jaroslav@597: /*
jaroslav@597:  * Copyright (c) 1996, 2003, Oracle and/or its affiliates. All rights reserved.
jaroslav@597:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@597:  *
jaroslav@597:  * This code is free software; you can redistribute it and/or modify it
jaroslav@597:  * under the terms of the GNU General Public License version 2 only, as
jaroslav@597:  * published by the Free Software Foundation.  Oracle designates this
jaroslav@597:  * particular file as subject to the "Classpath" exception as provided
jaroslav@597:  * by Oracle in the LICENSE file that accompanied this code.
jaroslav@597:  *
jaroslav@597:  * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@597:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@597:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jaroslav@597:  * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@597:  * accompanied this code).
jaroslav@597:  *
jaroslav@597:  * You should have received a copy of the GNU General Public License version
jaroslav@597:  * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@597:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@597:  *
jaroslav@597:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@597:  * or visit www.oracle.com if you need additional information or have any
jaroslav@597:  * questions.
jaroslav@597:  */
jaroslav@597: 
jaroslav@597: package java.util;
jaroslav@597: 
jaroslav@597: /**
jaroslav@597:  * <p>
jaroslav@597:  * The root class from which all event state objects shall be derived.
jaroslav@597:  * <p>
jaroslav@597:  * All Events are constructed with a reference to the object, the "source",
jaroslav@597:  * that is logically deemed to be the object upon which the Event in question
jaroslav@597:  * initially occurred upon.
jaroslav@597:  *
jaroslav@597:  * @since JDK1.1
jaroslav@597:  */
jaroslav@597: 
jaroslav@597: public class EventObject implements java.io.Serializable {
jaroslav@597: 
jaroslav@597:     private static final long serialVersionUID = 5516075349620653480L;
jaroslav@597: 
jaroslav@597:     /**
jaroslav@597:      * The object on which the Event initially occurred.
jaroslav@597:      */
jaroslav@597:     protected transient Object  source;
jaroslav@597: 
jaroslav@597:     /**
jaroslav@597:      * Constructs a prototypical Event.
jaroslav@597:      *
jaroslav@597:      * @param    source    The object on which the Event initially occurred.
jaroslav@597:      * @exception  IllegalArgumentException  if source is null.
jaroslav@597:      */
jaroslav@597:     public EventObject(Object source) {
jaroslav@597:         if (source == null)
jaroslav@597:             throw new IllegalArgumentException("null source");
jaroslav@597: 
jaroslav@597:         this.source = source;
jaroslav@597:     }
jaroslav@597: 
jaroslav@597:     /**
jaroslav@597:      * The object on which the Event initially occurred.
jaroslav@597:      *
jaroslav@597:      * @return   The object on which the Event initially occurred.
jaroslav@597:      */
jaroslav@597:     public Object getSource() {
jaroslav@597:         return source;
jaroslav@597:     }
jaroslav@597: 
jaroslav@597:     /**
jaroslav@597:      * Returns a String representation of this EventObject.
jaroslav@597:      *
jaroslav@597:      * @return  A a String representation of this EventObject.
jaroslav@597:      */
jaroslav@597:     public String toString() {
jaroslav@597:         return getClass().getName() + "[source=" + source + "]";
jaroslav@597:     }
jaroslav@597: }