piechartdemo6.java

这是一个segy数据显示程序

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ------------------
 * PieChartDemo6.java
 * ------------------
 * (C) Copyright 2004, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: PieChartDemo6.java,v 1.3 2004/04/26 19:12:00 taqua Exp $
 *
 * Changes
 * -------
 * 31-Mar-2004 : Version 1 (DG);
 *
 */

package org.jfree.chart.demo;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.labels.PieSectionLabelGenerator;
import org.jfree.chart.plot.PiePlot;
import org.jfree.data.DefaultPieDataset;
import org.jfree.data.PieDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;

/**
 * A pie chart with a custom label generator.
 */
public class PieChartDemo6 extends ApplicationFrame {

    /**
     * Creates a new demo instance.
     *
     * @param title  the frame title.
     */
    public PieChartDemo6(final String title) {
        super(title);
        final PieDataset dataset = createDataset();
        final JFreeChart chart = createChart(dataset);
        final ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
        setContentPane(chartPanel);
    }

    /**
     * Creates a sample dataset.
     * 
     * @return a sample dataset.
     */
    private PieDataset createDataset() {
        final DefaultPieDataset dataset = new DefaultPieDataset();
        dataset.setValue("One", new Double(43.2));
        dataset.setValue("Two", new Double(10.0));
        dataset.setValue("Three", new Double(27.5));
        dataset.setValue("Four", new Double(17.5));
        dataset.setValue("Five", new Double(11.0));
        dataset.setValue("Six", new Double(19.4));
        return dataset;        
    }
    
    // ****************************************************************************
    // * JFREECHART DEVELOPER GUIDE                                               *
    // * The JFreeChart Developer Guide, written by David Gilbert, is available   *
    // * to purchase from Object Refinery Limited:                                *
    // *                                                                          *
    // * http://www.object-refinery.com/jfreechart/guide.html                     *
    // *                                                                          *
    // * Sales are used to provide funding for the JFreeChart project - please    * 
    // * support us so that we can continue developing free software.             *
    // ****************************************************************************
    
    /**
     * Creates a chart.
     * 
     * @param dataset  the dataset.
     * 
     * @return a chart.
     */
    private JFreeChart createChart(final PieDataset dataset) {
        
        final JFreeChart chart = ChartFactory.createPieChart(
            "Pie Chart Demo 6",  // chart title
            dataset,             // data
            false,               // include legend
            true,
            false
        );

        final PiePlot plot = (PiePlot) chart.getPlot();
        plot.setLabelGenerator(new CustomLabelGenerator());
        return chart;
        
    }
    
    /**
     * Starting point for the demonstration application.
     *
     * @param args  ignored.
     */
    public static void main(final String[] args) {

        final PieChartDemo6 demo = new PieChartDemo6("Pie Chart Demo 6");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);

    }
    
    /**
     * A custom label generator (returns null for one item as a test).
     */
    static class CustomLabelGenerator implements PieSectionLabelGenerator {
        
        /**
         * Generates a label for a pie section.
         * 
         * @param dataset  the dataset (<code>null</code> not permitted).
         * @param key  the section key (<code>null</code> not permitted).
         * 
         * @return the label (possibly <code>null</code>).
         */
        public String generateSectionLabel(final PieDataset dataset, final Comparable key) {
            String result = null;    
            if (dataset != null) {
                if (!key.equals("Two")) {
                    result = key.toString();   
                }
            }
            return result;
        }
   
    }

}