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      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 
     17 package android.content;
     18 
     19 import android.app.ActivityManagerNative;
     20 import android.app.ActivityThread;
     21 import android.app.IActivityManager;
     22 import android.app.QueuedWork;
     23 import android.os.Bundle;
     24 import android.os.IBinder;
     25 import android.os.RemoteException;
     26 import android.util.Log;
     27 import android.util.Slog;
     28 
     29 /**
     30  * Base class for code that will receive intents sent by sendBroadcast().
     31  *
     32  * <p>If you don't need to send broadcasts across applications, consider using
     33  * this class with {@link android.support.v4.content.LocalBroadcastManager} instead
     34  * of the more general facilities described below.  This will give you a much
     35  * more efficient implementation (no cross-process communication needed) and allow
     36  * you to avoid thinking about any security issues related to other applications
     37  * being able to receive or send your broadcasts.
     38  *
     39  * <p>You can either dynamically register an instance of this class with
     40  * {@link Context#registerReceiver Context.registerReceiver()}
     41  * or statically publish an implementation through the
     42  * {@link android.R.styleable#AndroidManifestReceiver &lt;receiver&gt;}
     43  * tag in your <code>AndroidManifest.xml</code>.
     44  *
     45  * <p><em><strong>Note:</strong></em>
     46  * &nbsp;&nbsp;&nbsp;If registering a receiver in your
     47  * {@link android.app.Activity#onResume() Activity.onResume()}
     48  * implementation, you should unregister it in
     49  * {@link android.app.Activity#onPause() Activity.onPause()}.
     50  * (You won't receive intents when paused,
     51  * and this will cut down on unnecessary system overhead). Do not unregister in
     52  * {@link android.app.Activity#onSaveInstanceState(android.os.Bundle) Activity.onSaveInstanceState()},
     53  * because this won't be called if the user moves back in the history
     54  * stack.
     55  *
     56  * <p>There are two major classes of broadcasts that can be received:</p>
     57  * <ul>
     58  * <li> <b>Normal broadcasts</b> (sent with {@link Context#sendBroadcast(Intent)
     59  * Context.sendBroadcast}) are completely asynchronous.  All receivers of the
     60  * broadcast are run in an undefined order, often at the same time.  This is
     61  * more efficient, but means that receivers cannot use the result or abort
     62  * APIs included here.
     63  * <li> <b>Ordered broadcasts</b> (sent with {@link Context#sendOrderedBroadcast(Intent, String)
     64  * Context.sendOrderedBroadcast}) are delivered to one receiver at a time.
     65  * As each receiver executes in turn, it can propagate a result to the next
     66  * receiver, or it can completely abort the broadcast so that it won't be passed
     67  * to other receivers.  The order receivers run in can be controlled with the
     68  * {@link android.R.styleable#AndroidManifestIntentFilter_priority
     69  * android:priority} attribute of the matching intent-filter; receivers with
     70  * the same priority will be run in an arbitrary order.
     71  * </ul>
     72  *
     73  * <p>Even in the case of normal broadcasts, the system may in some
     74  * situations revert to delivering the broadcast one receiver at a time.  In
     75  * particular, for receivers that may require the creation of a process, only
     76  * one will be run at a time to avoid overloading the system with new processes.
     77  * In this situation, however, the non-ordered semantics hold: these receivers still
     78  * cannot return results or abort their broadcast.</p>
     79  *
     80  * <p>Note that, although the Intent class is used for sending and receiving
     81  * these broadcasts, the Intent broadcast mechanism here is completely separate
     82  * from Intents that are used to start Activities with
     83  * {@link Context#startActivity Context.startActivity()}.
     84  * There is no way for a BroadcastReceiver
     85  * to see or capture Intents used with startActivity(); likewise, when
     86  * you broadcast an Intent, you will never find or start an Activity.
     87  * These two operations are semantically very different: starting an
     88  * Activity with an Intent is a foreground operation that modifies what the
     89  * user is currently interacting with; broadcasting an Intent is a background
     90  * operation that the user is not normally aware of.
     91  *
     92  * <p>The BroadcastReceiver class (when launched as a component through
     93  * a manifest's {@link android.R.styleable#AndroidManifestReceiver &lt;receiver&gt;}
     94  * tag) is an important part of an
     95  * <a href="{@docRoot}guide/topics/fundamentals.html#lcycles">application's overall lifecycle</a>.</p>
     96  *
     97  * <p>Topics covered here:
     98  * <ol>
     99  * <li><a href="#Security">Security</a>
    100  * <li><a href="#ReceiverLifecycle">Receiver Lifecycle</a>
    101  * <li><a href="#ProcessLifecycle">Process Lifecycle</a>
    102  * </ol>
    103  *
    104  * <div class="special reference">
    105  * <h3>Developer Guides</h3>
    106  * <p>For information about how to use this class to receive and resolve intents, read the
    107  * <a href="{@docRoot}guide/topics/intents/intents-filters.html">Intents and Intent Filters</a>
    108  * developer guide.</p>
    109  * </div>
    110  *
    111  * <a name="Security"></a>
    112  * <h3>Security</h3>
    113  *
    114  * <p>Receivers used with the {@link Context} APIs are by their nature a
    115  * cross-application facility, so you must consider how other applications
    116  * may be able to abuse your use of them.  Some things to consider are:
    117  *
    118  * <ul>
    119  * <li><p>The Intent namespace is global.  Make sure that Intent action names and
    120  * other strings are written in a namespace you own, or else you may inadvertently
    121  * conflict with other applications.
    122  * <li><p>When you use {@link Context#registerReceiver(BroadcastReceiver, IntentFilter)},
    123  * <em>any</em> application may send broadcasts to that registered receiver.  You can
    124  * control who can send broadcasts to it through permissions described below.
    125  * <li><p>When you publish a receiver in your application's manifest and specify
    126  * intent-filters for it, any other application can send broadcasts to it regardless
    127  * of the filters you specify.  To prevent others from sending to it, make it
    128  * unavailable to them with <code>android:exported="false"</code>.
    129  * <li><p>When you use {@link Context#sendBroadcast(Intent)} or related methods,
    130  * normally any other application can receive these broadcasts.  You can control who
    131  * can receive such broadcasts through permissions described below.  Alternatively,
    132  * starting with {@link android.os.Build.VERSION_CODES#ICE_CREAM_SANDWICH}, you
    133  * can also safely restrict the broadcast to a single application with
    134  * {@link Intent#setPackage(String) Intent.setPackage}
    135  * </ul>
    136  *
    137  * <p>None of these issues exist when using
    138  * {@link android.support.v4.content.LocalBroadcastManager}, since intents
    139  * broadcast it never go outside of the current process.
    140  *
    141  * <p>Access permissions can be enforced by either the sender or receiver
    142  * of a broadcast.
    143  *
    144  * <p>To enforce a permission when sending, you supply a non-null
    145  * <var>permission</var> argument to
    146  * {@link Context#sendBroadcast(Intent, String)} or
    147  * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)}.
    148  * Only receivers who have been granted this permission
    149  * (by requesting it with the
    150  * {@link android.R.styleable#AndroidManifestUsesPermission &lt;uses-permission&gt;}
    151  * tag in their <code>AndroidManifest.xml</code>) will be able to receive
    152  * the broadcast.
    153  *
    154  * <p>To enforce a permission when receiving, you supply a non-null
    155  * <var>permission</var> when registering your receiver -- either when calling
    156  * {@link Context#registerReceiver(BroadcastReceiver, IntentFilter, String, android.os.Handler)}
    157  * or in the static
    158  * {@link android.R.styleable#AndroidManifestReceiver &lt;receiver&gt;}
    159  * tag in your <code>AndroidManifest.xml</code>.  Only broadcasters who have
    160  * been granted this permission (by requesting it with the
    161  * {@link android.R.styleable#AndroidManifestUsesPermission &lt;uses-permission&gt;}
    162  * tag in their <code>AndroidManifest.xml</code>) will be able to send an
    163  * Intent to the receiver.
    164  *
    165  * <p>See the <a href="{@docRoot}guide/topics/security/security.html">Security and Permissions</a>
    166  * document for more information on permissions and security in general.
    167  *
    168  * <a name="ReceiverLifecycle"></a>
    169  * <h3>Receiver Lifecycle</h3>
    170  *
    171  * <p>A BroadcastReceiver object is only valid for the duration of the call
    172  * to {@link #onReceive}.  Once your code returns from this function,
    173  * the system considers the object to be finished and no longer active.
    174  *
    175  * <p>This has important repercussions to what you can do in an
    176  * {@link #onReceive} implementation: anything that requires asynchronous
    177  * operation is not available, because you will need to return from the
    178  * function to handle the asynchronous operation, but at that point the
    179  * BroadcastReceiver is no longer active and thus the system is free to kill
    180  * its process before the asynchronous operation completes.
    181  *
    182  * <p>In particular, you may <i>not</i> show a dialog or bind to a service from
    183  * within a BroadcastReceiver.  For the former, you should instead use the
    184  * {@link android.app.NotificationManager} API.  For the latter, you can
    185  * use {@link android.content.Context#startService Context.startService()} to
    186  * send a command to the service.
    187  *
    188  * <a name="ProcessLifecycle"></a>
    189  * <h3>Process Lifecycle</h3>
    190  *
    191  * <p>A process that is currently executing a BroadcastReceiver (that is,
    192  * currently running the code in its {@link #onReceive} method) is
    193  * considered to be a foreground process and will be kept running by the
    194  * system except under cases of extreme memory pressure.
    195  *
    196  * <p>Once you return from onReceive(), the BroadcastReceiver is no longer
    197  * active, and its hosting process is only as important as any other application
    198  * components that are running in it.  This is especially important because if
    199  * that process was only hosting the BroadcastReceiver (a common case for
    200  * applications that the user has never or not recently interacted with), then
    201  * upon returning from onReceive() the system will consider its process
    202  * to be empty and aggressively kill it so that resources are available for other
    203  * more important processes.
    204  *
    205  * <p>This means that for longer-running operations you will often use
    206  * a {@link android.app.Service} in conjunction with a BroadcastReceiver to keep
    207  * the containing process active for the entire time of your operation.
    208  */
    209 public abstract class BroadcastReceiver {
    210     private PendingResult mPendingResult;
    211     private boolean mDebugUnregister;
    212 
    213     /**
    214      * State for a result that is pending for a broadcast receiver.  Returned
    215      * by {@link BroadcastReceiver#goAsync() goAsync()}
    216      * while in {@link BroadcastReceiver#onReceive BroadcastReceiver.onReceive()}.
    217      * This allows you to return from onReceive() without having the broadcast
    218      * terminate; you must call {@link #finish()} once you are done with the
    219      * broadcast.  This allows you to process the broadcast off of the main
    220      * thread of your app.
    221      *
    222      * <p>Note on threading: the state inside of this class is not itself
    223      * thread-safe, however you can use it from any thread if you properly
    224      * sure that you do not have races.  Typically this means you will hand
    225      * the entire object to another thread, which will be solely responsible
    226      * for setting any results and finally calling {@link #finish()}.
    227      */
    228     public static class PendingResult {
    229         /** @hide */
    230         public static final int TYPE_COMPONENT = 0;
    231         /** @hide */
    232         public static final int TYPE_REGISTERED = 1;
    233         /** @hide */
    234         public static final int TYPE_UNREGISTERED = 2;
    235 
    236         final int mType;
    237         final boolean mOrderedHint;
    238         final boolean mInitialStickyHint;
    239         final IBinder mToken;
    240         final int mSendingUser;
    241 
    242         int mResultCode;
    243         String mResultData;
    244         Bundle mResultExtras;
    245         boolean mAbortBroadcast;
    246         boolean mFinished;
    247 
    248         /** @hide */
    249         public PendingResult(int resultCode, String resultData, Bundle resultExtras,
    250                 int type, boolean ordered, boolean sticky, IBinder token, int userId) {
    251             mResultCode = resultCode;
    252             mResultData = resultData;
    253             mResultExtras = resultExtras;
    254             mType = type;
    255             mOrderedHint = ordered;
    256             mInitialStickyHint = sticky;
    257             mToken = token;
    258             mSendingUser = userId;
    259         }
    260 
    261         /**
    262          * Version of {@link BroadcastReceiver#setResultCode(int)
    263          * BroadcastReceiver.setResultCode(int)} for
    264          * asynchronous broadcast handling.
    265          */
    266         public final void setResultCode(int code) {
    267             checkSynchronousHint();
    268             mResultCode = code;
    269         }
    270 
    271         /**
    272          * Version of {@link BroadcastReceiver#getResultCode()
    273          * BroadcastReceiver.getResultCode()} for
    274          * asynchronous broadcast handling.
    275          */
    276         public final int getResultCode() {
    277             return mResultCode;
    278         }
    279 
    280         /**
    281          * Version of {@link BroadcastReceiver#setResultData(String)
    282          * BroadcastReceiver.setResultData(String)} for
    283          * asynchronous broadcast handling.
    284          */
    285         public final void setResultData(String data) {
    286             checkSynchronousHint();
    287             mResultData = data;
    288         }
    289 
    290         /**
    291          * Version of {@link BroadcastReceiver#getResultData()
    292          * BroadcastReceiver.getResultData()} for
    293          * asynchronous broadcast handling.
    294          */
    295         public final String getResultData() {
    296             return mResultData;
    297         }
    298 
    299         /**
    300          * Version of {@link BroadcastReceiver#setResultExtras(Bundle)
    301          * BroadcastReceiver.setResultExtras(Bundle)} for
    302          * asynchronous broadcast handling.
    303          */
    304         public final void setResultExtras(Bundle extras) {
    305             checkSynchronousHint();
    306             mResultExtras = extras;
    307         }
    308 
    309         /**
    310          * Version of {@link BroadcastReceiver#getResultExtras(boolean)
    311          * BroadcastReceiver.getResultExtras(boolean)} for
    312          * asynchronous broadcast handling.
    313          */
    314         public final Bundle getResultExtras(boolean makeMap) {
    315             Bundle e = mResultExtras;
    316             if (!makeMap) return e;
    317             if (e == null) mResultExtras = e = new Bundle();
    318             return e;
    319         }
    320 
    321         /**
    322          * Version of {@link BroadcastReceiver#setResult(int, String, Bundle)
    323          * BroadcastReceiver.setResult(int, String, Bundle)} for
    324          * asynchronous broadcast handling.
    325          */
    326         public final void setResult(int code, String data, Bundle extras) {
    327             checkSynchronousHint();
    328             mResultCode = code;
    329             mResultData = data;
    330             mResultExtras = extras;
    331         }
    332 
    333         /**
    334          * Version of {@link BroadcastReceiver#getAbortBroadcast()
    335          * BroadcastReceiver.getAbortBroadcast()} for
    336          * asynchronous broadcast handling.
    337          */
    338         public final boolean getAbortBroadcast() {
    339             return mAbortBroadcast;
    340         }
    341 
    342         /**
    343          * Version of {@link BroadcastReceiver#abortBroadcast()
    344          * BroadcastReceiver.abortBroadcast()} for
    345          * asynchronous broadcast handling.
    346          */
    347         public final void abortBroadcast() {
    348             checkSynchronousHint();
    349             mAbortBroadcast = true;
    350         }
    351 
    352         /**
    353          * Version of {@link BroadcastReceiver#clearAbortBroadcast()
    354          * BroadcastReceiver.clearAbortBroadcast()} for
    355          * asynchronous broadcast handling.
    356          */
    357         public final void clearAbortBroadcast() {
    358             mAbortBroadcast = false;
    359         }
    360 
    361         /**
    362          * Finish the broadcast.  The current result will be sent and the
    363          * next broadcast will proceed.
    364          */
    365         public final void finish() {
    366             if (mType == TYPE_COMPONENT) {
    367                 final IActivityManager mgr = ActivityManagerNative.getDefault();
    368                 if (QueuedWork.hasPendingWork()) {
    369                     // If this is a broadcast component, we need to make sure any
    370                     // queued work is complete before telling AM we are done, so
    371                     // we don't have our process killed before that.  We now know
    372                     // there is pending work; put another piece of work at the end
    373                     // of the list to finish the broadcast, so we don't block this
    374                     // thread (which may be the main thread) to have it finished.
    375                     //
    376                     // Note that we don't need to use QueuedWork.add() with the
    377                     // runnable, since we know the AM is waiting for us until the
    378                     // executor gets to it.
    379                     QueuedWork.singleThreadExecutor().execute( new Runnable() {
    380                         @Override public void run() {
    381                             if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
    382                                     "Finishing broadcast after work to component " + mToken);
    383                             sendFinished(mgr);
    384                         }
    385                     });
    386                 } else {
    387                     if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
    388                             "Finishing broadcast to component " + mToken);
    389                     sendFinished(mgr);
    390                 }
    391             } else if (mOrderedHint && mType != TYPE_UNREGISTERED) {
    392                 if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
    393                         "Finishing broadcast to " + mToken);
    394                 final IActivityManager mgr = ActivityManagerNative.getDefault();
    395                 sendFinished(mgr);
    396             }
    397         }
    398 
    399         /** @hide */
    400         public void setExtrasClassLoader(ClassLoader cl) {
    401             if (mResultExtras != null) {
    402                 mResultExtras.setClassLoader(cl);
    403             }
    404         }
    405 
    406         /** @hide */
    407         public void sendFinished(IActivityManager am) {
    408             synchronized (this) {
    409                 if (mFinished) {
    410                     throw new IllegalStateException("Broadcast already finished");
    411                 }
    412                 mFinished = true;
    413 
    414                 try {
    415                     if (mResultExtras != null) {
    416                         mResultExtras.setAllowFds(false);
    417                     }
    418                     if (mOrderedHint) {
    419                         am.finishReceiver(mToken, mResultCode, mResultData, mResultExtras,
    420                                 mAbortBroadcast);
    421                     } else {
    422                         // This broadcast was sent to a component; it is not ordered,
    423                         // but we still need to tell the activity manager we are done.
    424                         am.finishReceiver(mToken, 0, null, null, false);
    425                     }
    426                 } catch (RemoteException ex) {
    427                 }
    428             }
    429         }
    430 
    431         /** @hide */
    432         public int getSendingUserId() {
    433             return mSendingUser;
    434         }
    435 
    436         void checkSynchronousHint() {
    437             // Note that we don't assert when receiving the initial sticky value,
    438             // since that may have come from an ordered broadcast.  We'll catch
    439             // them later when the real broadcast happens again.
    440             if (mOrderedHint || mInitialStickyHint) {
    441                 return;
    442             }
    443             RuntimeException e = new RuntimeException(
    444                     "BroadcastReceiver trying to return result during a non-ordered broadcast");
    445             e.fillInStackTrace();
    446             Log.e("BroadcastReceiver", e.getMessage(), e);
    447         }
    448     }
    449 
    450     public BroadcastReceiver() {
    451     }
    452 
    453     /**
    454      * This method is called when the BroadcastReceiver is receiving an Intent
    455      * broadcast.  During this time you can use the other methods on
    456      * BroadcastReceiver to view/modify the current result values.  This method
    457      * is always called within the main thread of its process, unless you
    458      * explicitly asked for it to be scheduled on a different thread using
    459      * {@link android.content.Context#registerReceiver(BroadcastReceiver,
    460      * IntentFilter, String, android.os.Handler)}. When it runs on the main
    461      * thread you should
    462      * never perform long-running operations in it (there is a timeout of
    463      * 10 seconds that the system allows before considering the receiver to
    464      * be blocked and a candidate to be killed). You cannot launch a popup dialog
    465      * in your implementation of onReceive().
    466      *
    467      * <p><b>If this BroadcastReceiver was launched through a &lt;receiver&gt; tag,
    468      * then the object is no longer alive after returning from this
    469      * function.</b>  This means you should not perform any operations that
    470      * return a result to you asynchronously -- in particular, for interacting
    471      * with services, you should use
    472      * {@link Context#startService(Intent)} instead of
    473      * {@link Context#bindService(Intent, ServiceConnection, int)}.  If you wish
    474      * to interact with a service that is already running, you can use
    475      * {@link #peekService}.
    476      *
    477      * <p>The Intent filters used in {@link android.content.Context#registerReceiver}
    478      * and in application manifests are <em>not</em> guaranteed to be exclusive. They
    479      * are hints to the operating system about how to find suitable recipients. It is
    480      * possible for senders to force delivery to specific recipients, bypassing filter
    481      * resolution.  For this reason, {@link #onReceive(Context, Intent) onReceive()}
    482      * implementations should respond only to known actions, ignoring any unexpected
    483      * Intents that they may receive.
    484      *
    485      * @param context The Context in which the receiver is running.
    486      * @param intent The Intent being received.
    487      */
    488     public abstract void onReceive(Context context, Intent intent);
    489 
    490     /**
    491      * This can be called by an application in {@link #onReceive} to allow
    492      * it to keep the broadcast active after returning from that function.
    493      * This does <em>not</em> change the expectation of being relatively
    494      * responsive to the broadcast (finishing it within 10s), but does allow
    495      * the implementation to move work related to it over to another thread
    496      * to avoid glitching the main UI thread due to disk IO.
    497      *
    498      * @return Returns a {@link PendingResult} representing the result of
    499      * the active broadcast.  The BroadcastRecord itself is no longer active;
    500      * all data and other interaction must go through {@link PendingResult}
    501      * APIs.  The {@link PendingResult#finish PendingResult.finish()} method
    502      * must be called once processing of the broadcast is done.
    503      */
    504     public final PendingResult goAsync() {
    505         PendingResult res = mPendingResult;
    506         mPendingResult = null;
    507         return res;
    508     }
    509 
    510     /**
    511      * Provide a binder to an already-running service.  This method is synchronous
    512      * and will not start the target service if it is not present, so it is safe
    513      * to call from {@link #onReceive}.
    514      *
    515      * @param myContext The Context that had been passed to {@link #onReceive(Context, Intent)}
    516      * @param service The Intent indicating the service you wish to use.  See {@link
    517      * Context#startService(Intent)} for more information.
    518      */
    519     public IBinder peekService(Context myContext, Intent service) {
    520         IActivityManager am = ActivityManagerNative.getDefault();
    521         IBinder binder = null;
    522         try {
    523             service.prepareToLeaveProcess();
    524             binder = am.peekService(service, service.resolveTypeIfNeeded(
    525                     myContext.getContentResolver()));
    526         } catch (RemoteException e) {
    527         }
    528         return binder;
    529     }
    530 
    531     /**
    532      * Change the current result code of this broadcast; only works with
    533      * broadcasts sent through
    534      * {@link Context#sendOrderedBroadcast(Intent, String)
    535      * Context.sendOrderedBroadcast}.  Often uses the
    536      * Activity {@link android.app.Activity#RESULT_CANCELED} and
    537      * {@link android.app.Activity#RESULT_OK} constants, though the
    538      * actual meaning of this value is ultimately up to the broadcaster.
    539      *
    540      * <p class="note">This method does not work with non-ordered broadcasts such
    541      * as those sent with {@link Context#sendBroadcast(Intent)
    542      * Context.sendBroadcast}</p>
    543      *
    544      * @param code The new result code.
    545      *
    546      * @see #setResult(int, String, Bundle)
    547      */
    548     public final void setResultCode(int code) {
    549         checkSynchronousHint();
    550         mPendingResult.mResultCode = code;
    551     }
    552 
    553     /**
    554      * Retrieve the current result code, as set by the previous receiver.
    555      *
    556      * @return int The current result code.
    557      */
    558     public final int getResultCode() {
    559         return mPendingResult != null ? mPendingResult.mResultCode : 0;
    560     }
    561 
    562     /**
    563      * Change the current result data of this broadcast; only works with
    564      * broadcasts sent through
    565      * {@link Context#sendOrderedBroadcast(Intent, String)
    566      * Context.sendOrderedBroadcast}.  This is an arbitrary
    567      * string whose interpretation is up to the broadcaster.
    568      *
    569      * <p><strong>This method does not work with non-ordered broadcasts such
    570      * as those sent with {@link Context#sendBroadcast(Intent)
    571      * Context.sendBroadcast}</strong></p>
    572      *
    573      * @param data The new result data; may be null.
    574      *
    575      * @see #setResult(int, String, Bundle)
    576      */
    577     public final void setResultData(String data) {
    578         checkSynchronousHint();
    579         mPendingResult.mResultData = data;
    580     }
    581 
    582     /**
    583      * Retrieve the current result data, as set by the previous receiver.
    584      * Often this is null.
    585      *
    586      * @return String The current result data; may be null.
    587      */
    588     public final String getResultData() {
    589         return mPendingResult != null ? mPendingResult.mResultData : null;
    590     }
    591 
    592     /**
    593      * Change the current result extras of this broadcast; only works with
    594      * broadcasts sent through
    595      * {@link Context#sendOrderedBroadcast(Intent, String)
    596      * Context.sendOrderedBroadcast}.  This is a Bundle
    597      * holding arbitrary data, whose interpretation is up to the
    598      * broadcaster.  Can be set to null.  Calling this method completely
    599      * replaces the current map (if any).
    600      *
    601      * <p><strong>This method does not work with non-ordered broadcasts such
    602      * as those sent with {@link Context#sendBroadcast(Intent)
    603      * Context.sendBroadcast}</strong></p>
    604      *
    605      * @param extras The new extra data map; may be null.
    606      *
    607      * @see #setResult(int, String, Bundle)
    608      */
    609     public final void setResultExtras(Bundle extras) {
    610         checkSynchronousHint();
    611         mPendingResult.mResultExtras = extras;
    612     }
    613 
    614     /**
    615      * Retrieve the current result extra data, as set by the previous receiver.
    616      * Any changes you make to the returned Map will be propagated to the next
    617      * receiver.
    618      *
    619      * @param makeMap If true then a new empty Map will be made for you if the
    620      *                current Map is null; if false you should be prepared to
    621      *                receive a null Map.
    622      *
    623      * @return Map The current extras map.
    624      */
    625     public final Bundle getResultExtras(boolean makeMap) {
    626         if (mPendingResult == null) {
    627             return null;
    628         }
    629         Bundle e = mPendingResult.mResultExtras;
    630         if (!makeMap) return e;
    631         if (e == null) mPendingResult.mResultExtras = e = new Bundle();
    632         return e;
    633     }
    634 
    635     /**
    636      * Change all of the result data returned from this broadcasts; only works
    637      * with broadcasts sent through
    638      * {@link Context#sendOrderedBroadcast(Intent, String)
    639      * Context.sendOrderedBroadcast}.  All current result data is replaced
    640      * by the value given to this method.
    641      *
    642      * <p><strong>This method does not work with non-ordered broadcasts such
    643      * as those sent with {@link Context#sendBroadcast(Intent)
    644      * Context.sendBroadcast}</strong></p>
    645      *
    646      * @param code The new result code.  Often uses the
    647      * Activity {@link android.app.Activity#RESULT_CANCELED} and
    648      * {@link android.app.Activity#RESULT_OK} constants, though the
    649      * actual meaning of this value is ultimately up to the broadcaster.
    650      * @param data The new result data.  This is an arbitrary
    651      * string whose interpretation is up to the broadcaster; may be null.
    652      * @param extras The new extra data map.  This is a Bundle
    653      * holding arbitrary data, whose interpretation is up to the
    654      * broadcaster.  Can be set to null.  This completely
    655      * replaces the current map (if any).
    656      */
    657     public final void setResult(int code, String data, Bundle extras) {
    658         checkSynchronousHint();
    659         mPendingResult.mResultCode = code;
    660         mPendingResult.mResultData = data;
    661         mPendingResult.mResultExtras = extras;
    662     }
    663 
    664     /**
    665      * Returns the flag indicating whether or not this receiver should
    666      * abort the current broadcast.
    667      *
    668      * @return True if the broadcast should be aborted.
    669      */
    670     public final boolean getAbortBroadcast() {
    671         return mPendingResult != null ? mPendingResult.mAbortBroadcast : false;
    672     }
    673 
    674     /**
    675      * Sets the flag indicating that this receiver should abort the
    676      * current broadcast; only works with broadcasts sent through
    677      * {@link Context#sendOrderedBroadcast(Intent, String)
    678      * Context.sendOrderedBroadcast}.  This will prevent
    679      * any other broadcast receivers from receiving the broadcast. It will still
    680      * call {@link #onReceive} of the BroadcastReceiver that the caller of
    681      * {@link Context#sendOrderedBroadcast(Intent, String)
    682      * Context.sendOrderedBroadcast} passed in.
    683      *
    684      * <p><strong>This method does not work with non-ordered broadcasts such
    685      * as those sent with {@link Context#sendBroadcast(Intent)
    686      * Context.sendBroadcast}</strong></p>
    687      */
    688     public final void abortBroadcast() {
    689         checkSynchronousHint();
    690         mPendingResult.mAbortBroadcast = true;
    691     }
    692 
    693     /**
    694      * Clears the flag indicating that this receiver should abort the current
    695      * broadcast.
    696      */
    697     public final void clearAbortBroadcast() {
    698         if (mPendingResult != null) {
    699             mPendingResult.mAbortBroadcast = false;
    700         }
    701     }
    702 
    703     /**
    704      * Returns true if the receiver is currently processing an ordered
    705      * broadcast.
    706      */
    707     public final boolean isOrderedBroadcast() {
    708         return mPendingResult != null ? mPendingResult.mOrderedHint : false;
    709     }
    710 
    711     /**
    712      * Returns true if the receiver is currently processing the initial
    713      * value of a sticky broadcast -- that is, the value that was last
    714      * broadcast and is currently held in the sticky cache, so this is
    715      * not directly the result of a broadcast right now.
    716      */
    717     public final boolean isInitialStickyBroadcast() {
    718         return mPendingResult != null ? mPendingResult.mInitialStickyHint : false;
    719     }
    720 
    721     /**
    722      * For internal use, sets the hint about whether this BroadcastReceiver is
    723      * running in ordered mode.
    724      */
    725     public final void setOrderedHint(boolean isOrdered) {
    726         // Accidentally left in the SDK.
    727     }
    728 
    729     /**
    730      * For internal use to set the result data that is active. @hide
    731      */
    732     public final void setPendingResult(PendingResult result) {
    733         mPendingResult = result;
    734     }
    735 
    736     /**
    737      * For internal use to set the result data that is active. @hide
    738      */
    739     public final PendingResult getPendingResult() {
    740         return mPendingResult;
    741     }
    742 
    743     /** @hide */
    744     public int getSendingUserId() {
    745         return mPendingResult.mSendingUser;
    746     }
    747 
    748     /**
    749      * Control inclusion of debugging help for mismatched
    750      * calls to {@link Context#registerReceiver(BroadcastReceiver, IntentFilter)
    751      * Context.registerReceiver()}.
    752      * If called with true, before given to registerReceiver(), then the
    753      * callstack of the following {@link Context#unregisterReceiver(BroadcastReceiver)
    754      * Context.unregisterReceiver()} call is retained, to be printed if a later
    755      * incorrect unregister call is made.  Note that doing this requires retaining
    756      * information about the BroadcastReceiver for the lifetime of the app,
    757      * resulting in a leak -- this should only be used for debugging.
    758      */
    759     public final void setDebugUnregister(boolean debug) {
    760         mDebugUnregister = debug;
    761     }
    762 
    763     /**
    764      * Return the last value given to {@link #setDebugUnregister}.
    765      */
    766     public final boolean getDebugUnregister() {
    767         return mDebugUnregister;
    768     }
    769 
    770     void checkSynchronousHint() {
    771         if (mPendingResult == null) {
    772             throw new IllegalStateException("Call while result is not pending");
    773         }
    774 
    775         // Note that we don't assert when receiving the initial sticky value,
    776         // since that may have come from an ordered broadcast.  We'll catch
    777         // them later when the real broadcast happens again.
    778         if (mPendingResult.mOrderedHint || mPendingResult.mInitialStickyHint) {
    779             return;
    780         }
    781         RuntimeException e = new RuntimeException(
    782                 "BroadcastReceiver trying to return result during a non-ordered broadcast");
    783         e.fillInStackTrace();
    784         Log.e("BroadcastReceiver", e.getMessage(), e);
    785     }
    786 }
    787 
    788