTaskToBack(boolean nonRoot) {
3395        try {
3396            return ActivityManagerNative.getDefault().moveActivityTaskToBack(
3397                    mToken, nonRoot);
3398        } catch (RemoteException e) {
3399            // Empty
3400        }
3401        return false;
3402    }
3403
3404    /**
3405     * Returns class name for this activity with the package prefix removed.
3406     * This is the default name used to read and write settings.
3407     *
3408     * @return The local class name.
3409     */
3410    public String getLocalClassName() {
3411        final String pkg = getPackageName();
3412        final String cls = mComponent.getClassName();
3413        int packageLen = pkg.length();
3414        if (!cls.startsWith(pkg) || cls.length() <= packageLen
3415                || cls.charAt(packageLen) != '.') {
3416            return cls;
3417        }
3418        return cls.substring(packageLen+1);
3419    }
3420
3421    /**
3422     * Returns complete component name of this activity.
3423     *
3424     * @return Returns the complete component name for this activity
3425     */
3426    public ComponentName getComponentName()
3427    {
3428        return mComponent;
3429    }
3430
3431    /**
3432     * Retrieve a {@link SharedPreferences} object for accessing preferences
3433     * that are private to this activity.  This simply calls the underlying
3434     * {@link #getSharedPreferences(String, int)} method by passing in this activity's
3435     * class name as the preferences name.
3436     *
3437     * @param mode Operating mode.  Use {@link #MODE_PRIVATE} for the default
3438     *             operation, {@link #MODE_WORLD_READABLE} and
3439     *             {@link #MODE_WORLD_WRITEABLE} to control permissions.
3440     *
3441     * @return Returns the single SharedPreferences instance that can be used
3442     *         to retrieve and modify the preference values.
3443     */
3444    public SharedPreferences getPreferences(int mode) {
3445        return getSharedPreferences(getLocalClassName(), mode);
3446    }
3447
3448    private void ensureSearchManager() {
3449        if (mSearchManager != null) {
3450            return;
3451        }
3452
3453        mSearchManager = new SearchManager(this, null);
3454    }
3455
3456    @Override
3457    public Object getSystemService(String name) {
3458        if (getBaseContext() == null) {
3459            throw new IllegalStateException(
3460                    "System services not available to Activities before onCreate()");
3461        }
3462
3463        if (WINDOW_SERVICE.equals(name)) {
3464            return mWindowManager;
3465        } else if (SEARCH_SERVICE.equals(name)) {
3466            ensureSearchManager();
3467            return mSearchManager;
3468        }
3469        return super.getSystemService(name);
3470    }
3471
3472    /**
3473     * Change the title associated with this activity.  If this is a
3474     * top-level activity, the title for its window will change.  If it
3475     * is an embedded activity, the parent can do whatever it wants
3476     * with it.
3477     */
3478    public void setTitle(CharSequence title) {
3479        mTitle = title;
3480        onTitleChanged(title, mTitleColor);
3481
3482        if (mParent != null) {
3483            mParent.onChildTitleChanged(this, title);
3484        }
3485    }
3486
3487    /**
3488     * Change the title associated with this activity.  If this is a
3489     * top-level activity, the title for its window will change.  If it
3490     * is an embedded activity, the parent can do whatever it wants
3491     * with it.
3492     */
3493    public void setTitle(int titleId) {
3494        setTitle(getText(titleId));
3495    }
3496
3497    public void setTitleColor(int textColor) {
3498        mTitleColor = textColor;
3499        onTitleChanged(mTitle, textColor);
3500    }
3501
3502    public final CharSequence getTitle() {
3503        return mTitle;
3504    }
3505
3506    public final int getTitleColor() {
3507        return mTitleColor;
3508    }
3509
3510    protected void onTitleChanged(CharSequence title, int color) {
3511        if (mTitleReady) {
3512            final Window win = getWindow();
3513            if (win != null) {
3514                win.setTitle(title);
3515                if (color != 0) {
3516                    win.setTitleColor(color);
3517                }
3518            }
3519        }
3520    }
3521
3522    protected void onChildTitleChanged(Activity childActivity, CharSequence title) {
3523    }
3524
3525    /**
3526     * Sets the visibility of the progress bar in the title.
3527     * <p>
3528     * In order for the progress bar to be shown, the feature must be requested
3529     * via {@link #requestWindowFeature(int)}.
3530     *
3531     * @param visible Whether to show the progress bars in the title.
3532     */
3533    public final void setProgressBarVisibility(boolean visible) {
3534        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, visible ? Window.PROGRESS_VISIBILITY_ON :
3535            Window.PROGRESS_VISIBILITY_OFF);
3536    }
3537
3538    /**
3539     * Sets the visibility of the indeterminate progress bar in the title.
3540     * <p>
3541     * In order for the progress bar to be shown, the feature must be requested
3542     * via {@link #requestWindowFeature(int)}.
3543     *
3544     * @param visible Whether to show the progress bars in the title.
3545     */
3546    public final void setProgressBarIndeterminateVisibility(boolean visible) {
3547        getWindow().setFeatureInt(Window.FEATURE_INDETERMINATE_PROGRESS,
3548                visible ? Window.PROGRESS_VISIBILITY_ON : Window.PROGRESS_VISIBILITY_OFF);
3549    }
3550
3551    /**
3552     * Sets whether the horizontal progress bar in the title should be indeterminate (the circular
3553     * is always indeterminate).
3554     * <p>
3555     * In order for the progress bar to be shown, the feature must be requested
3556     * via {@link #requestWindowFeature(int)}.
3557     *
3558     * @param indeterminate Whether the horizontal progress bar should be indeterminate.
3559     */
3560    public final void setProgressBarIndeterminate(boolean indeterminate) {
3561        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3562                indeterminate ? Window.PROGRESS_INDETERMINATE_ON : Window.PROGRESS_INDETERMINATE_OFF);
3563    }
3564
3565    /**
3566     * Sets the progress for the progress bars in the title.
3567     * <p>
3568     * In order for the progress bar to be shown, the feature must be requested
3569     * via {@link #requestWindowFeature(int)}.
3570     *
3571     * @param progress The progress for the progress bar. Valid ranges are from
3572     *            0 to 10000 (both inclusive). If 10000 is given, the progress
3573     *            bar will be completely filled and will fade out.
3574     */
3575    public final void setProgress(int progress) {
3576        getWindow().setFeatureInt(Window.FEATURE_PROGRESS, progress + Window.PROGRESS_START);
3577    }
3578
3579    /**
3580     * Sets the secondary progress for the progress bar in the title. This
3581     * progress is drawn between the primary progress (set via
3582     * {@link #setProgress(int)} and the background. It can be ideal for media
3583     * scenarios such as showing the buffering progress while the default
3584     * progress shows the play progress.
3585     * <p>
3586     * In order for the progress bar to be shown, the feature must be requested
3587     * via {@link #requestWindowFeature(int)}.
3588     *
3589     * @param secondaryProgress The secondary progress for the progress bar. Valid ranges are from
3590     *            0 to 10000 (both inclusive).
3591     */
3592    public final void setSecondaryProgress(int secondaryProgress) {
3593        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
3594                secondaryProgress + Window.PROGRESS_SECONDARY_START);
3595    }
3596
3597    /**
3598     * Suggests an audio stream whose volume should be changed by the hardware
3599     * volume controls.
3600     * <p>
3601     * The suggested audio stream will be tied to the window of this Activity.
3602     * If the Activity is switched, the stream set here is no longer the
3603     * suggested stream. The client does not need to save and restore the old
3604     * suggested stream value in onPause and onResume.
3605     *
3606     * @param streamType The type of the audio stream whose volume should be
3607     *        changed by the hardware volume controls. It is not guaranteed that
3608     *        the hardware volume controls will always change this stream's
3609     *        volume (for example, if a call is in progress, its stream's volume
3610     *        may be changed instead). To reset back to the default, use
3611     *        {@link AudioManager#USE_DEFAULT_STREAM_TYPE}.
3612     */
3613    public final void setVolumeControlStream(int streamType) {
3614        getWindow().setVolumeControlStream(streamType);
3615    }
3616
3617    /**
3618     * Gets the suggested audio stream whose volume should be changed by the
3619     * harwdare volume controls.
3620     *
3621     * @return The suggested audio stream type whose volume should be changed by
3622     *         the hardware volume controls.
3623     * @see #setVolumeControlStream(int)
3624     */
3625    public final int getVolumeControlStream() {
3626        return getWindow().getVolumeControlStream();
3627    }
3628
3629    /**
3630     * Runs the specified action on the UI thread. If the current thread is the UI
3631     * thread, then the action is executed immediately. If the current thread is
3632     * not the UI thread, the action is posted to the event queue of the UI thread.
3633     *
3634     * @param action the action to run on the UI thread
3635     */
3636    public final void runOnUiThread(Runnable action) {
3637        if (Thread.currentThread() != mUiThread) {
3638            mHandler.post(action);
3639        } else {
3640            action.run();
3641        }
3642    }
3643
3644    /**
3645     * Stub implementation of {@link android.view.LayoutInflater.Factory#onCreateView} used when
3646     * inflating with the LayoutInflater returned by {@link #getSystemService}.  This
3647     * implementation simply returns null for all view names.
3648     *
3649     * @see android.view.LayoutInflater#createView
3650     * @see android.view.Window#getLayoutInflater
3651     */
3652    public View onCreateView(String name, Context context, AttributeSet attrs) {
3653        return null;
3654    }
3655
3656    // ------------------ Internal API ------------------
3657
3658    final void setParent(Activity parent) {
3659        mParent = parent;
3660    }
3661
3662    final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token,
3663            Application application, Intent intent, ActivityInfo info, CharSequence title,
3664            Activity parent, String id, Object lastNonConfigurationInstance,
3665            Configuration config) {
3666        attach(context, aThread, instr, token, 0, application, intent, info, title, parent, id,
3667            lastNonConfigurationInstance, null, config);
3668    }
3669
3670    final void attach(Context context, ActivityThread aThread,
3671            Instrumentation instr, IBinder token, int ident,
3672            Application application, Intent intent, ActivityInfo info,
3673            CharSequence title, Activity parent, String id,
3674            Object lastNonConfigurationInstance,
3675            HashMap<String,Object> lastNonConfigurationChildInstances,
3676            Configuration config) {
3677        attachBaseContext(context);
3678
3679        mWindow = PolicyManager.makeNewWindow(this);
3680        mWindow.setCallback(this);
3681        if (info.softInputMode != WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED) {
3682            mWindow.setSoftInputMode(info.softInputMode);
3683        }
3684        mUiThread = Thread.currentThread();
3685
3686        mMainThread = aThread;
3687        mInstrumentation = instr;
3688        mToken = token;
3689        mIdent = ident;
3690        mApplication = application;
3691        mIntent = intent;
3692        mComponent = intent.getComponent();
3693        mActivityInfo = info;
3694        mTitle = title;
3695        mParent = parent;
3696        mEmbeddedID = id;
3697        mLastNonConfigurationInstance = lastNonConfigurationInstance;
3698        mLastNonConfigurationChildInstances = lastNonConfigurationChildInstances;
3699
3700        mWindow.setWindowManager(null, mToken, mComponent.flattenToString());
3701        if (mParent != null) {
3702            mWindow.setContainer(mParent.getWindow());
3703        }
3704        mWindowManager = mWindow.getWindowManager();
3705        mCurrentConfig = config;
3706    }
3707
3708    final IBinder getActivityToken() {
3709        return mParent != null ? mParent.getActivityToken() : mToken;
3710    }
3711
3712    final void performStart() {
3713        mCalled = false;
3714        mInstrumentation.callActivityOnStart(this);
3715        if (!mCalled) {
3716            throw new SuperNotCalledException(
3717                "Activity " + mComponent.toShortString() +
3718                " did not call through to super.onStart()");
3719        }
3720    }
3721
3722    final void performRestart() {
3723        final int N = mManagedCursors.size();
3724        for (int i=0; i<N; i++) {
3725            ManagedCursor mc = mManagedCursors.get(i);
3726            if (mc.mReleased || mc.mUpdated) {
3727                mc.mCursor.requery();
3728                mc.mReleased = false;
3729                mc.mUpdated = false;
3730            }
3731        }
3732
3733        if (mStopped) {
3734            mStopped = false;
3735            mCalled = false;
3736            mInstrumentation.callActivityOnRestart(this);
3737            if (!mCalled) {
3738                throw new SuperNotCalledException(
3739                    "Activity " + mComponent.toShortString() +
3740                    " did not call through to super.onRestart()");
3741            }
3742            performStart();
3743        }
3744    }
3745
3746    final void performResume() {
3747        performRestart();
3748
3749        mLastNonConfigurationInstance = null;
3750
3751        // First call onResume() -before- setting mResumed, so we don't
3752        // send out any status bar / menu notifications the client makes.
3753        mCalled = false;
3754        mInstrumentation.callActivityOnResume(this);
3755        if (!mCalled) {
3756            throw new SuperNotCalledException(
3757                "Activity " + mComponent.toShortString() +
3758                " did not call through to super.onResume()");
3759        }
3760
3761        // Now really resume, and install the current status bar and menu.
3762        mResumed = true;
3763        mCalled = false;
3764        onPostResume();
3765        if (!mCalled) {
3766            throw new SuperNotCalledException(
3767                "Activity " + mComponent.toShortString() +
3768                " did not call through to super.onPostResume()");
3769        }
3770    }
3771
3772    final void performPause() {
3773        onPause();
3774    }
3775
3776    final void performUserLeaving() {
3777        onUserInteraction();
3778        onUserLeaveHint();
3779    }
3780
3781    final void performStop() {
3782        if (!mStopped) {
3783            if (mWindow != null) {
3784                mWindow.closeAllPanels();
3785            }
3786
3787            mCalled = false;
3788            mInstrumentation.callActivityOnStop(this);
3789            if (!mCalled) {
3790                throw new SuperNotCalledException(
3791                    "Activity " + mComponent.toShortString() +
3792                    " did not call through to super.onStop()");
3793            }
3794
3795            final int N = mManagedCursors.size();
3796            for (int i=0; i<N; i++) {
3797                ManagedCursor mc = mManagedCursors.get(i);
3798                if (!mc.mReleased) {
3799                    mc.mCursor.deactivate();
3800                    mc.mReleased = true;
3801                }
3802            }
3803
3804            mStopped = true;
3805        }
3806        mResumed = false;
3807    }
3808
3809    final boolean isResumed() {
3810        return mResumed;
3811    }
3812
3813    void dispatchActivityResult(String who, int requestCode,
3814        int resultCode, Intent data) {
3815        if (Config.LOGV) Log.v(
3816            TAG, "Dispatching result: who=" + who + ", reqCode=" + requestCode
3817            + ", resCode=" + resultCode + ", data=" + data);
3818        if (who == null) {
3819            onActivityResult(requestCode, resultCode, data);
3820        }
3821    }
3822}
3823