001/* ===========================================================
002 * Orson Charts : a 3D chart library for the Java(tm) platform
003 * ===========================================================
004 * 
005 * (C)opyright 2013-2022, by David Gilbert.  All rights reserved.
006 * 
007 * https://github.com/jfree/orson-charts
008 * 
009 * This program is free software: you can redistribute it and/or modify
010 * it under the terms of the GNU General Public License as published by
011 * the Free Software Foundation, either version 3 of the License, or
012 * (at your option) any later version.
013 *
014 * This program is distributed in the hope that it will be useful,
015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
017 * GNU General Public License for more details.
018 *
019 * You should have received a copy of the GNU General Public License
020 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
021 * 
022 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
023 * Other names may be trademarks of their respective owners.]
024 * 
025 * If you do not wish to be bound by the terms of the GPL, an alternative
026 * commercial license can be purchased.  For details, please see visit the
027 * Orson Charts home page:
028 * 
029 * http://www.object-refinery.com/orsoncharts/index.html
030 * 
031 */
032
033package org.jfree.chart3d.data;
034
035import java.util.EventListener;
036
037/**
038 * The base interface for datasets in Orson Charts.  All datasets must support
039 * the change event notification mechanism.  The idea is that when a dataset
040 * is changed, an event is passed to the plot.  The plot can react to this
041 * event, then pass on the change event to the chart.  The chart in turn will
042 * pass on the event and this can result in the chart being repainted (for
043 * example, if the chart is displayed in a
044 * {@link org.jfree.chart3d.Chart3DPanel}).
045 */
046public interface Dataset3D {
047
048    /**
049     * Registers a change listener to receive notification of changes to the
050     * dataset.
051     * 
052     * @param listener  the listener ({@code null} not permitted). 
053     */
054    void addChangeListener(Dataset3DChangeListener listener);  
055  
056    /**
057     * De-registers a change listener so that it no longer receives notification
058     * of changes to the dataset.
059     * 
060     * @param listener  the listener ({@code null} not permitted). 
061     */
062    void removeChangeListener(Dataset3DChangeListener listener);  
063
064    /**
065     * Returns {@code true} if the specified listener is registered with
066     * the dataset, and {@code false} otherwise.  This method is used
067     * for unit testing to confirm that listeners are removed correctly 
068     * following dataset switches.
069     * 
070     * @param listener  the listener.
071     * 
072     * @return A boolean. 
073     */
074    boolean hasListener(EventListener listener);
075}