sclass JImageSwitch > JLabel {
  S onImageID, offImageID;
  IVarWithNotify<Bool> var;
  bool on;
  
  *(S onImageID, S *offImageID, IVarWithNotify<Bool> var) {
    bindListenerToComponent(this, var, r { set(var!) });
    on = var!;
    updateIcon();
    onClick(this, -> switch);
  }

  void updateIcon {  
    setIcon(imageIcon(loadImage2(on ? onImageID : offImageID)));
  }
  
  void switch { set(!on); }
  
  void set(bool value) swing {
    if (on != value) {
      on = value;
      updateIcon();
      var.set(on);
    }
  }
}