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Diffstat (limited to 'core/java/android/content/BroadcastReceiver.java')
| -rw-r--r-- | core/java/android/content/BroadcastReceiver.java | 425 |
1 files changed, 0 insertions, 425 deletions
diff --git a/core/java/android/content/BroadcastReceiver.java b/core/java/android/content/BroadcastReceiver.java deleted file mode 100644 index 08f6191..0000000 --- a/core/java/android/content/BroadcastReceiver.java +++ /dev/null @@ -1,425 +0,0 @@ -/* - * 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.IActivityManager; -import android.os.Bundle; -import android.os.IBinder; -import android.os.RemoteException; -import android.util.Log; - -/** - * Base class for code that will receive intents sent by sendBroadcast(). - * You can either dynamically register an instance of this class with - * {@link Context#registerReceiver Context.registerReceiver()} - * or statically publish an implementation through the - * {@link android.R.styleable#AndroidManifestReceiver <receiver>} - * tag in your <code>AndroidManifest.xml</code>. <em><strong>Note:</strong></em> - * If registering a receiver in your - * {@link android.app.Activity#onResume() Activity.onResume()} - * implementation, you should unregister it in - * {@link android.app.Activity#onPause() Activity.onPause()}. - * (You won't receive intents when paused, - * and this will cut down on unnecessary system overhead). Do not unregister in - * {@link android.app.Activity#onSaveInstanceState(android.os.Bundle) Activity.onSaveInstanceState()}, - * because this won't be called if the user moves back in the history - * stack. - * - * <p>There are two major classes of broadcasts that can be received:</p> - * <ul> - * <li> <b>Normal broadcasts</b> (sent with {@link Context#sendBroadcast(Intent) - * Context.sendBroadcast}) are completely asynchronous. All receivers of the - * broadcast are run, in an undefined order, often at the same time. This is - * more efficient, but means that receivers can not use the result or abort - * APIs included here. - * <li> <b>Ordered broadcasts</b> (sent with {@link Context#sendOrderedBroadcast(Intent, String) - * Context.sendOrderedBroadcast}) are delivered to one receiver at a time. - * As each receiver executes in turn, it can propagate a result to the next - * receiver, or it can completely abort the broadcast so that it won't be passed - * to other receivers. The order receivers runs in can be controlled with the - * {@link android.R.styleable#AndroidManifestIntentFilter_priority - * android:priority} attribute of the matching intent-filter; receivers with - * the same priority will be run in an arbitrary order. - * </ul> - * - * <p>Even in the case of normal broadcasts, the system may in some - * situations revert to delivering the broadcast one receiver at a time. In - * particular, for receivers that may require the creation of a process, only - * one will be run at a time to avoid overloading the system with new processes. - * In this situation, however, the non-ordered semantics hold: these receivers - * can not return results or abort their broadcast.</p> - * - * <p>Note that, although the Intent class is used for sending and receiving - * these broadcasts, the Intent broadcast mechanism here is completely separate - * from Intents that are used to start Activities with - * {@link Context#startActivity Context.startActivity()}. - * There is no way for an BroadcastReceiver - * to see or capture Intents used with startActivity(); likewise, when - * you broadcast an Intent, you will never find or start an Activity. - * These two operations are semantically very different: starting an - * Activity with an Intent is a foreground operation that modifies what the - * user is currently interacting with; broadcasting an Intent is a background - * operation that the user is not normally aware of. - * - * <p>The BroadcastReceiver class (when launched as a component through - * a manifest's {@link android.R.styleable#AndroidManifestReceiver <receiver>} - * tag) is an important part of an - * <a href="{@docRoot}guide/topics/fundamentals.html#lcycles">application's overall lifecycle</a>.</p> - * - * <p>Topics covered here: - * <ol> - * <li><a href="#ReceiverLifecycle">Receiver Lifecycle</a> - * <li><a href="#Permissions">Permissions</a> - * <li><a href="#ProcessLifecycle">Process Lifecycle</a> - * </ol> - * - * <a name="ReceiverLifecycle"></a> - * <h3>Receiver Lifecycle</h3> - * - * <p>A BroadcastReceiver object is only valid for the duration of the call - * to {@link #onReceive}. Once your code returns from this function, - * the system considers the object to be finished and no longer active. - * - * <p>This has important repercussions to what you can do in an - * {@link #onReceive} implementation: anything that requires asynchronous - * operation is not available, because you will need to return from the - * function to handle the asynchronous operation, but at that point the - * BroadcastReceiver is no longer active and thus the system is free to kill - * its process before the asynchronous operation completes. - * - * <p>In particular, you may <i>not</i> show a dialog or bind to a service from - * within an BroadcastReceiver. For the former, you should instead use the - * {@link android.app.NotificationManager} API. For the latter, you can - * use {@link android.content.Context#startService Context.startService()} to - * send a command to the service. - * - * <a name="Permissions"></a> - * <h3>Permissions</h3> - * - * <p>Access permissions can be enforced by either the sender or receiver - * of an Intent. - * - * <p>To enforce a permission when sending, you supply a non-null - * <var>permission</var> argument to - * {@link Context#sendBroadcast(Intent, String)} or - * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)}. - * Only receivers who have been granted this permission - * (by requesting it with the - * {@link android.R.styleable#AndroidManifestUsesPermission <uses-permission>} - * tag in their <code>AndroidManifest.xml</code>) will be able to receive - * the broadcast. - * - * <p>To enforce a permission when receiving, you supply a non-null - * <var>permission</var> when registering your receiver -- either when calling - * {@link Context#registerReceiver(BroadcastReceiver, IntentFilter, String, android.os.Handler)} - * or in the static - * {@link android.R.styleable#AndroidManifestReceiver <receiver>} - * tag in your <code>AndroidManifest.xml</code>. Only broadcasters who have - * been granted this permission (by requesting it with the - * {@link android.R.styleable#AndroidManifestUsesPermission <uses-permission>} - * tag in their <code>AndroidManifest.xml</code>) will be able to send an - * Intent to the receiver. - * - * <p>See the <a href="{@docRoot}guide/topics/security/security.html">Security and Permissions</a> - * document for more information on permissions and security in general. - * - * <a name="ProcessLifecycle"></a> - * <h3>Process Lifecycle</h3> - * - * <p>A process that is currently executing an BroadcastReceiver (that is, - * currently running the code in its {@link #onReceive} method) is - * considered to be a foreground process and will be kept running by the - * system except under cases of extreme memory pressure. - * - * <p>Once you return from onReceive(), the BroadcastReceiver is no longer - * active, and its hosting process is only as important as any other application - * components that are running in it. This is especially important because if - * that process was only hosting the BroadcastReceiver (a common case for - * applications that the user has never or not recently interacted with), then - * upon returning from onReceive() the system will consider its process - * to be empty and aggressively kill it so that resources are available for other - * more important processes. - * - * <p>This means that for longer-running operations you will often use - * a {@link android.app.Service} in conjunction with an BroadcastReceiver to keep - * the containing process active for the entire time of your operation. - */ -public abstract class BroadcastReceiver { - 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. The function - * is normally called from the main thread of its process, so 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 -- in particular, for interacting - * with services, you should use - * {@link Context#startService(Intent)} instead of - * {@link Context#bindService(Intent, ServiceConnection, int)}. If you wish - * to interact with a service that is already running, you can use - * {@link #peekService}. - * - * @param context The Context in which the receiver is running. - * @param intent The Intent being received. - */ - public abstract void onReceive(Context context, Intent intent); - - /** - * Provide a binder to an already-running 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}. - * - * @param myContext The Context that had been passed to {@link #onReceive(Context, Intent)} - * @param service The Intent indicating the service you wish to use. See {@link - * Context#startService(Intent)} for more information. - */ - public IBinder peekService(Context myContext, Intent service) { - IActivityManager am = ActivityManagerNative.getDefault(); - IBinder binder = null; - try { - binder = am.peekService(service, service.resolveTypeIfNeeded( - myContext.getContentResolver())); - } 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><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. - * - * @see #setResult(int, String, Bundle) - */ - public final void setResultCode(int code) { - checkSynchronousHint(); - mResultCode = code; - } - - /** - * Retrieve the current result code, as set by the previous receiver. - * - * @return int The current result code. - */ - public final int getResultCode() { - return mResultCode; - } - - /** - * 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(); - 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 mResultData; - } - - /** - * 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(); - 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) { - Bundle e = mResultExtras; - if (!makeMap) return e; - if (e == null) 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(); - mResultCode = code; - mResultData = data; - 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 mAbortBroadcast; - } - - /** - * 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(); - mAbortBroadcast = true; - } - - /** - * Clears the flag indicating that this receiver should abort the current - * broadcast. - */ - public final void clearAbortBroadcast() { - mAbortBroadcast = false; - } - - /** - * For internal use, sets the hint about whether this BroadcastReceiver is - * running in ordered mode. - */ - public final void setOrderedHint(boolean isOrdered) { - mOrderedHint = isOrdered; - } - - /** - * Control inclusion of debugging help for mismatched - * calls to {@ 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 (mOrderedHint) { - return; - } - RuntimeException e = new RuntimeException( - "BroadcastReceiver trying to return result during a non-ordered broadcast"); - e.fillInStackTrace(); - Log.e("BroadcastReceiver", e.getMessage(), e); - } - - private int mResultCode; - private String mResultData; - private Bundle mResultExtras; - private boolean mAbortBroadcast; - private boolean mDebugUnregister; - private boolean mOrderedHint; -} - |