1 /*
2 * Copyright 1997-2004 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package java.beans.beancontext;
27
28 import java.util.EventObject;
29
30 import java.beans.beancontext.BeanContext;
31 import java.beans.beancontext.BeanContextEvent;
32
33 import java.util.Arrays;
34 import java.util.Collection;
35 import java.util.Iterator;
36
37 /**
38 * A <code>BeanContextMembershipEvent</code> encapsulates
39 * the list of children added to, or removed from,
40 * the membership of a particular <code>BeanContext</code>.
41 * An instance of this event is fired whenever a successful
42 * add(), remove(), retainAll(), removeAll(), or clear() is
43 * invoked on a given <code>BeanContext</code> instance.
44 * Objects interested in receiving events of this type must
45 * implement the <code>BeanContextMembershipListener</code>
46 * interface, and must register their intent via the
47 * <code>BeanContext</code>'s
48 * <code>addBeanContextMembershipListener(BeanContextMembershipListener bcml)
49 * </code> method.
50 *
51 * @author Laurence P. G. Cable
52 * @since 1.2
53 * @see java.beans.beancontext.BeanContext
54 * @see java.beans.beancontext.BeanContextEvent
55 * @see java.beans.beancontext.BeanContextMembershipListener
56 */
57 public class BeanContextMembershipEvent extends BeanContextEvent {
58
59 /**
60 * Contruct a BeanContextMembershipEvent
61 *
62 * @param bc The BeanContext source
63 * @param changes The Children affected
64 * @throws NullPointerException if <CODE>changes</CODE> is <CODE>null</CODE>
65 */
66
67 public BeanContextMembershipEvent(BeanContext bc, Collection changes) {
68 super(bc);
69
70 if (changes == null) throw new NullPointerException(
71 "BeanContextMembershipEvent constructor: changes is null.");
72
73 children = changes;
74 }
75
76 /**
77 * Contruct a BeanContextMembershipEvent
78 *
79 * @param bc The BeanContext source
80 * @param changes The Children effected
81 * @exception NullPointerException if changes associated with this
82 * event are null.
83 */
84
85 public BeanContextMembershipEvent(BeanContext bc, Object[] changes) {
86 super(bc);
87
88 if (changes == null) throw new NullPointerException(
89 "BeanContextMembershipEvent: changes is null.");
90
91 children = Arrays.asList(changes);
92 }
93
94 /**
95 * Gets the number of children affected by the notification.
96 * @return the number of children affected by the notification
97 */
98 public int size() { return children.size(); }
99
100 /**
101 * Is the child specified affected by the event?
102 * @return <code>true</code> if affected, <code>false</code>
103 * if not
104 */
105 public boolean contains(Object child) {
106 return children.contains(child);
107 }
108
109 /**
110 * Gets the array of children affected by this event.
111 * @return the array of children affected
112 */
113 public Object[] toArray() { return children.toArray(); }
114
115 /**
116 * Gets the array of children affected by this event.
117 * @return the array of children effected
118 */
119 public Iterator iterator() { return children.iterator(); }
120
121 /*
122 * fields
123 */
124
125 /**
126 * The list of children affected by this
127 * event notification.
128 */
129 protected Collection children;
130 }
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