GeofenceManager.java revision 6fa9ad4afcd762aea519ff61811386c23d18ddb2 
1/*
2 * Copyright (C) 20012 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.location;
18
19import java.io.PrintWriter;
20import java.util.Iterator;
21import java.util.LinkedList;
22import java.util.List;
23
24import android.Manifest.permission;
25import android.app.PendingIntent;
26import android.content.Context;
27import android.content.Intent;
28import android.location.Geofence;
29import android.location.Location;
30import android.location.LocationListener;
31import android.location.LocationManager;
32import android.location.LocationRequest;
33import android.os.Bundle;
34import android.os.Looper;
35import android.os.PowerManager;
36import android.os.SystemClock;
37
38public class GeofenceManager implements LocationListener, PendingIntent.OnFinished {
39    private static final String TAG = "GeofenceManager";
40
41    /**
42     * Assume a maximum land speed, as a heuristic to throttle location updates.
43     * (Air travel should result in an airplane mode toggle which will
44     * force a new location update anyway).
45     */
46    private static final int MAX_SPEED_M_S = 100;  // 360 km/hr (high speed train)
47
48    private final Context mContext;
49    private final LocationManager mLocationManager;
50    private final PowerManager.WakeLock mWakeLock;
51    private final Looper mLooper;  // looper thread to take location updates on
52
53    private Object mLock = new Object();
54
55    // access to members below is synchronized on mLock
56    private Location mLastLocation;
57    private List<GeofenceState> mFences = new LinkedList<GeofenceState>();
58
59    public GeofenceManager(Context context) {
60        mContext = context;
61        mLocationManager = (LocationManager) mContext.getSystemService(Context.LOCATION_SERVICE);
62        PowerManager powerManager = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
63        mWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
64        mLooper = Looper.myLooper();
65
66        LocationRequest request = new LocationRequest()
67                .setQuality(LocationRequest.POWER_NONE)
68                .setFastestInterval(0);
69        mLocationManager.requestLocationUpdates(request, this, Looper.myLooper());
70    }
71
72    public void addFence(LocationRequest request, Geofence geofence, PendingIntent intent, int uid,
73            String packageName) {
74        GeofenceState state = new GeofenceState(geofence, mLastLocation,
75                request.getExpireAt(), packageName, intent);
76
77        synchronized (mLock) {
78            // first make sure it doesn't already exist
79            for (int i = mFences.size() - 1; i >= 0; i--) {
80                GeofenceState w = mFences.get(i);
81                if (geofence.equals(w.mFence) && intent.equals(w.mIntent)) {
82                    // already exists, remove the old one
83                    mFences.remove(i);
84                    break;
85                }
86            }
87            mFences.add(state);
88            updateProviderRequirementsLocked();
89        }
90    }
91
92    public void removeFence(Geofence fence, PendingIntent intent) {
93        synchronized (mLock) {
94            Iterator<GeofenceState> iter = mFences.iterator();
95            while (iter.hasNext()) {
96                GeofenceState state = iter.next();
97                if (state.mIntent.equals(intent)) {
98
99                    if (fence == null) {
100                        // alwaus remove
101                        iter.remove();
102                    } else {
103                        // just remove matching fences
104                        if (fence.equals(state.mFence)) {
105                            iter.remove();
106                        }
107                    }
108                }
109            }
110            updateProviderRequirementsLocked();
111        }
112    }
113
114    public void removeFence(String packageName) {
115        synchronized (mLock) {
116            Iterator<GeofenceState> iter = mFences.iterator();
117            while (iter.hasNext()) {
118                GeofenceState state = iter.next();
119                if (state.mPackageName.equals(packageName)) {
120                    iter.remove();
121                }
122            }
123            updateProviderRequirementsLocked();
124        }
125    }
126
127    private void removeExpiredFencesLocked() {
128        long time = SystemClock.elapsedRealtime();
129        Iterator<GeofenceState> iter = mFences.iterator();
130        while (iter.hasNext()) {
131            GeofenceState state = iter.next();
132            if (state.mExpireAt < time) {
133                iter.remove();
134            }
135        }
136    }
137
138    private void processLocation(Location location) {
139        List<PendingIntent> enterIntents = new LinkedList<PendingIntent>();
140        List<PendingIntent> exitIntents = new LinkedList<PendingIntent>();
141
142        synchronized (mLock) {
143            mLastLocation = location;
144
145            removeExpiredFencesLocked();
146
147            for (GeofenceState state : mFences) {
148                int event = state.processLocation(location);
149                if ((event & GeofenceState.FLAG_ENTER) != 0) {
150                    enterIntents.add(state.mIntent);
151                }
152                if ((event & GeofenceState.FLAG_EXIT) != 0) {
153                    exitIntents.add(state.mIntent);
154                }
155            }
156            updateProviderRequirementsLocked();
157        }
158
159        // release lock before sending intents
160        for (PendingIntent intent : exitIntents) {
161            sendIntentExit(intent);
162        }
163        for (PendingIntent intent : enterIntents) {
164            sendIntentEnter(intent);
165        }
166    }
167
168    private void sendIntentEnter(PendingIntent pendingIntent) {
169        Intent intent = new Intent();
170        intent.putExtra(LocationManager.KEY_PROXIMITY_ENTERING, true);
171        sendIntent(pendingIntent, intent);
172    }
173
174    private void sendIntentExit(PendingIntent pendingIntent) {
175        Intent intent = new Intent();
176        intent.putExtra(LocationManager.KEY_PROXIMITY_ENTERING, false);
177        sendIntent(pendingIntent, intent);
178    }
179
180    private void sendIntent(PendingIntent pendingIntent, Intent intent) {
181        try {
182            mWakeLock.acquire();
183            pendingIntent.send(mContext, 0, intent, this, null, permission.ACCESS_FINE_LOCATION);
184        } catch (PendingIntent.CanceledException e) {
185            removeFence(null, pendingIntent);
186            mWakeLock.release();
187        }
188    }
189
190    private void updateProviderRequirementsLocked() {
191        double minDistance = Double.MAX_VALUE;
192        for (GeofenceState state : mFences) {
193            if (state.getDistance() < minDistance) {
194                minDistance = state.getDistance();
195            }
196        }
197
198        if (minDistance == Double.MAX_VALUE) {
199            disableLocationLocked();
200        } else {
201            int intervalMs = (int)(minDistance * 1000) / MAX_SPEED_M_S;
202            requestLocationLocked(intervalMs);
203        }
204    }
205
206    private void requestLocationLocked(int intervalMs) {
207        mLocationManager.requestLocationUpdates(new LocationRequest().setInterval(intervalMs), this,
208                mLooper);
209    }
210
211    private void disableLocationLocked() {
212        mLocationManager.removeUpdates(this);
213    }
214
215    @Override
216    public void onLocationChanged(Location location) {
217        processLocation(location);
218    }
219
220    @Override
221    public void onStatusChanged(String provider, int status, Bundle extras) { }
222
223    @Override
224    public void onProviderEnabled(String provider) { }
225
226    @Override
227    public void onProviderDisabled(String provider) { }
228
229    @Override
230    public void onSendFinished(PendingIntent pendingIntent, Intent intent, int resultCode,
231            String resultData, Bundle resultExtras) {
232        mWakeLock.release();
233    }
234
235    public void dump(PrintWriter pw) {
236        pw.println("  Geofences:");
237
238        for (GeofenceState state : mFences) {
239            pw.append("    ");
240            pw.append(state.mPackageName);
241            pw.append(" ");
242            pw.append(state.mFence.toString());
243            pw.append("\n");
244        }
245    }
246}
247