/* * @(#)Observer.java 1.23 06/10/10 * * Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER * * This program 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. * * This program 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 at /legal/license.txt). * * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 or visit www.sun.com if you need additional * information or have any questions. * */ package java.util; /** * A class can implement the Observer interface when it * wants to be informed of changes in observable objects. * * @author Chris Warth * @version 1.16, 02/02/00 * @see java.util.Observable * @since JDK1.0 */ public interface Observer { /** * This method is called whenever the observed object is changed. An * application calls an Observable object's * notifyObservers method to have all the object's * observers notified of the change. * * @param o the observable object. * @param arg an argument passed to the notifyObservers * method. */ void update(Observable o, Object arg); }
