/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2016, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
 * Other names may be trademarks of their respective owners.]
 *
 * ---------------------
 * ChartChangeEvent.java
 * ---------------------
 * (C) Copyright 2000-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes (from 24-Aug-2001)
 * --------------------------
 * 24-Aug-2001 : Added standard source header. Fixed DOS encoding problem (DG);
 * 07-Nov-2001 : Updated header (DG);
 *               Change event type names (DG);
 * 09-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 18-Feb-2005 : Changed the type from int to ChartChangeEventType (DG);
 *
 */

package org.jfree.chart.event;

import java.util.EventObject;

import org.jfree.chart.JFreeChart;

/**
 * A change event that encapsulates information about a change to a chart.
 */
public class ChartChangeEvent extends EventObject {

    /** The type of event. */
    private ChartChangeEventType type;

    /** The chart that generated the event. */
    private JFreeChart chart;

    /**
     * Creates a new chart change event.
     *
     * @param source  the source of the event (could be the chart, a title,
     *                an axis etc.)
     */
    public ChartChangeEvent(Object source) {
        this(source, null, ChartChangeEventType.GENERAL);
    }

    /**
     * Creates a new chart change event.
     *
     * @param source  the source of the event (could be the chart, a title, an
     *                axis etc.)
     * @param chart  the chart that generated the event.
     */
    public ChartChangeEvent(Object source, JFreeChart chart) {
        this(source, chart, ChartChangeEventType.GENERAL);
    }

    /**
     * Creates a new chart change event.
     *
     * @param source  the source of the event (could be the chart, a title, an
                      axis etc.)
     * @param chart  the chart that generated the event.
     * @param type  the type of event.
     */
    public ChartChangeEvent(Object source, JFreeChart chart,
                            ChartChangeEventType type) {
        super(source);
        this.chart = chart;
        this.type = type;
    }

    /**
     * Returns the chart that generated the change event.
     *
     * @return The chart that generated the change event.
     */
    public JFreeChart getChart() {
        return this.chart;
    }

    /**
     * Sets the chart that generated the change event.
     *
     * @param chart  the chart that generated the event.
     */
    public void setChart(JFreeChart chart) {
        this.chart = chart;
    }

    /**
     * Returns the event type.
     *
     * @return The event type.
     */
    public ChartChangeEventType getType() {
        return this.type;
    }

    /**
     * Sets the event type.
     *
     * @param type  the event type.
     */
    public void setType(ChartChangeEventType type) {
        this.type = type;
    }

}

@@ -217,10 +217,10 @@
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@@ -1349,10 +1349,10 @@
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@@ -1482,376 +1482,8 @@
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@@ -1587,16 +1587,51 @@
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+%0Aimport org.jfree.chart.util.Args;%0D
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@@ -2082,33 +2082,62 @@
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+, %7B@code null%7D not permitted).
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@@ -2407,33 +2407,62 @@
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+, %7B@code null%7D not permitted).
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@@ -2817,17 +2817,46 @@
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+, %7B@code null%7D not permitted).
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@@ -2940,24 +2940,53 @@
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+ (%7B@code null%7D not permitted)
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@@ -3047,32 +3047,16 @@
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-                
         
@@ -3109,24 +3109,70 @@
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+        Args.nullNotPermitted(type, %22type%22);%0D%0A
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@@ -3735,32 +3735,53 @@
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+ (never %7B@code null%7D)
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@@ -3929,32 +3929,61 @@
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+ (%7B@code null%7D not permitted)
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@@ -4024,32 +4024,78 @@
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+        Args.nullNotPermitted(type, %22type%22);%0D%0A
         this.typ

Add null argument checks and Javadocs.