1: /* EventObject.java -- represents an event on an object 2: Copyright (C) 1999, 2000, 2002, 2005 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package java.util; 40: 41: import java.io.Serializable; 42: 43: /** 44: * Represents Events fired by Objects. 45: * 46: * @author Eric Blake (ebb9@email.byu.edu) 47: * @see EventListener 48: * @since 1.1 49: * @status updated to 1.4 50: */ 51: public class EventObject implements Serializable 52: { 53: /** 54: * Compatible with JDK 1.1+. 55: */ 56: private static final long serialVersionUID = 5516075349620653480L; 57: 58: /** 59: * The source object; in other words, the object which this event takes 60: * place on. 61: */ 62: protected transient Object source; 63: 64: /** 65: * Constructs an EventObject with the specified source. 66: * 67: * @param source the source of the event 68: * @throws IllegalArgumentException if source is null (This is not 69: * specified, but matches the behavior of the JDK) 70: */ 71: public EventObject(Object source) 72: { 73: // This check for null is stupid, if you ask me, since source is 74: // protected and non-final, so a subclass can set it to null later on. 75: if (source == null) 76: throw new IllegalArgumentException(); 77: this.source = source; 78: } 79: 80: /** 81: * Returns the source of the event. 82: * 83: * @return the event source 84: */ 85: public Object getSource() 86: { 87: return source; 88: } 89: 90: /** 91: * Converts the event to a String. The format is not specified, but by 92: * observation, the JDK uses: 93: * <code>getClass().getName() + "[source=" + source + "]";</code>. 94: * 95: * @return String representation of the Event 96: */ 97: public String toString() 98: { 99: return getClass().getName() + "[source=" + source + "]"; 100: } 101: } // class EventObject