# PieChartTests.java

    /* ===========================================================
     * JFreeChart : a free chart library for the Java(tm) platform
     * ===========================================================
     *
     * (C) Copyright 2000-2007, 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.
     *
     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
     * in the United States and other countries.]
     *
     * ------------------
     * PieChartTests.java
     * ------------------
     * (C) Copyright 2002-2007, by Object Refinery Limited.
     *
     * Original Author:  David Gilbert (for Object Refinery Limited);
     * Contributor(s):   -;
     *
     * Changes:
     * --------
     * 11-Jun-2002 : Version 1 (DG);
     * 17-Oct-2002 : Fixed errors reported by Checkstyle (DG);
     *
     */

    package org.jfree.chart.junit;

    import junit.framework.Test;
    import junit.framework.TestCase;
    import junit.framework.TestSuite;

    import org.jfree.chart.ChartFactory;
    import org.jfree.chart.JFreeChart;
    import org.jfree.chart.event.ChartChangeEvent;
    import org.jfree.chart.event.ChartChangeListener;
    import org.jfree.chart.plot.PiePlot;
    import org.jfree.data.general.DefaultPieDataset;

    /**
     * Tests for a pie chart.
     *
     */
    public class PieChartTests extends TestCase {

        /** A chart. */
        private JFreeChart pieChart;

        /**
         * Returns the tests as a test suite.
         *
         * @return The test suite.
         */
        public static Test suite() {
            return new TestSuite(PieChartTests.class);
        }

        /**
         * Constructs a new set of tests.
         *
         * @param name  the name of the tests.
         */
        public PieChartTests(String name) {
            super(name);
        }

        /**
         * Common test setup.
         */
        protected void setUp() {

            this.pieChart = createPieChart();

        }

        /**
         * Using a regular pie chart, we replace the dataset with null.  Expect to
         * receive notification of a chart change event, and (of course) the
         * dataset should be null.
         */
        public void testReplaceDatasetOnPieChart() {
            LocalListener l = new LocalListener();
            this.pieChart.addChangeListener(l);
            PiePlot plot = (PiePlot) this.pieChart.getPlot();
            plot.setDataset(null);
            assertEquals(true, l.flag);
            assertNull(plot.getDataset());
        }

        /**
         * Creates a pie chart.
         *
         * @return The pie chart.
         */
        private static JFreeChart createPieChart() {
            // create a dataset...
            DefaultPieDataset data = new DefaultPieDataset();
            data.setValue("Java", new Double(43.2));
            data.setValue("Visual Basic", new Double(0.0));
            data.setValue("C/C++", new Double(17.5));

            // create the chart...
            return ChartFactory.createPieChart("Pie Chart",  // chart title
                                               data,         // data
                                               true,         // include legend
                                               true,
                                               false
                                               );
        }

        /**
         * A chart change listener.
         *
         */
        static class LocalListener implements ChartChangeListener {

            /** A flag. */
            private boolean flag = false;

            /**
             * Event handler.
             *
             * @param event  the event.
             */
            public void chartChanged(ChartChangeEvent event) {
                this.flag = true;
            }

        }

    }