1 /*
   2  * Copyright (c) 1996, 2020, 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 /**
  29  * An abstract adapter class for receiving window events.
  30  * The methods in this class are empty. This class exists as
  31  * convenience for creating listener objects.
  32  * <P>
  33  * Extend this class to create a {@code WindowEvent} listener
  34  * and override the methods for the events of interest. (If you implement the
  35  * {@code WindowListener} interface, you have to define all of
  36  * the methods in it. This abstract class defines null methods for them
  37  * all, so you can only have to define methods for events you care about.)
  38  * <P>
  39  * Create a listener object using the extended class and then register it with
  40  * a Window using the window's {@code addWindowListener}
  41  * method. When the window's status changes by virtue of being opened,
  42  * closed, activated or deactivated, iconified or deiconified,
  43  * the relevant method in the listener
  44  * object is invoked, and the {@code WindowEvent} is passed to it.
  45  *
  46  * @see WindowEvent
  47  * @see WindowListener
  48  * @see <a href="https://docs.oracle.com/javase/tutorial/uiswing/events/windowlistener.html">Tutorial: Writing a Window Listener</a>
  49  *
  50  * @author Carl Quinn
  51  * @author Amy Fowler
  52  * @author David Mendenhall
  53  * @since 1.1
  54  */
  55 public abstract class WindowAdapter
  56     implements WindowListener, WindowStateListener, WindowFocusListener
  57 {
  58     /**
  59      * Constructs a {@code WindowAdapter}.
  60      */
  61     protected WindowAdapter() {}
  62 
  63     /**
  64      * Invoked when a window has been opened.
  65      */
  66     public void windowOpened(WindowEvent e) {}
  67 
  68     /**
  69      * Invoked when a window is in the process of being closed.
  70      * The close operation can be overridden at this point.
  71      */
  72     public void windowClosing(WindowEvent e) {}
  73 
  74     /**
  75      * Invoked when a window has been closed.
  76      */
  77     public void windowClosed(WindowEvent e) {}
  78 
  79     /**
  80      * Invoked when a window is iconified.
  81      */
  82     public void windowIconified(WindowEvent e) {}
  83 
  84     /**
  85      * Invoked when a window is de-iconified.
  86      */
  87     public void windowDeiconified(WindowEvent e) {}
  88 
  89     /**
  90      * Invoked when a window is activated.
  91      */
  92     public void windowActivated(WindowEvent e) {}
  93 
  94     /**
  95      * Invoked when a window is de-activated.
  96      */
  97     public void windowDeactivated(WindowEvent e) {}
  98 
  99     /**
 100      * Invoked when a window state is changed.
 101      * @since 1.4
 102      */
 103     public void windowStateChanged(WindowEvent e) {}
 104 
 105     /**
 106      * Invoked when the Window is set to be the focused Window, which means
 107      * that the Window, or one of its subcomponents, will receive keyboard
 108      * events.
 109      *
 110      * @since 1.4
 111      */
 112     public void windowGainedFocus(WindowEvent e) {}
 113 
 114     /**
 115      * Invoked when the Window is no longer the focused Window, which means
 116      * that keyboard events will no longer be delivered to the Window or any of
 117      * its subcomponents.
 118      *
 119      * @since 1.4
 120      */
 121     public void windowLostFocus(WindowEvent e) {}
 122 }