org.richfaces.renderkit.util

Class ColorUtils

java.lang.Object

org.richfaces.renderkit.util.ColorUtils

public final class ColorUtils
extends Object

Utility methods that are useful for color processing.

Author:

carcasser

Method Summary

Methods

Modifier and Type	Method and Description
static Color	adjustBrightness(Color c, float difference) Increases/decreases brightness of the given color by the specified difference.
static Color	adjustLightness(Color c, float difference) Increases/decreases lightness of the given color by the specified difference.
static Color	convertHSLtoRGB(float h, float s, float l) Converts the components of a color, as specified by the HSL model, to an equivalent set of values for the default RGB model.
static float[]	convertRGBtoHSL(int r, int g, int b) Converts the components of a color, as specified by the default RGB model, to an equivalent set of values for hue, saturation, and lightness that are the three components of the HSL model.
static Color	overwriteAlpha(Color c, float alpha) Overwrites alpha value for given color.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

convertRGBtoHSL

public static float[] convertRGBtoHSL(int r,
                      int g,
                      int b)

Converts the components of a color, as specified by the default RGB model, to an equivalent set of values for hue, saturation, and lightness that are the three components of the HSL model.

Parameters:

r - the red component of the color

g - the green component of the color

b - the blue component of the color

Returns:

an array of three elements containing the hue, saturation, and lightness (in that order), of the color with the indicated red, green, and blue components.

convertHSLtoRGB

public static Color convertHSLtoRGB(float h,
                    float s,
                    float l)

Converts the components of a color, as specified by the HSL model, to an equivalent set of values for the default RGB model.

The saturation and lightness components should be floating-point values between zero and one (numbers in the range 0.0-1.0). The hue component can be any floating-point number. The floor of this number is subtracted from it to create a fraction between 0 and 1. This fractional number is then multiplied by 360 to produce the hue angle in the HSB color model.

Parameters:

h - the hue component of the color

s - the saturation of the color

l - the lightness of the color

Returns:

the RGB value of the color with the indicated hue, saturation, and lightness

adjustBrightness

public static Color adjustBrightness(Color c,
                     float difference)

Increases/decreases brightness of the given color by the specified difference.

The difference values in the range (-1.0, 1.0): 1.0 - the brightest value; -1.0 - the dimmest value.

Parameters:

c - color to adjust

difference - value to be added to the current brightness

Returns:

a new Color instance with increased/decreased brightness by specified difference

Throws:

IllegalArgumentException - if difference is outside of the range -1.0 to 1.0, inclusive

adjustLightness

public static Color adjustLightness(Color c,
                    float difference)

Increases/decreases lightness of the given color by the specified difference.

The difference values in the range (-1.0, 1.0): 1.0 - the lightest value; -1.0 - on the contrary.

Parameters:

c - color to adjust

difference - value to be added to the current lightness

Returns:

a new Color instance with increased/decreased lightness by specified difference

Throws:

IllegalArgumentException - if difference is outside of the range -1.0 to 1.0, inclusive

overwriteAlpha

public static Color overwriteAlpha(Color c,
                   float alpha)

Overwrites alpha value for given color.

Parameters:

c - color to overwrite

alpha - a new value of alpha

Returns:

a new Color object with a new specified alpha value