package util; import java.util.EventListener; /** * A listener that can be helped by ListenerHelper. HelpableListeners must use a ListenerHelper to maintain * their list of listeners. Whenever a query is performed on the HelpableListener it must assure * up-to-date-ness of its model by calling (@link ListenerHelper#needModelUpdate}. * * @see ListenerHelper * * @author Steffen Zschaler * @version 2.0 02/06/1999 * @since v2.0 */ public interface HelpableListener extends EventListener { /** * Called when the listener should subscribe to its own event source. * * @override Always */ public void subscribe(); /** * Called when the listener should unsubscribe from its own event source. * * @override Always */ public void unsubscribe(); /** * Called to update the listeners own model representation. * * @override Always */ public void updateModel(); }