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package java.awt.event;

import java.util.EventListener;

The listener interface for receiving hierarchy changed events.
The class that is interested in processing a hierarchy changed event
should implement this interface.
The listener object created from that class is then registered with a
Component using the Component's addHierarchyListener
method. When the hierarchy to which the Component belongs changes, the
hierarchyChanged method in the listener object is invoked,
and the HierarchyEvent is passed to it.

Hierarchy events are provided for notification purposes ONLY;
The AWT will automatically handle changes to the hierarchy internally so
that GUI layout, displayability, and visibility work properly regardless
of whether a program registers a HierarchyListener or not.
Author:
     David Mendenhall
See Also:
HierarchyEvent
Since:
      1.3/**
 * The listener interface for receiving hierarchy changed events.
 * The class that is interested in processing a hierarchy changed event
 * should implement this interface.
 * The listener object created from that class is then registered with a
 * Component using the Component's <code>addHierarchyListener</code>
 * method. When the hierarchy to which the Component belongs changes, the
 * <code>hierarchyChanged</code> method in the listener object is invoked,
 * and the <code>HierarchyEvent</code> is passed to it.
 * <p>
 * Hierarchy events are provided for notification purposes ONLY;
 * The AWT will automatically handle changes to the hierarchy internally so
 * that GUI layout, displayability, and visibility work properly regardless
 * of whether a program registers a <code>HierarchyListener</code> or not.
 *
 * @author      David Mendenhall
 * @see         HierarchyEvent
 * @since       1.3
 */
public interface HierarchyListener extends EventListener {
    
Called when the hierarchy has been changed. To discern the actual
type of change, call HierarchyEvent.getChangeFlags().
See Also:
getChangeFlags.getChangeFlags()/**
     * Called when the hierarchy has been changed. To discern the actual
     * type of change, call <code>HierarchyEvent.getChangeFlags()</code>.
     *
     * @see HierarchyEvent#getChangeFlags()
     */
    public void hierarchyChanged(HierarchyEvent e);
}