1 /*
2 * Copyright 1999 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package java.awt.event;
27
28 import java.util.EventListener;
29
30 /**
31 * The listener interface for receiving hierarchy changed events.
32 * The class that is interested in processing a hierarchy changed event
33 * should implement this interface.
34 * The listener object created from that class is then registered with a
35 * Component using the Component's <code>addHierarchyListener</code>
36 * method. When the hierarchy to which the Component belongs changes, the
37 * <code>hierarchyChanged</code> method in the listener object is invoked,
38 * and the <code>HierarchyEvent</code> is passed to it.
39 * <p>
40 * Hierarchy events are provided for notification purposes ONLY;
41 * The AWT will automatically handle changes to the hierarchy internally so
42 * that GUI layout, displayability, and visibility work properly regardless
43 * of whether a program registers a <code>HierarchyListener</code> or not.
44 *
45 * @author David Mendenhall
46 * @see HierarchyEvent
47 * @since 1.3
48 */
49 public interface HierarchyListener extends EventListener {
50 /**
51 * Called when the hierarchy has been changed. To discern the actual
52 * type of change, call <code>HierarchyEvent.getChangeFlags()</code>.
53 *
54 * @see HierarchyEvent#getChangeFlags()
55 */
56 public void hierarchyChanged(HierarchyEvent e);
57 }
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