How to determine min and max value for ItemMargin property in StackedBarChart using jFreeChart

Question

I am using jFreeChart api to make one application such that on movement of slider the gap width in between the two bars gets increased or decreased according to the value of

Answer 1

I think you just need to use more of the negative range, e.g. -50, 10.

SSCCE:

import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.BorderFactory;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.LegendItemCollection;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.GroupedStackedBarRenderer;
import org.jfree.data.KeyToGroupMap;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;

/** @see http://stackoverflow.com/a/17342522/230513 */
public class DomainTranslateDemo extends ApplicationFrame {

    private static class DemoPanel extends JPanel implements ChangeListener {

        private static int SLIDER_INITIAL_VALUE = -42;
        private static final double INCREMENT = 1 / 10.0;
        private JSlider slider;
        private GroupedStackedBarRenderer renderer;

        public DemoPanel() {
            super(new BorderLayout());
            final CategoryDataset dataset = createDataset();
            final JFreeChart chart = createChart(dataset);
            final ChartPanel chartPanel = new ChartPanel(chart);
            Dimension Dim = new Dimension(590, 350);
            chartPanel.setPreferredSize(Dim);
            add(chartPanel);

            JPanel dashboard = new JPanel(new BorderLayout());
            dashboard.setBorder(BorderFactory.createEmptyBorder(0, 4, 4, 4));

            this.slider = new JSlider(-50, 10, SLIDER_INITIAL_VALUE);
            this.slider.addChangeListener(this);
            dashboard.add(this.slider);
            add(dashboard, BorderLayout.SOUTH);
        }

        private CategoryDataset createDataset() {
            DefaultCategoryDataset result = new DefaultCategoryDataset();
            result.addValue(1.5, "5YEUR", "5Y");
            result.addValue(-1.5, "5YUSD", "5Y");
            result.addValue(0.5, "5Yx5YEUR", "5Yx5Y");
            result.addValue(-0.5, "5Yx5YUSD", "5Yx5Y");
            result.addValue(1.5, "10Yx5YEUR", "10Yx5Y");
            result.addValue(-1.5, "10Yx5YUSD", "10Yx5Y");
            result.addValue(1.5, "15Yx5YEUR", "15Yx5Y");
            result.addValue(-1.5, "15Yx5YUSD", "15Yx5Y");
            result.addValue(1.5, "20Yx5YEUR", "20Yx5Y");
            result.addValue(-1.5, "20Yx5YUSD", "20Yx5Y");
            result.addValue(1.5, "20Yx5YEUR", "25Yx5Y");
            result.addValue(-1.5, "20Yx5YUSD", "25Yx5Y");
            return result;
        }

        private JFreeChart createChart(final CategoryDataset dataset) {

            final JFreeChart chart = ChartFactory.createStackedBarChart(
                "Max Bar Width", // chart title
                "Category", // domain axis label
                "Value", // range axis label
                dataset, // data
                PlotOrientation.VERTICAL, // the plot orientation
                true, // legend
                true, // tooltips
                false // urls
                );

            renderer = new GroupedStackedBarRenderer();
            KeyToGroupMap map = new KeyToGroupMap("G1");
            map.mapKeyToGroup("5YEUR", "G1");
            map.mapKeyToGroup("5YUSD", "G1");
            map.mapKeyToGroup("5Yx5YEUR", "G2");
            map.mapKeyToGroup("5Yx5YUSD", "G2");
            map.mapKeyToGroup("10Yx5YEUR", "G3");
            map.mapKeyToGroup("10Yx5YUSD", "G3");
            map.mapKeyToGroup("15Yx5YEUR", "G4");
            map.mapKeyToGroup("15Yx5YUSD", "G4");
            map.mapKeyToGroup("20Yx5YEUR", "G5");
            map.mapKeyToGroup("20Yx5YUSD", "G5");
            map.mapKeyToGroup("25Yx5YEUR", "G6");
            map.mapKeyToGroup("25Yx5YUSD", "G6");
            renderer.setSeriesToGroupMap(map);
            double maxBarWidth = renderer.getMaximumBarWidth();
            renderer.setItemMargin(SLIDER_INITIAL_VALUE * INCREMENT);

            CategoryPlot plot = (CategoryPlot) chart.getPlot();
            plot.setRenderer(renderer);
            plot.setFixedLegendItems(createLegendItems());
            return chart;
        }

        private LegendItemCollection createLegendItems() {
            LegendItemCollection result = new LegendItemCollection();
            return result;
        }

        @Override
        public void stateChanged(ChangeEvent event) {
            int value = slider.getValue();
            System.out.println("value:" + value);
            renderer.setItemMargin(value * INCREMENT);
        }
    }

    public DomainTranslateDemo(String title) {
        super(title);
        setContentPane(new DemoPanel());
    }

    public static JPanel createDemoPanel() {
        return new DemoPanel();
    }

    public static void main(String[] args) {
        DomainTranslateDemo demo = new DomainTranslateDemo("Translate Demo");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);
    }
}