MemoryPanel.java

/*******************************************************************************
 * GenPlay, Einstein Genome Analyzer
 * Copyright (C) 2009, 2014 Albert Einstein College of Medicine
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * Authors: Julien Lajugie <julien.lajugie@einstein.yu.edu>
 *          Nicolas Fourel <nicolas.fourel@einstein.yu.edu>
 *          Eric Bouhassira <eric.bouhassira@einstein.yu.edu>
 * 
 * Website: <http://genplay.einstein.yu.edu>
 ******************************************************************************/
package edu.yu.einstein.genplay.gui.statusBar;

import java.awt.Color;
import java.awt.Dimension;
import java.text.NumberFormat;

import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.JProgressBar;
import javax.swing.UIManager;
import javax.swing.plaf.basic.BasicProgressBarUI;

import edu.yu.einstein.genplay.exception.ExceptionManager;
import edu.yu.einstein.genplay.util.colors.Colors;


/**
 * Panel showing the memory usage of the application
 * @author Julien Lajugie
 * @version 0.1
 */
public final class MemoryPanel extends JProgressBar {

	/**
	 * Thread checking the memory usage and updating the label at regular interval
	 * @author Julien Lajugie
	 * @version 0.1
	 */
	private class MemoryListener extends Thread {
		@Override
		public void run() {
			while (true) {
				long maxMemory =  RUN_TIME.maxMemory() / B_TO_MB_FACTOR;
				long usedMemory = (RUN_TIME.totalMemory() - RUN_TIME.freeMemory()) / B_TO_MB_FACTOR;
				setMemory(maxMemory, usedMemory);
				try {
					sleep(3000);
				} catch (InterruptedException e) {
					ExceptionManager.getInstance().caughtException(e);
				}
			}
		}
	}
	private static final long serialVersionUID = 5175483247820204875L; 	// generated ID
	private static final int 		HEIGHT = 15; 						// height of the progress bar
	private static final Runtime 	RUN_TIME = Runtime.getRuntime();	// application runtime


	private static final long 		B_TO_MB_FACTOR = 1048576;			// number of bytes in a megabyte;


	/**
	 * Creates an instance of {@link MemoryPanel}
	 */
	MemoryPanel() {
		super(0, 100);
		setBorder(BorderFactory.createMatteBorder(0, 1, 0, 0, Colors.LIGHT_GREY));
		setMinimumSize(new Dimension(getPreferredSize().width, HEIGHT));
		setStringPainted(true);
		new MemoryListener().start();
	}


	/**
	 * Changes the color of the string painted on the memory panel
	 */
	void customizeUI() {
		final Color stringColor = UIManager.getColor("Label.foreground");
		BasicProgressBarUI ui = new BasicProgressBarUI() {
			@Override
			protected Color getSelectionBackground() {
				return stringColor; // string color over the background
			}
			@Override
			protected Color getSelectionForeground() {
				return stringColor;	// string color over the foreground
			}
		};
		setUI(ui);
	}


	/**
	 * Associates a color to a memory usage.
	 * Green = low usage / Yellow = medium usage / Red = high usage
	 * @param memoryUsage a memory usage
	 * @return a Color
	 */
	private Color memoryToColor(int memoryUsage) {
		int red = 255;
		int green = 255;
		int blue = 0;
		if (memoryUsage < 50) {
			red = (int) ((memoryUsage / 50d) * 255);
		} else {
			green = (int) (255 - (((memoryUsage - 50) / 50d) * 255));
		}
		return new Color(red, green, blue);
	}


	/**
	 * Sets the memory string, the color of the progress bar and the value of the progress
	 * @param maxMemory memory available
	 * @param usedMemory used memory
	 */
	private synchronized void setMemory(long maxMemory, long usedMemory) {
		// compute the percentage of memory used
		int usedOnMax = (int)((usedMemory / (double)maxMemory) * 100);
		// use this percentage to set the progress of the progress bar
		setValue(usedOnMax);
		// set the color of the progress bar
		Color foregroundColor = memoryToColor(usedOnMax);
		setForeground(foregroundColor);
		// prepare the string that needs to be printed
		String stringToPrint = " " + NumberFormat.getInstance().format(usedMemory) + " MB / " + NumberFormat.getInstance().format(maxMemory) + " MB (" + usedOnMax + "%)";
		// compute the width of the string to print
		int width = getFontMetrics(getFont()).stringWidth(stringToPrint);
		// if the string is too large for the component we make the component bigger
		if ((width + 10) > getMinimumSize().width) {
			setMinimumSize(new Dimension(width + 10, getMinimumSize().height));
			if ((getParent() != null) && (getParent() instanceof JComponent)) {
				((JComponent) getParent()).revalidate();
			}
		}
		// print the new string
		setString(stringToPrint);
	}


	@Override
	public void updateUI() {
		super.updateUI();
		customizeUI();
	}
}