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
041package org.jfree.chart.annotations;
042
043import org.jfree.chart.event.AnnotationChangeEvent;
044import 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 */
051public 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}