core-utils/java/android/support/v4/content/LocalBroadcastManager.java - platform/frameworks/support - Git at Google

 /*
  * Copyright (C) 2011 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.support.v4.content;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Set;

 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.Uri;
 import android.os.Handler;
 import android.os.Message;
 import android.util.Log;

 /**
  * Helper to register for and send broadcasts of Intents to local objects
  * within your process.  This has a number of advantages over sending
  * global broadcasts with {@link android.content.Context#sendBroadcast}:
  * <ul>
  * <li> You know that the data you are broadcasting won't leave your app, so
  * don't need to worry about leaking private data.
  * <li> It is not possible for other applications to send these broadcasts to
  * your app, so you don't need to worry about having security holes they can
  * exploit.
  * <li> It is more efficient than sending a global broadcast through the
  * system.
  * </ul>
  */
 public final class LocalBroadcastManager {
     private static class ReceiverRecord {
         final IntentFilter filter;
         final BroadcastReceiver receiver;
         boolean broadcasting;

         ReceiverRecord(IntentFilter _filter, BroadcastReceiver _receiver) {
             filter = _filter;
             receiver = _receiver;
         }

         @Override
         public String toString() {
             StringBuilder builder = new StringBuilder(128);
             builder.append("Receiver{");
             builder.append(receiver);
             builder.append(" filter=");
             builder.append(filter);
             builder.append("}");
             return builder.toString();
         }
     }

     private static class BroadcastRecord {
         final Intent intent;
         final ArrayList<ReceiverRecord> receivers;

         BroadcastRecord(Intent _intent, ArrayList<ReceiverRecord> _receivers) {
             intent = _intent;
             receivers = _receivers;
         }
     }

     private static final String TAG = "LocalBroadcastManager";
     private static final boolean DEBUG = false;

     private final Context mAppContext;

     private final HashMap<BroadcastReceiver, ArrayList<IntentFilter>> mReceivers
             = new HashMap<BroadcastReceiver, ArrayList<IntentFilter>>();
     private final HashMap<String, ArrayList<ReceiverRecord>> mActions
             = new HashMap<String, ArrayList<ReceiverRecord>>();

     private final ArrayList<BroadcastRecord> mPendingBroadcasts
             = new ArrayList<BroadcastRecord>();

     static final int MSG_EXEC_PENDING_BROADCASTS = 1;

     private final Handler mHandler;

     private static final Object mLock = new Object();
     private static LocalBroadcastManager mInstance;

     public static LocalBroadcastManager getInstance(Context context) {
         synchronized (mLock) {
             if (mInstance == null) {
                 mInstance = new LocalBroadcastManager(context.getApplicationContext());
             }
             return mInstance;
         }
     }

     private LocalBroadcastManager(Context context) {
         mAppContext = context;
         mHandler = new Handler(context.getMainLooper()) {

             @Override
             public void handleMessage(Message msg) {
                 switch (msg.what) {
                     case MSG_EXEC_PENDING_BROADCASTS:
                         executePendingBroadcasts();
                         break;
                     default:
                         super.handleMessage(msg);
                 }
             }
         };
     }

     /**
      * Register a receive for any local broadcasts that match the given IntentFilter.
      *
      * @param receiver The BroadcastReceiver to handle the broadcast.
      * @param filter Selects the Intent broadcasts to be received.
      *
      * @see #unregisterReceiver
      */
     public void registerReceiver(BroadcastReceiver receiver, IntentFilter filter) {
         synchronized (mReceivers) {
             ReceiverRecord entry = new ReceiverRecord(filter, receiver);
             ArrayList<IntentFilter> filters = mReceivers.get(receiver);
             if (filters == null) {
                 filters = new ArrayList<IntentFilter>(1);
                 mReceivers.put(receiver, filters);
             }
             filters.add(filter);
             for (int i=0; i<filter.countActions(); i++) {
                 String action = filter.getAction(i);
                 ArrayList<ReceiverRecord> entries = mActions.get(action);
                 if (entries == null) {
                     entries = new ArrayList<ReceiverRecord>(1);
                     mActions.put(action, entries);
                 }
                 entries.add(entry);
             }
         }
     }

     /**
      * Unregister a previously registered BroadcastReceiver.  <em>All</em>
      * filters that have been registered for this BroadcastReceiver will be
      * removed.
      *
      * @param receiver The BroadcastReceiver to unregister.
      *
      * @see #registerReceiver
      */
     public void unregisterReceiver(BroadcastReceiver receiver) {
         synchronized (mReceivers) {
             ArrayList<IntentFilter> filters = mReceivers.remove(receiver);
             if (filters == null) {
                 return;
             }
             for (int i=0; i<filters.size(); i++) {
                 IntentFilter filter = filters.get(i);
                 for (int j=0; j<filter.countActions(); j++) {
                     String action = filter.getAction(j);
                     ArrayList<ReceiverRecord> receivers = mActions.get(action);
                     if (receivers != null) {
                         for (int k=0; k<receivers.size(); k++) {
                             if (receivers.get(k).receiver == receiver) {
                                 receivers.remove(k);
                                 k--;
                             }
                         }
                         if (receivers.size() <= 0) {
                             mActions.remove(action);
                         }
                     }
                 }
             }
         }
     }

     /**
      * Broadcast the given intent to all interested BroadcastReceivers.  This
      * call is asynchronous; it returns immediately, and you will continue
      * executing while the receivers are run.
      *
      * @param intent The Intent to broadcast; all receivers matching this
      *     Intent will receive the broadcast.
      *
      * @see #registerReceiver
      */
     public boolean sendBroadcast(Intent intent) {
         synchronized (mReceivers) {
             final String action = intent.getAction();
             final String type = intent.resolveTypeIfNeeded(
                     mAppContext.getContentResolver());
             final Uri data = intent.getData();
             final String scheme = intent.getScheme();
             final Set<String> categories = intent.getCategories();

             final boolean debug = DEBUG ||
                     ((intent.getFlags() & Intent.FLAG_DEBUG_LOG_RESOLUTION) != 0);
             if (debug) Log.v(
                     TAG, "Resolving type " + type + " scheme " + scheme
                     + " of intent " + intent);

             ArrayList<ReceiverRecord> entries = mActions.get(intent.getAction());
             if (entries != null) {
                 if (debug) Log.v(TAG, "Action list: " + entries);

                 ArrayList<ReceiverRecord> receivers = null;
                 for (int i=0; i<entries.size(); i++) {
                     ReceiverRecord receiver = entries.get(i);
                     if (debug) Log.v(TAG, "Matching against filter " + receiver.filter);

                     if (receiver.broadcasting) {
                         if (debug) {
                             Log.v(TAG, "  Filter's target already added");
                         }
                         continue;
                     }

                     int match = receiver.filter.match(action, type, scheme, data,
                             categories, "LocalBroadcastManager");
                     if (match >= 0) {
                         if (debug) Log.v(TAG, "  Filter matched!  match=0x" +
                                 Integer.toHexString(match));
                         if (receivers == null) {
                             receivers = new ArrayList<ReceiverRecord>();
                         }
                         receivers.add(receiver);
                         receiver.broadcasting = true;
                     } else {
                         if (debug) {
                             String reason;
                             switch (match) {
                                 case IntentFilter.NO_MATCH_ACTION: reason = "action"; break;
                                 case IntentFilter.NO_MATCH_CATEGORY: reason = "category"; break;
                                 case IntentFilter.NO_MATCH_DATA: reason = "data"; break;
                                 case IntentFilter.NO_MATCH_TYPE: reason = "type"; break;
                                 default: reason = "unknown reason"; break;
                             }
                             Log.v(TAG, "  Filter did not match: " + reason);
                         }
                     }
                 }

                 if (receivers != null) {
                     for (int i=0; i<receivers.size(); i++) {
                         receivers.get(i).broadcasting = false;
                     }
                     mPendingBroadcasts.add(new BroadcastRecord(intent, receivers));
                     if (!mHandler.hasMessages(MSG_EXEC_PENDING_BROADCASTS)) {
                         mHandler.sendEmptyMessage(MSG_EXEC_PENDING_BROADCASTS);
                     }
                     return true;
                 }
             }
         }
         return false;
     }

     /**
      * Like {@link #sendBroadcast(Intent)}, but if there are any receivers for
      * the Intent this function will block and immediately dispatch them before
      * returning.
      */
     public void sendBroadcastSync(Intent intent) {
         if (sendBroadcast(intent)) {
             executePendingBroadcasts();
         }
     }

     private void executePendingBroadcasts() {
         while (true) {
             BroadcastRecord[] brs = null;
             synchronized (mReceivers) {
                 final int N = mPendingBroadcasts.size();
                 if (N <= 0) {
                     return;
                 }
                 brs = new BroadcastRecord[N];
                 mPendingBroadcasts.toArray(brs);
                 mPendingBroadcasts.clear();
             }
             for (int i=0; i<brs.length; i++) {
                 BroadcastRecord br = brs[i];
                 for (int j=0; j<br.receivers.size(); j++) {
                     br.receivers.get(j).receiver.onReceive(mAppContext, br.intent);
                 }
             }
         }
     }
 }
	/*
	* Copyright (C) 2011 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.support.v4.content;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Set;

	import android.content.BroadcastReceiver;
	import android.content.Context;
	import android.content.Intent;
	import android.content.IntentFilter;
	import android.net.Uri;
	import android.os.Handler;
	import android.os.Message;
	import android.util.Log;

	/**
	* Helper to register for and send broadcasts of Intents to local objects
	* within your process. This has a number of advantages over sending
	* global broadcasts with {@link android.content.Context#sendBroadcast}:
	* <ul>
	* <li> You know that the data you are broadcasting won't leave your app, so
	* don't need to worry about leaking private data.
	* <li> It is not possible for other applications to send these broadcasts to
	* your app, so you don't need to worry about having security holes they can
	* exploit.
	* <li> It is more efficient than sending a global broadcast through the
	* system.
	* </ul>
	*/
	public final class LocalBroadcastManager {
	private static class ReceiverRecord {
	final IntentFilter filter;
	final BroadcastReceiver receiver;
	boolean broadcasting;

	ReceiverRecord(IntentFilter _filter, BroadcastReceiver _receiver) {
	filter = _filter;
	receiver = _receiver;
	}

	@Override
	public String toString() {
	StringBuilder builder = new StringBuilder(128);
	builder.append("Receiver{");
	builder.append(receiver);
	builder.append(" filter=");
	builder.append(filter);
	builder.append("}");
	return builder.toString();
	}
	}

	private static class BroadcastRecord {
	final Intent intent;
	final ArrayList<ReceiverRecord> receivers;

	BroadcastRecord(Intent _intent, ArrayList<ReceiverRecord> _receivers) {
	intent = _intent;
	receivers = _receivers;
	}
	}

	private static final String TAG = "LocalBroadcastManager";
	private static final boolean DEBUG = false;

	private final Context mAppContext;

	private final HashMap<BroadcastReceiver, ArrayList<IntentFilter>> mReceivers
	= new HashMap<BroadcastReceiver, ArrayList<IntentFilter>>();
	private final HashMap<String, ArrayList<ReceiverRecord>> mActions
	= new HashMap<String, ArrayList<ReceiverRecord>>();

	private final ArrayList<BroadcastRecord> mPendingBroadcasts
	= new ArrayList<BroadcastRecord>();

	static final int MSG_EXEC_PENDING_BROADCASTS = 1;

	private final Handler mHandler;

	private static final Object mLock = new Object();
	private static LocalBroadcastManager mInstance;

	public static LocalBroadcastManager getInstance(Context context) {
	synchronized (mLock) {
	if (mInstance == null) {
	mInstance = new LocalBroadcastManager(context.getApplicationContext());
	}
	return mInstance;
	}
	}

	private LocalBroadcastManager(Context context) {
	mAppContext = context;
	mHandler = new Handler(context.getMainLooper()) {

	@Override
	public void handleMessage(Message msg) {
	switch (msg.what) {
	case MSG_EXEC_PENDING_BROADCASTS:
	executePendingBroadcasts();
	break;
	default:
	super.handleMessage(msg);
	}
	}
	};
	}

	/**
	* Register a receive for any local broadcasts that match the given IntentFilter.
	*
	* @param receiver The BroadcastReceiver to handle the broadcast.
	* @param filter Selects the Intent broadcasts to be received.
	*
	* @see #unregisterReceiver
	*/
	public void registerReceiver(BroadcastReceiver receiver, IntentFilter filter) {
	synchronized (mReceivers) {
	ReceiverRecord entry = new ReceiverRecord(filter, receiver);
	ArrayList<IntentFilter> filters = mReceivers.get(receiver);
	if (filters == null) {
	filters = new ArrayList<IntentFilter>(1);
	mReceivers.put(receiver, filters);
	}
	filters.add(filter);
	for (int i=0; i<filter.countActions(); i++) {
	String action = filter.getAction(i);
	ArrayList<ReceiverRecord> entries = mActions.get(action);
	if (entries == null) {
	entries = new ArrayList<ReceiverRecord>(1);
	mActions.put(action, entries);
	}
	entries.add(entry);
	}
	}
	}

	/**
	* Unregister a previously registered BroadcastReceiver. <em>All</em>
	* filters that have been registered for this BroadcastReceiver will be
	* removed.
	*
	* @param receiver The BroadcastReceiver to unregister.
	*
	* @see #registerReceiver
	*/
	public void unregisterReceiver(BroadcastReceiver receiver) {
	synchronized (mReceivers) {
	ArrayList<IntentFilter> filters = mReceivers.remove(receiver);
	if (filters == null) {
	return;
	}
	for (int i=0; i<filters.size(); i++) {
	IntentFilter filter = filters.get(i);
	for (int j=0; j<filter.countActions(); j++) {
	String action = filter.getAction(j);
	ArrayList<ReceiverRecord> receivers = mActions.get(action);
	if (receivers != null) {
	for (int k=0; k<receivers.size(); k++) {
	if (receivers.get(k).receiver == receiver) {
	receivers.remove(k);
	k--;
	}
	}
	if (receivers.size() <= 0) {
	mActions.remove(action);
	}
	}
	}
	}
	}
	}

	/**
	* Broadcast the given intent to all interested BroadcastReceivers. This
	* call is asynchronous; it returns immediately, and you will continue
	* executing while the receivers are run.
	*
	* @param intent The Intent to broadcast; all receivers matching this
	* Intent will receive the broadcast.
	*
	* @see #registerReceiver
	*/
	public boolean sendBroadcast(Intent intent) {
	synchronized (mReceivers) {
	final String action = intent.getAction();
	final String type = intent.resolveTypeIfNeeded(
	mAppContext.getContentResolver());
	final Uri data = intent.getData();
	final String scheme = intent.getScheme();
	final Set<String> categories = intent.getCategories();

	final boolean debug = DEBUG \|\|
	((intent.getFlags() & Intent.FLAG_DEBUG_LOG_RESOLUTION) != 0);
	if (debug) Log.v(
	TAG, "Resolving type " + type + " scheme " + scheme
	+ " of intent " + intent);

	ArrayList<ReceiverRecord> entries = mActions.get(intent.getAction());
	if (entries != null) {
	if (debug) Log.v(TAG, "Action list: " + entries);

	ArrayList<ReceiverRecord> receivers = null;
	for (int i=0; i<entries.size(); i++) {
	ReceiverRecord receiver = entries.get(i);
	if (debug) Log.v(TAG, "Matching against filter " + receiver.filter);

	if (receiver.broadcasting) {
	if (debug) {
	Log.v(TAG, " Filter's target already added");
	}
	continue;
	}

	int match = receiver.filter.match(action, type, scheme, data,
	categories, "LocalBroadcastManager");
	if (match >= 0) {
	if (debug) Log.v(TAG, " Filter matched! match=0x" +
	Integer.toHexString(match));
	if (receivers == null) {
	receivers = new ArrayList<ReceiverRecord>();
	}
	receivers.add(receiver);
	receiver.broadcasting = true;
	} else {
	if (debug) {
	String reason;
	switch (match) {
	case IntentFilter.NO_MATCH_ACTION: reason = "action"; break;
	case IntentFilter.NO_MATCH_CATEGORY: reason = "category"; break;
	case IntentFilter.NO_MATCH_DATA: reason = "data"; break;
	case IntentFilter.NO_MATCH_TYPE: reason = "type"; break;
	default: reason = "unknown reason"; break;
	}
	Log.v(TAG, " Filter did not match: " + reason);
	}
	}
	}

	if (receivers != null) {
	for (int i=0; i<receivers.size(); i++) {
	receivers.get(i).broadcasting = false;
	}
	mPendingBroadcasts.add(new BroadcastRecord(intent, receivers));
	if (!mHandler.hasMessages(MSG_EXEC_PENDING_BROADCASTS)) {
	mHandler.sendEmptyMessage(MSG_EXEC_PENDING_BROADCASTS);
	}
	return true;
	}
	}
	}
	return false;
	}

	/**
	* Like {@link #sendBroadcast(Intent)}, but if there are any receivers for
	* the Intent this function will block and immediately dispatch them before
	* returning.
	*/
	public void sendBroadcastSync(Intent intent) {
	if (sendBroadcast(intent)) {
	executePendingBroadcasts();
	}
	}

	private void executePendingBroadcasts() {
	while (true) {
	BroadcastRecord[] brs = null;
	synchronized (mReceivers) {
	final int N = mPendingBroadcasts.size();
	if (N <= 0) {
	return;
	}
	brs = new BroadcastRecord[N];
	mPendingBroadcasts.toArray(brs);
	mPendingBroadcasts.clear();
	}
	for (int i=0; i<brs.length; i++) {
	BroadcastRecord br = brs[i];
	for (int j=0; j<br.receivers.size(); j++) {
	br.receivers.get(j).receiver.onReceive(mAppContext, br.intent);
	}
	}
	}
	}
	}