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;
25
26import com.google.common.collect.Lists;
27import com.google.common.util.concurrent.AbstractFuture;
28
29import java.util.Iterator;
30import java.util.List;
31import java.util.concurrent.ExecutionException;
32import java.util.concurrent.Future;
33import java.util.concurrent.TimeUnit;
34import java.util.concurrent.TimeoutException;
35
36/**
37 * {@link ContextWrapper} that can attach listeners for upcoming
38 * {@link Context#sendBroadcast(Intent)}.
39 */
40public class BroadcastInterceptingContext extends ContextWrapper {
41    private static final String TAG = "WatchingContext";
42
43    private final List<BroadcastInterceptor> mInterceptors = Lists.newArrayList();
44
45    public class BroadcastInterceptor extends AbstractFuture<Intent> {
46        private final BroadcastReceiver mReceiver;
47        private final IntentFilter mFilter;
48
49        public BroadcastInterceptor(BroadcastReceiver receiver, IntentFilter filter) {
50            mReceiver = receiver;
51            mFilter = filter;
52        }
53
54        public boolean dispatchBroadcast(Intent intent) {
55            if (mFilter.match(getContentResolver(), intent, false, TAG) > 0) {
56                if (mReceiver != null) {
57                    final Context context = BroadcastInterceptingContext.this;
58                    mReceiver.onReceive(context, intent);
59                    return false;
60                } else {
61                    set(intent);
62                    return true;
63                }
64            } else {
65                return false;
66            }
67        }
68
69        @Override
70        public Intent get() throws InterruptedException, ExecutionException {
71            try {
72                return get(5, TimeUnit.SECONDS);
73            } catch (TimeoutException e) {
74                throw new RuntimeException(e);
75            }
76        }
77    }
78
79    public BroadcastInterceptingContext(Context base) {
80        super(base);
81    }
82
83    public Future<Intent> nextBroadcastIntent(String action) {
84        return nextBroadcastIntent(new IntentFilter(action));
85    }
86
87    public Future<Intent> nextBroadcastIntent(IntentFilter filter) {
88        final BroadcastInterceptor interceptor = new BroadcastInterceptor(null, filter);
89        synchronized (mInterceptors) {
90            mInterceptors.add(interceptor);
91        }
92        return interceptor;
93    }
94
95    @Override
96    public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter) {
97        synchronized (mInterceptors) {
98            mInterceptors.add(new BroadcastInterceptor(receiver, filter));
99        }
100        return null;
101    }
102
103    @Override
104    public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter,
105            String broadcastPermission, Handler scheduler) {
106        return registerReceiver(receiver, filter);
107    }
108
109    @Override
110    public void unregisterReceiver(BroadcastReceiver receiver) {
111        synchronized (mInterceptors) {
112            final Iterator<BroadcastInterceptor> i = mInterceptors.iterator();
113            while (i.hasNext()) {
114                final BroadcastInterceptor interceptor = i.next();
115                if (receiver.equals(interceptor.mReceiver)) {
116                    i.remove();
117                }
118            }
119        }
120    }
121
122    @Override
123    public void sendBroadcast(Intent intent) {
124        synchronized (mInterceptors) {
125            final Iterator<BroadcastInterceptor> i = mInterceptors.iterator();
126            while (i.hasNext()) {
127                final BroadcastInterceptor interceptor = i.next();
128                if (interceptor.dispatchBroadcast(intent)) {
129                    i.remove();
130                }
131            }
132        }
133    }
134
135    @Override
136    public void sendStickyBroadcast(Intent intent) {
137        sendBroadcast(intent);
138    }
139
140    @Override
141    public void sendBroadcast(Intent intent, String receiverPermission) {
142        sendBroadcast(intent);
143    }
144
145    @Override
146    public void removeStickyBroadcast(Intent intent) {
147        // ignored
148    }
149}
150