ColorHelper.java

/*
 * Copyright 2005 MH-Software-Entwicklung. All rights reserved.
 * Use is subject to license terms.
 */
package com.jtattoo.plaf;

import java.awt.*;

/**
 * @author Michael Hagen
 */
public class ColorHelper {

    private ColorHelper() {
    }

    public static final Color createColor(int r, int g, int b) {
        return new Color(((r & 0xFF) << 16) | ((g & 0xFF) << 8) | ((b & 0xFF) << 0));
    }

    public static Color[] createColorArr(Color c1, Color c2, int steps) {
        if (c1 == null || c2 == null) {
            return null;
        }

        Color colors[] = new Color[steps];
        double r = c1.getRed();
        double g = c1.getGreen();
        double b = c1.getBlue();
        double dr = ((double) c2.getRed() - r) / steps;
        double dg = ((double) c2.getGreen() - g) / steps;
        double db = ((double) c2.getBlue() - b) / steps;
        colors[0] = c1;
        for (int i = 1; i < steps - 1; i++) {
            r += dr;
            g += dg;
            b += db;
            colors[i] = createColor((int) r, (int) g, (int) b);
        }
        colors[steps - 1] = c2;
        return colors;
    }

    public static Color brighter(Color c, double p) {
        if (c == null) {
            return null;
        }
        
        double r = c.getRed();
        double g = c.getGreen();
        double b = c.getBlue();

        double rd = 255.0 - r;
        double gd = 255.0 - g;
        double bd = 255.0 - b;

        r += (rd * p) / 100.0;
        g += (gd * p) / 100.0;
        b += (bd * p) / 100.0;
        return createColor((int) r, (int) g, (int) b);
    }

    public static Color darker(Color c, double p) {
        if (c == null) {
            return null;
        }

        double r = c.getRed();
        double g = c.getGreen();
        double b = c.getBlue();

        r -= (r * p) / 100.0;
        g -= (g * p) / 100.0;
        b -= (b * p) / 100.0;

        return createColor((int) r, (int) g, (int) b);
    }

    public static Color median(Color c1, Color c2) {
        if ((c1 == null || c2 == null)) {
            return null;
        }

        int r = (c1.getRed() + c2.getRed()) / 2;
        int g = (c1.getGreen() + c2.getGreen()) / 2;
        int b = (c1.getBlue() + c2.getBlue()) / 2;
        return createColor(r, g, b);
    }

    public static int getGrayValue(Color c) {
        if (c == null) {
            return 0;
        }

        double r = c.getRed();
        double g = c.getGreen();
        double b = c.getBlue();
        return Math.min(255, (int) (r * 0.28 + g * 0.59 + b * 0.13));
    }

    public static Color toGray(Color c) {
        if (c == null) {
            return null;
        }

        int gray = getGrayValue(c);
        return new Color(gray, gray, gray, c.getAlpha());
    }
}