1. /* ===========================================================

  2.  * JFreeChart : a free chart library for the Java(tm) platform

  3.  * ===========================================================

  4.  *

  5.  * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.

  6.  *

  7.  * Project Info:  http://www.jfree.org/jfreechart/index.html

  8.  *

  9.  * This library is free software; you can redistribute it and/or modify it under the terms

  10.  * of the GNU Lesser General Public License as published by the Free Software Foundation;

  11.  * either version 2.1 of the License, or (at your option) any later version.

  12.  *

  13.  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

  14.  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  15.  * See the GNU Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public License along with this

  18.  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,

  19.  * Boston, MA 02111-1307, USA.

  20.  *

  21.  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

  22.  * in the United States and other countries.]

  23.  *

  24.  * -----------------------

  25.  * DatasetChangeEvent.java

  26.  * -----------------------

  27.  * (C) Copyright 2000-2004, by Object Refinery Limited.

  28.  *

  29.  * Original Author:  David Gilbert (for Object Refinery Limited);

  30.  * Contributor(s):   -;

  31.  *

  32.  * $Id: DatasetChangeEvent.java,v 1.2 2004/10/05 16:26:05 mungady Exp $

  33.  *

  34.  * Changes (from 24-Aug-2001)

  35.  * --------------------------

  36.  * 24-Aug-2001 : Added standard source header. Fixed DOS encoding problem (DG);

  37.  * 15-Oct-2001 : Move to new package (com.jrefinery.data.*) (DG);

  38.  * 22-Oct-2001 : Renamed DataSource.java --> Dataset.java etc. (DG);

  39.  * 11-Jun-2002 : Separated the event source from the dataset to cover the case where the dataset

  40.  *               is changed to null in the Plot class.  Updated Javadocs (DG);

  41.  * 04-Oct-2002 : Fixed errors reported by Checkstyle (DG);

  42.  * 05-Oct-2004 : Minor Javadoc updates (DG);

  43.  *

  44.  */

  45. 

  46. package org.jfree.data.general;

  47. 

  48. /**

  49.  * A change event that encapsulates information about a change to a dataset.

  50.  */

  51. public class DatasetChangeEvent extends java.util.EventObject {

  52. 

  53.     /**

  54.      * The dataset that generated the change event.

  55.      */

  56.     private Dataset dataset;

  57. 

  58.     /**

  59.      * Constructs a new event.  The source is either the dataset or the 

  60.      * {@link org.jfree.chart.plot.Plot} class.  The dataset can be 

  61.      * <code>null</code> (in this case the source will be the 

  62.      * {@link org.jfree.chart.plot.Plot} class).

  63.      *

  64.      * @param source  the source of the event.

  65.      * @param dataset  the dataset that generated the event (<code>null</code>

  66.      *                 permitted).

  67.      */

  68.     public DatasetChangeEvent(Object source, Dataset dataset) {

  69.         super(source);

  70.         this.dataset = dataset;

  71.     }

  72. 

  73.     /**

  74.      * Returns the dataset that generated the event.  Note that the dataset

  75.      * may be <code>null</code> since adding a <code>null</code> dataset to a 

  76.      * plot will generated a change event.

  77.      *

  78.      * @return The dataset (possibly <code>null</code>).

  79.      */

  80.     public Dataset getDataset() {

  81.         return this.dataset;

  82.     }

  83. 

  84. }