Camera: open Camera and start Preview in a seperate thread.

Start openCamera and start preview in a separate thread so that
UI initialization and preview can run parallely. This is to
improve camera cold start latency.

Change-Id: I57af45bc90a4db1630c73449d543c3ff0992e55c

4 files changed, 107 insertions, 57 deletions

diff --git a/src/com/android/camera/CameraActivity.java b/src/com/android/camera/CameraActivity.java
index 17d69794b..327052251 100644
--- a/src/com/android/camera/CameraActivity.java
+++ b/src/com/android/camera/CameraActivity.java
@@ -183,6 +183,7 @@ public class CameraActivity extends Activity
     private ViewGroup mUndoDeletionBar;
     private boolean mIsUndoingDeletion = false;
     private boolean mIsEditActivityInProgress = false;
+    protected boolean mIsModuleSwitchInProgress = false;
 
     private Uri[] mNfcPushUris = new Uri[1];
 
@@ -1465,6 +1466,7 @@ public class CameraActivity extends Activity
             return;
         }
 
+        mIsModuleSwitchInProgress = true;
         CameraHolder.instance().keep();
         closeModule(mCurrentModule);
         setModuleFromIndex(moduleIndex);
@@ -1479,6 +1481,7 @@ public class CameraActivity extends Activity
         // starts up.
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
         prefs.edit().putInt(CameraSettings.KEY_STARTUP_MODULE_INDEX, moduleIndex).apply();
+        mIsModuleSwitchInProgress = false;
     }
 
     /**
diff --git a/src/com/android/camera/PhotoController.java b/src/com/android/camera/PhotoController.java
index c1c3a8562..b08f8c088 100644
--- a/src/com/android/camera/PhotoController.java
+++ b/src/com/android/camera/PhotoController.java
@@ -23,7 +23,7 @@ import com.android.camera.ShutterButton.OnShutterButtonListener;
 
 
 public interface PhotoController extends OnShutterButtonListener {
-
+    public static final int INIT = -1;
     public static final int PREVIEW_STOPPED = 0;
     public static final int IDLE = 1;  // preview is active
     // Focus is in progress. The exact focus state is in Focus.java.
diff --git a/src/com/android/camera/PhotoModule.java b/src/com/android/camera/PhotoModule.java
index 3843ed4ae..75e17a351 100644
--- a/src/com/android/camera/PhotoModule.java
+++ b/src/com/android/camera/PhotoModule.java
@@ -135,6 +135,7 @@ public class PhotoModule
     private static final int SET_PHOTO_UI_PARAMS = 12;
     private static final int SWITCH_TO_GCAM_MODULE = 13;
     private static final int CONFIGURE_SKIN_TONE_FACTOR = 14;
+    private static final int ON_PREVIEW_STARTED = 15;
     private static final int UPDATE_ASD_ICON = 16;
     private static final int CLEAR_ASD_ICON = 17;
 
@@ -227,6 +228,15 @@ public class PhotoModule
         }
     };
 
+    private class OpenCameraThread extends Thread {
+        @Override
+        public void run() {
+            openCamera();
+            startPreview();
+        }
+    }
+
+    private OpenCameraThread mOpenCameraThread = null;
     /**
      * An unpublished intent flag requesting to return as soon as capturing
      * is completed.
@@ -250,7 +260,7 @@ public class PhotoModule
     private boolean mFirstTimeInitialized;
     private boolean mIsImageCaptureIntent;
 
-    private int mCameraState = PREVIEW_STOPPED;
+    private int mCameraState = INIT;
     private boolean mSnapshotOnIdle = false;
 
     private ContentResolver mContentResolver;
@@ -454,6 +464,10 @@ public class PhotoModule
                     }
                     break;
                 }
+                case ON_PREVIEW_STARTED: {
+                    onPreviewStarted();
+                    break;
+                }
                 case UPDATE_ASD_ICON: {
                     if (!mSceneDetection) {
                         mUI.updateSceneDetectionIcon(null);
@@ -481,7 +495,6 @@ public class PhotoModule
     public void init(CameraActivity activity, View parent) {
         mActivity = activity;
         mRootView = parent;
-        mUI = new PhotoUI(activity, this, parent);
         mPreferences = new ComboPreferences(mActivity);
         CameraSettings.upgradeGlobalPreferences(mPreferences.getGlobal());
         mCameraId = getPreferredCameraId(mPreferences);
@@ -503,9 +516,11 @@ public class PhotoModule
         // Power shutter
         mActivity.initPowerShutter(mPreferences);
 
-        // we need to reset exposure for the preview
-        resetExposureCompensation();
-
+        if (mOpenCameraThread == null && !mActivity.mIsModuleSwitchInProgress) {
+            mOpenCameraThread = new OpenCameraThread();
+            mOpenCameraThread.start();
+        }
+        mUI = new PhotoUI(activity, this, parent);
         initializeControlByIntent();
         mQuickCapture = mActivity.getIntent().getBooleanExtra(EXTRA_QUICK_CAPTURE, false);
         mLocationManager = new LocationManager(mActivity, mUI);
@@ -530,6 +545,7 @@ public class PhotoModule
 
     private void onPreviewStarted() {
         setCameraState(IDLE);
+        mFocusManager.onPreviewStarted();
         startFaceDetection();
         locationFirstRun();
     }
@@ -558,7 +574,20 @@ public class PhotoModule
 
     @Override
     public void onPreviewUIReady() {
-        startPreview();
+        if (mPaused || mCameraDevice == null) {
+            return;
+        }
+        Log.v(TAG, "onPreviewUIReady");
+        if (mCameraState == PREVIEW_STOPPED) {
+            startPreview();
+        } else {
+            SurfaceTexture st = mUI.getSurfaceTexture();
+            if (st == null) {
+                Log.w(TAG, "startPreview: surfaceTexture is not ready.");
+                return;
+            }
+            mCameraDevice.setPreviewTexture(st);
+        }
     }
 
     @Override
@@ -566,6 +595,7 @@ public class PhotoModule
         if (mCameraDevice == null) {
             return;
         }
+        Log.v(TAG, "onPreviewUIDestroyed");
         stopPreview();
         mCameraDevice.setPreviewTexture(null);
     }
@@ -580,12 +610,10 @@ public class PhotoModule
     }
 
     private void onCameraOpened() {
-        View root = mUI.getRootView();
-        // These depend on camera parameters.
-
-        int width = root.getWidth();
-        int height = root.getHeight();
-        mFocusManager.setPreviewSize(width, height);
+        if (mPaused) {
+            return;
+        }
+        Log.v(TAG, "onCameraOpened");
         openCameraCommon();
         resizeForPreviewAspectRatio();
     }
@@ -617,6 +645,7 @@ public class PhotoModule
             return;
         }
         mParameters = mCameraDevice.getParameters();
+        mInitialParams = mParameters;
         initializeCapabilities();
         CameraInfo info = CameraHolder.instance().getCameraInfo()[mCameraId];
         mMirror = (info.facing == CameraInfo.CAMERA_FACING_FRONT);
@@ -650,8 +679,6 @@ public class PhotoModule
         }
         updateSceneMode();
         showTapToFocusToastIfNeeded();
-
-
     }
 
     @Override
@@ -743,8 +770,6 @@ public class PhotoModule
         mFirstTimeInitialized = true;
         Log.d(TAG, "addIdleHandler in first time initialization");
         addIdleHandler();
-
-        mActivity.updateStorageSpaceAndHint();
     }
 
     // If the activity is paused and resumed, this method will be called in
@@ -800,6 +825,8 @@ public class PhotoModule
 
     @Override
     public void startFaceDetection() {
+        if (mCameraDevice == null) return;
+
         if (mFaceDetectionEnabled == false
                || mFaceDetectionStarted || mCameraState != IDLE) return;
         if (mParameters.getMaxNumDetectedFaces() > 0) {
@@ -1527,7 +1554,8 @@ public class PhotoModule
         if (orientation == OrientationEventListener.ORIENTATION_UNKNOWN) return;
         int oldOrientation = mOrientation;
         mOrientation = CameraUtil.roundOrientation(orientation, mOrientation);
-        if (oldOrientation != mOrientation) {
+        if (oldOrientation != mOrientation &&
+            oldOrientation != OrientationEventListener.ORIENTATION_UNKNOWN) {
             Log.v(TAG, "onOrientationChanged, update parameters");
             if (mParameters != null && mCameraDevice != null) {
                 onSharedPreferenceChanged();
@@ -1786,28 +1814,28 @@ public class PhotoModule
         mPaused = false;
     }
 
-    private boolean prepareCamera() {
+    private void openCamera() {
         // We need to check whether the activity is paused before long
         // operations to ensure that onPause() can be done ASAP.
+        if (mPaused) {
+            return;
+        }
         Log.v(TAG, "Open camera device.");
         mCameraDevice = CameraUtil.openCamera(
                 mActivity, mCameraId, mHandler,
                 mActivity.getCameraOpenErrorCallback());
         if (mCameraDevice == null) {
             Log.e(TAG, "Failed to open camera:" + mCameraId);
-            return false;
+            mHandler.sendEmptyMessage(OPEN_CAMERA_FAIL);
+            return;
         }
         mParameters = mCameraDevice.getParameters();
-
-        initializeCapabilities();
-        if (mFocusManager == null) initializeFocusManager();
-        setCameraParameters(UPDATE_PARAM_ALL);
-        mHandler.sendEmptyMessage(CAMERA_OPEN_DONE);
         mCameraPreviewParamsReady = true;
-        startPreview();
-        mOnResumeTime = SystemClock.uptimeMillis();
-        checkDisplayRotation();
-        return true;
+        mInitialParams = mParameters;
+        if (mFocusManager == null) initializeFocusManager();
+        initializeCapabilities();
+        mHandler.sendEmptyMessageDelayed(CAMERA_OPEN_DONE,100);
+        return;
     }
 
     @Override
@@ -1836,13 +1864,14 @@ public class PhotoModule
         Log.v(TAG, "Executing onResumeTasks.");
         if (mOpenCameraFail || mCameraDisabled) return;
 
+        if (mOpenCameraThread == null) {
+            mOpenCameraThread = new OpenCameraThread();
+            mOpenCameraThread.start();
+        }
+
         mJpegPictureCallbackTime = 0;
         mZoomValue = 0;
         resetExposureCompensation();
-        if (!prepareCamera()) {
-            // Camera failure.
-            return;
-        }
 
         if (mSkinToneSeekBar != true)
         {
@@ -1858,6 +1887,8 @@ public class PhotoModule
         }
         mUI.initDisplayChangeListener();
         keepScreenOnAwhile();
+        mUI.updateOnScreenIndicators(mParameters, mPreferenceGroup,
+                        mPreferences);
 
         UsageStatistics.onContentViewChanged(
                 UsageStatistics.COMPONENT_CAMERA, "PhotoModule");
@@ -1871,6 +1902,9 @@ public class PhotoModule
         if (msensor != null) {
             mSensorManager.registerListener(this, msensor, SensorManager.SENSOR_DELAY_NORMAL);
         }
+
+        mOnResumeTime = SystemClock.uptimeMillis();
+        checkDisplayRotation();
     }
 
     @Override
@@ -1895,6 +1929,14 @@ public class PhotoModule
         Log.v(TAG, "On pause.");
         mUI.showPreviewCover();
 
+        try {
+            if (mOpenCameraThread != null) {
+                mOpenCameraThread.join();
+            }
+        } catch (InterruptedException ex) {
+            // ignore
+        }
+        mOpenCameraThread = null;
         // Reset the focus first. Camera CTS does not guarantee that
         // cancelAutoFocus is allowed after preview stops.
         if (mCameraDevice != null && mCameraState != PREVIEW_STOPPED) {
@@ -1952,6 +1994,12 @@ public class PhotoModule
                     mInitialParams, this, mMirror,
                     mActivity.getMainLooper(), mUI);
         }
+        View root = mUI.getRootView();
+        // These depend on camera parameters.
+
+        int width = root.getWidth();
+        int height = root.getHeight();
+        mFocusManager.setPreviewSize(width, height);
     }
 
     @Override
@@ -2141,7 +2189,9 @@ public class PhotoModule
             mFaceDetectionStarted = false;
             mCameraDevice = null;
             setCameraState(PREVIEW_STOPPED);
-            mFocusManager.onCameraReleased();
+            if (mFocusManager != null) {
+                mFocusManager.onCameraReleased();
+            }
         }
     }
 
@@ -2165,19 +2215,17 @@ public class PhotoModule
         startPreview();
     }
 
-    /** This can run on a background thread, post any view updates to MainHandler. */
+    /** This can run on a background thread, so don't do UI updates here. Post any
+             view updates to MainHandler or do it on onPreviewStarted() .  */
     private void startPreview() {
         if (mPaused || mCameraDevice == null) {
             return;
         }
 
-         // Any decisions we make based on the surface texture state
-         // need to be protected.
+        Log.v(TAG, "startPreview");
+
         SurfaceTexture st = mUI.getSurfaceTexture();
-        if (st == null) {
-            Log.w(TAG, "startPreview: surfaceTexture is not ready.");
-            return;
-        }
+        mCameraDevice.setPreviewTexture(st);
 
         if (!mCameraPreviewParamsReady) {
             Log.w(TAG, "startPreview: parameters for preview is not ready.");
@@ -2186,11 +2234,16 @@ public class PhotoModule
         mCameraDevice.setErrorCallback(mErrorCallback);
 
         // Preview needs to be stopped when changing resolution
-        if (mRestartPreview && mCameraState != PREVIEW_STOPPED) {
+        if (mRestartPreview && mCameraState != PREVIEW_STOPPED && mCameraState != INIT) {
             stopPreview();
             mRestartPreview = false;
         }
 
+        setCameraParameters(UPDATE_PARAM_ALL);
+
+        mCameraDevice.startPreview();
+        mHandler.sendEmptyMessage(ON_PREVIEW_STARTED);
+
         setDisplayOrientation();
 
         if (!mSnapshotOnIdle) {
@@ -2203,10 +2256,6 @@ public class PhotoModule
                 }
             }
             mFocusManager.setAeAwbLock(false); // Unlock AE and AWB.
-        }
-        setCameraParameters(UPDATE_PARAM_ALL);
-        // Let UI set its expected aspect ratio
-        mCameraDevice.setPreviewTexture(st);
 
         // Callback for automatic scene detection, if supported.
         // Will run on UI thread
@@ -2215,16 +2264,11 @@ public class PhotoModule
             mCameraDevice.setMetadataCallback(mHandler, mASDCallback);
         }
 
-        Log.v(TAG, "startPreview");
-        mCameraDevice.startPreview();
-        mFocusManager.onPreviewStarted();
-        onPreviewStarted();
-
         // Set camera mode
         CameraSettings.setVideoMode(mParameters, false);
         mCameraDevice.setParameters(mParameters);
 
-        if (mSnapshotOnIdle && mBurstShotsDone > 0) {
+        } else if (mBurstShotsDone > 0) {
             mHandler.post(mDoSnapRunnable);
         }
     }
@@ -2302,6 +2346,7 @@ public class PhotoModule
         return ret;
     }
 
+    /** This can run on a background thread, so don't do UI updates here.*/
     private void qcomUpdateCameraParametersPreference() {
         // Set Picture Format
         // Picture Formats specified in UI should be consistent with
@@ -2582,6 +2627,7 @@ public class PhotoModule
         }
     }
 
+    /** This can run on a background thread, so don't do UI updates here.*/
     private boolean updateCameraParametersPreference() {
         setAutoExposureLockIfSupported();
         setAutoWhiteBalanceLockIfSupported();
@@ -2969,7 +3015,6 @@ public class PhotoModule
     }
 
     private void initializeCapabilities() {
-        mInitialParams = mCameraDevice.getParameters();
         mFocusAreaSupported = CameraUtil.isFocusAreaSupported(mInitialParams);
         mMeteringAreaSupported = CameraUtil.isMeteringAreaSupported(mInitialParams);
         mAeLockSupported = CameraUtil.isAutoExposureLockSupported(mInitialParams);
diff --git a/src/com/android/camera/PhotoUI.java b/src/com/android/camera/PhotoUI.java
index c4260effb..8727271b3 100644
--- a/src/com/android/camera/PhotoUI.java
+++ b/src/com/android/camera/PhotoUI.java
@@ -292,10 +292,12 @@ public class PhotoUI implements PieListener,
             ratio = 1 / ratio;
         }
 
-        Log.d(TAG,"setAspectRatio() ratio["+ratio+"] mAspectRatio["+mAspectRatio+"]");
-        mAspectRatio = ratio;
-        mAspectRatioResize = true;
-        mTextureView.requestLayout();
+        if (mAspectRatio != ratio) {
+            Log.d(TAG,"setAspectRatio() ratio["+ratio+"] mAspectRatio["+mAspectRatio+"]");
+            mAspectRatio = ratio;
+            mAspectRatioResize = true;
+            mTextureView.requestLayout();
+        }
     }
 
     public void setSurfaceTextureSizeChangedListener(SurfaceTextureSizeChangedListener listener) {