charttiming4.java

Web图形化的Java库

/* ======================================
 * JFreeChart : a free Java chart library
 * ======================================
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 * Project Lead:  David Gilbert ([e-mail]);
 *
 * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors.
 *
 * 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.
 *
 * -----------------
 * ChartTiming4.java
 * -----------------
 * (C) Copyright 2002, 2003, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: ChartTiming4.java,v 1.8 2003/07/24 10:52:29 mungady Exp $
 *
 * Changes
 * -------
 * 29-Oct-2002 : Version 1 (DG);
 *
 */

package org.jfree.chart.demo;

import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;

import javax.swing.Timer;

import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.FastScatterPlot;
import org.jfree.chart.plot.Plot;

/**
 * Draws a scatter plot over and over for 10 seconds.  Reports on how many redraws were achieved.
 * <p>
 * On my PC (SuSE Linux 8.2, JDK 1.4, 256mb RAM, 2.66ghz Pentium) I get 31 charts per second.
 *
 * @author David Gilbert
 */
public class ChartTiming4 implements ActionListener {

    /** A flag that indicates when time is up. */
    private boolean finished;

    /** Storage for the data. */
    private float[][] data = new float[2][1440];

    /**
     * Creates a new application.
     */
    public ChartTiming4() {
    }

    /**
     * Runs the test.
     */
    public void run() {

        this.finished = false;

        // create a dataset...
        populateData();

        // create a fast scatter chart...
        Plot plot = new FastScatterPlot(this.data, new NumberAxis("X"), new NumberAxis("Y"));
        JFreeChart chart = new JFreeChart("Fast Scatter Plot Timing",
                                          JFreeChart.DEFAULT_TITLE_FONT,
                                          plot, true);

        BufferedImage image = new BufferedImage(400, 300, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = image.createGraphics();
        Rectangle2D chartArea = new Rectangle2D.Double(0, 0, 400, 300);

        // set up the timer...
        Timer timer = new Timer(10000, this);
        timer.setRepeats(false);
        int count = 0;
        timer.start();
        while (!finished) {
            chart.draw(g2, chartArea, null);
            System.out.println("Charts drawn..." + count);
            if (!finished) {
                count++;
            }
        }
        System.out.println("DONE");

    }

    /**
     * Receives notification of action events (in this case, from the Timer).
     *
     * @param event  the event.
     */
    public void actionPerformed(ActionEvent event) {
        this.finished = true;
    }

    /**
     * Populates the data array with random values.
     */
    private void populateData() {

        for (int i = 0; i < data[0].length; i++) {

            float x = (float) i;
            data[0][i] = x;
            data[1][i] = 100 + (2 * x) + (float) Math.random() * 1440;
        }

    }

    /**
     * Starting point for the application.
     *
     * @param args  ignored.
     */
    public static void main(String[] args) {

        ChartTiming4 app = new ChartTiming4();
        app.run();

    }

}