Colors.java

package ilarkesto.base;

import ilarkesto.console.ColorsConsoleApp;

import java.awt.Color;

/**
 * A Class that provides utility methods for mixing colours.
 */
public class Colors {

	public static void main(String[] args) {
		ColorsConsoleApp.main(args);
	}

	public static Color blend(Color one, Color two, float ratio) {
		if (ratio < 0 || ratio > 1) throw new IllegalArgumentException("Color blend ratio r must be between 0 and 1.");

		float r1 = ratio;
		float r2 = 1 - ratio;

		float[] rgb1 = new float[3];
		float[] rgb2 = new float[3];
		one.getColorComponents(rgb1);
		two.getColorComponents(rgb2);

		return new Color(rgb1[0] * r1 + rgb2[0] * r2, rgb1[1] * r1 + rgb2[1] * r2, rgb1[2] * r1 + rgb2[2] * r2);
	}

	public static Color blend(Color one, Color two) {
		return blend(one, two, 0.5f);
	}

	public static String blend(String hexOne, String hexTwo, float ratio) {
		return toHex(blend(fromHex(hexOne), fromHex(hexTwo), ratio));
	}

	public static String blend(String hexOne, String hexTwo) {
		return blend(hexOne, hexTwo, 0.5f);
	}

	public static Color darken(Color color) {
		float[] rgb = new float[3];
		color.getColorComponents(rgb);

		rgb[0] = (rgb[0] <= 0.1f) ? 0.0f : rgb[0] - 0.1f;
		rgb[1] = (rgb[1] <= 0.1f) ? 0.0f : rgb[1] - 0.1f;
		rgb[2] = (rgb[2] <= 0.1f) ? 0.0f : rgb[2] - 0.1f;

		return new Color(rgb[0], rgb[1], rgb[2]);
	}

	public static Color lighten(Color color) {
		float[] rgb = new float[3];
		color.getColorComponents(rgb);

		rgb[0] = (rgb[0] >= 0.9f) ? 1.0f : rgb[0] + 0.1f;
		rgb[1] = (rgb[1] >= 0.9f) ? 1.0f : rgb[1] + 0.1f;
		rgb[2] = (rgb[2] >= 0.9f) ? 1.0f : rgb[2] + 0.1f;

		return new Color(rgb[0], rgb[1], rgb[2]);
	}

	public static String darken(String hexColor) {
		return toHex(darken(fromHex(hexColor)));
	}

	public static String lighten(String hexColor) {
		return toHex(lighten(fromHex(hexColor)));
	}

	public static Color fromHex(String hexColor) {
		try {
			return Color.decode(hexColor);
		} catch (NumberFormatException e) {
			throw new IllegalArgumentException("'" + hexColor
					+ "' is not a valid color. Use the format #RRGGBB where R, G and B are values 0-9 or A-F.");
		}
	}

	public static String toHex(Color color) {
		return String.format("#%02X%02X%02X", color.getRed(), color.getGreen(), color.getBlue());
	}

	public static boolean isHexColor(String hexColor) {
		return hexColor.matches("#[0-9A-F]{6}");
	}
}