1/*
2 * Copyright (C) 2015 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.app.ActivityManager;
20import android.app.StatusBarManager;
21import android.content.BroadcastReceiver;
22import android.content.Context;
23import android.content.Intent;
24import android.content.IntentFilter;
25import android.content.res.Resources;
26import android.database.ContentObserver;
27import android.hardware.Sensor;
28import android.hardware.SensorEvent;
29import android.hardware.SensorEventListener;
30import android.hardware.SensorManager;
31import android.os.Handler;
32import android.os.PowerManager;
33import android.os.PowerManager.WakeLock;
34import android.os.SystemClock;
35import android.os.SystemProperties;
36import android.provider.Settings;
37import android.util.Slog;
38import android.view.KeyEvent;
39
40import com.android.internal.logging.MetricsLogger;
41import com.android.server.statusbar.StatusBarManagerInternal;
42
43/**
44 * The service that listens for gestures detected in sensor firmware and starts the intent
45 * accordingly.
46 * <p>For now, only camera launch gesture is supported, and in the future, more gestures can be
47 * added.</p>
48 * @hide
49 */
50public class GestureLauncherService extends SystemService {
51    private static final boolean DBG = false;
52    private static final String TAG = "GestureLauncherService";
53
54    /**
55     * Time in milliseconds in which the power button must be pressed twice so it will be considered
56     * as a camera launch.
57     */
58    private static final long CAMERA_POWER_DOUBLE_TAP_MAX_TIME_MS = 300;
59    private static final long CAMERA_POWER_DOUBLE_TAP_MIN_TIME_MS = 120;
60
61    /** The listener that receives the gesture event. */
62    private final GestureEventListener mGestureListener = new GestureEventListener();
63
64    private Sensor mCameraLaunchSensor;
65    private Context mContext;
66
67    /** The wake lock held when a gesture is detected. */
68    private WakeLock mWakeLock;
69    private boolean mRegistered;
70    private int mUserId;
71
72    // Below are fields used for event logging only.
73    /** Elapsed real time when the camera gesture is turned on. */
74    private long mCameraGestureOnTimeMs = 0L;
75
76    /** Elapsed real time when the last camera gesture was detected. */
77    private long mCameraGestureLastEventTime = 0L;
78
79    /**
80     * How long the sensor 1 has been turned on since camera launch sensor was
81     * subscribed to and when the last camera launch gesture was detected.
82     * <p>Sensor 1 is the main sensor used to detect camera launch gesture.</p>
83     */
84    private long mCameraGestureSensor1LastOnTimeMs = 0L;
85
86    /**
87     * If applicable, how long the sensor 2 has been turned on since camera
88     * launch sensor was subscribed to and when the last camera launch
89     * gesture was detected.
90     * <p>Sensor 2 is the secondary sensor used to detect camera launch gesture.
91     * This is optional and if only sensor 1 is used for detect camera launch
92     * gesture, this value would always be 0.</p>
93     */
94    private long mCameraGestureSensor2LastOnTimeMs = 0L;
95
96    /**
97     * Extra information about the event when the last camera launch gesture
98     * was detected.
99     */
100    private int mCameraLaunchLastEventExtra = 0;
101
102    /**
103     * Whether camera double tap power button gesture is currently enabled;
104     */
105    private boolean mCameraDoubleTapPowerEnabled;
106    private long mLastPowerDown;
107
108    public GestureLauncherService(Context context) {
109        super(context);
110        mContext = context;
111    }
112
113    public void onStart() {
114        LocalServices.addService(GestureLauncherService.class, this);
115    }
116
117    public void onBootPhase(int phase) {
118        if (phase == PHASE_THIRD_PARTY_APPS_CAN_START) {
119            Resources resources = mContext.getResources();
120            if (!isGestureLauncherEnabled(resources)) {
121                if (DBG) Slog.d(TAG, "Gesture launcher is disabled in system properties.");
122                return;
123            }
124
125            PowerManager powerManager = (PowerManager) mContext.getSystemService(
126                    Context.POWER_SERVICE);
127            mWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
128                    "GestureLauncherService");
129            updateCameraRegistered();
130            updateCameraDoubleTapPowerEnabled();
131
132            mUserId = ActivityManager.getCurrentUser();
133            mContext.registerReceiver(mUserReceiver, new IntentFilter(Intent.ACTION_USER_SWITCHED));
134            registerContentObservers();
135        }
136    }
137
138    private void registerContentObservers() {
139        mContext.getContentResolver().registerContentObserver(
140                Settings.Secure.getUriFor(Settings.Secure.CAMERA_GESTURE_DISABLED),
141                false, mSettingObserver, mUserId);
142        mContext.getContentResolver().registerContentObserver(
143                Settings.Secure.getUriFor(Settings.Secure.CAMERA_DOUBLE_TAP_POWER_GESTURE_DISABLED),
144                false, mSettingObserver, mUserId);
145    }
146
147    private void updateCameraRegistered() {
148        Resources resources = mContext.getResources();
149        if (isCameraLaunchSettingEnabled(mContext, mUserId)) {
150            registerCameraLaunchGesture(resources);
151        } else {
152            unregisterCameraLaunchGesture();
153        }
154    }
155
156    private void updateCameraDoubleTapPowerEnabled() {
157        boolean enabled = isCameraDoubleTapPowerSettingEnabled(mContext, mUserId);
158        synchronized (this) {
159            mCameraDoubleTapPowerEnabled = enabled;
160        }
161    }
162
163    private void unregisterCameraLaunchGesture() {
164        if (mRegistered) {
165            mRegistered = false;
166            mCameraGestureOnTimeMs = 0L;
167            mCameraGestureLastEventTime = 0L;
168            mCameraGestureSensor1LastOnTimeMs = 0;
169            mCameraGestureSensor2LastOnTimeMs = 0;
170            mCameraLaunchLastEventExtra = 0;
171
172            SensorManager sensorManager = (SensorManager) mContext.getSystemService(
173                    Context.SENSOR_SERVICE);
174            sensorManager.unregisterListener(mGestureListener);
175        }
176    }
177
178    /**
179     * Registers for the camera launch gesture.
180     */
181    private void registerCameraLaunchGesture(Resources resources) {
182        if (mRegistered) {
183            return;
184        }
185        mCameraGestureOnTimeMs = SystemClock.elapsedRealtime();
186        mCameraGestureLastEventTime = mCameraGestureOnTimeMs;
187        SensorManager sensorManager = (SensorManager) mContext.getSystemService(
188                Context.SENSOR_SERVICE);
189        int cameraLaunchGestureId = resources.getInteger(
190                com.android.internal.R.integer.config_cameraLaunchGestureSensorType);
191        if (cameraLaunchGestureId != -1) {
192            mRegistered = false;
193            String sensorName = resources.getString(
194                com.android.internal.R.string.config_cameraLaunchGestureSensorStringType);
195            mCameraLaunchSensor = sensorManager.getDefaultSensor(
196                    cameraLaunchGestureId,
197                    true /*wakeUp*/);
198
199            // Compare the camera gesture string type to that in the resource file to make
200            // sure we are registering the correct sensor. This is redundant check, it
201            // makes the code more robust.
202            if (mCameraLaunchSensor != null) {
203                if (sensorName.equals(mCameraLaunchSensor.getStringType())) {
204                    mRegistered = sensorManager.registerListener(mGestureListener,
205                            mCameraLaunchSensor, 0);
206                } else {
207                    String message = String.format("Wrong configuration. Sensor type and sensor "
208                            + "string type don't match: %s in resources, %s in the sensor.",
209                            sensorName, mCameraLaunchSensor.getStringType());
210                    throw new RuntimeException(message);
211                }
212            }
213            if (DBG) Slog.d(TAG, "Camera launch sensor registered: " + mRegistered);
214        } else {
215            if (DBG) Slog.d(TAG, "Camera launch sensor is not specified.");
216        }
217    }
218
219    public static boolean isCameraLaunchSettingEnabled(Context context, int userId) {
220        return isCameraLaunchEnabled(context.getResources())
221                && (Settings.Secure.getIntForUser(context.getContentResolver(),
222                        Settings.Secure.CAMERA_GESTURE_DISABLED, 0, userId) == 0);
223    }
224
225    public static boolean isCameraDoubleTapPowerSettingEnabled(Context context, int userId) {
226        return isCameraDoubleTapPowerEnabled(context.getResources())
227                && (Settings.Secure.getIntForUser(context.getContentResolver(),
228                        Settings.Secure.CAMERA_DOUBLE_TAP_POWER_GESTURE_DISABLED, 0, userId) == 0);
229    }
230
231    /**
232     * Whether to enable the camera launch gesture.
233     */
234    public static boolean isCameraLaunchEnabled(Resources resources) {
235        boolean configSet = resources.getInteger(
236                com.android.internal.R.integer.config_cameraLaunchGestureSensorType) != -1;
237        return configSet &&
238                !SystemProperties.getBoolean("gesture.disable_camera_launch", false);
239    }
240
241    public static boolean isCameraDoubleTapPowerEnabled(Resources resources) {
242        return resources.getBoolean(
243                com.android.internal.R.bool.config_cameraDoubleTapPowerGestureEnabled);
244    }
245
246    /**
247     * Whether GestureLauncherService should be enabled according to system properties.
248     */
249    public static boolean isGestureLauncherEnabled(Resources resources) {
250        return isCameraLaunchEnabled(resources) || isCameraDoubleTapPowerEnabled(resources);
251    }
252
253    public boolean interceptPowerKeyDown(KeyEvent event, boolean interactive) {
254        boolean launched = false;
255        boolean intercept = false;
256        long doubleTapInterval;
257        synchronized (this) {
258            doubleTapInterval = event.getEventTime() - mLastPowerDown;
259            if (mCameraDoubleTapPowerEnabled
260                    && doubleTapInterval < CAMERA_POWER_DOUBLE_TAP_MAX_TIME_MS
261                    && doubleTapInterval > CAMERA_POWER_DOUBLE_TAP_MIN_TIME_MS) {
262                launched = true;
263                intercept = interactive;
264            }
265            mLastPowerDown = event.getEventTime();
266        }
267        if (launched) {
268            Slog.i(TAG, "Power button double tap gesture detected, launching camera. Interval="
269                    + doubleTapInterval + "ms");
270            launched = handleCameraLaunchGesture(false /* useWakelock */,
271                    StatusBarManager.CAMERA_LAUNCH_SOURCE_POWER_DOUBLE_TAP);
272            if (launched) {
273                MetricsLogger.action(mContext, MetricsLogger.ACTION_DOUBLE_TAP_POWER_CAMERA_GESTURE,
274                        (int) doubleTapInterval);
275            }
276        }
277        MetricsLogger.histogram(mContext, "power_double_tap_interval", (int) doubleTapInterval);
278        return intercept && launched;
279    }
280
281    /**
282     * @return true if camera was launched, false otherwise.
283     */
284    private boolean handleCameraLaunchGesture(boolean useWakelock, int source) {
285        boolean userSetupComplete = Settings.Secure.getInt(mContext.getContentResolver(),
286                Settings.Secure.USER_SETUP_COMPLETE, 0) != 0;
287        if (!userSetupComplete) {
288            if (DBG) Slog.d(TAG, String.format(
289                    "userSetupComplete = %s, ignoring camera launch gesture.",
290                    userSetupComplete));
291            return false;
292        }
293        if (DBG) Slog.d(TAG, String.format(
294                "userSetupComplete = %s, performing camera launch gesture.",
295                userSetupComplete));
296
297        if (useWakelock) {
298            // Make sure we don't sleep too early
299            mWakeLock.acquire(500L);
300        }
301        StatusBarManagerInternal service = LocalServices.getService(
302                StatusBarManagerInternal.class);
303        service.onCameraLaunchGestureDetected(source);
304        return true;
305    }
306
307    private final BroadcastReceiver mUserReceiver = new BroadcastReceiver() {
308        @Override
309        public void onReceive(Context context, Intent intent) {
310            if (Intent.ACTION_USER_SWITCHED.equals(intent.getAction())) {
311                mUserId = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0);
312                mContext.getContentResolver().unregisterContentObserver(mSettingObserver);
313                registerContentObservers();
314                updateCameraRegistered();
315                updateCameraDoubleTapPowerEnabled();
316            }
317        }
318    };
319
320    private final ContentObserver mSettingObserver = new ContentObserver(new Handler()) {
321        public void onChange(boolean selfChange, android.net.Uri uri, int userId) {
322            if (userId == mUserId) {
323                updateCameraRegistered();
324                updateCameraDoubleTapPowerEnabled();
325            }
326        }
327    };
328
329    private final class GestureEventListener implements SensorEventListener {
330        @Override
331        public void onSensorChanged(SensorEvent event) {
332            if (!mRegistered) {
333              if (DBG) Slog.d(TAG, "Ignoring gesture event because it's unregistered.");
334              return;
335            }
336            if (event.sensor == mCameraLaunchSensor) {
337                if (DBG) {
338                    float[] values = event.values;
339                    Slog.d(TAG, String.format("Received a camera launch event: " +
340                            "values=[%.4f, %.4f, %.4f].", values[0], values[1], values[2]));
341                }
342                if (handleCameraLaunchGesture(true /* useWakelock */,
343                        StatusBarManager.CAMERA_LAUNCH_SOURCE_WIGGLE)) {
344                    MetricsLogger.action(mContext, MetricsLogger.ACTION_WIGGLE_CAMERA_GESTURE);
345                    trackCameraLaunchEvent(event);
346                }
347                return;
348            }
349        }
350
351        @Override
352        public void onAccuracyChanged(Sensor sensor, int accuracy) {
353            // Ignored.
354        }
355
356        private void trackCameraLaunchEvent(SensorEvent event) {
357            long now = SystemClock.elapsedRealtime();
358            long totalDuration = now - mCameraGestureOnTimeMs;
359            // values[0]: ratio between total time duration when accel is turned on and time
360            //            duration since camera launch gesture is subscribed.
361            // values[1]: ratio between total time duration when gyro is turned on and time duration
362            //            since camera launch gesture is subscribed.
363            // values[2]: extra information
364            float[] values = event.values;
365
366            long sensor1OnTime = (long) (totalDuration * (double) values[0]);
367            long sensor2OnTime = (long) (totalDuration * (double) values[1]);
368            int extra = (int) values[2];
369
370            // We only log the difference in the event log to make aggregation easier.
371            long gestureOnTimeDiff = now - mCameraGestureLastEventTime;
372            long sensor1OnTimeDiff = sensor1OnTime - mCameraGestureSensor1LastOnTimeMs;
373            long sensor2OnTimeDiff = sensor2OnTime - mCameraGestureSensor2LastOnTimeMs;
374            int extraDiff = extra - mCameraLaunchLastEventExtra;
375
376            // Gating against negative time difference. This doesn't usually happen, but it may
377            // happen because of numeric errors.
378            if (gestureOnTimeDiff < 0 || sensor1OnTimeDiff < 0 || sensor2OnTimeDiff < 0) {
379                if (DBG) Slog.d(TAG, "Skipped event logging because negative numbers.");
380                return;
381            }
382
383            if (DBG) Slog.d(TAG, String.format("totalDuration: %d, sensor1OnTime: %s, " +
384                    "sensor2OnTime: %d, extra: %d",
385                    gestureOnTimeDiff,
386                    sensor1OnTimeDiff,
387                    sensor2OnTimeDiff,
388                    extraDiff));
389            EventLogTags.writeCameraGestureTriggered(
390                    gestureOnTimeDiff,
391                    sensor1OnTimeDiff,
392                    sensor2OnTimeDiff,
393                    extraDiff);
394
395            mCameraGestureLastEventTime = now;
396            mCameraGestureSensor1LastOnTimeMs = sensor1OnTime;
397            mCameraGestureSensor2LastOnTimeMs = sensor2OnTime;
398            mCameraLaunchLastEventExtra = extra;
399        }
400    }
401}
402