001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, 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 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * -----------------------
028 * DatasetChangeEvent.java
029 * -----------------------
030 * (C) Copyright 2000-2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes (from 24-Aug-2001)
036 * --------------------------
037 * 24-Aug-2001 : Added standard source header. Fixed DOS encoding problem (DG);
038 * 15-Oct-2001 : Move to new package (com.jrefinery.data.*) (DG);
039 * 22-Oct-2001 : Renamed DataSource.java --> Dataset.java etc. (DG);
040 * 11-Jun-2002 : Separated the event source from the dataset to cover the case
041 * where the dataset is changed to null in the Plot class.
042 * Updated Javadocs (DG);
043 * 04-Oct-2002 : Fixed errors reported by Checkstyle (DG);
044 * 05-Oct-2004 : Minor Javadoc updates (DG);
045 *
046 */
047
048 package org.jfree.data.general;
049
050 /**
051 * A change event that encapsulates information about a change to a dataset.
052 */
053 public class DatasetChangeEvent extends java.util.EventObject {
054
055 /**
056 * The dataset that generated the change event.
057 */
058 private Dataset dataset;
059
060 /**
061 * Constructs a new event. The source is either the dataset or the
062 * {@link org.jfree.chart.plot.Plot} class. The dataset can be
063 * <code>null</code> (in this case the source will be the
064 * {@link org.jfree.chart.plot.Plot} class).
065 *
066 * @param source the source of the event.
067 * @param dataset the dataset that generated the event (<code>null</code>
068 * permitted).
069 */
070 public DatasetChangeEvent(Object source, Dataset dataset) {
071 super(source);
072 this.dataset = dataset;
073 }
074
075 /**
076 * Returns the dataset that generated the event. Note that the dataset
077 * may be <code>null</code> since adding a <code>null</code> dataset to a
078 * plot will generated a change event.
079 *
080 * @return The dataset (possibly <code>null</code>).
081 */
082 public Dataset getDataset() {
083 return this.dataset;
084 }
085
086 }