    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2007, 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 2000-2007, 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    }