Package org.jdesktop.swingx.color

Class ColorUtil

java.lang.Object

org.jdesktop.swingx.color.ColorUtil

public final class ColorUtil
extends java.lang.Object

A collection of utility methods for working with Colors.

Author:

joshua.marinacci@sun.com, Karl George Schaefer

Method Summary

Modifier and Type	Method	Description
static java.awt.Color	blend(java.awt.Color origin, java.awt.Color over)	Blends two colors to create a new color.
static java.awt.Color	computeForeground(java.awt.Color bg)	Computes an appropriate foreground color (either white or black) for the given background color.
static java.awt.Paint	getCheckerPaint()	Creates a new Paint that is a checkered effect using the colors gray and Color.WHITE.
static java.awt.Paint	getCheckerPaint(java.awt.Color c1, java.awt.Color c2, int size)	Creates a new Paint that is a checkered effect using the specified colors.
static java.awt.Color	interpolate(java.awt.Color b, java.awt.Color a, float t)
static java.awt.Color	removeAlpha(java.awt.Color color)	Returns a new color equal to the old one, except that there is no alpha (transparency) channel.
static java.awt.Color	setAlpha(java.awt.Color color, int alpha)	Returns a new color equal to the old one, except alpha (transparency) channel is set to the new value.
static java.awt.Color	setBrightness(java.awt.Color color, float brightness)	Returns a new color equal to the old one, except the brightness is set to the new value.
static java.awt.Color	setSaturation(java.awt.Color color, float saturation)	Returns a new color equal to the old one, except the saturation is set to the new value.
static void	tileStretchPaint(java.awt.Graphics g, javax.swing.JComponent comp, java.awt.image.BufferedImage img, java.awt.Insets ins)	Draws an image on top of a component by doing a 3x3 grid stretch of the image using the specified insets.
static java.lang.String	toHexString(java.awt.Color color)	Creates a String that represents the supplied color as a hex-value RGB triplet, including the "#".

Methods inherited from class java.lang.Object

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

Method Detail

removeAlpha

public static java.awt.Color removeAlpha(java.awt.Color color)

Returns a new color equal to the old one, except that there is no alpha (transparency) channel.

This method is a convenience and has the same effect as setAlpha(color, 255).

Parameters:

color - the color to remove the alpha (transparency) from

Returns:

a new non-transparent Color

Throws:

java.lang.NullPointerException - if color is null

setAlpha

public static java.awt.Color setAlpha(java.awt.Color color,
                                      int alpha)

Returns a new color equal to the old one, except alpha (transparency) channel is set to the new value.

Parameters:

color - the color to modify

alpha - the new alpha (transparency) level. Must be an int between 0 and 255

Returns:

a new alpha-applied Color

Throws:

java.lang.IllegalArgumentException - if alpha is not between 0 and 255 inclusive

java.lang.NullPointerException - if color is null

setSaturation

public static java.awt.Color setSaturation(java.awt.Color color,
                                           float saturation)

Returns a new color equal to the old one, except the saturation is set to the new value. The new color will have the same alpha (transparency) as the original color.

The color is modified using HSB calculations. The saturation must be a float between 0 and 1. If 0 the resulting color will be gray. If 1 the resulting color will be the most saturated possible form of the passed in color.

Parameters:

color - the color to modify

saturation - the saturation to use in the new color

Returns:

a new saturation-applied Color

Throws:

java.lang.IllegalArgumentException - if saturation is not between 0 and 1 inclusive

java.lang.NullPointerException - if color is null

setBrightness

public static java.awt.Color setBrightness(java.awt.Color color,
                                           float brightness)

Returns a new color equal to the old one, except the brightness is set to the new value. The new color will have the same alpha (transparency) as the original color.

The color is modified using HSB calculations. The brightness must be a float between 0 and 1. If 0 the resulting color will be black. If 1 the resulting color will be the brightest possible form of the passed in color.

Parameters:

color - the color to modify

brightness - the brightness to use in the new color

Returns:

a new brightness-applied Color

Throws:

java.lang.IllegalArgumentException - if brightness is not between 0 and 1 inclusive

java.lang.NullPointerException - if color is null

toHexString

public static java.lang.String toHexString(java.awt.Color color)

Creates a String that represents the supplied color as a hex-value RGB triplet, including the "#". The return value is suitable for use in HTML. The alpha (transparency) channel is neither include nor used in producing the string.

Parameters:

color - the color to convert

Returns:

the hex String

computeForeground

public static java.awt.Color computeForeground(java.awt.Color bg)

Computes an appropriate foreground color (either white or black) for the given background color.

Parameters:

bg - the background color

Returns:

Color.WHITE or Color.BLACK

Throws:

java.lang.NullPointerException - if bg is null

blend

public static java.awt.Color blend(java.awt.Color origin,
                                   java.awt.Color over)

Blends two colors to create a new color. The origin color is the base for the new color and regardless of its alpha component, it is treated as fully opaque (alpha 255).

Parameters:

origin - the base of the new color

over - the alpha-enabled color to add to the origin color

Returns:

a new color comprised of the origin and over colors

interpolate

public static java.awt.Color interpolate(java.awt.Color b,
                                         java.awt.Color a,
                                         float t)

getCheckerPaint

public static java.awt.Paint getCheckerPaint()

Creates a new Paint that is a checkered effect using the colors gray and Color.WHITE.

Returns:

a the checkered paint

getCheckerPaint

public static java.awt.Paint getCheckerPaint(java.awt.Color c1,
                                             java.awt.Color c2,
                                             int size)

Creates a new Paint that is a checkered effect using the specified colors.

While this method supports transparent colors, this implementation performs painting operations using the second color after it performs operations using the first color. This means that to create a checkered paint with a fully-transparent color, you MUST specify that color first.

Parameters:

c1 - the first color

c2 - the second color

size - the size of the paint

Returns:

a new Paint checkering the supplied colors

tileStretchPaint

public static void tileStretchPaint(java.awt.Graphics g,
                                    javax.swing.JComponent comp,
                                    java.awt.image.BufferedImage img,
                                    java.awt.Insets ins)

Draws an image on top of a component by doing a 3x3 grid stretch of the image using the specified insets.

TODO this is image related; move to GraphicsUtilities