001 /*
002 * Copyright 1997-2004 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.beans.beancontext;
027
028 import java.util.EventObject;
029
030 import java.beans.beancontext.BeanContext;
031 import java.beans.beancontext.BeanContextEvent;
032
033 import java.util.Arrays;
034 import java.util.Collection;
035 import java.util.Iterator;
036
037 /**
038 * A <code>BeanContextMembershipEvent</code> encapsulates
039 * the list of children added to, or removed from,
040 * the membership of a particular <code>BeanContext</code>.
041 * An instance of this event is fired whenever a successful
042 * add(), remove(), retainAll(), removeAll(), or clear() is
043 * invoked on a given <code>BeanContext</code> instance.
044 * Objects interested in receiving events of this type must
045 * implement the <code>BeanContextMembershipListener</code>
046 * interface, and must register their intent via the
047 * <code>BeanContext</code>'s
048 * <code>addBeanContextMembershipListener(BeanContextMembershipListener bcml)
049 * </code> method.
050 *
051 * @author Laurence P. G. Cable
052 * @version 1.15
053 * @since 1.2
054 * @see java.beans.beancontext.BeanContext
055 * @see java.beans.beancontext.BeanContextEvent
056 * @see java.beans.beancontext.BeanContextMembershipListener
057 */
058 public class BeanContextMembershipEvent extends BeanContextEvent {
059
060 /**
061 * Contruct a BeanContextMembershipEvent
062 *
063 * @param bc The BeanContext source
064 * @param changes The Children affected
065 * @throws NullPointerException if <CODE>changes</CODE> is <CODE>null</CODE>
066 */
067
068 public BeanContextMembershipEvent(BeanContext bc, Collection changes) {
069 super (bc);
070
071 if (changes == null)
072 throw new NullPointerException(
073 "BeanContextMembershipEvent constructor: changes is null.");
074
075 children = changes;
076 }
077
078 /**
079 * Contruct a BeanContextMembershipEvent
080 *
081 * @param bc The BeanContext source
082 * @param changes The Children effected
083 * @exception NullPointerException if changes associated with this
084 * event are null.
085 */
086
087 public BeanContextMembershipEvent(BeanContext bc, Object[] changes) {
088 super (bc);
089
090 if (changes == null)
091 throw new NullPointerException(
092 "BeanContextMembershipEvent: changes is null.");
093
094 children = Arrays.asList(changes);
095 }
096
097 /**
098 * Gets the number of children affected by the notification.
099 * @return the number of children affected by the notification
100 */
101 public int size() {
102 return children.size();
103 }
104
105 /**
106 * Is the child specified affected by the event?
107 * @return <code>true</code> if affected, <code>false</code>
108 * if not
109 */
110 public boolean contains(Object child) {
111 return children.contains(child);
112 }
113
114 /**
115 * Gets the array of children affected by this event.
116 * @return the array of children affected
117 */
118 public Object[] toArray() {
119 return children.toArray();
120 }
121
122 /**
123 * Gets the array of children affected by this event.
124 * @return the array of children effected
125 */
126 public Iterator iterator() {
127 return children.iterator();
128 }
129
130 /*
131 * fields
132 */
133
134 /**
135 * The list of children affected by this
136 * event notification.
137 */
138 protected Collection children;
139 }
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