JFreeChart - customizing RingChart

问题:

I want to make two ring charts that look like the following:

But the RingPlot doesn't seem very customizable. The best I could come up with is this:

Any chance of doing what I want with JFreeChart?

回答1:

JFreeChart can do most things, this should get you started (I'll probably incorporate the center text feature into the upcoming 1.0.18 release so that the subclassing isn't necessary):

package org.jfree.chart.demo;  import java.awt.Color; import java.awt.Dimension; import java.awt.Font; import java.awt.GradientPaint; import java.awt.Graphics2D; import java.awt.Point; import java.awt.geom.Rectangle2D; import javax.swing.JPanel;  import org.jfree.chart.ChartPanel; import org.jfree.chart.JFreeChart; import org.jfree.chart.plot.PiePlotState; import org.jfree.chart.plot.RingPlot; import org.jfree.chart.title.TextTitle; import org.jfree.data.general.DefaultPieDataset; import org.jfree.data.general.PieDataset; import org.jfree.text.TextUtilities; import org.jfree.ui.ApplicationFrame; import org.jfree.ui.HorizontalAlignment; import org.jfree.ui.RectangleInsets; import org.jfree.ui.RefineryUtilities; import org.jfree.ui.TextAnchor;  /**  * A simple demonstration application showing how to create a ring chart using  * data from a {@link DefaultPieDataset}.  */ public class RingChartDemo1 extends ApplicationFrame {      private static final long serialVersionUID = 1L;      static class CustomRingPlot extends RingPlot {          private Font centerTextFont;           private Color centerTextColor;          public CustomRingPlot(PieDataset dataset) {             super(dataset);             this.centerTextFont = new Font(Font.SANS_SERIF, Font.BOLD, 24);             this.centerTextColor = Color.LIGHT_GRAY;         }          @Override         protected void drawItem(Graphics2D g2, int section,                  Rectangle2D dataArea, PiePlotState state, int currentPass) {             super.drawItem(g2, section, dataArea, state, currentPass);             if (currentPass == 1 && section == 0) {                 Number n = this.getDataset().getValue(section);                 g2.setFont(this.centerTextFont);                 g2.setPaint(this.centerTextColor);                 TextUtilities.drawAlignedString(n.toString(), g2,                          (float) dataArea.getCenterX(),                          (float) dataArea.getCenterY(),                           TextAnchor.CENTER);             }         }      }      /**      * Default constructor.      *      * @param title  the frame title.      */     public RingChartDemo1(String title) {         super(title);         setContentPane(createDemoPanel());     }      /**      * Creates a sample dataset.      *      * @return A sample dataset.      */     private static PieDataset createDataset() {         DefaultPieDataset dataset = new DefaultPieDataset();         dataset.setValue("A", new Double(210));         dataset.setValue("B", new Double(150));         return dataset;     }      /**      * Creates a chart.      *      * @param dataset  the dataset.      *      * @return A chart.      */     private static JFreeChart createChart(PieDataset dataset) {         CustomRingPlot plot = new CustomRingPlot(dataset);         JFreeChart chart = new JFreeChart("Custom Ring Chart",                  JFreeChart.DEFAULT_TITLE_FONT, plot, false);         chart.setBackgroundPaint(new GradientPaint(new Point(0, 0),                  new Color(20, 20, 20), new Point(400, 200), Color.DARK_GRAY));          // customise the title position and font         TextTitle t = chart.getTitle();         t.setHorizontalAlignment(HorizontalAlignment.LEFT);         t.setPaint(new Color(240, 240, 240));         t.setFont(new Font("Arial", Font.BOLD, 26));          plot.setBackgroundPaint(null);         plot.setOutlineVisible(false);         plot.setLabelGenerator(null);         plot.setSectionPaint("A", Color.ORANGE);         plot.setSectionPaint("B", new Color(100, 100, 100));         plot.setSectionDepth(0.05);         plot.setSectionOutlinesVisible(false);         plot.setShadowPaint(null);          return chart;      }      /**      * Creates a panel for the demo (used by SuperDemo.java).      *      * @return A panel.      */     public static JPanel createDemoPanel() {         JFreeChart chart = createChart(createDataset());         chart.setPadding(new RectangleInsets(4, 8, 2, 2));         ChartPanel panel = new ChartPanel(chart);         panel.setMouseWheelEnabled(true);         panel.setPreferredSize(new Dimension(600, 300));         return panel;     }      /**      * Starting point for the demonstration application.      *      * @param args  ignored.      */     public static void main(String[] args) {         RingChartDemo1 demo = new RingChartDemo1("JFreeChart: Ring Chart Demo 1");         demo.pack();         RefineryUtilities.centerFrameOnScreen(demo);         demo.setVisible(true);     }  } 

文章来源: JFreeChart - customizing RingChart