Java tutorial
/* =========================================================== * 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.general.DefaultPieDataset; import org.jfree.data.general.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; } } }