SnapdragonCamera: fix screen flash on resuming

Currently preview cover will be hidden shortly after preview started,
but if the actual first frame comes late, the main screen will flash.
Register a oneshot preview callback to hide preview cover.

CRs-Fixed: 881290
Change-Id: I5d93e57f0b9aa338c6b34461d5e3ee31806b6706

3 files changed, 19 insertions, 1 deletions

diff --git a/src/com/android/camera/AndroidCameraManagerImpl.java b/src/com/android/camera/AndroidCameraManagerImpl.java
index 1a9e2a7dc..3bfe0c2cb 100644
--- a/src/com/android/camera/AndroidCameraManagerImpl.java
+++ b/src/com/android/camera/AndroidCameraManagerImpl.java
@@ -74,6 +74,7 @@ class AndroidCameraManagerImpl implements CameraManager {
     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;
+    private static final int SET_ONESHOT_PREVIEW_CALLBACK =     108;
     // Parameters
     private static final int SET_PARAMETERS =     201;
     private static final int GET_PARAMETERS =     202;
@@ -340,6 +341,9 @@ class AndroidCameraManagerImpl implements CameraManager {
                         mCamera.setPreviewCallback((PreviewCallback) msg.obj);
                         return;
 
+                    case SET_ONESHOT_PREVIEW_CALLBACK:
+                        mCamera.setOneShotPreviewCallback((PreviewCallback) msg.obj);
+
                     case ENABLE_SHUTTER_SOUND:
                         enableShutterSound((msg.arg1 == 1) ? true : false);
                         return;
@@ -498,6 +502,13 @@ class AndroidCameraManagerImpl implements CameraManager {
         }
 
         @Override
+        public void setOneShotPreviewCallback(Handler handler, CameraPreviewDataCallback cb) {
+            mCameraHandler.obtainMessage(
+                    SET_ONESHOT_PREVIEW_CALLBACK,
+                    PreviewCallbackForward.getNewInstance(handler, this, cb)).sendToTarget();
+        }
+
+        @Override
         public void addCallbackBuffer(byte[] callbackBuffer) {
             mCameraHandler.obtainMessage(ADD_CALLBACK_BUFFER, callbackBuffer).sendToTarget();
         }
diff --git a/src/com/android/camera/CameraManager.java b/src/com/android/camera/CameraManager.java
index 1856ec85c..e7d535060 100644
--- a/src/com/android/camera/CameraManager.java
+++ b/src/com/android/camera/CameraManager.java
@@ -240,6 +240,7 @@ public interface CameraManager {
          */
         public void setPreviewDataCallbackWithBuffer(Handler handler, CameraPreviewDataCallback cb);
 
+        public void setOneShotPreviewCallback(Handler handler, CameraPreviewDataCallback cb);
         /**
          * Adds buffer for the preview callback.
          *
diff --git a/src/com/android/camera/PhotoModule.java b/src/com/android/camera/PhotoModule.java
index fd251cee3..54787bd2b 100644
--- a/src/com/android/camera/PhotoModule.java
+++ b/src/com/android/camera/PhotoModule.java
@@ -532,7 +532,6 @@ public class PhotoModule
         if (mCameraState == SNAPSHOT_IN_PROGRESS) {
             return;
         }
-        mUI.hidePreviewCover();
         setCameraState(IDLE);
         mFocusManager.onPreviewStarted();
         startFaceDetection();
@@ -2646,6 +2645,13 @@ public class PhotoModule
         setCameraParameters(UPDATE_PARAM_ALL);
 
         mCameraDevice.startPreview();
+        mCameraDevice.setOneShotPreviewCallback(mHandler,
+                new CameraManager.CameraPreviewDataCallback() {
+                    @Override
+                    public void onPreviewFrame(byte[] data, CameraProxy camera) {
+                        mUI.hidePreviewCover();
+                    }
+                });
         mHandler.sendEmptyMessage(ON_PREVIEW_STARTED);
 
         setDisplayOrientation();