Source for java.util.prefs.PreferenceChangeEvent

   1: /* PreferenceChangeEvent - ObjectEvent fired when a Preferences entry changes
   2:    Copyright (C) 2001, 2006 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package java.util.prefs;
  39: 
  40: import java.io.IOException;
  41: import java.io.NotSerializableException;
  42: import java.io.ObjectInputStream;
  43: import java.io.ObjectOutputStream;
  44: import java.util.EventObject;
  45: 
  46: /**
  47:  * ObjectEvent fired when a Preferences entry changes.
  48:  * This event is generated when a entry is added, changed or removed.
  49:  * When an entry is removed then <code>getNewValue</code> will return null.
  50:  * <p>
  51:  * Preference change events are only generated for entries in one particular
  52:  * preference node. Notification of subnode addition/removal is given by a
  53:  * <code>NodeChangeEvent</code>.
  54:  * <p>
  55:  * Note that although this class is marked as serializable, attempts to
  56:  * serialize it will fail with NotSerializableException.
  57:  *
  58:  * @since 1.4
  59:  * @author Mark Wielaard (mark@klomp.org)
  60:  */
  61: public class PreferenceChangeEvent extends EventObject {
  62: 
  63:   // We have this to placate the compiler.
  64:   private static final long serialVersionUID = 793724513368024975L;
  65: 
  66:     /**
  67:      * The key of the changed entry.
  68:      */
  69:     private final String key;
  70: 
  71:     /**
  72:      * The new value of the changed entry, or null when the entry was removed.
  73:      */
  74:     private final String newValue;
  75: 
  76:     /**
  77:      * Creates a new PreferenceChangeEvent.
  78:      *
  79:      * @param node The source preference node for which an entry was added,
  80:      * changed or removed
  81:      * @param key The key of the entry that was added, changed or removed
  82:      * @param value The new value of the entry that was added or changed, or
  83:      * null when the entry was removed
  84:      */
  85:     public PreferenceChangeEvent(Preferences node, String key, String value) {
  86:         super(node);
  87:         this.key = key;
  88:         this.newValue = value;
  89:     }
  90: 
  91:     /**
  92:      * Returns the source Preference node from which an entry was added,
  93:      * changed or removed.
  94:      */
  95:     public Preferences getNode() {
  96:         return (Preferences) source;
  97:     }
  98: 
  99:     /**
 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: }