public void quitSynchronously() {
    state = State.DONE;
    CameraManager.get().stopPreview();
    Message quit = Message.obtain(decodeThread.getHandler(), R.id.quit);
    quit.sendToTarget();
    try {
      decodeThread.join();
    } catch (InterruptedException e) {
      // continue
    }

    // Be absolutely sure we don't send any queued up messages
    removeMessages(R.id.decode_succeeded);
    removeMessages(R.id.decode_failed);
  }