barchartdemo3.java

在软件开发中用来绘制各种图表的源码

/* ------------------
 * BarChartDemo3.java
 * ------------------
 * (C) Copyright 2002-2005, by Object Refinery Limited.
 *
 */

package demo;

import java.awt.Color;
import java.awt.Paint;

import javax.swing.JPanel;

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.ItemLabelAnchor;
import org.jfree.chart.labels.ItemLabelPosition;
import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryMarker;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.BarRenderer;
import org.jfree.chart.renderer.category.CategoryItemRenderer;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.general.DatasetUtilities;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.Layer;
import org.jfree.ui.LengthAdjustmentType;
import org.jfree.ui.RectangleAnchor;
import org.jfree.ui.RefineryUtilities;
import org.jfree.ui.TextAnchor;

/**
 * A bar chart that uses a custom renderer to display different colors within a
 * series.  No legend is displayed because there is only one series but the 
 * colors are not consistent.  Also, a domain marker is used to highlight one
 * category.
 */
public class BarChartDemo3 extends ApplicationFrame {

    /**
     * A custom renderer that returns a different color for each item in a 
     * single series.
     */
    static class CustomRenderer extends BarRenderer {

        /** The colors. */
        private Paint[] colors;

        /**
         * Creates a new renderer.
         *
         * @param colors  the colors.
         */
        public CustomRenderer(Paint[] colors) {
            this.colors = colors;
        }

        /**
         * Returns the paint for an item.  Overrides the default behaviour 
         * inherited from AbstractSeriesRenderer.
         *
         * @param row  the series.
         * @param column  the category.
         *
         * @return The item color.
         */
        public Paint getItemPaint(int row, int column) {
            return this.colors[column % this.colors.length];
        }
    }

    /**
     * Creates a new demo.
     *
     * @param title  the frame title.
     */
    public BarChartDemo3(String title) {
        super(title);
        CategoryDataset dataset = createDataset();
        JFreeChart chart = createChart(dataset);
        ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
        setContentPane(chartPanel);
    }

    /**
     * Creates a sample dataset.
     * 
     * @return a sample dataset.
     */
    private static CategoryDataset createDataset() {
        double[][] data = new double[][] {{4.0, 3.0, -2.0, 3.0, 6.0}};
        return DatasetUtilities.createCategoryDataset("Series ", "Category ",
            data);
    }
    
    /**
     * Creates a sample chart.
     * 
     * @param dataset  the dataset.
     * 
     * @return a sample chart.
     */
    private static JFreeChart createChart(CategoryDataset dataset) {

        JFreeChart chart = ChartFactory.createBarChart(
            "Bar Chart Demo 3",       // chart title
            "Category",               // domain axis label
            "Value",                  // range axis label
            dataset,                  // data
            PlotOrientation.VERTICAL, // the plot orientation
            false,                    // include legend
            true,
            false
        );

        chart.setBackgroundPaint(Color.lightGray);

        // get a reference to the plot for further customisation...
        CategoryPlot plot = (CategoryPlot) chart.getPlot();
        plot.setNoDataMessage("NO DATA!");

        CategoryItemRenderer renderer = new CustomRenderer(
            new Paint[] {Color.red, Color.blue, Color.green,
                Color.yellow, Color.orange, Color.cyan,
                Color.magenta, Color.blue}
        );
        renderer.setItemLabelGenerator(
            new StandardCategoryItemLabelGenerator()
        );
        renderer.setItemLabelsVisible(true);
        ItemLabelPosition p = new ItemLabelPosition(
            ItemLabelAnchor.CENTER, TextAnchor.CENTER, TextAnchor.CENTER, 45.0
        );
        renderer.setPositiveItemLabelPosition(p);
        plot.setRenderer(renderer);

        CategoryMarker marker = new CategoryMarker("Category 3");
        marker.setLabel("Special");
        marker.setPaint(new Color(0xDD, 0xFF, 0xDD, 0x80));
        marker.setAlpha(0.5f);
        marker.setLabelAnchor(RectangleAnchor.TOP_LEFT);
        marker.setLabelTextAnchor(TextAnchor.TOP_LEFT);
        marker.setLabelOffsetType(LengthAdjustmentType.CONTRACT);
        plot.addDomainMarker(marker, Layer.BACKGROUND);
        
        // change the margin at the top of the range axis...
        NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
        rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
        rangeAxis.setLowerMargin(0.15);
        rangeAxis.setUpperMargin(0.15);

        return chart;

    }
        
    /**
     * Creates a panel for the demo (used by SuperDemo.java).
     * 
     * @return A panel.
     */
    public static JPanel createDemoPanel() {
        JFreeChart chart = createChart(createDataset());
        return new ChartPanel(chart);
    }
    
    /**
     * Starting point for the demonstration application.
     *
     * @param args  ignored.
     */
    public static void main(String[] args) {

        BarChartDemo3 demo = new BarChartDemo3("Bar Chart Demo 3");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);

    }

}