Java tutorial
/* * Copyright (c) 1996, 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; /** * An abstract adapter class for receiving keyboard events. * The methods in this class are empty. This class exists as * convenience for creating listener objects. * <P> * Extend this class to create a {@code KeyEvent} listener * and override the methods for the events of interest. (If you implement the * {@code KeyListener} interface, you have to define all of * the methods in it. This abstract class defines null methods for them * all, so you can only have to define methods for events you care about.) * <P> * Create a listener object using the extended class and then register it with * a component using the component's {@code addKeyListener} * method. When a key is pressed, released, or typed, * the relevant method in the listener object is invoked, * and the {@code KeyEvent} is passed to it. * * @author Carl Quinn * * @see KeyEvent * @see KeyListener * @see <a href="https://docs.oracle.com/javase/tutorial/uiswing/events/keylistener.html">Tutorial: Writing a Key Listener</a> * * @since 1.1 */ public abstract class KeyAdapter implements KeyListener { /** * Invoked when a key has been typed. * This event occurs when a key press is followed by a key release. */ public void keyTyped(KeyEvent e) { } /** * Invoked when a key has been pressed. */ public void keyPressed(KeyEvent e) { } /** * Invoked when a key has been released. */ public void keyReleased(KeyEvent e) { } }