01: /*
02: * @(#)EventObject.java 1.22 06/10/10
03: *
04: * Copyright 1990-2006 Sun Microsystems, Inc. All Rights Reserved.
05: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
06: *
07: * This program is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU General Public License version
09: * 2 only, as published by the Free Software Foundation.
10: *
11: * This program 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 version 2 for more details (a copy is
15: * included at /legal/license.txt).
16: *
17: * You should have received a copy of the GNU General Public License
18: * version 2 along with this work; if not, write to the Free Software
19: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA
21: *
22: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
23: * Clara, CA 95054 or visit www.sun.com if you need additional
24: * information or have any questions.
25: *
26: */
27:
28: package java.util;
29:
30: /**
31: * <p>
32: * The root class from which all event state objects shall be derived.
33: * <p>
34: * All Events are constructed with a reference to the object, the "source",
35: * that is logically deemed to be the object upon which the Event in question
36: * initially occurred upon.
37: *
38: * @since JDK1.1
39: */
40:
41: public class EventObject implements java.io.Serializable {
42: /**
43: * The object on which the Event initially occurred.
44: */
45: protected transient Object source;
46:
47: /**
48: * Constructs a prototypical Event.
49: *
50: * @param source The object on which the Event initially occurred.
51: */
52: public EventObject(Object source) {
53: if (source == null)
54: throw new IllegalArgumentException("null source");
55:
56: this .source = source;
57: }
58:
59: /**
60: * The object on which the Event initially occurred.
61: *
62: * @return The object on which the Event initially occurred.
63: */
64: public Object getSource() {
65: return source;
66: }
67:
68: /**
69: * Returns a String representation of this EventObject.
70: *
71: * @return A a String representation of this EventObject.
72: */
73: public String toString() {
74: return getClass().getName() + "[source=" + source + "]";
75: }
76: }
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