ancestorListener = new AncestorHandler(); progressBar.addAncestorListener(ancestorListener);  componentListener = new ComponentHandler(); progressBar.addComponentListener(componentListener);
  protected void installListeners()  {    changeListener = new ChangeHandler();    propertyListener = new PropertyChangeHandler();    animation = new Animator();    progressBar.addChangeListener(changeListener);    progressBar.addPropertyChangeListener(propertyListener);    animationTimer.addActionListener(animation);  }