MemoryUsagePanel.java

/*
 * MemoryUsagePanel.java
 *
 * Created on August 17, 2006, 11:24 AM
 */

package ika.gui;

import javax.swing.*;
import java.awt.*;
import java.util.*;

/**
 * A utility dialog that displays the total and the free memory. For debugging
 * purposes only.
 * @author  jenny
 */
public class MemoryUsagePanel extends javax.swing.JPanel {
    
    /** Creates new form MemoryUsagePanel */
    public MemoryUsagePanel() {
        initComponents();
    }
    
    private static JDialog dialog = null;
    private java.util.Timer timer = new java.util.Timer();
    private Updater updater = new Updater();
    
    private String bytesToString (long bytes) {
        bytes /= 1024;
        if (bytes > 1024)
            return Long.toString(bytes / 1024) + " MB";
        else
            return Long.toString(bytes) + " KB";
    }
    
    private class Updater extends TimerTask {
        public void run() {
            long tot = Runtime.getRuntime().totalMemory();
            long free = Runtime.getRuntime().freeMemory();
            
            totalMemoryLabel.setText(bytesToString(tot));
            freeMemoryLabel.setText(bytesToString(free));
            bar.setValue((int)(100 - 100. * free / tot));
        }
    }

    public static void showMemoryUsagePanel() {
        
        if (dialog != null){
            dialog.setVisible(true);
            return;
        }
        
        final MemoryUsagePanel panel = new MemoryUsagePanel();
        
        dialog = new JDialog();
        dialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
        dialog.addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowClosing(java.awt.event.WindowEvent evt)
            {
                try {panel.timer.cancel();} catch (Exception e) {}
                dialog.setVisible(false); 
            }
        });
        dialog.getContentPane().add(panel);
        dialog.setTitle("Memory Usage");
        dialog.pack();
        dialog.setResizable(false);
        dialog.setAlwaysOnTop(true);
        java.awt.Dimension screen = dialog.getToolkit().getScreenSize();
        java.awt.Dimension size = dialog.getSize();
        dialog.setLocation((screen.width - size.width) / 2,
                (screen.height - size.height) / 2 );
        dialog.setVisible(true);
        
        panel.timer.schedule(panel.updater, 0, 1000);
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
    private void initComponents() {
        java.awt.GridBagConstraints gridBagConstraints;

        bar = new javax.swing.JProgressBar();
        jLabel1 = new javax.swing.JLabel();
        totalMemoryLabel = new javax.swing.JLabel();
        jLabel3 = new javax.swing.JLabel();
        freeMemoryLabel = new javax.swing.JLabel();

        setLayout(new java.awt.GridBagLayout());

        setPreferredSize(new java.awt.Dimension(250, 120));
        bar.setMinimumSize(new java.awt.Dimension(150, 20));
        bar.setPreferredSize(new java.awt.Dimension(150, 20));
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new java.awt.Insets(10, 0, 0, 0);
        add(bar, gridBagConstraints);

        jLabel1.setText("Total Reserved Memory:");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.anchor = java.awt.GridBagConstraints.WEST;
        add(jLabel1, gridBagConstraints);

        totalMemoryLabel.setHorizontalAlignment(javax.swing.SwingConstants.TRAILING);
        totalMemoryLabel.setText("-");
        totalMemoryLabel.setMaximumSize(new java.awt.Dimension(100, 16));
        totalMemoryLabel.setMinimumSize(new java.awt.Dimension(50, 16));
        totalMemoryLabel.setPreferredSize(new java.awt.Dimension(100, 16));
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new java.awt.Insets(0, 10, 0, 0);
        add(totalMemoryLabel, gridBagConstraints);

        jLabel3.setText("Free Memory:");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.WEST;
        gridBagConstraints.insets = new java.awt.Insets(10, 0, 10, 0);
        add(jLabel3, gridBagConstraints);

        freeMemoryLabel.setHorizontalAlignment(javax.swing.SwingConstants.TRAILING);
        freeMemoryLabel.setText("-");
        freeMemoryLabel.setMaximumSize(new java.awt.Dimension(100, 16));
        freeMemoryLabel.setMinimumSize(new java.awt.Dimension(50, 16));
        freeMemoryLabel.setPreferredSize(new java.awt.Dimension(100, 16));
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        gridBagConstraints.insets = new java.awt.Insets(0, 10, 0, 0);
        add(freeMemoryLabel, gridBagConstraints);

    }// </editor-fold>//GEN-END:initComponents
    
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JProgressBar bar;
    private javax.swing.JLabel freeMemoryLabel;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel totalMemoryLabel;
    // End of variables declaration//GEN-END:variables
    
}