001/* NodeChangeEvent - ObjectEvent fired when a Preference node is added/removed 002 Copyright (C) 2001, 2006 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package java.util.prefs; 039 040import java.io.IOException; 041import java.io.NotSerializableException; 042import java.io.ObjectInputStream; 043import java.io.ObjectOutputStream; 044import java.util.EventObject; 045 046/** 047 * ObjectEvent fired when a Preference node is added/removed. 048 * This event is only generated when a new subnode is added or a subnode is 049 * removed from a preference node. Changes in the entries of a preference node 050 * are indicated with a <code>PreferenceChangeEvent</code>. 051 * <p> 052 * Note that although this class is marked as serializable, attempts to 053 * serialize it will fail with NotSerializableException. 054 * 055 * @since 1.4 056 * @author Mark Wielaard (mark@klomp.org) 057 */ 058public class NodeChangeEvent extends EventObject { 059 060 // We have this to placate the compiler. 061 private static final long serialVersionUID =8068949086596572957L; 062 063 /** 064 * The sub node that was added or removed. 065 * Defined transient just like <code>EventObject.source</code> since 066 * this object should be serializable, but Preferences is in general not 067 * serializable. 068 */ 069 private final transient Preferences child; 070 071 /** 072 * Creates a new NodeChangeEvent. 073 * 074 * @param parentNode The source preference node from which a subnode was 075 * added or removed 076 * @param childNode The preference node that was added or removed 077 */ 078 public NodeChangeEvent(Preferences parentNode, Preferences childNode) { 079 super(parentNode); 080 child = childNode; 081 } 082 083 /** 084 * Returns the source parent preference node from which a subnode was 085 * added or removed. 086 */ 087 public Preferences getParent() { 088 return (Preferences) source; 089 } 090 091 /** 092 * Returns the child preference subnode that was added or removed. 093 * To see wether it is still a valid preference node one has to call 094 * <code>event.getChild().nodeExists("")</code>. 095 */ 096 public Preferences getChild() { 097 return child; 098 } 099 100 private void readObject(ObjectInputStream ois) 101 throws IOException 102 { 103 throw new NotSerializableException("LineEvent is not serializable"); 104 } 105 106 private void writeObject(ObjectOutputStream oos) 107 throws IOException 108 { 109 throw new NotSerializableException("LineEvent is not serializable"); 110 } 111}