1 /*
   2  * Copyright (c) 1996, 2006, Oracle and/or its affiliates. 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.awt.event;
  27 
  28 import java.util.EventListener;
  29 
  30 /**
  31  * The listener interface for receiving container events.
  32  * The class that is interested in processing a container event
  33  * either implements this interface (and all the methods it
  34  * contains) or extends the abstract <code>ContainerAdapter</code> class
  35  * (overriding only the methods of interest).
  36  * The listener object created from that class is then registered with a
  37  * component using the component's <code>addContainerListener</code>
  38  * method. When the container's contents change because a component
  39  * has been added or removed, the relevant method in the listener object
  40  * is invoked, and the <code>ContainerEvent</code> is passed to it.
  41  * <P>
  42  * Container events are provided for notification purposes ONLY;
  43  * The AWT will automatically handle add and remove operations
  44  * internally so the program works properly regardless of
  45  * whether the program registers a {@code ContainerListener} or not.
  46  *
  47  * @see ContainerAdapter
  48  * @see ContainerEvent
  49  * @see <a href="http://java.sun.com/docs/books/tutorial/post1.0/ui/containerlistener.html">Tutorial: Writing a Container Listener</a>
  50  *
  51  * @author Tim Prinzing
  52  * @author Amy Fowler
  53  * @since 1.1
  54  */
  55 public interface ContainerListener extends EventListener {
  56     /**
  57      * Invoked when a component has been added to the container.
  58      */
  59     public void componentAdded(ContainerEvent e);
  60 
  61     /**
  62      * Invoked when a component has been removed from the container.
  63      */
  64     public void componentRemoved(ContainerEvent e);
  65 
  66 }