/**
  * Removes the scale listener.
  *
  * @param sl the sl
  */
 public void removeScaleListener(final ScaleListener sl) {
   OptionEventDispatcher.remove(sl);
 }
 /**
  * Removes the background listener.
  *
  * @param bl the bl
  */
 public void removeBackgroundListener(final BackgroundListener bl) {
   OptionEventDispatcher.remove(bl);
 }