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.] * ------------------- * ItemLabelDemo1.java * ------------------- * (C) Copyright 2004, by Object Refinery Limited and Contributors. * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * $Id: ItemLabelDemo1.java,v 1.1 2011-01-31 09:01:43 klukas Exp $ * Changes * ------- * 19-Feb-2004 : Version 1 (DG); */ package org.jfree.chart.demo; import java.awt.Color; import java.awt.Dimension; import org.jfree.chart.ChartFactory; import org.jfree.chart.ChartPanel; import org.jfree.chart.JFreeChart; import org.jfree.chart.axis.NumberAxis; import org.jfree.chart.labels.CategoryLabelGenerator; import org.jfree.chart.plot.CategoryPlot; import org.jfree.chart.plot.PlotOrientation; import org.jfree.chart.renderer.CategoryItemRenderer; import org.jfree.data.CategoryDataset; import org.jfree.data.DefaultCategoryDataset; import org.jfree.ui.ApplicationFrame; import org.jfree.ui.RefineryUtilities; /** * A simple demo showing a label generator that only displays labels for items * with a value that is greater than some threshold. */ public class ItemLabelDemo1 extends ApplicationFrame { /** * A custom label generator. */ static class LabelGenerator implements CategoryLabelGenerator { /** The threshold. */ private double threshold; /** * Creates a new generator that only displays labels that are greater * than or equal to the threshold value. * * @param threshold * the threshold value. */ public LabelGenerator(final double threshold) { this.threshold = threshold; } /** * Generates a label for the specified item. The label is typically a * formatted version of the data value, but any text can be used. * * @param dataset * the dataset (<code>null</code> not permitted). * @param series * the series index (zero-based). * @param category * the category index (zero-based). * @return the label (possibly <code>null</code>). */ public String generateLabel(final CategoryDataset dataset, final int series, final int category) { String result = null; final Number value = dataset.getValue(series, category); if (value != null) { final double v = value.doubleValue(); if (v > this.threshold) { result = value.toString(); // could apply formatting here } } return result; } } /** * Creates a new demo instance. * * @param title * the frame title. */ public ItemLabelDemo1(final String title) { super(title); final CategoryDataset dataset = createDataset(); final JFreeChart chart = createChart(dataset); final ChartPanel chartPanel = new ChartPanel(chart); chartPanel.setPreferredSize(new Dimension(500, 270)); setContentPane(chartPanel); } /** * Returns a sample dataset. * * @return the dataset. */ private CategoryDataset createDataset() { final DefaultCategoryDataset dataset = new DefaultCategoryDataset(); dataset.addValue(11.0, "S1", "C1"); dataset.addValue(44.3, "S1", "C2"); dataset.addValue(93.0, "S1", "C3"); dataset.addValue(35.6, "S1", "C4"); dataset.addValue(75.1, "S1", "C5"); return dataset; } /** * Creates a sample chart. * * @param dataset * the dataset. * @return the chart. */ private JFreeChart createChart(final CategoryDataset dataset) { // create the chart... final JFreeChart chart = ChartFactory.createBarChart("Item Label Demo 1", // chart title "Category", // domain axis label "Value", // range axis label dataset, // data PlotOrientation.VERTICAL, // orientation false, // include legend true, // tooltips? false // URLs? ); chart.setBackgroundPaint(Color.white); final CategoryPlot plot = chart.getCategoryPlot(); plot.setBackgroundPaint(Color.lightGray); plot.setDomainGridlinePaint(Color.white); plot.setRangeGridlinePaint(Color.white); final NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis(); rangeAxis.setUpperMargin(0.15); final CategoryItemRenderer renderer = plot.getRenderer(); renderer.setLabelGenerator(new LabelGenerator(50.0)); renderer.setItemLabelsVisible(true); return chart; } /** * Starting point for the demonstration application. * * @param args * ignored. */ public static void main(final String[] args) { final ItemLabelDemo1 demo = new ItemLabelDemo1("Item Label Demo 1"); demo.pack(); RefineryUtilities.centerFrameOnScreen(demo); demo.setVisible(true); } }