2 * Copyright (C) 2009 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 package com.android.camera;
19 import static com.android.camera.Util.Assert;
21 import android.hardware.Camera.CameraInfo;
22 import android.hardware.Camera.Parameters;
23 import android.os.Build;
24 import android.os.Handler;
25 import android.os.HandlerThread;
26 import android.os.Looper;
27 import android.os.Message;
28 import android.util.Log;
30 import com.android.camera.CameraManager.CameraProxy;
32 import java.io.IOException;
33 import java.text.SimpleDateFormat;
34 import java.util.ArrayList;
35 import java.util.Date;
38 * The class is used to hold an {@code android.hardware.Camera} instance.
40 * <p>The {@code open()} and {@code release()} calls are similar to the ones
41 * in {@code android.hardware.Camera}. The difference is if {@code keep()} is
42 * called before {@code release()}, CameraHolder will try to hold the {@code
43 * android.hardware.Camera} instance for a while, so if {@code open()} is
44 * called soon after, we can avoid the cost of {@code open()} in {@code
45 * android.hardware.Camera}.
47 * <p>This is used in switching between different modules.
49 public class CameraHolder {
50 private static final String TAG = "CameraHolder";
51 private static final int KEEP_CAMERA_TIMEOUT = 3000; // 3 seconds
52 private CameraProxy mCameraDevice;
53 private long mKeepBeforeTime; // Keep the Camera before this time.
54 private final Handler mHandler;
55 private boolean mCameraOpened; // true if camera is opened
56 private final int mNumberOfCameras;
57 private int mCameraId = -1; // current camera id
58 private int mBackCameraId = -1;
59 private int mFrontCameraId = -1;
60 private final CameraInfo[] mInfo;
61 private static CameraProxy mMockCamera[];
62 private static CameraInfo mMockCameraInfo[];
64 /* Debug double-open issue */
65 private static final boolean DEBUG_OPEN_RELEASE = true;
66 private static class OpenReleaseState {
72 private static ArrayList<OpenReleaseState> sOpenReleaseStates =
73 new ArrayList<OpenReleaseState>();
74 private static SimpleDateFormat sDateFormat = new SimpleDateFormat(
75 "yyyy-MM-dd HH:mm:ss.SSS");
77 private static synchronized void collectState(int id, CameraProxy device) {
78 OpenReleaseState s = new OpenReleaseState();
79 s.time = System.currentTimeMillis();
84 s.device = device.toString();
87 StackTraceElement[] stack = Thread.currentThread().getStackTrace();
88 String[] lines = new String[stack.length];
89 for (int i = 0; i < stack.length; i++) {
90 lines[i] = stack[i].toString();
94 if (sOpenReleaseStates.size() > 10) {
95 sOpenReleaseStates.remove(0);
97 sOpenReleaseStates.add(s);
100 private static synchronized void dumpStates() {
101 for (int i = sOpenReleaseStates.size() - 1; i >= 0; i--) {
102 OpenReleaseState s = sOpenReleaseStates.get(i);
103 String date = sDateFormat.format(new Date(s.time));
104 Log.d(TAG, "State " + i + " at " + date);
105 Log.d(TAG, "mCameraId = " + s.id + ", mCameraDevice = " + s.device);
106 Log.d(TAG, "Stack:");
107 for (int j = 0; j < s.stack.length; j++) {
108 Log.d(TAG, " " + s.stack[j]);
113 // We store the camera parameters when we actually open the device,
114 // so we can restore them in the subsequent open() requests by the user.
115 // This prevents the parameters set by PhotoModule used by VideoModule
117 private Parameters mParameters;
120 private static CameraHolder sHolder;
121 public static synchronized CameraHolder instance() {
122 if (sHolder == null) {
123 sHolder = new CameraHolder();
128 private static final int RELEASE_CAMERA = 1;
129 private class MyHandler extends Handler {
130 MyHandler(Looper looper) {
135 public void handleMessage(Message msg) {
138 synchronized (CameraHolder.this) {
139 // In 'CameraHolder.open', the 'RELEASE_CAMERA' message
140 // will be removed if it is found in the queue. However,
141 // there is a chance that this message has been handled
142 // before being removed. So, we need to add a check
144 if (!mCameraOpened) release();
151 public static void injectMockCamera(CameraInfo[] info, CameraProxy[] camera) {
152 mMockCameraInfo = info;
153 mMockCamera = camera;
154 sHolder = new CameraHolder();
157 private CameraHolder() {
158 HandlerThread ht = new HandlerThread("CameraHolder");
160 mHandler = new MyHandler(ht.getLooper());
161 if (mMockCameraInfo != null) {
162 mNumberOfCameras = mMockCameraInfo.length;
163 mInfo = mMockCameraInfo;
165 mNumberOfCameras = android.hardware.Camera.getNumberOfCameras();
166 mInfo = new CameraInfo[mNumberOfCameras];
167 for (int i = 0; i < mNumberOfCameras; i++) {
168 mInfo[i] = new CameraInfo();
169 android.hardware.Camera.getCameraInfo(i, mInfo[i]);
173 // get the first (smallest) back and first front camera id
174 for (int i = 0; i < mNumberOfCameras; i++) {
175 if (mBackCameraId == -1 && mInfo[i].facing == CameraInfo.CAMERA_FACING_BACK) {
177 } else if (mFrontCameraId == -1 && mInfo[i].facing == CameraInfo.CAMERA_FACING_FRONT) {
183 public int getNumberOfCameras() {
184 return mNumberOfCameras;
187 public CameraInfo[] getCameraInfo() {
191 public synchronized CameraProxy open(int cameraId)
192 throws CameraHardwareException {
193 if (DEBUG_OPEN_RELEASE) {
194 collectState(cameraId, mCameraDevice);
196 Log.e(TAG, "double open");
200 Assert(!mCameraOpened);
201 if (mCameraDevice != null && mCameraId != cameraId) {
202 mCameraDevice.release();
203 mCameraDevice = null;
206 if (mCameraDevice == null) {
208 Log.v(TAG, "open camera " + cameraId);
209 if (mMockCameraInfo == null) {
210 mCameraDevice = CameraManagerFactory
211 .getAndroidCameraManager().cameraOpen(cameraId);
213 if (mMockCamera == null)
214 throw new RuntimeException();
215 mCameraDevice = mMockCamera[cameraId];
217 mCameraId = cameraId;
218 } catch (RuntimeException e) {
219 Log.e(TAG, "fail to connect Camera", e);
220 throw new CameraHardwareException(e);
222 mParameters = mCameraDevice.getParameters();
225 mCameraDevice.reconnect();
226 } catch (IOException e) {
227 Log.e(TAG, "reconnect failed.");
228 throw new CameraHardwareException(e);
230 mCameraDevice.setParameters(mParameters);
232 mCameraOpened = true;
233 mHandler.removeMessages(RELEASE_CAMERA);
235 return mCameraDevice;
239 * Tries to open the hardware camera. If the camera is being used or
240 * unavailable then return {@code null}.
242 public synchronized CameraProxy tryOpen(int cameraId) {
244 return !mCameraOpened ? open(cameraId) : null;
245 } catch (CameraHardwareException e) {
246 // In eng build, we throw the exception so that test tool
247 // can detect it and report it
248 if ("eng".equals(Build.TYPE)) {
249 throw new RuntimeException(e);
255 public synchronized void release() {
256 if (DEBUG_OPEN_RELEASE) {
257 collectState(mCameraId, mCameraDevice);
260 if (mCameraDevice == null) return;
262 long now = System.currentTimeMillis();
263 if (now < mKeepBeforeTime) {
265 mCameraOpened = false;
266 mCameraDevice.stopPreview();
268 mHandler.sendEmptyMessageDelayed(RELEASE_CAMERA,
269 mKeepBeforeTime - now);
272 mCameraOpened = false;
273 mCameraDevice.release();
274 mCameraDevice = null;
275 // We must set this to null because it has a reference to Camera.
276 // Camera has references to the listeners.
282 keep(KEEP_CAMERA_TIMEOUT);
285 public synchronized void keep(int time) {
286 // We allow mCameraOpened in either state for the convenience of the
287 // calling activity. The activity may not have a chance to call open()
288 // before the user switches to another activity.
289 mKeepBeforeTime = System.currentTimeMillis() + time;
292 public int getBackCameraId() {
293 return mBackCameraId;
296 public int getFrontCameraId() {
297 return mFrontCameraId;