1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.server;
18
19import android.content.BroadcastReceiver;
20import android.content.Context;
21import android.content.ContextWrapper;
22import android.content.Intent;
23import android.content.IntentFilter;
24import android.os.Handler;
25import android.os.UserHandle;
26
27import com.google.common.collect.Lists;
28import com.google.common.util.concurrent.AbstractFuture;
29
30import java.util.Iterator;
31import java.util.List;
32import java.util.concurrent.ExecutionException;
33import java.util.concurrent.Future;
34import java.util.concurrent.TimeUnit;
35import java.util.concurrent.TimeoutException;
36
37/**
38 * {@link ContextWrapper} that can attach listeners for upcoming
39 * {@link Context#sendBroadcast(Intent)}.
40 */
41public class BroadcastInterceptingContext extends ContextWrapper {
42    private static final String TAG = "WatchingContext";
43
44    private final List<BroadcastInterceptor> mInterceptors = Lists.newArrayList();
45
46    public class BroadcastInterceptor extends AbstractFuture<Intent> {
47        private final BroadcastReceiver mReceiver;
48        private final IntentFilter mFilter;
49
50        public BroadcastInterceptor(BroadcastReceiver receiver, IntentFilter filter) {
51            mReceiver = receiver;
52            mFilter = filter;
53        }
54
55        public boolean dispatchBroadcast(Intent intent) {
56            if (mFilter.match(getContentResolver(), intent, false, TAG) > 0) {
57                if (mReceiver != null) {
58                    final Context context = BroadcastInterceptingContext.this;
59                    mReceiver.onReceive(context, intent);
60                    return false;
61                } else {
62                    set(intent);
63                    return true;
64                }
65            } else {
66                return false;
67            }
68        }
69
70        @Override
71        public Intent get() throws InterruptedException, ExecutionException {
72            try {
73                return get(5, TimeUnit.SECONDS);
74            } catch (TimeoutException e) {
75                throw new RuntimeException(e);
76            }
77        }
78    }
79
80    public BroadcastInterceptingContext(Context base) {
81        super(base);
82    }
83
84    public Future<Intent> nextBroadcastIntent(String action) {
85        return nextBroadcastIntent(new IntentFilter(action));
86    }
87
88    public Future<Intent> nextBroadcastIntent(IntentFilter filter) {
89        final BroadcastInterceptor interceptor = new BroadcastInterceptor(null, filter);
90        synchronized (mInterceptors) {
91            mInterceptors.add(interceptor);
92        }
93        return interceptor;
94    }
95
96    @Override
97    public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter) {
98        synchronized (mInterceptors) {
99            mInterceptors.add(new BroadcastInterceptor(receiver, filter));
100        }
101        return null;
102    }
103
104    @Override
105    public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter,
106            String broadcastPermission, Handler scheduler) {
107        return registerReceiver(receiver, filter);
108    }
109
110    @Override
111    public void unregisterReceiver(BroadcastReceiver receiver) {
112        synchronized (mInterceptors) {
113            final Iterator<BroadcastInterceptor> i = mInterceptors.iterator();
114            while (i.hasNext()) {
115                final BroadcastInterceptor interceptor = i.next();
116                if (receiver.equals(interceptor.mReceiver)) {
117                    i.remove();
118                }
119            }
120        }
121    }
122
123    @Override
124    public void sendBroadcast(Intent intent) {
125        synchronized (mInterceptors) {
126            final Iterator<BroadcastInterceptor> i = mInterceptors.iterator();
127            while (i.hasNext()) {
128                final BroadcastInterceptor interceptor = i.next();
129                if (interceptor.dispatchBroadcast(intent)) {
130                    i.remove();
131                }
132            }
133        }
134    }
135
136    @Override
137    public void sendBroadcast(Intent intent, String receiverPermission) {
138        sendBroadcast(intent);
139    }
140
141    @Override
142    public void sendBroadcastAsUser(Intent intent, UserHandle user) {
143        sendBroadcast(intent);
144    }
145
146    @Override
147    public void sendBroadcastAsUser(Intent intent, UserHandle user,
148            String receiverPermission) {
149        sendBroadcast(intent);
150    }
151
152    @Override
153    public void sendStickyBroadcast(Intent intent) {
154        sendBroadcast(intent);
155    }
156
157    @Override
158    public void sendStickyBroadcastAsUser(Intent intent, UserHandle user) {
159        sendBroadcast(intent);
160    }
161
162    @Override
163    public void removeStickyBroadcast(Intent intent) {
164        // ignored
165    }
166}
167