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}