1/*
2 * Copyright (C) 2014 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.systemui.statusbar.policy;
18
19import android.content.Context;
20import android.content.pm.PackageManager;
21import android.hardware.camera2.CameraAccessException;
22import android.hardware.camera2.CameraCharacteristics;
23import android.hardware.camera2.CameraManager;
24import android.os.Handler;
25import android.os.HandlerThread;
26import android.os.Process;
27import android.text.TextUtils;
28import android.util.Log;
29
30import com.android.systemui.statusbar.policy.FlashlightController.FlashlightListener;
31
32import java.io.FileDescriptor;
33import java.io.PrintWriter;
34import java.lang.ref.WeakReference;
35import java.util.ArrayList;
36
37/**
38 * Manages the flashlight.
39 */
40public class FlashlightControllerImpl implements FlashlightController {
41
42    private static final String TAG = "FlashlightController";
43    private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
44
45    private static final int DISPATCH_ERROR = 0;
46    private static final int DISPATCH_CHANGED = 1;
47    private static final int DISPATCH_AVAILABILITY_CHANGED = 2;
48
49    private final CameraManager mCameraManager;
50    private final Context mContext;
51    /** Call {@link #ensureHandler()} before using */
52    private Handler mHandler;
53
54    /** Lock on mListeners when accessing */
55    private final ArrayList<WeakReference<FlashlightListener>> mListeners = new ArrayList<>(1);
56
57    /** Lock on {@code this} when accessing */
58    private boolean mFlashlightEnabled;
59
60    private String mCameraId;
61    private boolean mTorchAvailable;
62
63    public FlashlightControllerImpl(Context context) {
64        mContext = context;
65        mCameraManager = (CameraManager) mContext.getSystemService(Context.CAMERA_SERVICE);
66
67        tryInitCamera();
68    }
69
70    private void tryInitCamera() {
71        try {
72            mCameraId = getCameraId();
73        } catch (Throwable e) {
74            Log.e(TAG, "Couldn't initialize.", e);
75            return;
76        }
77
78        if (mCameraId != null) {
79            ensureHandler();
80            mCameraManager.registerTorchCallback(mTorchCallback, mHandler);
81        }
82    }
83
84    public void setFlashlight(boolean enabled) {
85        boolean pendingError = false;
86        synchronized (this) {
87            if (mCameraId == null) return;
88            if (mFlashlightEnabled != enabled) {
89                mFlashlightEnabled = enabled;
90                try {
91                    mCameraManager.setTorchMode(mCameraId, enabled);
92                } catch (CameraAccessException e) {
93                    Log.e(TAG, "Couldn't set torch mode", e);
94                    mFlashlightEnabled = false;
95                    pendingError = true;
96                }
97            }
98        }
99        dispatchModeChanged(mFlashlightEnabled);
100        if (pendingError) {
101            dispatchError();
102        }
103    }
104
105    public boolean hasFlashlight() {
106        return mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
107    }
108
109    public synchronized boolean isEnabled() {
110        return mFlashlightEnabled;
111    }
112
113    public synchronized boolean isAvailable() {
114        return mTorchAvailable;
115    }
116
117    public void addCallback(FlashlightListener l) {
118        synchronized (mListeners) {
119            if (mCameraId == null) {
120                tryInitCamera();
121            }
122            cleanUpListenersLocked(l);
123            mListeners.add(new WeakReference<>(l));
124            l.onFlashlightAvailabilityChanged(mTorchAvailable);
125            l.onFlashlightChanged(mFlashlightEnabled);
126        }
127    }
128
129    public void removeCallback(FlashlightListener l) {
130        synchronized (mListeners) {
131            cleanUpListenersLocked(l);
132        }
133    }
134
135    private synchronized void ensureHandler() {
136        if (mHandler == null) {
137            HandlerThread thread = new HandlerThread(TAG, Process.THREAD_PRIORITY_BACKGROUND);
138            thread.start();
139            mHandler = new Handler(thread.getLooper());
140        }
141    }
142
143    private String getCameraId() throws CameraAccessException {
144        String[] ids = mCameraManager.getCameraIdList();
145        for (String id : ids) {
146            CameraCharacteristics c = mCameraManager.getCameraCharacteristics(id);
147            Boolean flashAvailable = c.get(CameraCharacteristics.FLASH_INFO_AVAILABLE);
148            Integer lensFacing = c.get(CameraCharacteristics.LENS_FACING);
149            if (flashAvailable != null && flashAvailable
150                    && lensFacing != null && lensFacing == CameraCharacteristics.LENS_FACING_BACK) {
151                return id;
152            }
153        }
154        return null;
155    }
156
157    private void dispatchModeChanged(boolean enabled) {
158        dispatchListeners(DISPATCH_CHANGED, enabled);
159    }
160
161    private void dispatchError() {
162        dispatchListeners(DISPATCH_CHANGED, false /* argument (ignored) */);
163    }
164
165    private void dispatchAvailabilityChanged(boolean available) {
166        dispatchListeners(DISPATCH_AVAILABILITY_CHANGED, available);
167    }
168
169    private void dispatchListeners(int message, boolean argument) {
170        synchronized (mListeners) {
171            final int N = mListeners.size();
172            boolean cleanup = false;
173            for (int i = 0; i < N; i++) {
174                FlashlightListener l = mListeners.get(i).get();
175                if (l != null) {
176                    if (message == DISPATCH_ERROR) {
177                        l.onFlashlightError();
178                    } else if (message == DISPATCH_CHANGED) {
179                        l.onFlashlightChanged(argument);
180                    } else if (message == DISPATCH_AVAILABILITY_CHANGED) {
181                        l.onFlashlightAvailabilityChanged(argument);
182                    }
183                } else {
184                    cleanup = true;
185                }
186            }
187            if (cleanup) {
188                cleanUpListenersLocked(null);
189            }
190        }
191    }
192
193    private void cleanUpListenersLocked(FlashlightListener listener) {
194        for (int i = mListeners.size() - 1; i >= 0; i--) {
195            FlashlightListener found = mListeners.get(i).get();
196            if (found == null || found == listener) {
197                mListeners.remove(i);
198            }
199        }
200    }
201
202    private final CameraManager.TorchCallback mTorchCallback =
203            new CameraManager.TorchCallback() {
204
205        @Override
206        public void onTorchModeUnavailable(String cameraId) {
207            if (TextUtils.equals(cameraId, mCameraId)) {
208                setCameraAvailable(false);
209            }
210        }
211
212        @Override
213        public void onTorchModeChanged(String cameraId, boolean enabled) {
214            if (TextUtils.equals(cameraId, mCameraId)) {
215                setCameraAvailable(true);
216                setTorchMode(enabled);
217            }
218        }
219
220        private void setCameraAvailable(boolean available) {
221            boolean changed;
222            synchronized (FlashlightControllerImpl.this) {
223                changed = mTorchAvailable != available;
224                mTorchAvailable = available;
225            }
226            if (changed) {
227                if (DEBUG) Log.d(TAG, "dispatchAvailabilityChanged(" + available + ")");
228                dispatchAvailabilityChanged(available);
229            }
230        }
231
232        private void setTorchMode(boolean enabled) {
233            boolean changed;
234            synchronized (FlashlightControllerImpl.this) {
235                changed = mFlashlightEnabled != enabled;
236                mFlashlightEnabled = enabled;
237            }
238            if (changed) {
239                if (DEBUG) Log.d(TAG, "dispatchModeChanged(" + enabled + ")");
240                dispatchModeChanged(enabled);
241            }
242        }
243    };
244
245    public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
246        pw.println("FlashlightController state:");
247
248        pw.print("  mCameraId=");
249        pw.println(mCameraId);
250        pw.print("  mFlashlightEnabled=");
251        pw.println(mFlashlightEnabled);
252        pw.print("  mTorchAvailable=");
253        pw.println(mTorchAvailable);
254    }
255}
256