Unable to display center text in ring chart

user_4077701 0
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I am trying to generate a donut or ring chart using jfree chart library. Ringchart was generated successfully but only the problem is centered text inside ring was not displaying. The following is the sample snippet. chart generation code

JFreeChart chart = ChartFactory.createRingChart(heading, dataSet, legend, tooltips, urls);

And centered text related code is like below

RingPlot pie = (RingPlot) chart.getPlot();
pie.setBackgroundPaint(Color.WHITE);
pie.setOutlineVisible(false);
pie.setShadowPaint(null);
pie.setLabelGenerator(null);
pie.setCenterTextMode(CenterTextMode.VALUE);
Font font = new Font("Arial",1,30);
pie.setCenterTextFont(font);
pie.setCenterTextColor(Color.getHSBColor(222, 1, 1));
pie.setSectionDepth(0.1);
pie.setSectionOutlinesVisible(false);
pie.setSeparatorsVisible(false);
pie.setIgnoreZeroValues(false);

I am using jfreechart verison 1.5.0

jfreechart java
1 Answers

It's not clear where your fragment is going awry, but this minimal complete example gives the expected result. As an aside, note the use of Font.BOLD for clarity and the use of deriveFont() to minimize the risk of an unfortunate font substitution; see also *Initial Threads*.

pie.setCenterTextMode(CenterTextMode.VALUE);
pie.setCenterTextFont(pie.getCenterTextFont().deriveFont(Font.BOLD, 30f));
pie.setCenterTextColor(Color.getHSBColor(0, 1, 1));

ring plot with value

I tried pie.setCenterText("Vijay");

Instead of CenterTextMode.VALUE; specify CenterTextMode.FIXED:

pie.setCenterTextMode(CenterTextMode.FIXED);
pie.setCenterText("Vijay");

ring plot with fixed text

The above code is not setting any value if the first dataset value is zero.

Correct. RingPlot::drawItem() ignores center text unless values exceed the rendering threshold; you can specify a value that passes the threshold yet displays correctly when formatted:

dataset.setValue("Critical", RingPlot.DEFAULT_MINIMUM_ARC_ANGLE_TO_DRAW);

ring plot zero

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import javax.swing.JFrame;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.CenterTextMode;
import org.jfree.chart.plot.RingPlot;
import org.jfree.data.general.DefaultPieDataset;

/**
 * @see https://stackoverflow.com/a/56672573/230513
 * @see https://stackoverflow.com/a/37414338/230513
 */
public class TestRing {

    private void display() {
        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        DefaultPieDataset dataset = new DefaultPieDataset();
        dataset.setValue("Critical", Integer.valueOf(42));
        dataset.setValue("Important", Integer.valueOf(21));
        dataset.setValue("Moderate", Integer.valueOf(7));
        dataset.setValue("Low", Integer.valueOf(3));
        JFreeChart chart = ChartFactory.createRingChart(
            "Test", dataset, false, true, false);
        RingPlot pie = (RingPlot) chart.getPlot();
        pie.setSimpleLabels(true);
        pie.setCenterTextMode(CenterTextMode.VALUE);
        pie.setCenterTextFont(pie.getCenterTextFont().deriveFont(Font.BOLD, 30f));
        pie.setCenterTextColor(Color.getHSBColor(0, 1, 1));
        f.add(new ChartPanel(chart){
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(400, 400);
            }
        });
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new TestRing()::display);
    }
}
user_2305130
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