001/* Listener for changes to objects implementing Settable.
002
003 Copyright (c) 1998-2013 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026 */
027package ptolemy.kernel.util;
028
029///////////////////////////////////////////////////////////////////
030//// ValueListener
031
032/**
033 This is an interface for listeners that are notified when the value
034 of an object implementing Settable changes.
035
036 @author  Edward A. Lee
037 @version $Id$
038 @since Ptolemy II 1.0
039 @Pt.ProposedRating Green (eal)
040 @Pt.AcceptedRating Green (cxh)
041 @see ptolemy.data.expr.Variable
042 */
043public interface ValueListener {
044    ///////////////////////////////////////////////////////////////////
045    ////                         public methods                    ////
046
047    /** React to the fact that the specified Settable has changed.
048     *  @param settable The object that has changed value.
049     */
050    public void valueChanged(Settable settable);
051}