Refactor CameraManager.

1. CameraManager should be the only class accessing android.hardware.Camera.
2. For potential future upgrade in Camera HAL and android.hardward.Camera API
   upgrade, CameraManager should be just an interface instead of concrete
   implementation.
3. waitDone() in CameraProxy is removed.
4. ShutterCallback, PreviewCallback, PictureCallback and AF Callbacks are
   wrapped by our own interfaces.

Change-Id: I595da17a1a9c6d476ee805b71c7f45ebb609e465
diff --git a/src/com/android/camera/AndroidCameraManagerImpl.java b/src/com/android/camera/AndroidCameraManagerImpl.java
new file mode 100644
index 0000000..8ffdb42
--- /dev/null
+++ b/src/com/android/camera/AndroidCameraManagerImpl.java
@@ -0,0 +1,737 @@
+/*
+ * Copyright (C) 2013 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.annotation.TargetApi;
+import android.graphics.SurfaceTexture;
+import android.hardware.Camera;
+import android.hardware.Camera.AutoFocusCallback;
+import android.hardware.Camera.AutoFocusMoveCallback;
+import android.hardware.Camera.ErrorCallback;
+import android.hardware.Camera.FaceDetectionListener;
+import android.hardware.Camera.OnZoomChangeListener;
+import android.hardware.Camera.Parameters;
+import android.hardware.Camera.PictureCallback;
+import android.hardware.Camera.PreviewCallback;
+import android.hardware.Camera.ShutterCallback;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Looper;
+import android.os.Message;
+import android.util.Log;
+import android.view.SurfaceHolder;
+
+import com.android.gallery3d.common.ApiHelper;
+
+import java.io.IOException;
+
+/**
+ * A class to implement {@link CameraManager} of the Android camera framework.
+ */
+class AndroidCameraManagerImpl implements CameraManager {
+    private static final String TAG = "CAM_" +
+            AndroidCameraManagerImpl.class.getSimpleName();
+
+    private Parameters mParameters;
+    private boolean mParametersIsDirty;
+    private IOException mReconnectIOException;
+
+    /* Messages used in CameraHandler. */
+    // Camera initialization/finalization
+    private static final int OPEN_CAMERA = 1;
+    private static final int RELEASE =     2;
+    private static final int RECONNECT =   3;
+    private static final int UNLOCK =      4;
+    private static final int LOCK =        5;
+    // Preview
+    private static final int SET_PREVIEW_TEXTURE_ASYNC =        101;
+    private static final int START_PREVIEW_ASYNC =              102;
+    private static final int STOP_PREVIEW =                     103;
+    private static final int SET_PREVIEW_CALLBACK_WITH_BUFFER = 104;
+    private static final int ADD_CALLBACK_BUFFER =              105;
+    private static final int SET_PREVIEW_DISPLAY_ASYNC =        106;
+    private static final int SET_PREVIEW_CALLBACK =             107;
+    // Parameters
+    private static final int SET_PARAMETERS =     201;
+    private static final int GET_PARAMETERS =     202;
+    private static final int REFRESH_PARAMETERS = 203;
+    // Focus, Zoom
+    private static final int AUTO_FOCUS =                   301;
+    private static final int CANCEL_AUTO_FOCUS =            302;
+    private static final int SET_AUTO_FOCUS_MOVE_CALLBACK = 303;
+    private static final int SET_ZOOM_CHANGE_LISTENER =     304;
+    // Face detection
+    private static final int SET_FACE_DETECTION_LISTENER = 461;
+    private static final int START_FACE_DETECTION =        462;
+    private static final int STOP_FACE_DETECTION =         463;
+    private static final int SET_ERROR_CALLBACK =          464;
+    // Presentation
+    private static final int ENABLE_SHUTTER_SOUND =    501;
+    private static final int SET_DISPLAY_ORIENTATION = 502;
+
+    private CameraHandler mCameraHandler;
+    private android.hardware.Camera mCamera;
+
+    // Used to retain a copy of Parameters for setting parameters.
+    private Parameters mParamsToSet;
+
+    AndroidCameraManagerImpl() {
+        HandlerThread ht = new HandlerThread("Camera Handler Thread");
+        ht.start();
+        mCameraHandler = new CameraHandler(ht.getLooper());
+    }
+
+    private class CameraHandler extends Handler {
+        CameraHandler(Looper looper) {
+            super(looper);
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
+        private void startFaceDetection() {
+            mCamera.startFaceDetection();
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
+        private void stopFaceDetection() {
+            mCamera.stopFaceDetection();
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
+        private void setFaceDetectionListener(FaceDetectionListener listener) {
+            mCamera.setFaceDetectionListener(listener);
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.HONEYCOMB)
+        private void setPreviewTexture(Object surfaceTexture) {
+            try {
+                mCamera.setPreviewTexture((SurfaceTexture) surfaceTexture);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN_MR1)
+        private void enableShutterSound(boolean enable) {
+            mCamera.enableShutterSound(enable);
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN)
+        private void setAutoFocusMoveCallback(
+                android.hardware.Camera camera, Object cb) {
+            camera.setAutoFocusMoveCallback((AutoFocusMoveCallback) cb);
+        }
+
+        public void requestTakePicture(
+                final ShutterCallback shutter,
+                final PictureCallback raw,
+                final PictureCallback postView,
+                final PictureCallback jpeg) {
+            post(new Runnable() {
+                @Override
+                public void run() {
+                    try {
+                        mCamera.takePicture(shutter, raw, postView, jpeg);
+                    } catch (RuntimeException e) {
+                        // TODO: output camera state and focus state for debugging.
+                        Log.e(TAG, "take picture failed.");
+                        throw e;
+                    }
+                }
+            });
+        }
+
+        /**
+         * Waits for all the {@code Message} and {@code Runnable} currently in the queue
+         * are processed.
+         *
+         * @return {@code false} if the wait was interrupted, {@code true} otherwise.
+         */
+        public boolean waitDone() {
+            final Object waitDoneLock = new Object();
+            final Runnable unlockRunnable = new Runnable() {
+                @Override
+                public void run() {
+                    synchronized (waitDoneLock) {
+                        waitDoneLock.notifyAll();
+                    }
+                }
+            };
+
+            synchronized (waitDoneLock) {
+                mCameraHandler.post(unlockRunnable);
+                try {
+                    waitDoneLock.wait();
+                } catch (InterruptedException ex) {
+                    Log.v(TAG, "waitDone interrupted");
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        /**
+         * This method does not deal with the API level check.  Everyone should
+         * check first for supported operations before sending message to this handler.
+         */
+        @Override
+        public void handleMessage(final Message msg) {
+            try {
+                switch (msg.what) {
+                    case OPEN_CAMERA:
+                        mCamera = android.hardware.Camera.open();
+                        if (mCamera != null) {
+                            mParametersIsDirty = true;
+
+                            // Get a instance of Camera.Parameters for later use.
+                            if (mParamsToSet == null) {
+                                mParamsToSet = mCamera.getParameters();
+                            }
+                        }
+                        return;
+
+                    case RELEASE:
+                        mCamera.release();
+                        mCamera = null;
+                        return;
+
+                    case RECONNECT:
+                        mReconnectIOException = null;
+                        try {
+                            mCamera.reconnect();
+                        } catch (IOException ex) {
+                            mReconnectIOException = ex;
+                        }
+                        return;
+
+                    case UNLOCK:
+                        mCamera.unlock();
+                        return;
+
+                    case LOCK:
+                        mCamera.lock();
+                        return;
+
+                    case SET_PREVIEW_TEXTURE_ASYNC:
+                        setPreviewTexture(msg.obj);
+                        return;
+
+                    case SET_PREVIEW_DISPLAY_ASYNC:
+                        try {
+                            mCamera.setPreviewDisplay((SurfaceHolder) msg.obj);
+                        } catch (IOException e) {
+                            throw new RuntimeException(e);
+                        }
+                        return;
+
+                    case START_PREVIEW_ASYNC:
+                        mCamera.startPreview();
+                        return;
+
+                    case STOP_PREVIEW:
+                        mCamera.stopPreview();
+                        return;
+
+                    case SET_PREVIEW_CALLBACK_WITH_BUFFER:
+                        mCamera.setPreviewCallbackWithBuffer(
+                            (PreviewCallback) msg.obj);
+                        return;
+
+                    case ADD_CALLBACK_BUFFER:
+                        mCamera.addCallbackBuffer((byte[]) msg.obj);
+                        return;
+
+                    case AUTO_FOCUS:
+                        mCamera.autoFocus((AutoFocusCallback) msg.obj);
+                        return;
+
+                    case CANCEL_AUTO_FOCUS:
+                        mCamera.cancelAutoFocus();
+                        return;
+
+                    case SET_AUTO_FOCUS_MOVE_CALLBACK:
+                        setAutoFocusMoveCallback(mCamera, msg.obj);
+                        return;
+
+                    case SET_DISPLAY_ORIENTATION:
+                        mCamera.setDisplayOrientation(msg.arg1);
+                        return;
+
+                    case SET_ZOOM_CHANGE_LISTENER:
+                        mCamera.setZoomChangeListener(
+                            (OnZoomChangeListener) msg.obj);
+                        return;
+
+                    case SET_FACE_DETECTION_LISTENER:
+                        setFaceDetectionListener((FaceDetectionListener) msg.obj);
+                        return;
+
+                    case START_FACE_DETECTION:
+                        startFaceDetection();
+                        return;
+
+                    case STOP_FACE_DETECTION:
+                        stopFaceDetection();
+                        return;
+
+                    case SET_ERROR_CALLBACK:
+                        mCamera.setErrorCallback((ErrorCallback) msg.obj);
+                        return;
+
+                    case SET_PARAMETERS:
+                        mParametersIsDirty = true;
+                        mParamsToSet.unflatten((String) msg.obj);
+                        mCamera.setParameters(mParamsToSet);
+                        return;
+
+                    case GET_PARAMETERS:
+                        if (mParametersIsDirty) {
+                            mParameters = mCamera.getParameters();
+                            mParametersIsDirty = false;
+                        }
+                        return;
+
+                    case SET_PREVIEW_CALLBACK:
+                        mCamera.setPreviewCallback((PreviewCallback) msg.obj);
+                        return;
+
+                    case ENABLE_SHUTTER_SOUND:
+                        enableShutterSound((msg.arg1 == 1) ? true : false);
+                        return;
+
+                    case REFRESH_PARAMETERS:
+                        mParametersIsDirty = true;
+                        return;
+
+                    default:
+                        throw new RuntimeException("Invalid CameraProxy message=" + msg.what);
+                }
+            } catch (RuntimeException e) {
+                if (msg.what != RELEASE && mCamera != null) {
+                    try {
+                        mCamera.release();
+                    } catch (Exception ex) {
+                        Log.e(TAG, "Fail to release the camera.");
+                    }
+                    mCamera = null;
+                }
+                throw e;
+            }
+        }
+    }
+
+    @Override
+    public CameraManager.CameraProxy cameraOpen(int cameraId) {
+        mCameraHandler.obtainMessage(OPEN_CAMERA, cameraId, 0).sendToTarget();
+        mCameraHandler.waitDone();
+        if (mCamera != null) {
+            return new AndroidCameraProxyImpl();
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * A class which implements {@link CameraManager.CameraProxy} and 
+     * camera handler thread.
+     */
+    public class AndroidCameraProxyImpl implements CameraManager.CameraProxy {
+
+        private AndroidCameraProxyImpl() {
+            Assert(mCamera != null);
+        }
+
+        @Override
+        public android.hardware.Camera getCamera() {
+            return mCamera;
+        }
+
+        @Override
+        public void release() {
+            // release() must be synchronous so we know exactly when the camera
+            // is released and can continue on.
+            mCameraHandler.sendEmptyMessage(RELEASE);
+            mCameraHandler.waitDone();
+        }
+
+        @Override
+        public void reconnect() throws IOException {
+            mCameraHandler.sendEmptyMessage(RECONNECT);
+            mCameraHandler.waitDone();
+            if (mReconnectIOException != null) {
+                throw mReconnectIOException;
+            }
+        }
+
+        @Override
+        public void unlock() {
+            mCameraHandler.sendEmptyMessage(UNLOCK);
+            mCameraHandler.waitDone();
+        }
+
+        @Override
+        public void lock() {
+            mCameraHandler.sendEmptyMessage(LOCK);
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.HONEYCOMB)
+        @Override
+        public void setPreviewTexture(final SurfaceTexture surfaceTexture) {
+            mCameraHandler.obtainMessage(SET_PREVIEW_TEXTURE_ASYNC, surfaceTexture).sendToTarget();
+        }
+
+        @Override
+        public void setPreviewDisplay(final SurfaceHolder surfaceHolder) {
+            mCameraHandler.obtainMessage(SET_PREVIEW_DISPLAY_ASYNC, surfaceHolder).sendToTarget();
+        }
+
+        @Override
+        public void startPreview() {
+            mCameraHandler.sendEmptyMessage(START_PREVIEW_ASYNC);
+        }
+
+        @Override
+        public void stopPreview() {
+            mCameraHandler.sendEmptyMessage(STOP_PREVIEW);
+            mCameraHandler.waitDone();
+        }
+
+        @Override
+        public void setPreviewDataCallback(
+                Handler handler, final CameraPreviewDataCallback cb) {
+            mCameraHandler.obtainMessage(
+                    SET_PREVIEW_CALLBACK,
+                    PreviewCallbackForward.instance(handler, this, cb)).sendToTarget();
+        }
+
+        @Override
+        public void setPreviewDataCallbackWithBuffer(
+                Handler handler, final CameraPreviewDataCallback cb) {
+            mCameraHandler.obtainMessage(
+                    SET_PREVIEW_CALLBACK_WITH_BUFFER,
+                    PreviewCallbackForward.instance(handler, this, cb)).sendToTarget();
+        }
+
+        @Override
+        public void addCallbackBuffer(byte[] callbackBuffer) {
+            mCameraHandler.obtainMessage(ADD_CALLBACK_BUFFER, callbackBuffer).sendToTarget();
+        }
+
+        @Override
+        public void autoFocus(Handler handler, CameraAFCallback cb) {
+            mCameraHandler.obtainMessage(
+                    AUTO_FOCUS,
+                    AFCallbackForward.instance(handler, this, cb)).sendToTarget();
+        }
+
+        @Override
+        public void cancelAutoFocus() {
+            mCameraHandler.removeMessages(AUTO_FOCUS);
+            mCameraHandler.sendEmptyMessage(CANCEL_AUTO_FOCUS);
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN)
+        @Override
+        public void setAutoFocusMoveCallback(
+                Handler handler, final CameraAFMoveCallback cb) {
+            mCameraHandler.obtainMessage(
+                    SET_AUTO_FOCUS_MOVE_CALLBACK,
+                    AFMoveCallbackForward.instance(handler, this, cb)).sendToTarget();
+        }
+
+        @Override
+        public void takePicture(
+                final Handler handler,
+                final CameraShutterCallback shutter,
+                final CameraPictureCallback raw,
+                final CameraPictureCallback post,
+                final CameraPictureCallback jpeg) {
+            mCameraHandler.requestTakePicture(
+                    ShutterCallbackForward.instance(handler, this, shutter),
+                    PictureCallbackForward.instance(handler, this, raw),
+                    PictureCallbackForward.instance(handler, this, post),
+                    PictureCallbackForward.instance(handler, this, jpeg));
+        }
+
+        @Override
+        public void setDisplayOrientation(int degrees) {
+            mCameraHandler.obtainMessage(SET_DISPLAY_ORIENTATION, degrees, 0)
+                    .sendToTarget();
+        }
+
+        @Override
+        public void setZoomChangeListener(OnZoomChangeListener listener) {
+            mCameraHandler.obtainMessage(SET_ZOOM_CHANGE_LISTENER, listener).sendToTarget();
+        }
+
+        @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
+        public void setFaceDetectionListener(FaceDetectionListener listener) {
+            mCameraHandler.obtainMessage(SET_FACE_DETECTION_LISTENER, listener).sendToTarget();
+        }
+
+        @Override
+        public void startFaceDetection() {
+            mCameraHandler.sendEmptyMessage(START_FACE_DETECTION);
+        }
+
+        @Override
+        public void stopFaceDetection() {
+            mCameraHandler.sendEmptyMessage(STOP_FACE_DETECTION);
+        }
+
+        @Override
+        public void setErrorCallback(ErrorCallback cb) {
+            mCameraHandler.obtainMessage(SET_ERROR_CALLBACK, cb).sendToTarget();
+        }
+
+        @Override
+        public void setParameters(Parameters params) {
+            if (params == null) {
+                Log.v(TAG, "null parameters in setParameters()");
+                return;
+            }
+            mCameraHandler.obtainMessage(SET_PARAMETERS, params.flatten())
+                    .sendToTarget();
+        }
+
+        @Override
+        public Parameters getParameters() {
+            mCameraHandler.sendEmptyMessage(GET_PARAMETERS);
+            mCameraHandler.waitDone();
+            return mParameters;
+        }
+
+        @Override
+        public void refreshParameters() {
+            mCameraHandler.sendEmptyMessage(REFRESH_PARAMETERS);
+        }
+
+        @Override
+        public void enableShutterSound(boolean enable) {
+            mCameraHandler.obtainMessage(
+                    ENABLE_SHUTTER_SOUND, (enable ? 1 : 0), 0).sendToTarget();
+        }
+    }
+
+    /**
+     * A helper class to forward AutoFocusCallback to another thread.
+     */
+    private static class AFCallbackForward implements AutoFocusCallback {
+        private final Handler mHandler;
+        private final CameraProxy mCamera;
+        private final CameraAFCallback mCallback;
+
+        /**
+         * Returns an instance of {@link AFCallbackForward}.
+         *
+         * @param handler The handler in which the callback will be invoked in.
+         * @param camera  The {@link CameraProxy} which the callback is from.
+         * @param cb      The callback to be invoked.
+         * @return        The instance of the {@link AFCallbackForward},
+         *                or null if any one of other parameters is null.
+         */
+        public static AFCallbackForward instance(
+                Handler handler, CameraProxy camera, CameraAFCallback cb) {
+            if (handler == null || camera == null || cb == null) return null;
+            return new AFCallbackForward(handler, camera, cb);
+        }
+
+        private AFCallbackForward(
+                Handler h, CameraProxy camera, CameraAFCallback cb) {
+            mHandler = h;
+            mCamera = camera;
+            mCallback = cb;
+        }
+
+        @Override
+        public void onAutoFocus(final boolean b, Camera camera) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mCallback.onAutoFocus(b, mCamera);
+                }
+            });
+        }
+    }
+
+    /** A helper class to forward AutoFocusMoveCallback to another thread. */
+    @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN)
+    private static class AFMoveCallbackForward implements AutoFocusMoveCallback {
+        private final Handler mHandler;
+        private final CameraAFMoveCallback mCallback;
+        private final CameraProxy mCamera;
+
+        /**
+         * Returns an instance of {@link AFMoveCallbackForward}.
+         *
+         * @param handler The handler in which the callback will be invoked in.
+         * @param camera  The {@link CameraProxy} which the callback is from.
+         * @param cb      The callback to be invoked.
+         * @return        The instance of the {@link AFMoveCallbackForward},
+         *                or null if any one of other parameters is null.
+         */
+        public static AFMoveCallbackForward instance(
+                Handler handler, CameraProxy camera, CameraAFMoveCallback cb) {
+            if (handler == null || camera == null || cb == null) return null;
+            return new AFMoveCallbackForward(handler, camera, cb);
+        }
+
+        private AFMoveCallbackForward(
+                Handler h, CameraProxy camera, CameraAFMoveCallback cb) {
+            mHandler = h;
+            mCamera = camera;
+            mCallback = cb;
+        }
+
+        @Override
+        public void onAutoFocusMoving(
+                final boolean moving, android.hardware.Camera camera) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mCallback.onAutoFocusMoving(moving, mCamera);
+                }
+            });
+        }
+    }
+
+    /**
+     * A helper class to forward ShutterCallback to to another thread.
+     */
+    private static class ShutterCallbackForward implements ShutterCallback {
+        private final Handler mHandler;
+        private final CameraShutterCallback mCallback;
+        private final CameraProxy mCamera;
+
+        /**
+         * Returns an instance of {@link ShutterCallbackForward}.
+         *
+         * @param handler The handler in which the callback will be invoked in.
+         * @param camera  The {@link CameraProxy} which the callback is from.
+         * @param cb      The callback to be invoked.
+         * @return        The instance of the {@link ShutterCallbackForward},
+         *                or null if any one of other parameters is null.
+         */
+        public static ShutterCallbackForward instance(
+                Handler handler, CameraProxy camera, CameraShutterCallback cb) {
+            if (handler == null || camera == null || cb == null) return null;
+            return new ShutterCallbackForward(handler, camera, cb);
+        }
+
+        private ShutterCallbackForward(
+                Handler h, CameraProxy camera, CameraShutterCallback cb) {
+            mHandler = h;
+            mCamera = camera;
+            mCallback = cb;
+        }
+
+        @Override
+        public void onShutter() {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mCallback.onShutter(mCamera);
+                }
+            });
+        }
+    }
+
+    /**
+     * A helper class to forward PictureCallback to another thread.
+     */
+    private static class PictureCallbackForward implements PictureCallback {
+        private final Handler mHandler;
+        private final CameraPictureCallback mCallback;
+        private final CameraProxy mCamera;
+
+        /**
+         * Returns an instance of {@link PictureCallbackForward}.
+         *
+         * @param handler The handler in which the callback will be invoked in.
+         * @param camera  The {@link CameraProxy} which the callback is from.
+         * @param cb      The callback to be invoked.
+         * @return        The instance of the {@link PictureCallbackForward},
+         *                or null if any one of other parameters is null.
+         */
+        public static PictureCallbackForward instance(
+                Handler handler, CameraProxy camera, CameraPictureCallback cb) {
+            if (handler == null || camera == null || cb == null) return null;
+            return new PictureCallbackForward(handler, camera, cb);
+        }
+
+        private PictureCallbackForward(
+                Handler h, CameraProxy camera, CameraPictureCallback cb) {
+            mHandler = h;
+            mCamera = camera;
+            mCallback = cb;
+        }
+
+        @Override
+        public void onPictureTaken(
+                final byte[] data, android.hardware.Camera camera) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mCallback.onPictureTaken(data, mCamera);
+                }
+            });
+        }
+    }
+
+    /**
+     * A helper class to forward PreviewCallback to another thread.
+     */
+    private static class PreviewCallbackForward implements PreviewCallback {
+        private final Handler mHandler;
+        private final CameraPreviewDataCallback mCallback;
+        private final CameraProxy mCamera;
+
+        /**
+         * Returns an instance of {@link PreviewCallbackForward}.
+         *
+         * @param handler The handler in which the callback will be invoked in.
+         * @param camera  The {@link CameraProxy} which the callback is from.
+         * @param cb      The callback to be invoked.
+         * @return        The instance of the {@link PictureCallbackForward},
+         *                or null if any one of other parameters is null.
+         */
+        public static PreviewCallbackForward instance(
+                Handler handler, CameraProxy camera, CameraPreviewDataCallback cb) {
+            if (handler == null || camera == null || cb == null) return null;
+            return new PreviewCallbackForward(handler, camera, cb);
+        }
+
+        private PreviewCallbackForward(
+                Handler h, CameraProxy camera, CameraPreviewDataCallback cb) {
+            mHandler = h;
+            mCamera = camera;
+            mCallback = cb;
+        }
+
+        @Override
+        public void onPreviewFrame(
+                final byte[] data, android.hardware.Camera camera) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mCallback.onPreviewFrame(data, mCamera);
+                }
+            });
+        }
+    }
+}
diff --git a/src/com/android/camera/CameraHolder.java b/src/com/android/camera/CameraHolder.java
index 5b7bbfd..d913df7 100644
--- a/src/com/android/camera/CameraHolder.java
+++ b/src/com/android/camera/CameraHolder.java
@@ -207,7 +207,8 @@
             try {
                 Log.v(TAG, "open camera " + cameraId);
                 if (mMockCameraInfo == null) {
-                    mCameraDevice = CameraManager.instance().cameraOpen(cameraId);
+                    mCameraDevice = CameraManagerFactory
+                            .getAndroidCameraManager().cameraOpen(cameraId);
                 } else {
                     if (mMockCamera == null)
                         throw new RuntimeException();
diff --git a/src/com/android/camera/CameraManager.java b/src/com/android/camera/CameraManager.java
index c7005cf5..e4a0667 100644
--- a/src/com/android/camera/CameraManager.java
+++ b/src/com/android/camera/CameraManager.java
@@ -16,466 +16,288 @@
 
 package com.android.camera;
 
-import static com.android.camera.Util.Assert;
-
 import android.annotation.TargetApi;
 import android.graphics.SurfaceTexture;
-import android.hardware.Camera.AutoFocusCallback;
-import android.hardware.Camera.AutoFocusMoveCallback;
 import android.hardware.Camera.ErrorCallback;
 import android.hardware.Camera.FaceDetectionListener;
 import android.hardware.Camera.OnZoomChangeListener;
 import android.hardware.Camera.Parameters;
-import android.hardware.Camera.PictureCallback;
-import android.hardware.Camera.PreviewCallback;
-import android.hardware.Camera.ShutterCallback;
 import android.os.Handler;
-import android.os.HandlerThread;
-import android.os.Looper;
-import android.os.Message;
-import android.util.Log;
 import android.view.SurfaceHolder;
 
 import com.android.gallery3d.common.ApiHelper;
 
 import java.io.IOException;
 
-public class CameraManager {
-    private static final String TAG = "CameraManager";
-    private static CameraManager sCameraManager = new CameraManager();
+/**
+ * An interface which provides possible camera device operations. 
+ *
+ * The client should call {@code CameraManager.cameraOpen} to get an instance
+ * of {@link CameraManager.CameraProxy} to control the camera. Classes
+ * implementing this interface should have its own one unique {@code Thread}
+ * other than the main thread for camera operations. Camera device callbacks
+ * are wrapped since the client should not deal with
+ * {@code android.hardware.Camera} directly.
+ *
+ * TODO: provide callback interfaces for:
+ * {@code android.hardware.Camera.ErrorCallback},
+ * {@code android.hardware.Camera.FaceDetectionListener},
+ * {@code android.hardware.Camera.OnZoomChangeListener}, and
+ * {@code android.hardware.Camera.Parameters}.
+ */
+public interface CameraManager {
 
-    private Parameters mParameters;
-    private boolean mParametersIsDirty;
-    private IOException mReconnectIOException;
-
-    private static final int RELEASE = 1;
-    private static final int RECONNECT = 2;
-    private static final int UNLOCK = 3;
-    private static final int LOCK = 4;
-    private static final int SET_PREVIEW_TEXTURE_ASYNC = 5;
-    private static final int START_PREVIEW_ASYNC = 6;
-    private static final int STOP_PREVIEW = 7;
-    private static final int SET_PREVIEW_CALLBACK_WITH_BUFFER = 8;
-    private static final int ADD_CALLBACK_BUFFER = 9;
-    private static final int AUTO_FOCUS = 10;
-    private static final int CANCEL_AUTO_FOCUS = 11;
-    private static final int SET_AUTO_FOCUS_MOVE_CALLBACK = 12;
-    private static final int SET_DISPLAY_ORIENTATION = 13;
-    private static final int SET_ZOOM_CHANGE_LISTENER = 14;
-    private static final int SET_FACE_DETECTION_LISTENER = 15;
-    private static final int START_FACE_DETECTION = 16;
-    private static final int STOP_FACE_DETECTION = 17;
-    private static final int SET_ERROR_CALLBACK = 18;
-    private static final int SET_PARAMETERS = 19;
-    private static final int GET_PARAMETERS = 20;
-    private static final int SET_PREVIEW_DISPLAY_ASYNC = 21;
-    private static final int SET_PREVIEW_CALLBACK = 22;
-    private static final int ENABLE_SHUTTER_SOUND = 23;
-    private static final int REFRESH_PARAMETERS = 24;
-
-    private Handler mCameraHandler;
-    private android.hardware.Camera mCamera;
-
-    // Used to retain a copy of Parameters for setting parameters.
-    private Parameters mParamsToSet;
-
-
-    // This holder is used when we need to pass the exception
-    // back to the calling thread. SynchornousQueue doesn't
-    // allow we to pass a null object thus a holder is needed.
-    private class IOExceptionHolder {
-        public IOException ex;
+    /**
+     * An interface which wraps
+     * {@link android.hardware.Camera.AutoFocusCallback}.
+     */
+    public interface CameraAFCallback {
+        public void onAutoFocus(boolean focused, CameraProxy camera);
     }
 
-    public static CameraManager instance() {
-        return sCameraManager;
+    /**
+     * An interface which wraps
+     * {@link android.hardware.Camera.AutoFocusMoveCallback}.
+     */
+    public interface CameraAFMoveCallback {
+        public void onAutoFocusMoving(boolean moving, CameraProxy camera);
     }
 
-    private CameraManager() {
-        HandlerThread ht = new HandlerThread("Camera Handler Thread");
-        ht.start();
-        mCameraHandler = new CameraHandler(ht.getLooper());
+    /**
+     * An interface which wraps
+     * {@link android.hardware.Camera.ShutterCallback}.
+     */
+    public interface CameraShutterCallback {
+        public void onShutter(CameraProxy camera);
     }
 
-    private class CameraHandler extends Handler {
-        CameraHandler(Looper looper) {
-            super(looper);
-        }
+    /**
+     * An interface which wraps
+     * {@link android.hardware.Camera.PictureCallback}.
+     */
+    public interface CameraPictureCallback {
+        public void onPictureTaken(byte[] data, CameraProxy camera);
+    }
 
-        @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
-        private void startFaceDetection() {
-            mCamera.startFaceDetection();
-        }
+    /**
+     * An interface which wraps
+     * {@link android.hardware.Camera.PreviewCallback}.
+     */
+    public interface CameraPreviewDataCallback {
+        public void onPreviewFrame(byte[] data, CameraProxy camera);
+    }
 
-        @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
-        private void stopFaceDetection() {
-            mCamera.stopFaceDetection();
-        }
+    /**
+     * Opens the camera of the specified ID synchronously.
+     *
+     * @param cameraId      The camera ID to open.
+     * @return   An instance of {@link CameraProxy} on success. null on failure.
+     */
+    public CameraProxy cameraOpen(int cameraId);
 
-        @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
-        private void setFaceDetectionListener(FaceDetectionListener listener) {
-            mCamera.setFaceDetectionListener(listener);
-        }
+    /**
+     * An interface that takes camera operation requests and post messages to the
+     * camera handler thread. All camera operations made through this interface is
+     * asynchronous by default except those mentioned specifically.
+     */
+    public interface CameraProxy {
 
-        @TargetApi(ApiHelper.VERSION_CODES.HONEYCOMB)
-        private void setPreviewTexture(Object surfaceTexture) {
-            try {
-                mCamera.setPreviewTexture((SurfaceTexture) surfaceTexture);
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            }
-        }
-
-        @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN_MR1)
-        private void enableShutterSound(boolean enable) {
-            mCamera.enableShutterSound(enable);
-        }
-
-        /*
-         * This method does not deal with the build version check.  Everyone should
-         * check first before sending message to this handler.
+        /**
+         * Returns the underlying {@link android.hardware.Camera} object used
+         * by this proxy. This method should only be used when handing the
+         * camera device over to {@link android.media.MediaRecorder} for
+         * recording.
          */
-        @Override
-        public void handleMessage(final Message msg) {
-            try {
-                switch (msg.what) {
-                    case RELEASE:
-                        mCamera.release();
-                        mCamera = null;
-                        return;
+        public android.hardware.Camera getCamera();
 
-                    case RECONNECT:
-                        mReconnectIOException = null;
-                        try {
-                            mCamera.reconnect();
-                        } catch (IOException ex) {
-                            mReconnectIOException = ex;
-                        }
-                        return;
+        /**
+         * Releases the camera device synchronously.
+         * This function must be synchronous so the caller knows exactly when the camera
+         * is released and can continue on.
+         */
+        public void release();
 
-                    case UNLOCK:
-                        mCamera.unlock();
-                        return;
+        /**
+         * Reconnects to the camera device.
+         *
+         * @see android.hardware.Camera#reconnect()
+         */
+        public void reconnect() throws IOException;
 
-                    case LOCK:
-                        mCamera.lock();
-                        return;
+        /**
+         * Unlocks the camera device.
+         *
+         * @see android.hardware.Camera#unlock()
+         */
+        public void unlock();
 
-                    case SET_PREVIEW_TEXTURE_ASYNC:
-                        setPreviewTexture(msg.obj);
-                        return;
+        /**
+         * Locks the camera device.
+         * @see android.hardware.Camera#lock()
+         */
+        public void lock();
 
-                    case SET_PREVIEW_DISPLAY_ASYNC:
-                        try {
-                            mCamera.setPreviewDisplay((SurfaceHolder) msg.obj);
-                        } catch (IOException e) {
-                            throw new RuntimeException(e);
-                        }
-                        return;
-
-                    case START_PREVIEW_ASYNC:
-                        mCamera.startPreview();
-                        return;
-
-                    case STOP_PREVIEW:
-                        mCamera.stopPreview();
-                        return;
-
-                    case SET_PREVIEW_CALLBACK_WITH_BUFFER:
-                        mCamera.setPreviewCallbackWithBuffer(
-                            (PreviewCallback) msg.obj);
-                        return;
-
-                    case ADD_CALLBACK_BUFFER:
-                        mCamera.addCallbackBuffer((byte[]) msg.obj);
-                        return;
-
-                    case AUTO_FOCUS:
-                        mCamera.autoFocus((AutoFocusCallback) msg.obj);
-                        return;
-
-                    case CANCEL_AUTO_FOCUS:
-                        mCamera.cancelAutoFocus();
-                        return;
-
-                    case SET_AUTO_FOCUS_MOVE_CALLBACK:
-                        setAutoFocusMoveCallback(mCamera, msg.obj);
-                        return;
-
-                    case SET_DISPLAY_ORIENTATION:
-                        mCamera.setDisplayOrientation(msg.arg1);
-                        return;
-
-                    case SET_ZOOM_CHANGE_LISTENER:
-                        mCamera.setZoomChangeListener(
-                            (OnZoomChangeListener) msg.obj);
-                        return;
-
-                    case SET_FACE_DETECTION_LISTENER:
-                        setFaceDetectionListener((FaceDetectionListener) msg.obj);
-                        return;
-
-                    case START_FACE_DETECTION:
-                        startFaceDetection();
-                        return;
-
-                    case STOP_FACE_DETECTION:
-                        stopFaceDetection();
-                        return;
-
-                    case SET_ERROR_CALLBACK:
-                        mCamera.setErrorCallback((ErrorCallback) msg.obj);
-                        return;
-
-                    case SET_PARAMETERS:
-                        mParametersIsDirty = true;
-                        mParamsToSet.unflatten((String) msg.obj);
-                        mCamera.setParameters(mParamsToSet);
-                        return;
-
-                    case GET_PARAMETERS:
-                        if (mParametersIsDirty) {
-                            mParameters = mCamera.getParameters();
-                            mParametersIsDirty = false;
-                        }
-                        return;
-
-                    case SET_PREVIEW_CALLBACK:
-                        mCamera.setPreviewCallback((PreviewCallback) msg.obj);
-                        return;
-
-                    case ENABLE_SHUTTER_SOUND:
-                        enableShutterSound((msg.arg1 == 1) ? true : false);
-                        return;
-
-                    case REFRESH_PARAMETERS:
-                        mParametersIsDirty = true;
-                        return;
-
-                    default:
-                        throw new RuntimeException("Invalid CameraProxy message=" + msg.what);
-                }
-            } catch (RuntimeException e) {
-                if (msg.what != RELEASE && mCamera != null) {
-                    try {
-                        mCamera.release();
-                    } catch (Exception ex) {
-                        Log.e(TAG, "Fail to release the camera.");
-                    }
-                    mCamera = null;
-                }
-                throw e;
-            }
-        }
-    }
-
-    @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN)
-    private void setAutoFocusMoveCallback(android.hardware.Camera camera,
-            Object cb) {
-        camera.setAutoFocusMoveCallback((AutoFocusMoveCallback) cb);
-    }
-
-    // Open camera synchronously. This method is invoked in the context of a
-    // background thread.
-    CameraProxy cameraOpen(int cameraId) {
-        // Cannot open camera in mCameraHandler, otherwise all camera events
-        // will be routed to mCameraHandler looper, which in turn will call
-        // event handler like Camera.onFaceDetection, which in turn will modify
-        // UI and cause exception like this:
-        // CalledFromWrongThreadException: Only the original thread that created
-        // a view hierarchy can touch its views.
-        mCamera = android.hardware.Camera.open(cameraId);
-        if (mCamera != null) {
-            mParametersIsDirty = true;
-            if (mParamsToSet == null) {
-                mParamsToSet = mCamera.getParameters();
-            }
-            return new CameraProxy();
-        } else {
-            return null;
-        }
-    }
-
-    public class CameraProxy {
-
-        private CameraProxy() {
-            Assert(mCamera != null);
-        }
-
-        public android.hardware.Camera getCamera() {
-            return mCamera;
-        }
-
-        public void release() {
-            // release() must be synchronous so we know exactly when the camera
-            // is released and can continue on.
-            mCameraHandler.sendEmptyMessage(RELEASE);
-            waitDone();
-        }
-
-        public void reconnect() throws IOException {
-            mCameraHandler.sendEmptyMessage(RECONNECT);
-            waitDone();
-            if (mReconnectIOException != null) {
-                throw mReconnectIOException;
-            }
-        }
-
-        public void unlock() {
-            mCameraHandler.sendEmptyMessage(UNLOCK);
-        }
-
-        public void lock() {
-            mCameraHandler.sendEmptyMessage(LOCK);
-        }
-
+        /**
+         * Sets the {@link android.graphics.SurfaceTexture} for preview.
+         *
+         * @param surfaceTexture The {@link SurfaceTexture} for preview.
+         */
         @TargetApi(ApiHelper.VERSION_CODES.HONEYCOMB)
-        public void setPreviewTextureAsync(final SurfaceTexture surfaceTexture) {
-            mCameraHandler.obtainMessage(SET_PREVIEW_TEXTURE_ASYNC, surfaceTexture).sendToTarget();
-        }
+        public void setPreviewTexture(final SurfaceTexture surfaceTexture);
 
-        public void setPreviewDisplayAsync(final SurfaceHolder surfaceHolder) {
-            mCameraHandler.obtainMessage(SET_PREVIEW_DISPLAY_ASYNC, surfaceHolder).sendToTarget();
-        }
+        /**
+         * Sets the {@link android.view.SurfaceHolder} for preview.
+         *
+         * @param surfaceHolder The {@link SurfaceHolder} for preview.
+         */
+        public void setPreviewDisplay(final SurfaceHolder surfaceHolder);
 
-        public void startPreviewAsync() {
-            mCameraHandler.sendEmptyMessage(START_PREVIEW_ASYNC);
-        }
+        /**
+         * Starts the camera preview.
+         */
+        public void startPreview();
 
-        // stopPreview() is synchronous because many resources should be released after
-        // the preview is stopped.
-        public void stopPreview() {
-            mCameraHandler.sendEmptyMessage(STOP_PREVIEW);
-            waitDone();
-        }
+        /**
+         * Stops the camera preview synchronously.
+         * {@code stopPreview()} must be synchronous to ensure that the caller can
+         * continues to release resources related to camera preview.
+         */
+        public void stopPreview();
 
-        public void setPreviewCallback(final PreviewCallback cb) {
-            mCameraHandler.obtainMessage(SET_PREVIEW_CALLBACK, cb).sendToTarget();
-        }
+        /**
+         * Sets the callback for preview data.
+         *
+         * @param handler    handler in which the callback was handled.
+         * @param cb         The callback to be invoked when the preview data is available.
+         * @see  android.hardware.Camera#setPreviewCallback(android.hardware.Camera.PreviewCallback)
+         */
+        public void setPreviewDataCallback(Handler handler, CameraPreviewDataCallback cb);
 
-        public void setPreviewCallbackWithBuffer(final PreviewCallback cb) {
-            mCameraHandler.obtainMessage(SET_PREVIEW_CALLBACK_WITH_BUFFER, cb).sendToTarget();
-        }
+        /**
+         * Sets the callback for preview data.
+         *
+         * @param handler The handler in which the callback will be invoked.
+         * @param cb      The callback to be invoked when the preview data is available.
+         * @see android.hardware.Camera#setPreviewCallbackWithBuffer(android.hardware.Camera.PreviewCallback)
+         */
+        public void setPreviewDataCallbackWithBuffer(Handler handler, CameraPreviewDataCallback cb);
 
-        public void addCallbackBuffer(byte[] callbackBuffer) {
-            mCameraHandler.obtainMessage(ADD_CALLBACK_BUFFER, callbackBuffer).sendToTarget();
-        }
+        /**
+         * Adds buffer for the preview callback.
+         *
+         * @param callbackBuffer The buffer allocated for the preview data.
+         */
+        public void addCallbackBuffer(byte[] callbackBuffer);
 
-        public void autoFocus(AutoFocusCallback cb) {
-            mCameraHandler.obtainMessage(AUTO_FOCUS, cb).sendToTarget();
-        }
+        /**
+         * Starts the auto-focus process. The result will be returned through the callback.
+         *
+         * @param handler The handler in which the callback will be invoked.
+         * @param cb      The auto-focus callback.
+         */
+        public void autoFocus(Handler handler, CameraAFCallback cb);
 
-        public void cancelAutoFocus() {
-            mCameraHandler.removeMessages(AUTO_FOCUS);
-            mCameraHandler.sendEmptyMessage(CANCEL_AUTO_FOCUS);
-        }
+        /**
+         * Cancels the auto-focus process.
+         */
+        public void cancelAutoFocus();
 
+        /**
+         * Sets the auto-focus callback
+         *
+         * @param handler The handler in which the callback will be invoked.
+         * @param cb      The callback to be invoked when the preview data is available.
+         */
         @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN)
-        public void setAutoFocusMoveCallback(AutoFocusMoveCallback cb) {
-            mCameraHandler.obtainMessage(SET_AUTO_FOCUS_MOVE_CALLBACK, cb).sendToTarget();
-        }
+        public void setAutoFocusMoveCallback(Handler handler, CameraAFMoveCallback cb);
 
-        public void takePicture(final ShutterCallback shutter, final PictureCallback raw,
-                final PictureCallback postview, final PictureCallback jpeg) {
-            // Too many parameters, so use post for simplicity
-            mCameraHandler.post(new Runnable() {
-                @Override
-                public void run() {
-                    mCamera.takePicture(shutter, raw, postview, jpeg);
-                }
-            });
-        }
+        /**
+         * Instrument the camera to take a picture.
+         *
+         * @param handler   The handler in which the callback will be invoked.
+         * @param shutter   The callback for shutter action, may be null.
+         * @param raw       The callback for uncompressed data, may be null.
+         * @param postview  The callback for postview image data, may be null.
+         * @param jpeg      The callback for jpeg image data, may be null.
+         * @see android.hardware.Camera#takePicture(
+         *         android.hardware.Camera.ShutterCallback,
+         *         android.hardware.Camera.PictureCallback,
+         *         android.hardware.Camera.PictureCallback)
+         */
+        public void takePicture(
+                Handler handler,
+                CameraShutterCallback shutter,
+                CameraPictureCallback raw,
+                CameraPictureCallback postview,
+                CameraPictureCallback jpeg);
 
-        public void takePicture2(final ShutterCallback shutter, final PictureCallback raw,
-                final PictureCallback postview, final PictureCallback jpeg,
-                final int cameraState, final int focusState) {
-            // Too many parameters, so use post for simplicity
-            mCameraHandler.post(new Runnable() {
-                @Override
-                public void run() {
-                    try {
-                        mCamera.takePicture(shutter, raw, postview, jpeg);
-                    } catch (RuntimeException e) {
-                        Log.w(TAG, "take picture failed; cameraState:" + cameraState
-                            + ", focusState:" + focusState);
-                        throw e;
-                    }
-                }
-            });
-        }
+        /**
+         * Sets the display orientation for camera to adjust the preview orientation.
+         *
+         * @param degrees The rotation in degrees. Should be 0, 90, 180 or 270.
+         */
+        public void setDisplayOrientation(int degrees);
 
-        public void setDisplayOrientation(int degrees) {
-            mCameraHandler.obtainMessage(SET_DISPLAY_ORIENTATION, degrees, 0)
-                    .sendToTarget();
-        }
+        /**
+         * Sets the listener for zoom change.
+         *
+         * @param listener The listener.
+         */
+        public void setZoomChangeListener(OnZoomChangeListener listener);
 
-        public void setZoomChangeListener(OnZoomChangeListener listener) {
-            mCameraHandler.obtainMessage(SET_ZOOM_CHANGE_LISTENER, listener).sendToTarget();
-        }
-
+        /**
+         * Sets the face detection listener.
+         *
+         * @param listener The listener for face detection results.
+         */
         @TargetApi(ApiHelper.VERSION_CODES.ICE_CREAM_SANDWICH)
-        public void setFaceDetectionListener(FaceDetectionListener listener) {
-            mCameraHandler.obtainMessage(SET_FACE_DETECTION_LISTENER, listener).sendToTarget();
-        }
+        public void setFaceDetectionListener(FaceDetectionListener listener);
 
-        public void startFaceDetection() {
-            mCameraHandler.sendEmptyMessage(START_FACE_DETECTION);
-        }
+        /**
+         * Starts the face detection.
+         */
+        public void startFaceDetection();
 
-        public void stopFaceDetection() {
-            mCameraHandler.sendEmptyMessage(STOP_FACE_DETECTION);
-        }
+        /**
+         * Stops the face detection.
+         */
+        public void stopFaceDetection();
 
-        public void setErrorCallback(ErrorCallback cb) {
-            mCameraHandler.obtainMessage(SET_ERROR_CALLBACK, cb).sendToTarget();
-        }
+        /**
+         * Registers an error callback.
+         *
+         * @param cb The error callback.
+         * @see android.hardware.Camera#setErrorCallback(android.hardware.Camera.ErrorCallback)
+         */
+        public void setErrorCallback(ErrorCallback cb);
 
-        public void setParameters(Parameters params) {
-            if (params == null) {
-                Log.v(TAG, "null parameters in setParameters()");
-                return;
-            }
-            mCameraHandler.obtainMessage(SET_PARAMETERS, params.flatten())
-                    .sendToTarget();
-        }
+        /**
+         * Sets the camera parameters.
+         *
+         * @param params The camera parameters to use.
+         */
+        public void setParameters(Parameters params);
 
-        public Parameters getParameters() {
-            mCameraHandler.sendEmptyMessage(GET_PARAMETERS);
-            waitDone();
-            return mParameters;
-        }
+        /**
+         * Gets the current camera parameters synchronously. This method is
+         * synchronous since the caller has to wait for the camera to return
+         * the parameters. If the parameters are already cached, it returns
+         * immediately.
+         */
+        public Parameters getParameters();
 
-        public void refreshParameters() {
-            mCameraHandler.sendEmptyMessage(REFRESH_PARAMETERS);
-        }
+        /**
+         * Forces {@code CameraProxy} to update the cached version of the camera
+         * parameters regardless of the dirty bit.
+         */
+        public void refreshParameters();
 
-        public void enableShutterSound(boolean enable) {
-            mCameraHandler.obtainMessage(
-                    ENABLE_SHUTTER_SOUND, (enable ? 1 : 0), 0).sendToTarget();
-        }
-
-        // return false if cancelled.
-        public boolean waitDone() {
-            final Object waitDoneLock = new Object();
-            final Runnable unlockRunnable = new Runnable() {
-                @Override
-                public void run() {
-                    synchronized (waitDoneLock) {
-                        waitDoneLock.notifyAll();
-                    }
-                }
-            };
-
-            synchronized (waitDoneLock) {
-                mCameraHandler.post(unlockRunnable);
-                try {
-                    waitDoneLock.wait();
-                } catch (InterruptedException ex) {
-                    Log.v(TAG, "waitDone interrupted");
-                    return false;
-                }
-            }
-            return true;
-        }
+        /**
+         * Enables/Disables the camera shutter sound.
+         *
+         * @param enable   {@code true} to enable the shutter sound,
+         *                 {@code false} to disable it.
+         */
+        public void enableShutterSound(boolean enable);
     }
 }
diff --git a/src/com/android/camera/CameraManagerFactory.java b/src/com/android/camera/CameraManagerFactory.java
new file mode 100644
index 0000000..914ebb2
--- /dev/null
+++ b/src/com/android/camera/CameraManagerFactory.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2013 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;
+
+/**
+ * A factory class for {@link CameraManager}.
+ */
+public class CameraManagerFactory {
+
+    private static AndroidCameraManagerImpl sAndroidCameraManager;
+
+    /**
+     * Returns the android camera implementation of {@link CameraManager}.
+     *
+     * @return The {@link CameraManager} to control the camera device.
+     */
+    public static synchronized CameraManager getAndroidCameraManager() {
+        if (sAndroidCameraManager == null) {
+            sAndroidCameraManager = new AndroidCameraManagerImpl();
+        }
+        return sAndroidCameraManager;
+    }
+}
diff --git a/src/com/android/camera/EffectsRecorder.java b/src/com/android/camera/EffectsRecorder.java
index 2db44c7..4bf8d41 100644
--- a/src/com/android/camera/EffectsRecorder.java
+++ b/src/com/android/camera/EffectsRecorder.java
@@ -30,7 +30,6 @@
 import com.android.gallery3d.common.ApiHelper;
 
 import java.io.FileDescriptor;
-import java.io.IOException;
 import java.io.Serializable;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationHandler;
@@ -650,7 +649,7 @@
                 // Switching effects while running. Stop existing runner.
                 // The stop callback will take care of starting new runner.
                 mCameraDevice.stopPreview();
-                mCameraDevice.setPreviewTextureAsync(null);
+                mCameraDevice.setPreviewTexture(null);
                 invoke(mOldRunner, sGraphRunnerStop);
             }
         }
@@ -862,9 +861,9 @@
 
             mCameraDevice.stopPreview();
             if (mLogVerbose) Log.v(TAG, "Runner active, connecting effects preview");
-            mCameraDevice.setPreviewTextureAsync(mTextureSource);
+            mCameraDevice.setPreviewTexture(mTextureSource);
 
-            mCameraDevice.startPreviewAsync();
+            mCameraDevice.startPreview();
 
             // Unlock AE/AWB after preview started
             tryEnable3ALocks(false);
@@ -995,7 +994,7 @@
             return;
         }
         mCameraDevice.stopPreview();
-        mCameraDevice.setPreviewTextureAsync(null);
+        mCameraDevice.setPreviewTexture(null);
     }
 
     // Stop and release effect resources
diff --git a/src/com/android/camera/PhotoModule.java b/src/com/android/camera/PhotoModule.java
index 361f111..6140848 100644
--- a/src/com/android/camera/PhotoModule.java
+++ b/src/com/android/camera/PhotoModule.java
@@ -28,7 +28,6 @@
 import android.graphics.SurfaceTexture;
 import android.hardware.Camera.CameraInfo;
 import android.hardware.Camera.Parameters;
-import android.hardware.Camera.PictureCallback;
 import android.hardware.Camera.Size;
 import android.hardware.Sensor;
 import android.hardware.SensorEvent;
@@ -52,7 +51,11 @@
 import android.view.View;
 import android.view.WindowManager;
 
+import com.android.camera.CameraManager.CameraAFCallback;
+import com.android.camera.CameraManager.CameraAFMoveCallback;
+import com.android.camera.CameraManager.CameraPictureCallback;
 import com.android.camera.CameraManager.CameraProxy;
+import com.android.camera.CameraManager.CameraShutterCallback;
 import com.android.camera.ui.CountDownView.OnCountDownFinishedListener;
 import com.android.camera.ui.PopupManager;
 import com.android.camera.ui.RotateTextToast;
@@ -623,7 +626,7 @@
         if (mCameraDevice == null || mCameraStartUpThread != null)
             return;
 
-        mCameraDevice.setPreviewDisplayAsync(holder);
+        mCameraDevice.setPreviewDisplay(holder);
         // This happens when onConfigurationChanged arrives, surface has been
         // destroyed, and there is no onFullScreenChanged.
         if (mCameraState == PREVIEW_STOPPED) {
@@ -680,7 +683,7 @@
     }
 
     private final class ShutterCallback
-            implements android.hardware.Camera.ShutterCallback {
+            implements CameraShutterCallback {
 
         private boolean mAnimateFlash;
 
@@ -689,7 +692,7 @@
         }
 
         @Override
-        public void onShutter() {
+        public void onShutter(CameraProxy camera) {
             mShutterCallbackTime = System.currentTimeMillis();
             mShutterLag = mShutterCallbackTime - mCaptureStartTime;
             Log.v(TAG, "mShutterLag = " + mShutterLag + "ms");
@@ -699,10 +702,10 @@
         }
     }
 
-    private final class PostViewPictureCallback implements PictureCallback {
+    private final class PostViewPictureCallback
+            implements CameraPictureCallback {
         @Override
-        public void onPictureTaken(
-                byte [] data, android.hardware.Camera camera) {
+        public void onPictureTaken(byte [] data, CameraProxy camera) {
             mPostViewPictureCallbackTime = System.currentTimeMillis();
             Log.v(TAG, "mShutterToPostViewCallbackTime = "
                     + (mPostViewPictureCallbackTime - mShutterCallbackTime)
@@ -710,17 +713,18 @@
         }
     }
 
-    private final class RawPictureCallback implements PictureCallback {
+    private final class RawPictureCallback
+            implements CameraPictureCallback {
         @Override
-        public void onPictureTaken(
-                byte [] rawData, android.hardware.Camera camera) {
+        public void onPictureTaken(byte [] rawData, CameraProxy camera) {
             mRawPictureCallbackTime = System.currentTimeMillis();
             Log.v(TAG, "mShutterToRawCallbackTime = "
                     + (mRawPictureCallbackTime - mShutterCallbackTime) + "ms");
         }
     }
 
-    private final class JpegPictureCallback implements PictureCallback {
+    private final class JpegPictureCallback
+            implements CameraPictureCallback {
         Location mLocation;
 
         public JpegPictureCallback(Location loc) {
@@ -728,8 +732,7 @@
         }
 
         @Override
-        public void onPictureTaken(
-                final byte [] jpegData, final android.hardware.Camera camera) {
+        public void onPictureTaken(final byte [] jpegData, CameraProxy camera) {
             if (mPaused) {
                 return;
             }
@@ -841,11 +844,10 @@
         }
     }
 
-    private final class AutoFocusCallback
-            implements android.hardware.Camera.AutoFocusCallback {
+    private final class AutoFocusCallback implements CameraAFCallback {
         @Override
         public void onAutoFocus(
-                boolean focused, android.hardware.Camera camera) {
+                boolean focused, CameraProxy camera) {
             if (mPaused) return;
 
             mAutoFocusTime = System.currentTimeMillis() - mFocusStartTime;
@@ -857,10 +859,10 @@
 
     @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN)
     private final class AutoFocusMoveCallback
-            implements android.hardware.Camera.AutoFocusMoveCallback {
+            implements CameraAFMoveCallback {
         @Override
         public void onAutoFocusMoving(
-            boolean moving, android.hardware.Camera camera) {
+            boolean moving, CameraProxy camera) {
                 mFocusManager.onAutoFocusMoving(moving);
         }
     }
@@ -965,10 +967,10 @@
         Util.setGpsParameters(mParameters, loc);
         mCameraDevice.setParameters(mParameters);
 
-        mCameraDevice.takePicture2(new ShutterCallback(!animateBefore),
+        mCameraDevice.takePicture(mHandler,
+                new ShutterCallback(!animateBefore),
                 mRawPictureCallback, mPostViewPictureCallback,
-                new JpegPictureCallback(loc), mCameraState,
-                mFocusManager.getFocusState());
+                new JpegPictureCallback(loc));
 
         mNamedImages.nameNewImage(mContentResolver, mCaptureStartTime);
 
@@ -1408,7 +1410,7 @@
     @Override
     public void autoFocus() {
         mFocusStartTime = System.currentTimeMillis();
-        mCameraDevice.autoFocus(mAutoFocusCallback);
+        mCameraDevice.autoFocus(mHandler, mAutoFocusCallback);
         setCameraState(FOCUSING);
     }
 
@@ -1558,11 +1560,11 @@
         mUI.setPreviewSize(mParameters.getPreviewSize());
         Object st = mUI.getSurfaceTexture();
         if (st != null) {
-           mCameraDevice.setPreviewTextureAsync((SurfaceTexture) st);
+           mCameraDevice.setPreviewTexture((SurfaceTexture) st);
         }
 
         Log.v(TAG, "startPreview");
-        mCameraDevice.startPreviewAsync();
+        mCameraDevice.startPreview();
         mFocusManager.onPreviewStarted();
 
         if (mSnapshotOnIdle) {
@@ -1769,10 +1771,10 @@
     @TargetApi(ApiHelper.VERSION_CODES.JELLY_BEAN)
     private void updateAutoFocusMoveCallback() {
         if (mParameters.getFocusMode().equals(Util.FOCUS_MODE_CONTINUOUS_PICTURE)) {
-            mCameraDevice.setAutoFocusMoveCallback(
-                (AutoFocusMoveCallback) mAutoFocusMoveCallback);
+            mCameraDevice.setAutoFocusMoveCallback(mHandler,
+                    (CameraManager.CameraAFMoveCallback) mAutoFocusMoveCallback);
         } else {
-            mCameraDevice.setAutoFocusMoveCallback(null);
+            mCameraDevice.setAutoFocusMoveCallback(null, null);
         }
     }
 
diff --git a/src/com/android/camera/Util.java b/src/com/android/camera/Util.java
index 3a0b619..ccc2d90 100644
--- a/src/com/android/camera/Util.java
+++ b/src/com/android/camera/Util.java
@@ -38,6 +38,7 @@
 import android.location.Location;
 import android.net.Uri;
 import android.os.Build;
+import android.os.Handler;
 import android.os.ParcelFileDescriptor;
 import android.telephony.TelephonyManager;
 import android.util.DisplayMetrics;
@@ -310,7 +311,8 @@
         }
     }
 
-    public static CameraManager.CameraProxy openCamera(Activity activity, int cameraId)
+    public static CameraManager.CameraProxy openCamera(
+            Activity activity, int cameraId)
             throws CameraHardwareException, CameraDisabledException {
         throwIfCameraDisabled(activity);
 
diff --git a/src/com/android/camera/VideoModule.java b/src/com/android/camera/VideoModule.java
index bba2363..e3efa22 100644
--- a/src/com/android/camera/VideoModule.java
+++ b/src/com/android/camera/VideoModule.java
@@ -31,7 +31,6 @@
 import android.graphics.SurfaceTexture;
 import android.hardware.Camera.CameraInfo;
 import android.hardware.Camera.Parameters;
-import android.hardware.Camera.PictureCallback;
 import android.hardware.Camera.Size;
 import android.location.Location;
 import android.media.CamcorderProfile;
@@ -55,6 +54,7 @@
 import android.view.WindowManager;
 import android.widget.Toast;
 
+import com.android.camera.CameraManager.CameraPictureCallback;
 import com.android.camera.CameraManager.CameraProxy;
 import com.android.camera.ui.PopupManager;
 import com.android.camera.ui.RotateTextToast;
@@ -114,7 +114,6 @@
     private int mCameraId;
     private Parameters mParameters;
 
-    private boolean mCameraOpened = false;
     private boolean mIsInReviewMode;
     private boolean mSnapshotInProgress = false;
 
@@ -228,9 +227,8 @@
 
     private void openCamera() {
         try {
-            if (!mCameraOpened) {
+            if (mCameraDevice == null) {
                 mCameraDevice = Util.openCamera(mActivity, mCameraId);
-                mCameraOpened = true;
             }
             mParameters = mCameraDevice.getParameters();
         } catch (CameraHardwareException e) {
@@ -449,7 +447,8 @@
         mCameraDevice.setParameters(mParameters);
 
         Log.v(TAG, "Video snapshot start");
-        mCameraDevice.takePicture(null, null, null, new JpegPictureCallback(loc));
+        mCameraDevice.takePicture(mHandler,
+                null, null, null, new JpegPictureCallback(loc));
         showVideoSnapshotUI(true);
         mSnapshotInProgress = true;
         UsageStatistics.onEvent(UsageStatistics.COMPONENT_CAMERA,
@@ -832,8 +831,8 @@
 
         try {
             if (!effectsActive()) {
-                mCameraDevice.setPreviewTextureAsync(surfaceTexture);
-                mCameraDevice.startPreviewAsync();
+                mCameraDevice.setPreviewTexture(surfaceTexture);
+                mCameraDevice.startPreview();
                 mPreviewing = true;
                 onPreviewStarted();
             } else {
@@ -911,10 +910,7 @@
         if (closeEffectsAlso) closeEffects();
         mCameraDevice.setZoomChangeListener(null);
         mCameraDevice.setErrorCallback(null);
-        if (mCameraOpened) {
-            CameraHolder.instance().release();
-        }
-        mCameraOpened = false;
+        CameraHolder.instance().release();
         mCameraDevice = null;
         mPreviewing = false;
         mSnapshotInProgress = false;
@@ -1070,7 +1066,7 @@
             // We stop the preview here before unlocking the device because we
             // need to change the SurfaceTexture to SurfaceView for preview.
             stopPreview();
-            mCameraDevice.setPreviewDisplayAsync(mUI.getSurfaceHolder());
+            mCameraDevice.setPreviewDisplay(mUI.getSurfaceHolder());
             // The orientation for SurfaceTexture is different from that for
             // SurfaceView. For SurfaceTexture we don't need to consider the
             // display rotation. Just consider the sensor's orientation and we
@@ -1080,7 +1076,7 @@
             // display rotation is considered.
             mCameraDevice.setDisplayOrientation(
                     Util.getDisplayOrientation(mDisplayRotation, mCameraId));
-            mCameraDevice.startPreviewAsync();
+            mCameraDevice.startPreview();
             mPreviewing = true;
             mMediaRecorder.setPreviewDisplay(mUI.getSurfaceHolder().getSurface());
         }
@@ -1124,7 +1120,6 @@
         setupMediaRecorderPreviewDisplay();
         // Unlock the camera object before passing it to media recorder.
         mCameraDevice.unlock();
-        mCameraDevice.waitDone();
         mMediaRecorder.setCamera(mCameraDevice.getCamera());
         if (!mCaptureTimeLapse) {
             mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
@@ -1446,7 +1441,8 @@
             return;
         }
 
-        if (!mCameraDevice.waitDone()) return;
+        //??
+        //if (!mCameraDevice.waitDone()) return;
         mCurrentVideoUri = null;
         if (effectsActive()) {
             initializeEffectsRecording();
@@ -1613,7 +1609,6 @@
             releaseMediaRecorder();
             if (!mPaused) {
                 mCameraDevice.lock();
-                mCameraDevice.waitDone();
                 if (!ApiHelper.HAS_SURFACE_TEXTURE_RECORDING) {
                     stopPreview();
                     mUI.hideSurfaceView();
@@ -2129,7 +2124,7 @@
         mUI.onSwitchMode(toCamera);
     }
 
-    private final class JpegPictureCallback implements PictureCallback {
+    private final class JpegPictureCallback implements CameraPictureCallback {
         Location mLocation;
 
         public JpegPictureCallback(Location loc) {
@@ -2137,7 +2132,7 @@
         }
 
         @Override
-        public void onPictureTaken(byte [] jpegData, android.hardware.Camera camera) {
+        public void onPictureTaken(byte [] jpegData, CameraProxy camera) {
             Log.v(TAG, "onPictureTaken");
             mSnapshotInProgress = false;
             showVideoSnapshotUI(false);