001 /* PreferenceChangeEvent - ObjectEvent fired when a Preferences entry changes 002 Copyright (C) 2001, 2006 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 package java.util.prefs; 039 040 import java.io.IOException; 041 import java.io.NotSerializableException; 042 import java.io.ObjectInputStream; 043 import java.io.ObjectOutputStream; 044 import java.util.EventObject; 045 046 /** 047 * ObjectEvent fired when a Preferences entry changes. 048 * This event is generated when a entry is added, changed or removed. 049 * When an entry is removed then <code>getNewValue</code> will return null. 050 * <p> 051 * Preference change events are only generated for entries in one particular 052 * preference node. Notification of subnode addition/removal is given by a 053 * <code>NodeChangeEvent</code>. 054 * <p> 055 * Note that although this class is marked as serializable, attempts to 056 * serialize it will fail with NotSerializableException. 057 * 058 * @since 1.4 059 * @author Mark Wielaard (mark@klomp.org) 060 */ 061 public class PreferenceChangeEvent extends EventObject { 062 063 // We have this to placate the compiler. 064 private static final long serialVersionUID = 793724513368024975L; 065 066 /** 067 * The key of the changed entry. 068 */ 069 private final String key; 070 071 /** 072 * The new value of the changed entry, or null when the entry was removed. 073 */ 074 private final String newValue; 075 076 /** 077 * Creates a new PreferenceChangeEvent. 078 * 079 * @param node The source preference node for which an entry was added, 080 * changed or removed 081 * @param key The key of the entry that was added, changed or removed 082 * @param value The new value of the entry that was added or changed, or 083 * null when the entry was removed 084 */ 085 public PreferenceChangeEvent(Preferences node, String key, String value) { 086 super(node); 087 this.key = key; 088 this.newValue = value; 089 } 090 091 /** 092 * Returns the source Preference node from which an entry was added, 093 * changed or removed. 094 */ 095 public Preferences getNode() { 096 return (Preferences) source; 097 } 098 099 /** 100 * Returns the key of the entry that was added, changed or removed. 101 */ 102 public String getKey() { 103 return key; 104 } 105 106 /** 107 * Returns the new value of the entry that was added or changed, or 108 * returns null when the entry was removed. 109 */ 110 public String getNewValue() { 111 return newValue; 112 } 113 114 private void readObject(ObjectInputStream ois) 115 throws IOException 116 { 117 throw new NotSerializableException("LineEvent is not serializable"); 118 } 119 120 private void writeObject(ObjectOutputStream oos) 121 throws IOException 122 { 123 throw new NotSerializableException("LineEvent is not serializable"); 124 } 125 }