protected void fireValueChanged(){
  ChangeEvent evt=new ChangeEvent(this);
  for (  ChangeListener listener : listenerList.getListeners(ChangeListener.class)) {
    listener.stateChanged(evt);
  }
}

protected void fireValueChanged ( ) { ChangeEvent evt = new ChangeEvent ( this ) ; for ( ChangeListener listener : listenerList . getListeners ( ChangeListener . class ) ) { listener . stateChanged ( evt ) ; } }
notify listeners of a changed value .
