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/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.camera;
import static com.android.camera.Util.Assert;
import android.hardware.Camera.CameraInfo;
import android.hardware.Camera.Parameters;
import android.os.Build;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
import com.android.camera.CameraManager.CameraProxy;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
/**
* The class is used to hold an {@code android.hardware.Camera} instance.
*
* <p>The {@code open()} and {@code release()} calls are similar to the ones
* in {@code android.hardware.Camera}. The difference is if {@code keep()} is
* called before {@code release()}, CameraHolder will try to hold the {@code
* android.hardware.Camera} instance for a while, so if {@code open()} is
* called soon after, we can avoid the cost of {@code open()} in {@code
* android.hardware.Camera}.
*
* <p>This is used in switching between different modules.
*/
public class CameraHolder {
private static final String TAG = "CameraHolder";
private static final int KEEP_CAMERA_TIMEOUT = 3000; // 3 seconds
private CameraProxy mCameraDevice;
private long mKeepBeforeTime; // Keep the Camera before this time.
private final Handler mHandler;
private boolean mCameraOpened; // true if camera is opened
private final int mNumberOfCameras;
private int mCameraId = -1; // current camera id
private int mBackCameraId = -1;
private int mFrontCameraId = -1;
private final CameraInfo[] mInfo;
private static CameraProxy mMockCamera[];
private static CameraInfo mMockCameraInfo[];
/* Debug double-open issue */
private static final boolean DEBUG_OPEN_RELEASE = true;
private static class OpenReleaseState {
long time;
int id;
String device;
String[] stack;
}
private static ArrayList<OpenReleaseState> sOpenReleaseStates =
new ArrayList<OpenReleaseState>();
private static SimpleDateFormat sDateFormat = new SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss.SSS");
private static synchronized void collectState(int id, CameraProxy device) {
OpenReleaseState s = new OpenReleaseState();
s.time = System.currentTimeMillis();
s.id = id;
if (device == null) {
s.device = "(null)";
} else {
s.device = device.toString();
}
StackTraceElement[] stack = Thread.currentThread().getStackTrace();
String[] lines = new String[stack.length];
for (int i = 0; i < stack.length; i++) {
lines[i] = stack[i].toString();
}
s.stack = lines;
if (sOpenReleaseStates.size() > 10) {
sOpenReleaseStates.remove(0);
}
sOpenReleaseStates.add(s);
}
private static synchronized void dumpStates() {
for (int i = sOpenReleaseStates.size() - 1; i >= 0; i--) {
OpenReleaseState s = sOpenReleaseStates.get(i);
String date = sDateFormat.format(new Date(s.time));
Log.d(TAG, "State " + i + " at " + date);
Log.d(TAG, "mCameraId = " + s.id + ", mCameraDevice = " + s.device);
Log.d(TAG, "Stack:");
for (int j = 0; j < s.stack.length; j++) {
Log.d(TAG, " " + s.stack[j]);
}
}
}
// We store the camera parameters when we actually open the device,
// so we can restore them in the subsequent open() requests by the user.
// This prevents the parameters set by PhotoModule used by VideoModule
// inadvertently.
private Parameters mParameters;
// Use a singleton.
private static CameraHolder sHolder;
public static synchronized CameraHolder instance() {
if (sHolder == null) {
sHolder = new CameraHolder();
}
return sHolder;
}
private static final int RELEASE_CAMERA = 1;
private class MyHandler extends Handler {
MyHandler(Looper looper) {
super(looper);
}
@Override
public void handleMessage(Message msg) {
switch(msg.what) {
case RELEASE_CAMERA:
synchronized (CameraHolder.this) {
// In 'CameraHolder.open', the 'RELEASE_CAMERA' message
// will be removed if it is found in the queue. However,
// there is a chance that this message has been handled
// before being removed. So, we need to add a check
// here:
if (!mCameraOpened) release();
}
break;
}
}
}
public static void injectMockCamera(CameraInfo[] info, CameraProxy[] camera) {
mMockCameraInfo = info;
mMockCamera = camera;
sHolder = new CameraHolder();
}
private CameraHolder() {
HandlerThread ht = new HandlerThread("CameraHolder");
ht.start();
mHandler = new MyHandler(ht.getLooper());
if (mMockCameraInfo != null) {
mNumberOfCameras = mMockCameraInfo.length;
mInfo = mMockCameraInfo;
} else {
mNumberOfCameras = android.hardware.Camera.getNumberOfCameras();
mInfo = new CameraInfo[mNumberOfCameras];
for (int i = 0; i < mNumberOfCameras; i++) {
mInfo[i] = new CameraInfo();
android.hardware.Camera.getCameraInfo(i, mInfo[i]);
}
}
// get the first (smallest) back and first front camera id
for (int i = 0; i < mNumberOfCameras; i++) {
if (mBackCameraId == -1 && mInfo[i].facing == CameraInfo.CAMERA_FACING_BACK) {
mBackCameraId = i;
} else if (mFrontCameraId == -1 && mInfo[i].facing == CameraInfo.CAMERA_FACING_FRONT) {
mFrontCameraId = i;
}
}
}
public int getNumberOfCameras() {
return mNumberOfCameras;
}
public CameraInfo[] getCameraInfo() {
return mInfo;
}
public synchronized CameraProxy open(int cameraId)
throws CameraHardwareException {
if (DEBUG_OPEN_RELEASE) {
collectState(cameraId, mCameraDevice);
if (mCameraOpened) {
Log.e(TAG, "double open");
dumpStates();
}
}
Assert(!mCameraOpened);
if (mCameraDevice != null && mCameraId != cameraId) {
mCameraDevice.release();
mCameraDevice = null;
mCameraId = -1;
}
if (mCameraDevice == null) {
try {
Log.v(TAG, "open camera " + cameraId);
if (mMockCameraInfo == null) {
mCameraDevice = CameraManager.instance().cameraOpen(cameraId);
} else {
if (mMockCamera == null)
throw new RuntimeException();
mCameraDevice = mMockCamera[cameraId];
}
mCameraId = cameraId;
} catch (RuntimeException e) {
Log.e(TAG, "fail to connect Camera", e);
throw new CameraHardwareException(e);
}
mParameters = mCameraDevice.getParameters();
} else {
try {
mCameraDevice.reconnect();
} catch (IOException e) {
Log.e(TAG, "reconnect failed.");
throw new CameraHardwareException(e);
}
mCameraDevice.setParameters(mParameters);
}
mCameraOpened = true;
mHandler.removeMessages(RELEASE_CAMERA);
mKeepBeforeTime = 0;
return mCameraDevice;
}
/**
* Tries to open the hardware camera. If the camera is being used or
* unavailable then return {@code null}.
*/
public synchronized CameraProxy tryOpen(int cameraId) {
try {
return !mCameraOpened ? open(cameraId) : null;
} catch (CameraHardwareException e) {
// In eng build, we throw the exception so that test tool
// can detect it and report it
if ("eng".equals(Build.TYPE)) {
throw new RuntimeException(e);
}
return null;
}
}
public synchronized void release() {
if (DEBUG_OPEN_RELEASE) {
collectState(mCameraId, mCameraDevice);
}
if (mCameraDevice == null) return;
long now = System.currentTimeMillis();
if (now < mKeepBeforeTime) {
if (mCameraOpened) {
mCameraOpened = false;
mCameraDevice.stopPreview();
}
mHandler.sendEmptyMessageDelayed(RELEASE_CAMERA,
mKeepBeforeTime - now);
return;
}
mCameraOpened = false;
mCameraDevice.release();
mCameraDevice = null;
// We must set this to null because it has a reference to Camera.
// Camera has references to the listeners.
mParameters = null;
mCameraId = -1;
}
public void keep() {
keep(KEEP_CAMERA_TIMEOUT);
}
public synchronized void keep(int time) {
// We allow mCameraOpened in either state for the convenience of the
// calling activity. The activity may not have a chance to call open()
// before the user switches to another activity.
mKeepBeforeTime = System.currentTimeMillis() + time;
}
public int getBackCameraId() {
return mBackCameraId;
}
public int getFrontCameraId() {
return mFrontCameraId;
}
}