Allow Camera.setDisplayOrientation to be called when preview is active.

bug:5422679

Change-Id: I4c936ab00428fc158b5947fe8f10b1028869bbdb

Author: Wu-cheng Li

core/java/android/hardware/Camera.java

@@ -1007,6 +1007,10 @@ public final void takePicture(ShutterCallback shutter, PictureCallback raw,
      *     camera.setDisplayOrientation(result);
      * }
      * </pre>
+     *
+     * <p>Starting from API level 14, this method can be called when preview is
+     * active.
+     *
      * @param degrees the angle that the picture will be rotated clockwise.
      *                Valid values are 0, 90, 180, and 270. The starting
      *                position is 0 (landscape).

services/camera/libcameraservice/CameraService.cpp

@@ -849,16 +849,16 @@ status_t CameraService::Client::sendCommand(int32_t cmd, int32_t arg1, int32_t a
     if (result != NO_ERROR) return result;
 
     if (cmd == CAMERA_CMD_SET_DISPLAY_ORIENTATION) {
-        // The orientation cannot be set during preview.
-        if (mHardware->previewEnabled()) {
-            return INVALID_OPERATION;
-        }
         // Mirror the preview if the camera is front-facing.
         orientation = getOrientation(arg1, mCameraFacing == CAMERA_FACING_FRONT);
         if (orientation == -1) return BAD_VALUE;
 
         if (mOrientation != orientation) {
             mOrientation = orientation;
+            if (mPreviewWindow != 0) {
+                native_window_set_buffers_transform(mPreviewWindow.get(),
+                        mOrientation);
+            }
         }
         return OK;
     } else if (cmd == CAMERA_CMD_ENABLE_SHUTTER_SOUND) {