@Override
        public boolean handleMessage(Message msg) {
            if (msg.what == MESSAGE_FOCUS) {
                focus();
                return true;
            }
            return false;
        }
This should be created and used from the camera thread only. The thread message queue is used
to run all operations on the same thread.
zxing-android-embedded/src/com/journeyapps/barcodescanner/camera/AutoFocusManager.java