Java example source code file (WindowFocusListener.java)

This example Java source code file (WindowFocusListener.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

eventlistener, util, windowfocuslistener

The WindowFocusListener.java Java example source code

/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.awt.event;

import java.util.EventListener;

/**
 * The listener interface for receiving <code>WindowEvents, including
 * <code>WINDOW_GAINED_FOCUS and WINDOW_LOST_FOCUS events.
 * The class that is interested in processing a <code>WindowEvent
 * either implements this interface (and
 * all the methods it contains) or extends the abstract
 * <code>WindowAdapter class (overriding only the methods of interest).
 * The listener object created from that class is then registered with a
 * <code>Window
 * using the <code>Window's addWindowFocusListener method.
 * When the <code>Window's
 * status changes by virtue of it being opened, closed, activated, deactivated,
 * iconified, or deiconified, or by focus being transfered into or out of the
 * <code>Window, the relevant method in the listener object is invoked,
 * and the <code>WindowEvent is passed to it.
 *
 * @author David Mendenhall
 *
 * @see WindowAdapter
 * @see WindowEvent
 * @see <a href="http://docs.oracle.com/javase/tutorial/uiswing/events/windowlistener.html">Tutorial: Writing a Window Listener
 *
 * @since 1.4
 */
public interface WindowFocusListener extends EventListener {

    /**
     * Invoked when the Window is set to be the focused Window, which means
     * that the Window, or one of its subcomponents, will receive keyboard
     * events.
     */
    public void windowGainedFocus(WindowEvent e);

    /**
     * Invoked when the Window is no longer the focused Window, which means
     * that keyboard events will no longer be delivered to the Window or any of
     * its subcomponents.
     */
    public void windowLostFocus(WindowEvent e);
}