1. /*

  2.  * @(#)WindowFocusListener.java	1.6 03/12/19

  3.  *

  4.  * Copyright 2004 Sun Microsystems, Inc. All rights reserved.

  5.  * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.

  6.  */

  7. 

  8. package java.awt.event;

  9. 

  10. import java.util.EventListener;

  11. 

  12. /**

  13.  * The listener interface for receiving <code>WindowEvents</code>, including

  14.  * <code>WINDOW_GAINED_FOCUS</code> and <code>WINDOW_LOST_FOCUS</code> events.

  15.  * The class that is interested in processing a <code>WindowEvent</code>

  16.  * either implements this interface (and

  17.  * all the methods it contains) or extends the abstract

  18.  * <code>WindowAdapter</code> class (overriding only the methods of interest).

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

  20.  * <code>Window</code>

  21.  * using the <code>Window</code>'s <code>addWindowFocusListener</code> method.

  22.  * When the <code>Window</code>'s

  23.  * status changes by virtue of it being opened, closed, activated, deactivated,

  24.  * iconified, or deiconified, or by focus being transfered into or out of the

  25.  * <code>Window</code>, the relevant method in the listener object is invoked,

  26.  * and the <code>WindowEvent</code> is passed to it.

  27.  *

  28.  * @author David Mendenhall

  29.  * @version 1.6, 12/19/03

  30.  *

  31.  * @see WindowAdapter

  32.  * @see WindowEvent

  33.  * @see <a href="http://java.sun.com/docs/books/tutorial/post1.0/ui/windowlistener.html">Tutorial: Writing a Window Listener</a>

  34.  * @see <a href="http://www.awl.com/cp/javaseries/jcl1_2.html">Reference: The Java Class Libraries (update file)</a>

  35.  *

  36.  * @since 1.4

  37.  */

  38. public interface WindowFocusListener extends EventListener {

  39. 

  40.     /**

  41.      * Invoked when the Window is set to be the focused Window, which means

  42.      * that the Window, or one of its subcomponents, will receive keyboard

  43.      * events.

  44.      */

  45.     public void windowGainedFocus(WindowEvent e);

  46. 

  47.     /**

  48.      * Invoked when the Window is no longer the focused Window, which means

  49.      * that keyboard events will no longer be delivered to the Window or any of

  50.      * its subcomponents.

  51.      */

  52.     public void windowLostFocus(WindowEvent e);

  53. }