J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1996-2006 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; |
| 27 | |
| 28 | /** |
| 29 | * A "PropertyChange" event gets delivered whenever a bean changes a "bound" |
| 30 | * or "constrained" property. A PropertyChangeEvent object is sent as an |
| 31 | * argument to the PropertyChangeListener and VetoableChangeListener methods. |
| 32 | * <P> |
| 33 | * Normally PropertyChangeEvents are accompanied by the name and the old |
| 34 | * and new value of the changed property. If the new value is a primitive |
| 35 | * type (such as int or boolean) it must be wrapped as the |
| 36 | * corresponding java.lang.* Object type (such as Integer or Boolean). |
| 37 | * <P> |
| 38 | * Null values may be provided for the old and the new values if their |
| 39 | * true values are not known. |
| 40 | * <P> |
| 41 | * An event source may send a null object as the name to indicate that an |
| 42 | * arbitrary set of if its properties have changed. In this case the |
| 43 | * old and new values should also be null. |
| 44 | */ |
| 45 | |
| 46 | public class PropertyChangeEvent extends java.util.EventObject { |
| 47 | |
| 48 | /** |
| 49 | * Constructs a new <code>PropertyChangeEvent</code>. |
| 50 | * |
| 51 | * @param source The bean that fired the event. |
| 52 | * @param propertyName The programmatic name of the property |
| 53 | * that was changed. |
| 54 | * @param oldValue The old value of the property. |
| 55 | * @param newValue The new value of the property. |
| 56 | */ |
| 57 | public PropertyChangeEvent(Object source, String propertyName, |
| 58 | Object oldValue, Object newValue) { |
| 59 | super(source); |
| 60 | this.propertyName = propertyName; |
| 61 | this.newValue = newValue; |
| 62 | this.oldValue = oldValue; |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Gets the programmatic name of the property that was changed. |
| 67 | * |
| 68 | * @return The programmatic name of the property that was changed. |
| 69 | * May be null if multiple properties have changed. |
| 70 | */ |
| 71 | public String getPropertyName() { |
| 72 | return propertyName; |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * Gets the new value for the property, expressed as an Object. |
| 77 | * |
| 78 | * @return The new value for the property, expressed as an Object. |
| 79 | * May be null if multiple properties have changed. |
| 80 | */ |
| 81 | public Object getNewValue() { |
| 82 | return newValue; |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Gets the old value for the property, expressed as an Object. |
| 87 | * |
| 88 | * @return The old value for the property, expressed as an Object. |
| 89 | * May be null if multiple properties have changed. |
| 90 | */ |
| 91 | public Object getOldValue() { |
| 92 | return oldValue; |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Sets the propagationId object for the event. |
| 97 | * |
| 98 | * @param propagationId The propagationId object for the event. |
| 99 | */ |
| 100 | public void setPropagationId(Object propagationId) { |
| 101 | this.propagationId = propagationId; |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * The "propagationId" field is reserved for future use. In Beans 1.0 |
| 106 | * the sole requirement is that if a listener catches a PropertyChangeEvent |
| 107 | * and then fires a PropertyChangeEvent of its own, then it should |
| 108 | * make sure that it propagates the propagationId field from its |
| 109 | * incoming event to its outgoing event. |
| 110 | * |
| 111 | * @return the propagationId object associated with a bound/constrained |
| 112 | * property update. |
| 113 | */ |
| 114 | public Object getPropagationId() { |
| 115 | return propagationId; |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * name of the property that changed. May be null, if not known. |
| 120 | * @serial |
| 121 | */ |
| 122 | private String propertyName; |
| 123 | |
| 124 | /** |
| 125 | * New value for property. May be null if not known. |
| 126 | * @serial |
| 127 | */ |
| 128 | private Object newValue; |
| 129 | |
| 130 | /** |
| 131 | * Previous value for property. May be null if not known. |
| 132 | * @serial |
| 133 | */ |
| 134 | private Object oldValue; |
| 135 | |
| 136 | /** |
| 137 | * Propagation ID. May be null. |
| 138 | * @serial |
| 139 | * @see #getPropagationId |
| 140 | */ |
| 141 | private Object propagationId; |
| 142 | } |