1. /*

  2.  * @(#)HierarchyListener.java	1.5 00/02/02

  3.  *

  4.  * Copyright 1997-2000 Sun Microsystems, Inc. All Rights Reserved.

  5.  * 

  6.  * This software is the proprietary information of Sun Microsystems, Inc.  

  7.  * Use is subject to license terms.

  8.  * 

  9.  */

  10. 

  11. package java.awt.event;

  12. 

  13. import java.util.EventListener;

  14. 

  15. /**

  16.  * The listener interface for receiving hierarchy changed events.

  17.  * The class that is interested in processing a hierarchy changed event

  18.  * should implement this interface.

  19.  * The listener object created from that class is then registered with a

  20.  * Component using the Component's <code>addHierarchyListener</code> 

  21.  * method. When the hierarchy to which the Component belongs changes, the

  22.  * <code>hierarchyChanged</code> method in the listener object is invoked,

  23.  * and the <code>HierarchyEvent</code> is passed to it.

  24.  * <p>

  25.  * Hierarchy events are provided for notification purposes ONLY;

  26.  * The AWT will automatically handle changes to the hierarchy internally so

  27.  * that GUI layout, displayability, and visibility work properly regardless

  28.  * of whether a program registers a <code>HierarchyListener</code> or not.

  29.  *

  30.  * @author	David Mendenhall

  31.  * @version	1.5, 02/02/00

  32.  * @see		HierarchyEvent

  33.  * @since 	1.3

  34.  */

  35. public interface HierarchyListener extends EventListener {

  36.     /**

  37.      * Called when the hierarchy has been changed. To discern the actual

  38.      * type of change, call <code>HierarchyEvent.getChangeFlags()</code>.

  39.      *

  40.      * @see HierarchyEvent#getChangeFlags()

  41.      */

  42.     public void hierarchyChanged(HierarchyEvent e);

  43. }