ColorCache.java

/*
 * Copyright PMEase (c) 2005 - 2010,
 * Date: Jan 13, 2010 1:53:09 AM
 *
 * All rights reserved.
 * 
 * Revision: $Id$
 */
package com.pmease.quickbuild.monitor.cache;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Display;

/**
 * Taken from the blog: http://hexapixel.com/2009/06/30/creating-a-notification-popup-widget
 * 
 * Class for caching colors
 * 
 * @author Emil
 *
 */

public final class ColorCache {

    public static final RGB        BLACK = new RGB(0, 0, 0);
    public static final RGB        WHITE = new RGB(255, 255, 255);

    private static Map<RGB, Color> _colorTable;
    private static ColorCache      _instance;

    static {
        _colorTable = new HashMap<RGB, Color>();
        new ColorCache();
    }

    private ColorCache() {
        _instance = this;
    }

    public static ColorCache getInstance() {
        return _instance;
    }

    /**
     * Disposes of all colors. DO ONLY CALL THIS WHEN YOU ARE SHUTTING DOWN YOUR
     * APPLICATION!
     */
    public static void dispose() {
        Iterator<Color> e = _colorTable.values().iterator();
        while (e.hasNext())
            e.next().dispose();

        _colorTable.clear();
    }

    public static Color getWhite() {
        return getColorFromRGB(new RGB(255, 255, 255));
    }

    public static Color getBlack() {
        return getColorFromRGB(new RGB(0, 0, 0));
    }

    public static Color getColorFromRGB(RGB rgb) {
        Color color = _colorTable.get(rgb);

        if (color == null) {
            color = new Color(Display.getCurrent(), rgb);
            _colorTable.put(rgb, color);
        }

        return color;
    }

    public static Color getColor(int r, int g, int b) {
        RGB rgb = new RGB(r, g, b);
        Color color = _colorTable.get(rgb);

        if (color == null) {
            color = new Color(Display.getCurrent(), rgb);
            _colorTable.put(rgb, color);
        }

        return color;
    }
}