001/* Represents an undo or redo action.
002
003 Copyright (c) 2003-2013 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.undo;
028
029///////////////////////////////////////////////////////////////////
030//// UndoAction
031
032/**
033 This interface represents an undo or redo action that is
034 maintained on an undo/redo stack, such as that maintained by
035 UndoStackAttribute.
036
037 @see UndoStackAttribute
038 @author  Edward A. Lee
039 @version $Id$
040 @since Ptolemy II 3.1
041 @Pt.ProposedRating Green (eal)
042 @Pt.AcceptedRating Green (hyzheng)
043 */
044public interface UndoAction {
045    // NOTE: Except for the fact that execute() throws Exception,
046    // we could have used the Java Runnable interface.
047    ///////////////////////////////////////////////////////////////////
048    ////                         public methods                    ////
049
050    /** Execute the undo or redo action.
051     *  @exception Exception If something goes wrong.
052     */
053    public void execute() throws Exception;
054}