Gwt-Query fade animation

gistfile1.txt

  private Integer fadeDelay = 250;
  private Boolean blockFade = false;
  private String lastDesc = "";

  /**
   * {@link Function} that insure that we wait until every fade animation is
   * finished before unblocking upcoming fade animation.
   */
  private Function fadeFunction = new Function() {
    @Override
    public void f(Element e) {
      blockFade = false;
    }
  };

  @Override
  public void fadeDescription(SafeHtml desc) {
    // Make sure that fading effect isn't blocked.
    if (!blockFade && !lastDesc.equals(desc.toString())) {
      lastDesc = desc.toString();

      if (fadeBlockTwo.isVisible() && !fadeBlockOne.isVisible()) {
        switchFade(fadeBlockOne, fadeBlockTwo.getElement(), desc);
      } else if (!fadeBlockTwo.isVisible()) {
        switchFade(fadeBlockTwo, fadeBlockOne.getElement(), desc);
      }
    }
  }

  private void switchFade(HTML fadeBlock, Element element, SafeHtml desc) {
    fadeBlock.setHTML(desc);

    if (fadeBlock.isAttached()) {
      blockFade = true;

      $(fadeBlock).fadeIn(fadeDelay, fadeFunction);
      $(element).fadeOut(fadeDelay, fadeFunction);
    } else {
      fadeBlockOne.setVisible(false);
      fadeBlockTwo.setVisible(false);

      fadeBlock.setVisible(true);
    }
  }