/* $Id: HeapMonitor.java 17841 2010-01-12 19:17:52Z linus $

  *****************************************************************************

  * Copyright (c) 2009 Contributors - see below

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

  * which accompanies this distribution, and is available at

  * http://www.eclipse.org/legal/epl-v10.html

  *

  * Contributors:

  *    tfmorris

  *****************************************************************************

  *

  * Some portions of this file was previously release using the BSD License:

  */

 // Copyright (c) 2007 The Regents of the University of California. All

 // Rights Reserved. Permission to use, copy, modify, and distribute this

 // software and its documentation without fee, and without a written

 // agreement is hereby granted, provided that the above copyright notice

 // and this paragraph appear in all copies. This software program and

 // documentation are copyrighted by The Regents of the University of

 // California. The software program and documentation are supplied "AS

 // IS", without any accompanying services from The Regents. The Regents

 // does not warrant that the operation of the program will be

 // uninterrupted or error-free. The end-user understands that the program

 // was developed for research purposes and is advised not to rely

 // exclusively on the program for any reason. IN NO EVENT SHALL THE

 // UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,

 // SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,

 // ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF

 // THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF

 // SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY

 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE

 // PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF

 // CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,

 // UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 package org.argouml.ui;

 import java.awt.Color;

 import java.awt.Dimension;

 import java.awt.Graphics;

 import java.awt.Rectangle;

 import java.awt.event.ActionEvent;

 import java.awt.event.ActionListener;

 import java.text.MessageFormat;

 import javax.swing.JComponent;

 import javax.swing.Timer;

 /**

  * Swing component to monitor Java heap usage.

  * 

  * @author Tom Morris <tfmorris@gmail.com>

  */

 public class HeapMonitor extends JComponent implements ActionListener {

     // % thresholds for bar color changes

     private static final int ORANGE_THRESHOLD = 70;

     private static final int RED_THRESHOLD = 90;

     private static final Color GREEN = new Color(0, 255, 0);

     private static final Color ORANGE  = new Color(255, 190, 125);

     private static final Color RED = new Color(255, 70, 70);

     private static final long M = 1024 * 1024;

     // Virtual memory (heap) stats

     private long free;

     private long total;

     private long max;

     private long used;

     /**

      * Construct a graphical JVM heap monitor component.

      */

     public HeapMonitor() {

          super();

         Dimension size = new Dimension(200, 20);

         setPreferredSize(size);

         // TODO: Add a button to force garbage collection

         updateStats();

         Timer timer = new Timer(1000, this);

         timer.start();

     }

     public void paint (Graphics g) {        

         Rectangle bounds = getBounds();

         int usedX = (int) (used * bounds.width / total);

         int warnX = ORANGE_THRESHOLD * bounds.width / 100;

         int dangerX = RED_THRESHOLD * bounds.width / 100;

         Color savedColor = g.getColor();

 //      g.setColor(GREEN);

         // TODO: We want something minimally distracting here.  Another option

         // might be just the background color with a solid end line.

         g.setColor(getBackground().darker());

         g.fillRect(0, 0, Math.min(usedX, warnX), bounds.height);

         g.setColor(ORANGE);

         g.fillRect(warnX, 0, 

                 Math.min(usedX - warnX, dangerX - warnX), 

                 bounds.height);

         g.setColor(RED);

         g.fillRect(dangerX, 0, 

                 Math.min(usedX - dangerX, bounds.width - dangerX), 

                 bounds.height);

         g.setColor(getForeground());

         String s = MessageFormat.format("{0}M used of {1}M total",

                 new Object[] {(long) (used / M), (long) (total / M) });

         int x = (bounds.width - g.getFontMetrics().stringWidth(s)) / 2;

         int y = (bounds.height + g.getFontMetrics().getHeight()) / 2;

         g.drawString(s, x, y);

         g.setColor(savedColor);

     }

     /*

      * Timer action method.  Periodically update our stats and force a repaint.

      */

     public void actionPerformed(ActionEvent e) {

         updateStats();

         repaint();

     }

     private void updateStats() {

         free = Runtime.getRuntime().freeMemory();

         total = Runtime.getRuntime().totalMemory();

         max = Runtime.getRuntime().maxMemory();

         used = total - free;

         String tip = MessageFormat.format(

                 "Heap use: {0}%  {1}M used of {2}M total.  Max: {3}M", 

                 new Object[] {used * 100 / total, (long) (used / M),

                               (long) (total / M), (long) (max / M)

                 });

         setToolTipText(tip);

     }

 }