/* --------------------
* MemoryUsageDemo.java
* --------------------
* (C) Copyright 2002-2006, by Object Refinery Limited.
*/
package ca.bc.webarts.tools;

import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYItemRenderer;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.time.Millisecond;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.ui.RectangleInsets;

/**
* A demo application showing a dynamically updated chart that displays the
* current JVM memory usage.
* <p>
* IMPORTANT NOTE: THIS DEMO IS DOCUMENTED IN THE JFREECHART DEVELOPER GUIDE.
* DO NOT MAKE CHANGES WITHOUT UPDATING THE GUIDE ALSO!!
*/
public class MemoryUsageDemo extends JPanel {
/** Time series for total memory used. */
private TimeSeries total;
/** Time series for free memory. */
private TimeSeries free;

/**
* Creates a new application.
*
* @param maxAge the maximum age (in milliseconds).
*/
public MemoryUsageDemo(int maxAge) {
super(new BorderLayout());
// create two series that automatically discard data more than 30
// seconds old...
this.total = new TimeSeries("Total Memory", Millisecond.class);
this.total.setMaximumItemAge(maxAge);
this.free = new TimeSeries("Free Memory", Millisecond.class);
this.free.setMaximumItemAge(maxAge);
TimeSeriesCollection dataset = new TimeSeriesCollection();
dataset.addSeries(this.total);
dataset.addSeries(this.free);
DateAxis domain = new DateAxis("Time");
NumberAxis range = new NumberAxis("Memory");
domain.setTickLabelFont(new Font("SansSerif", Font.PLAIN, 12));
range.setTickLabelFont(new Font("SansSerif", Font.PLAIN, 12));
domain.setLabelFont(new Font("SansSerif", Font.PLAIN, 14));
range.setLabelFont(new Font("SansSerif", Font.PLAIN, 14));
XYItemRenderer renderer = new XYLineAndShapeRenderer(true, false);
renderer.setSeriesPaint(0, Color.red);
renderer.setSeriesPaint(1, Color.green);
renderer.setStroke(new BasicStroke(3f, BasicStroke.CAP_BUTT,
BasicStroke.JOIN_BEVEL));
XYPlot plot = new XYPlot(dataset, domain, range, renderer);
plot.setBackgroundPaint(Color.lightGray);
plot.setDomainGridlinePaint(Color.white);
plot.setRangeGridlinePaint(Color.white);
plot.setAxisOffset(new RectangleInsets(5.0, 5.0, 5.0, 5.0));
domain.setAutoRange(true);
domain.setLowerMargin(0.0);
domain.setUpperMargin(0.0);
domain.setTickLabelsVisible(true);
range.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
JFreeChart chart = new JFreeChart("JVM Memory Usage",
new Font("SansSerif", Font.BOLD, 24), plot, true);
chart.setBackgroundPaint(Color.white);
ChartPanel chartPanel = new ChartPanel(chart);
chartPanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createEmptyBorder(4, 4, 4, 4),
BorderFactory.createLineBorder(Color.black)));
add(chartPanel);
}


/**
* Adds an observation to the ’total memory’ time series.
*
* @param y the total memory used.
*/
private void addTotalObservation(double y) {
this.total.add(new Millisecond(), y);
}


/**
* Adds an observation to the ’free memory’ time series.
*
* @param y the free memory.
*/
private void addFreeObservation(double y) {
this.free.add(new Millisecond(), y);
}


/**
* The data generator.
*/
class DataGenerator extends Timer implements ActionListener {
/**
* Constructor.
*
* @param interval the interval (in milliseconds)
*/
DataGenerator(int interval) {
super(interval, null);
addActionListener(this);
}


/**
* Adds a new free/total memory reading to the dataset.
*
* @param event the action event.
*/
public void actionPerformed(ActionEvent event) {
  long f = Runtime.getRuntime().freeMemory();
  long t = Runtime.getRuntime().totalMemory();
  addTotalObservation(t);
  addFreeObservation(f);
}
}


/**
* Entry point for the sample application.
*
* @param args ignored.
*/
public static void main(String[] args)
{
  JFrame frame = new JFrame("Memory Usage Demo");
  MemoryUsageDemo panel = new MemoryUsageDemo(30000);
  frame.getContentPane().add(panel, BorderLayout.CENTER);
  frame.setBounds(200, 120, 600, 280);
  frame.setVisible(true);
  panel.new DataGenerator(100).start();
  frame.addWindowListener(new WindowAdapter()
  {
    public void windowClosing(WindowEvent e)
    {
      System.exit(0);
    }
  });
}
}