/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.content;
import android.app.ActivityManagerNative;
import android.app.ActivityThread;
import android.app.IActivityManager;
import android.app.QueuedWork;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import android.util.Slog;
/**
* Base class for code that receives and handles broadcast intents sent by
* {@link android.content.Context#sendBroadcast(Intent)}.
*
* <p>You can either dynamically register an instance of this class with
* {@link Context#registerReceiver Context.registerReceiver()}
* or statically declare an implementation with the
* {@link android.R.styleable#AndroidManifestReceiver <receiver>}
* tag in your <code>AndroidManifest.xml</code>.
*
* <div class="special reference">
* <h3>Developer Guides</h3>
* <p>For more information about using BroadcastReceiver, read the
* <a href="{@docRoot}guide/components/broadcasts.html">Broadcasts</a> developer guide.</p></div>
*
*/
public abstract class BroadcastReceiver {
private PendingResult mPendingResult;
private boolean mDebugUnregister;
/**
* State for a result that is pending for a broadcast receiver. Returned
* by {@link BroadcastReceiver#goAsync() goAsync()}
* while in {@link BroadcastReceiver#onReceive BroadcastReceiver.onReceive()}.
* This allows you to return from onReceive() without having the broadcast
* terminate; you must call {@link #finish()} once you are done with the
* broadcast. This allows you to process the broadcast off of the main
* thread of your app.
*
* <p>Note on threading: the state inside of this class is not itself
* thread-safe, however you can use it from any thread if you properly
* sure that you do not have races. Typically this means you will hand
* the entire object to another thread, which will be solely responsible
* for setting any results and finally calling {@link #finish()}.
*/
public static class PendingResult {
/** @hide */
public static final int TYPE_COMPONENT = 0;
/** @hide */
public static final int TYPE_REGISTERED = 1;
/** @hide */
public static final int TYPE_UNREGISTERED = 2;
final int mType;
final boolean mOrderedHint;
final boolean mInitialStickyHint;
final IBinder mToken;
final int mSendingUser;
final int mFlags;
int mResultCode;
String mResultData;
Bundle mResultExtras;
boolean mAbortBroadcast;
boolean mFinished;
/** @hide */
public PendingResult(int resultCode, String resultData, Bundle resultExtras, int type,
boolean ordered, boolean sticky, IBinder token, int userId, int flags) {
mResultCode = resultCode;
mResultData = resultData;
mResultExtras = resultExtras;
mType = type;
mOrderedHint = ordered;
mInitialStickyHint = sticky;
mToken = token;
mSendingUser = userId;
mFlags = flags;
}
/**
* Version of {@link BroadcastReceiver#setResultCode(int)
* BroadcastReceiver.setResultCode(int)} for
* asynchronous broadcast handling.
*/
public final void setResultCode(int code) {
checkSynchronousHint();
mResultCode = code;
}
/**
* Version of {@link BroadcastReceiver#getResultCode()
* BroadcastReceiver.getResultCode()} for
* asynchronous broadcast handling.
*/
public final int getResultCode() {
return mResultCode;
}
/**
* Version of {@link BroadcastReceiver#setResultData(String)
* BroadcastReceiver.setResultData(String)} for
* asynchronous broadcast handling.
*/
public final void setResultData(String data) {
checkSynchronousHint();
mResultData = data;
}
/**
* Version of {@link BroadcastReceiver#getResultData()
* BroadcastReceiver.getResultData()} for
* asynchronous broadcast handling.
*/
public final String getResultData() {
return mResultData;
}
/**
* Version of {@link BroadcastReceiver#setResultExtras(Bundle)
* BroadcastReceiver.setResultExtras(Bundle)} for
* asynchronous broadcast handling.
*/
public final void setResultExtras(Bundle extras) {
checkSynchronousHint();
mResultExtras = extras;
}
/**
* Version of {@link BroadcastReceiver#getResultExtras(boolean)
* BroadcastReceiver.getResultExtras(boolean)} for
* asynchronous broadcast handling.
*/
public final Bundle getResultExtras(boolean makeMap) {
Bundle e = mResultExtras;
if (!makeMap) return e;
if (e == null) mResultExtras = e = new Bundle();
return e;
}
/**
* Version of {@link BroadcastReceiver#setResult(int, String, Bundle)
* BroadcastReceiver.setResult(int, String, Bundle)} for
* asynchronous broadcast handling.
*/
public final void setResult(int code, String data, Bundle extras) {
checkSynchronousHint();
mResultCode = code;
mResultData = data;
mResultExtras = extras;
}
/**
* Version of {@link BroadcastReceiver#getAbortBroadcast()
* BroadcastReceiver.getAbortBroadcast()} for
* asynchronous broadcast handling.
*/
public final boolean getAbortBroadcast() {
return mAbortBroadcast;
}
/**
* Version of {@link BroadcastReceiver#abortBroadcast()
* BroadcastReceiver.abortBroadcast()} for
* asynchronous broadcast handling.
*/
public final void abortBroadcast() {
checkSynchronousHint();
mAbortBroadcast = true;
}
/**
* Version of {@link BroadcastReceiver#clearAbortBroadcast()
* BroadcastReceiver.clearAbortBroadcast()} for
* asynchronous broadcast handling.
*/
public final void clearAbortBroadcast() {
mAbortBroadcast = false;
}
/**
* Finish the broadcast. The current result will be sent and the
* next broadcast will proceed.
*/
public final void finish() {
if (mType == TYPE_COMPONENT) {
final IActivityManager mgr = ActivityManagerNative.getDefault();
if (QueuedWork.hasPendingWork()) {
// If this is a broadcast component, we need to make sure any
// queued work is complete before telling AM we are done, so
// we don't have our process killed before that. We now know
// there is pending work; put another piece of work at the end
// of the list to finish the broadcast, so we don't block this
// thread (which may be the main thread) to have it finished.
//
// Note that we don't need to use QueuedWork.add() with the
// runnable, since we know the AM is waiting for us until the
// executor gets to it.
QueuedWork.singleThreadExecutor().execute( new Runnable() {
@Override public void run() {
if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
"Finishing broadcast after work to component " + mToken);
sendFinished(mgr);
}
});
} else {
if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
"Finishing broadcast to component " + mToken);
sendFinished(mgr);
}
} else if (mOrderedHint && mType != TYPE_UNREGISTERED) {
if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
"Finishing broadcast to " + mToken);
final IActivityManager mgr = ActivityManagerNative.getDefault();
sendFinished(mgr);
}
}
/** @hide */
public void setExtrasClassLoader(ClassLoader cl) {
if (mResultExtras != null) {
mResultExtras.setClassLoader(cl);
}
}
/** @hide */
public void sendFinished(IActivityManager am) {
synchronized (this) {
if (mFinished) {
throw new IllegalStateException("Broadcast already finished");
}
mFinished = true;
try {
if (mResultExtras != null) {
mResultExtras.setAllowFds(false);
}
if (mOrderedHint) {
am.finishReceiver(mToken, mResultCode, mResultData, mResultExtras,
mAbortBroadcast, mFlags);
} else {
// This broadcast was sent to a component; it is not ordered,
// but we still need to tell the activity manager we are done.
am.finishReceiver(mToken, 0, null, null, false, mFlags);
}
} catch (RemoteException ex) {
}
}
}
/** @hide */
public int getSendingUserId() {
return mSendingUser;
}
void checkSynchronousHint() {
// Note that we don't assert when receiving the initial sticky value,
// since that may have come from an ordered broadcast. We'll catch
// them later when the real broadcast happens again.
if (mOrderedHint || mInitialStickyHint) {
return;
}
RuntimeException e = new RuntimeException(
"BroadcastReceiver trying to return result during a non-ordered broadcast");
e.fillInStackTrace();
Log.e("BroadcastReceiver", e.getMessage(), e);
}
}
public BroadcastReceiver() {
}
/**
* This method is called when the BroadcastReceiver is receiving an Intent
* broadcast. During this time you can use the other methods on
* BroadcastReceiver to view/modify the current result values. This method
* is always called within the main thread of its process, unless you
* explicitly asked for it to be scheduled on a different thread using
* {@link android.content.Context#registerReceiver(BroadcastReceiver,
* IntentFilter, String, android.os.Handler)}. When it runs on the main
* thread you should
* never perform long-running operations in it (there is a timeout of
* 10 seconds that the system allows before considering the receiver to
* be blocked and a candidate to be killed). You cannot launch a popup dialog
* in your implementation of onReceive().
*
* <p><b>If this BroadcastReceiver was launched through a <receiver> tag,
* then the object is no longer alive after returning from this
* function.</b> This means you should not perform any operations that
* return a result to you asynchronously. If you need to perform any follow up
* background work, schedule a {@link android.app.job.JobService} with
* {@link android.app.job.JobScheduler}.
*
* If you wish to interact with a service that is already running and previously
* bound using {@link android.content.Context#bindService(Intent, ServiceConnection, int) bindService()},
* you can use {@link #peekService}.
*
* <p>The Intent filters used in {@link android.content.Context#registerReceiver}
* and in application manifests are <em>not</em> guaranteed to be exclusive. They
* are hints to the operating system about how to find suitable recipients. It is
* possible for senders to force delivery to specific recipients, bypassing filter
* resolution. For this reason, {@link #onReceive(Context, Intent) onReceive()}
* implementations should respond only to known actions, ignoring any unexpected
* Intents that they may receive.
*
* @param context The Context in which the receiver is running.
* @param intent The Intent being received.
*/
public abstract void onReceive(Context context, Intent intent);
/**
* This can be called by an application in {@link #onReceive} to allow
* it to keep the broadcast active after returning from that function.
* This does <em>not</em> change the expectation of being relatively
* responsive to the broadcast (finishing it within 10s), but does allow
* the implementation to move work related to it over to another thread
* to avoid glitching the main UI thread due to disk IO.
*
* @return Returns a {@link PendingResult} representing the result of
* the active broadcast. The BroadcastRecord itself is no longer active;
* all data and other interaction must go through {@link PendingResult}
* APIs. The {@link PendingResult#finish PendingResult.finish()} method
* must be called once processing of the broadcast is done.
*/
public final PendingResult goAsync() {
PendingResult res = mPendingResult;
mPendingResult = null;
return res;
}
/**
* Provide a binder to an already-bound service. This method is synchronous
* and will not start the target service if it is not present, so it is safe
* to call from {@link #onReceive}.
*
* For peekService() to return a non null {@link android.os.IBinder} interface
* the service must have published it before. In other words some component
* must have called {@link android.content.Context#bindService(Intent, ServiceConnection, int)} on it.
*
* @param myContext The Context that had been passed to {@link #onReceive(Context, Intent)}
* @param service Identifies the already-bound service you wish to use. See
* {@link android.content.Context#bindService(Intent, ServiceConnection, int)}
* for more information.
*/
public IBinder peekService(Context myContext, Intent service) {
IActivityManager am = ActivityManagerNative.getDefault();
IBinder binder = null;
try {
service.prepareToLeaveProcess(myContext);
binder = am.peekService(service, service.resolveTypeIfNeeded(
myContext.getContentResolver()), myContext.getOpPackageName());
} catch (RemoteException e) {
}
return binder;
}
/**
* Change the current result code of this broadcast; only works with
* broadcasts sent through
* {@link Context#sendOrderedBroadcast(Intent, String)
* Context.sendOrderedBroadcast}. Often uses the
* Activity {@link android.app.Activity#RESULT_CANCELED} and
* {@link android.app.Activity#RESULT_OK} constants, though the
* actual meaning of this value is ultimately up to the broadcaster.
*
* <p class="note">This method does not work with non-ordered broadcasts such
* as those sent with {@link Context#sendBroadcast(Intent)
* Context.sendBroadcast}</p>
*
* @param code The new result code.
*
* @see #setResult(int, String, Bundle)
*/
public final void setResultCode(int code) {
checkSynchronousHint();
mPendingResult.mResultCode = code;
}
/**
* Retrieve the current result code, as set by the previous receiver.
*
* @return int The current result code.
*/
public final int getResultCode() {
return mPendingResult != null ? mPendingResult.mResultCode : 0;
}
/**
* Change the current result data of this broadcast; only works with
* broadcasts sent through
* {@link Context#sendOrderedBroadcast(Intent, String)
* Context.sendOrderedBroadcast}. This is an arbitrary
* string whose interpretation is up to the broadcaster.
*
* <p><strong>This method does not work with non-ordered broadcasts such
* as those sent with {@link Context#sendBroadcast(Intent)
* Context.sendBroadcast}</strong></p>
*
* @param data The new result data; may be null.
*
* @see #setResult(int, String, Bundle)
*/
public final void setResultData(String data) {
checkSynchronousHint();
mPendingResult.mResultData = data;
}
/**
* Retrieve the current result data, as set by the previous receiver.
* Often this is null.
*
* @return String The current result data; may be null.
*/
public final String getResultData() {
return mPendingResult != null ? mPendingResult.mResultData : null;
}
/**
* Change the current result extras of this broadcast; only works with
* broadcasts sent through
* {@link Context#sendOrderedBroadcast(Intent, String)
* Context.sendOrderedBroadcast}. This is a Bundle
* holding arbitrary data, whose interpretation is up to the
* broadcaster. Can be set to null. Calling this method completely
* replaces the current map (if any).
*
* <p><strong>This method does not work with non-ordered broadcasts such
* as those sent with {@link Context#sendBroadcast(Intent)
* Context.sendBroadcast}</strong></p>
*
* @param extras The new extra data map; may be null.
*
* @see #setResult(int, String, Bundle)
*/
public final void setResultExtras(Bundle extras) {
checkSynchronousHint();
mPendingResult.mResultExtras = extras;
}
/**
* Retrieve the current result extra data, as set by the previous receiver.
* Any changes you make to the returned Map will be propagated to the next
* receiver.
*
* @param makeMap If true then a new empty Map will be made for you if the
* current Map is null; if false you should be prepared to
* receive a null Map.
*
* @return Map The current extras map.
*/
public final Bundle getResultExtras(boolean makeMap) {
if (mPendingResult == null) {
return null;
}
Bundle e = mPendingResult.mResultExtras;
if (!makeMap) return e;
if (e == null) mPendingResult.mResultExtras = e = new Bundle();
return e;
}
/**
* Change all of the result data returned from this broadcasts; only works
* with broadcasts sent through
* {@link Context#sendOrderedBroadcast(Intent, String)
* Context.sendOrderedBroadcast}. All current result data is replaced
* by the value given to this method.
*
* <p><strong>This method does not work with non-ordered broadcasts such
* as those sent with {@link Context#sendBroadcast(Intent)
* Context.sendBroadcast}</strong></p>
*
* @param code The new result code. Often uses the
* Activity {@link android.app.Activity#RESULT_CANCELED} and
* {@link android.app.Activity#RESULT_OK} constants, though the
* actual meaning of this value is ultimately up to the broadcaster.
* @param data The new result data. This is an arbitrary
* string whose interpretation is up to the broadcaster; may be null.
* @param extras The new extra data map. This is a Bundle
* holding arbitrary data, whose interpretation is up to the
* broadcaster. Can be set to null. This completely
* replaces the current map (if any).
*/
public final void setResult(int code, String data, Bundle extras) {
checkSynchronousHint();
mPendingResult.mResultCode = code;
mPendingResult.mResultData = data;
mPendingResult.mResultExtras = extras;
}
/**
* Returns the flag indicating whether or not this receiver should
* abort the current broadcast.
*
* @return True if the broadcast should be aborted.
*/
public final boolean getAbortBroadcast() {
return mPendingResult != null ? mPendingResult.mAbortBroadcast : false;
}
/**
* Sets the flag indicating that this receiver should abort the
* current broadcast; only works with broadcasts sent through
* {@link Context#sendOrderedBroadcast(Intent, String)
* Context.sendOrderedBroadcast}. This will prevent
* any other broadcast receivers from receiving the broadcast. It will still
* call {@link #onReceive} of the BroadcastReceiver that the caller of
* {@link Context#sendOrderedBroadcast(Intent, String)
* Context.sendOrderedBroadcast} passed in.
*
* <p><strong>This method does not work with non-ordered broadcasts such
* as those sent with {@link Context#sendBroadcast(Intent)
* Context.sendBroadcast}</strong></p>
*/
public final void abortBroadcast() {
checkSynchronousHint();
mPendingResult.mAbortBroadcast = true;
}
/**
* Clears the flag indicating that this receiver should abort the current
* broadcast.
*/
public final void clearAbortBroadcast() {
if (mPendingResult != null) {
mPendingResult.mAbortBroadcast = false;
}
}
/**
* Returns true if the receiver is currently processing an ordered
* broadcast.
*/
public final boolean isOrderedBroadcast() {
return mPendingResult != null ? mPendingResult.mOrderedHint : false;
}
/**
* Returns true if the receiver is currently processing the initial
* value of a sticky broadcast -- that is, the value that was last
* broadcast and is currently held in the sticky cache, so this is
* not directly the result of a broadcast right now.
*/
public final boolean isInitialStickyBroadcast() {
return mPendingResult != null ? mPendingResult.mInitialStickyHint : false;
}
/**
* For internal use, sets the hint about whether this BroadcastReceiver is
* running in ordered mode.
*/
public final void setOrderedHint(boolean isOrdered) {
// Accidentally left in the SDK.
}
/**
* For internal use to set the result data that is active. @hide
*/
public final void setPendingResult(PendingResult result) {
mPendingResult = result;
}
/**
* For internal use to set the result data that is active. @hide
*/
public final PendingResult getPendingResult() {
return mPendingResult;
}
/** @hide */
public int getSendingUserId() {
return mPendingResult.mSendingUser;
}
/**
* Control inclusion of debugging help for mismatched
* calls to {@link Context#registerReceiver(BroadcastReceiver, IntentFilter)
* Context.registerReceiver()}.
* If called with true, before given to registerReceiver(), then the
* callstack of the following {@link Context#unregisterReceiver(BroadcastReceiver)
* Context.unregisterReceiver()} call is retained, to be printed if a later
* incorrect unregister call is made. Note that doing this requires retaining
* information about the BroadcastReceiver for the lifetime of the app,
* resulting in a leak -- this should only be used for debugging.
*/
public final void setDebugUnregister(boolean debug) {
mDebugUnregister = debug;
}
/**
* Return the last value given to {@link #setDebugUnregister}.
*/
public final boolean getDebugUnregister() {
return mDebugUnregister;
}
void checkSynchronousHint() {
if (mPendingResult == null) {
throw new IllegalStateException("Call while result is not pending");
}
// Note that we don't assert when receiving the initial sticky value,
// since that may have come from an ordered broadcast. We'll catch
// them later when the real broadcast happens again.
if (mPendingResult.mOrderedHint || mPendingResult.mInitialStickyHint) {
return;
}
RuntimeException e = new RuntimeException(
"BroadcastReceiver trying to return result during a non-ordered broadcast");
e.fillInStackTrace();
Log.e("BroadcastReceiver", e.getMessage(), e);
}
}