1 /* 2 * Copyright (c) 2000, 2013, 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 <code>WindowEvents</code>, including 32 * <code>WINDOW_GAINED_FOCUS</code> and <code>WINDOW_LOST_FOCUS</code> events. 33 * The class that is interested in processing a <code>WindowEvent</code> 34 * either implements this interface (and 35 * all the methods it contains) or extends the abstract 36 * <code>WindowAdapter</code> class (overriding only the methods of interest). 37 * The listener object created from that class is then registered with a 38 * <code>Window</code> 39 * using the <code>Window</code>'s <code>addWindowFocusListener</code> method. 40 * When the <code>Window</code>'s 41 * status changes by virtue of it being opened, closed, activated, deactivated, 42 * iconified, or deiconified, or by focus being transfered into or out of the 43 * <code>Window</code>, the relevant method in the listener object is invoked, 44 * and the <code>WindowEvent</code> is passed to it. 45 * 46 * @author David Mendenhall 47 * 48 * @see WindowAdapter 49 * @see WindowEvent 50 * @see <a href="http://docs.oracle.com/javase/tutorial/uiswing/events/windowlistener.html">Tutorial: Writing a Window Listener</a> 51 * 52 * @since 1.4 53 */ 54 public interface WindowFocusListener extends EventListener { 55 56 /** 57 * Invoked when the Window is set to be the focused Window, which means 58 * that the Window, or one of its subcomponents, will receive keyboard 59 * events. 60 * @param e the event to be processed 61 */ 62 public void windowGainedFocus(WindowEvent e); 63 64 /** 65 * Invoked when the Window is no longer the focused Window, which means 66 * that keyboard events will no longer be delivered to the Window or any of 67 * its subcomponents. 68 * @param e the event to be processed 69 */ 70 public void windowLostFocus(WindowEvent e); 71 }