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

    helper = new GlassActionBarHelper().contentLayout(R.layout.activity_changing_content);
    setContentView(helper.createView(this));
    imageView = (ImageView) findViewById(R.id.imageView);
  }
 public void changeImage(View view) {
   imageView.setImageResource(IMAGES[++currentImage % IMAGES.length]);
   helper.invalidate();
 }