public class XYStepChartTests extends TestCase {

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

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

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

    /**
     * Common test setup.
     */
    protected void setUp() {
        this.chart = createChart();
    }

    /**
     * Draws the chart with a null info object to make sure that no exceptions 
     * are thrown (a problem that was occurring at one point).
     */
    public void testDrawWithNullInfo() {

        boolean success = false;
        try {
            BufferedImage image = new BufferedImage(200 , 100, 
                    BufferedImage.TYPE_INT_RGB);
            Graphics2D g2 = image.createGraphics();
            this.chart.draw(g2, new Rectangle2D.Double(0, 0, 200, 100), null, 
                    null);
            g2.dispose();
            success = true;
        }
        catch (Exception e) {
          success = false;
          e.printStackTrace();
        }
        assertTrue(success);

    }

    /**
     * Replaces the dataset and checks that it has changed as expected.
     */
    public void testReplaceDataset() {

        // create a dataset...
        XYSeries series1 = new XYSeries("Series 1");
        series1.add(10.0, 10.0);
        series1.add(20.0, 20.0);
        series1.add(30.0, 30.0);
        XYDataset dataset = new XYSeriesCollection(series1);

        LocalListener l = new LocalListener();
        this.chart.addChangeListener(l);
        XYPlot plot = (XYPlot) this.chart.getPlot();
        plot.setDataset(dataset);
        assertEquals(true, l.flag);
        ValueAxis axis = plot.getRangeAxis();
        Range range = axis.getRange();
        assertTrue("Expecting the lower bound of the range to be around 10: "
                   + range.getLowerBound(), range.getLowerBound() <= 10);
        assertTrue("Expecting the upper bound of the range to be around 30: "
                   + range.getUpperBound(), range.getUpperBound() >= 30);

    }

    /**
     * Check that setting a tool tip generator for a series does override the
     * default generator.
     */
    public void testSetSeriesToolTipGenerator() {
        XYPlot plot = (XYPlot) this.chart.getPlot();
        XYItemRenderer renderer = plot.getRenderer();
        StandardXYToolTipGenerator tt = new StandardXYToolTipGenerator();
        renderer.setSeriesToolTipGenerator(0, tt);
        XYToolTipGenerator tt2 = renderer.getToolTipGenerator(0, 0);
        assertTrue(tt2 == tt);
    }
    
    /**
     * Create a horizontal bar chart with sample data in the range -3 to +3.
     *
     * @return The chart.
     */
    private static JFreeChart createChart() {

        // create a dataset...
        XYSeries series1 = new XYSeries("Series 1");
        series1.add(1.0, 1.0);
        series1.add(2.0, 2.0);
        series1.add(3.0, 3.0);
        XYDataset dataset = new XYSeriesCollection(series1);

        // create the chart...
        return ChartFactory.createXYStepChart(
            "Step Chart",  // chart title
            "Domain",
            "Range",
            dataset,         // data
            PlotOrientation.VERTICAL,
            true,            // include legend
            true,            // tooltips
            true             // urls
        );

    }

    /**
     * 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;