@Override
  protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);

    // Trigger the initial hide() shortly after the activity has been
    // created, to briefly hint to the user that UI controls
    // are available.
    delayedHide(100);
  }
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_fullscreen);

    mVisible = true;
    mControlsView = findViewById(R.id.fullscreen_content_controls);
    mContentView = findViewById(R.id.fullscreen_content);

    // Set up the user interaction to manually show or hide the system UI.
    mContentView.setOnClickListener(
        new View.OnClickListener() {
          @Override
          public void onClick(View view) {
            toggle();
          }
        });

    // Upon interacting with UI controls, delay any scheduled hide()
    // operations to prevent the jarring behavior of controls going away
    // while interacting with the UI.
    findViewById(R.id.dummy_button).setOnTouchListener(mDelayHideTouchListener);
  }