To accomplish our task, we change the class definition to implement InteractorListener, add the zoomInteractor and unzoomInteractor fields, also the necessary interactor button fields to the Sample3 application:

public class Sample3 extends JFrame
implements InteractorListener 
{ 
  IlvManager manager; 
  IlvManagerView mgrview;
  IlvSelectInteractor selectInteractor;
  IlvManagerViewInteractor zoomInteractor, unZoomInteractor;
  Button selectButton, zoomButton, unZoomButton;
  ....
}