001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it
010     * under the terms of the GNU Lesser General Public License as published by
011     * the Free Software Foundation; either version 2.1 of the License, or
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022     * USA.
023     *
024     * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025     * Other names may be trademarks of their respective owners.]
026     *
027     * ---------------
028     * Annotation.java
029     * ---------------
030     * (C) Copyright 2009, 2011 by Object Refinery Limited and Contributors.
031     *
032     * Original Author:  Peter Kolb (see patch 2809117);
033     * Contributor(s):   ;
034     *
035     * Changes:
036     * --------
037     * 20-Jun-2009 : Version 1 (PK);
038     *
039     */
040    
041    package org.jfree.chart.annotations;
042    
043    import org.jfree.chart.event.AnnotationChangeEvent;
044    import org.jfree.chart.event.AnnotationChangeListener;
045    
046    /**
047     * The base interface for annotations.  All annotations should support the
048     * {@link AnnotationChangeEvent} mechanism by allowing listeners to register
049     * and receive notification of any changes to the annotation.
050     */
051    public interface Annotation {
052    
053        /**
054         * Registers an object for notification of changes to the annotation.
055         *
056         * @param listener  the object to register.
057         */
058        public void addChangeListener(AnnotationChangeListener listener);
059    
060        /**
061         * Deregisters an object for notification of changes to the annotation.
062         *
063         * @param listener  the object to deregister.
064         */
065        public void removeChangeListener(AnnotationChangeListener listener);
066    
067    }