java.awt
Class Color

java.lang.Object
  |
  +--java.awt.Color

Direct Known Subclasses:

ColorUIResource, SystemColor

public class Color

extends Object

implements Paint, Serializable

A class to encapsulate colors in the default sRGB color space or colors in arbitrary color spaces identified by a ColorSpace. Every color has an implicit alpha value of 1.0 or an explicit one provided in the constructor. When constructing a Color with an explicit alpha or getting the color/alpha components of a Color, the color components are never premultiplied by the alpha component.

The default color space for the Java 2D API is sRGB, a proposed standard RGB color space. For further information on sRGB, see http://www.w3.org/pub/WWW/Graphics/Color/sRGB.html .

Eventually this class should supersede java.awt.Color, but for now it is defined to be part of the java.java2d package, so we can generate documentation for a single package for review.

See Also:

ColorSpace, Serialized Form

Field Summary

static Color	black The color black.
static Color	blue The color blue.
static Color	cyan The color cyan.
static Color	darkGray The color dark gray.
static Color	gray The color gray.
static Color	green The color green.
static Color	lightGray The color light gray.
static Color	magenta The color magenta.
static Color	orange The color orange.
static Color	pink The color pink.
static Color	red The color red.
static Color	white The color white.
static Color	yellow The color yellow.

Constructor Summary

Color(ColorSpace cspace, float[] components, float alpha)
Creates a color in the color space of the supplied ColorSpace with the color components specified in the float array and the specified alpha.

Color(float r, float g, float b)
Creates an opaque sRGB color with the specified red, green, and blue values in the range (0.0 - 1.0).

Color(float r, float g, float b, float a)
Creates an sRGB color with the specified red, green, blue, and alpha values in the range (0.0 - 1.0).

Color(int rgb)
Creates an opaque sRGB color with the specified combined RGB value consisting of the red component in bits 16-23, the green component in bits 8-15, and the blue component in bits 0-7.

Color(int rgba, boolean hasalpha)
Creates an sRGB color with the specified combined RGBA value consisting of the alpha component in bits 24-31, the red component in bits 16-23, the green component in bits 8-15, and the blue component in bits 0-7.

Color(int r, int g, int b)
Creates an opaque sRGB color with the specified red, green, and blue values in the range (0 - 255).

Color(int r, int g, int b, int a)
Creates an sRGB color with the specified red, green, blue, and alpha values in the range (0 - 255).

Method Summary

Color	brighter() Creates a brighter version of this color.
PaintContext	createContext(ColorModel cm, Rectangle r, Rectangle2D r2d, AffineTransform xform, RenderingHints hints) Create and return a PaintContext used to generate a solid color pattern.
Color	darker() Creates a darker version of this color.
static Color	decode(String nm) Converts a string to an integer and returns the specified opaque color.
boolean	equals(Object obj) Determines whether another object is equal to this color.
int	getAlpha() Returns the alpha component.
int	getBlue() Returns the blue component.
static Color	getColor(String nm) Finds a color in the system properties.
static Color	getColor(String nm, Color v) Finds a color in the system properties.
static Color	getColor(String nm, int v) Finds a color in the system properties.
float[]	getColorComponents(ColorSpace cspace, float[] compArray) Returns a float array containing the color components (no alpha) of the Color, in the ColorSpace specified by the cspace parameter.
float[]	getColorComponents(float[] compArray) Returns a float array containing the color components (no alpha) of the Color, in the ColorSpace of the color.
ColorSpace	getColorSpace() Returns the ColorSpace of the Color.
float[]	getComponents(ColorSpace cspace, float[] compArray) Returns a float array containing the color and alpha components of the Color, in the ColorSpace specified by the cspace parameter.
float[]	getComponents(float[] compArray) Returns a float array containing the color and alpha components of the Color, in the ColorSpace of the Color.
int	getGreen() Returns the green component.
static Color	getHSBColor(float h, float s, float b) Creates a Color object based on values supplied for the HSB color model.
int	getRed() Returns the red component.
int	getRGB() Returns the RGB value representing the color in the default sRGB ColorModel.
float[]	getRGBColorComponents(float[] compArray) Returns a float array containing the color components (no alpha) of the Color, in the default sRGB color space.
float[]	getRGBComponents(float[] compArray) Returns a float array containing the color and alpha components of the Color, as represented in the default sRGB color space.
int	getTransparency() Return the transparency mode for this Color.
int	hashCode() Computes the hash code for this color.
static int	HSBtoRGB(float hue, float saturation, float brightness) Converts the components of a color, as specified by the HSB model, to an equivalent set of values for the default RGB model.
static float[]	RGBtoHSB(int r, int g, int b, float[] hsbvals) Converts the components of a color, as specified by the default RGB model, to an equivalent set of values for hue, saturation, and brightness, the three components of the HSB model.
String	toString() Returns a string representation of this color.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

white

public static final Color white

The color white. In the default sRGB space.

lightGray

public static final Color lightGray

The color light gray. In the default sRGB space.

gray

public static final Color gray

The color gray. In the default sRGB space.

darkGray

public static final Color darkGray

The color dark gray. In the default sRGB space.

black

public static final Color black

The color black. In the default sRGB space.

red

public static final Color red

The color red. In the default sRGB space.

pink

public static final Color pink

The color pink. In the default sRGB space.

orange

public static final Color orange

The color orange. In the default sRGB space.

yellow

public static final Color yellow

The color yellow. In the default sRGB space.

green

public static final Color green

The color green. In the default sRGB space.

magenta

public static final Color magenta

The color magenta. In the default sRGB space.

cyan

public static final Color cyan

The color cyan. In the default sRGB space.

blue

public static final Color blue

The color blue. In the default sRGB space.

Constructor Detail

Color

public Color(int r,
             int g,
             int b)

Creates an opaque sRGB color with the specified red, green, and blue values in the range (0 - 255). The actual color used in rendering will depend on finding the best match given the color space available for a given output device. Alpha is defaulted to 255.

Parameters:

r - the red component

g - the green component

b - the blue component

See Also:

getRed(), getGreen(), getBlue(), getRGB()

Color

public Color(int r,
             int g,
             int b,
             int a)

Creates an sRGB color with the specified red, green, blue, and alpha values in the range (0 - 255).

Parameters:

r - the red component

g - the green component

b - the blue component

a - the alpha component

See Also:

getRed(), getGreen(), getBlue(), getAlpha(), getRGB()

Color

public Color(int rgb)

Creates an opaque sRGB color with the specified combined RGB value consisting of the red component in bits 16-23, the green component in bits 8-15, and the blue component in bits 0-7. The actual color used in rendering will depend on finding the best match given the color space available for a given output device. Alpha is defaulted to 255.

Parameters:

rgb - the combined RGB components

See Also:

ColorModel.getRGBdefault(), getRed(), getGreen(), getBlue(), getRGB()

Color

public Color(int rgba,
             boolean hasalpha)

Creates an sRGB color with the specified combined RGBA value consisting of the alpha component in bits 24-31, the red component in bits 16-23, the green component in bits 8-15, and the blue component in bits 0-7. If the hasalpha argument is False, alpha is defaulted to 255.

Parameters:

rgba - the combined RGBA components

hasalpha - true if the alpha bits are valid, false otherwise

See Also:

ColorModel.getRGBdefault(), getRed(), getGreen(), getBlue(), getAlpha(), getRGB()

Color

public Color(float r,
             float g,
             float b)

Creates an opaque sRGB color with the specified red, green, and blue values in the range (0.0 - 1.0). Alpha is defaulted to 1.0. The actual color used in rendering will depend on finding the best match given the color space available for a given output device.

Parameters:

r - the red component

g - the green component

b - the blue component

See Also:

getRed(), getGreen(), getBlue(), getRGB()

Color

public Color(float r,
             float g,
             float b,
             float a)

Creates an sRGB color with the specified red, green, blue, and alpha values in the range (0.0 - 1.0). The actual color used in rendering will depend on finding the best match given the color space available for a given output device.

Parameters:

r - the red component

g - the green component

b - the blue component

a - the alpha component

See Also:

getRed(), getGreen(), getBlue(), getAlpha(), getRGB()

Color

public Color(ColorSpace cspace,
             float[] components,
             float alpha)

Creates a color in the color space of the supplied ColorSpace with the color components specified in the float array and the specified alpha. The number of components is determined by the color space type of the ColorSpace (e.g. RGB requires 3 components, CMYK requires 4, etc.).

Parameters:

cspace - The ColorSpace to be used to interpret the components

components - An arbitrary number of color components that is compatible with the ColorSpace

alpha - Alpha value

See Also:

getComponents(float[]), getColorComponents(float[])

Method Detail

getRed

public int getRed()

Returns the red component. In the range 0-255 in the default sRGB space.

See Also:

getRGB()

getGreen

public int getGreen()

Returns the green component. In the range 0-255 in the default sRGB space.

See Also:

getRGB()

getBlue

public int getBlue()

Returns the blue component. In the range 0-255 in the default sRGB space.

See Also:

getRGB()

getAlpha

public int getAlpha()

Returns the alpha component. In the range 0-255.

See Also:

getRGB()

getRGB

public int getRGB()

Returns the RGB value representing the color in the default sRGB ColorModel. (Bits 24-31 are 0xff, 16-23 are red, 8-15 are green, 0-7 are blue).

Since:

JDK1.0

See Also:

ColorModel.getRGBdefault(), getRed(), getGreen(), getBlue()

brighter

public Color brighter()

Creates a brighter version of this color.

This method applies an arbitrary scale factor to each of the three RGB components of the color to create a brighter version of the same color. Although brighter and darker are inverse operations, the results of a series of invocations of these two methods may be inconsistent because of rounding errors.

Returns:

a new Color object, a brighter version of this color.

Since:

JDK1.0

See Also:

darker()

darker

public Color darker()

Creates a darker version of this color.

This method applies an arbitrary scale factor to each of the three RGB components of the color to create a darker version of the same color. Although brighter and darker are inverse operations, the results of a series of invocations of these two methods may be inconsistent because of rounding errors.

Returns:

a new Color object, a darker version of this color.

Since:

JDK1.0

See Also:

brighter()

hashCode

public int hashCode()

Computes the hash code for this color.

Returns:

a hash code value for this object.

Overrides:

hashCode in class Object

Since:

JDK1.0

equals

public boolean equals(Object obj)

Determines whether another object is equal to this color.

The result is true if and only if the argument is not null and is a Color object that has the same red, green, and blue values as this object.

Parameters:

obj - the object to compare with.

Returns:

true if the objects are the same; false otherwise.

Overrides:

equals in class Object

Since:

JDK1.0

toString

public String toString()

Returns a string representation of this color. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.

Returns:

a string representation of this color.

Overrides:

toString in class Object

decode

public static Color decode(String nm)
                    throws NumberFormatException

Converts a string to an integer and returns the specified opaque color. This method handles string formats that are used to represent octal and hexidecimal numbers.

Parameters:

nm - a string that represents an opaque color as a 24-bit integer.

Returns:

the new color

Throws:

NumberFormatException - if the specified string cannot be interpreted as a decimal, octal, or hexidecimal integer.

Since:

JDK1.1

See Also:

Integer.decode(java.lang.String)

getColor

public static Color getColor(String nm)

Finds a color in the system properties.

The argument is treated as the name of a system property to be obtained. The string value of this property is then interpreted as an integer which is then converted to a color.

If the specified property is not found, or could not be parsed as an integer, then null is returned.

Parameters:

nm - the name of the color property

Returns:

the color value of the property.

Since:

JDK1.0

See Also:

System.getProperty(java.lang.String), Integer.getInteger(java.lang.String), Color(int)

getColor

public static Color getColor(String nm,
                             Color v)

Finds a color in the system properties.

The first argument is treated as the name of a system property to be obtained. The string value of this property is then interpreted as an integer which is then converted to a color.

If the specified property is not found, or cannot be parsed as an integer, then the color specified by the second argument is returned instead.

Parameters:

nm - the name of the color property

v - the default color value.

Returns:

the color value of the property.

Since:

JDK1.0

See Also:

System.getProperty(java.lang.String), Integer.getInteger(java.lang.String), Color(int)

getColor

public static Color getColor(String nm,
                             int v)

Finds a color in the system properties.

The first argument is treated as the name of a system property to be obtained. The string value of this property is then interpreted as an integer which is then converted to a color.

If the specified property is not found, or could not be parsed as an integer, then the integer value v is used instead, and is converted to a color.

Parameters:

nm - the name of the color property.

v - the default color value, as an integer.

Returns:

the color value of the property.

Since:

JDK1.0

See Also:

System.getProperty(java.lang.String), Integer.getInteger(java.lang.String), Color(int)

HSBtoRGB

public static int HSBtoRGB(float hue,
                           float saturation,
                           float brightness)

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

The integer that is returned by HSBtoRGB encodes the value of a color in bits 0&endash;23 of an integer value, the same format used by the method getRGB. This integer can be supplied as an argument to the Color constructor that takes a single integer argument.

Parameters:

hue - the hue component of the color.

saturation - the saturation of the color.

brightness - the brightness of the color.

Returns:

the RGB value of the color with the indicated hue, saturation, and brightness.

Since:

JDK1.0

See Also:

getRGB(), Color(int), ColorModel.getRGBdefault()

RGBtoHSB

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

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

If the hsbvals argument is null, then a new array is allocated to return the result. Otherwise, the method returns the array hsbvals, with the values put into that array.

Parameters:

r - the red component of the color.

g - the green component of the color.

b - the blue component of the color.

hsbvals - the array to be used to return the three HSB values, or null.

Returns:

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

Since:

JDK1.0

See Also:

getRGB(), Color(int), ColorModel.getRGBdefault()

getHSBColor

public static Color getHSBColor(float h,
                                float s,
                                float b)

Creates a Color object based on values supplied for the HSB color model.

Each of the three components should be a floating-point value between zero and one (a number in the range 0.0 ≤ h, s, b ≤ 1.0).

Parameters:

h - the hue component.

s - the saturation of the color.

b - the brightness of the color.

Returns:

a Color object with the specified hue, saturation, and brightness.

Since:

JDK1.0

getRGBComponents

public float[] getRGBComponents(float[] compArray)

Returns a float array containing the color and alpha components of the Color, as represented in the default sRGB color space. If componentarray is null, an array of length 4 is created for the return value. Otherwise, componentarray must have length 4 or greater, and it will be filled in with the components and returned.

Returns:

the RGBA components in a float array

getRGBColorComponents

public float[] getRGBColorComponents(float[] compArray)

Returns a float array containing the color components (no alpha) of the Color, in the default sRGB color space. If componentarray is null, an array of length 3 is created for the return value. Otherwise, componentarray must have length 3 or greater, and it will be filled in with the components and returned.

Returns:

the RGB components in a float array

getComponents

public float[] getComponents(float[] compArray)

Returns a float array containing the color and alpha components of the Color, in the ColorSpace of the Color. If componentarray is null, an array with length equal to the number of components in the associated ColorSpace plus one is created for the return value. Otherwise, componentarray must have at least this length, and it will be filled in with the components and returned.

Returns:

the color and alpha components in a float array

getColorComponents

public float[] getColorComponents(float[] compArray)

Returns a float array containing the color components (no alpha) of the Color, in the ColorSpace of the color. If componentarray is null, an array with length equal to the number of components in the associated ColorSpace is created for the return value. Otherwise, componentarray must have at least this length, and it will be filled in with the components and returned.

Returns:

the color components in a float array

getComponents

public float[] getComponents(ColorSpace cspace,
                             float[] compArray)

Returns a float array containing the color and alpha components of the Color, in the ColorSpace specified by the cspace parameter. If componentarray is null, an array with length equal to the number of components in cspace plus one is created for the return value. Otherwise, componentarray must have at least this length, and it will be filled in with the components and returned.

Returns:

the color and alpha components in a float array

getColorComponents

public float[] getColorComponents(ColorSpace cspace,
                                  float[] compArray)

Returns a float array containing the color components (no alpha) of the Color, in the ColorSpace specified by the cspace parameter. If componentarray is null, an array with length equal to the number of components in cspace is created for the return value. Otherwise, componentarray must have at least this length, and it will be filled in with the components and returned.

Returns:

the color components in a float array

getColorSpace

public ColorSpace getColorSpace()

Returns the ColorSpace of the Color.

createContext

public PaintContext createContext(ColorModel cm,
                                  Rectangle r,
                                  Rectangle2D r2d,
                                  AffineTransform xform,
                                  RenderingHints hints)

Create and return a PaintContext used to generate a solid color pattern. This enables a Color object to be used as an argument to any method requiring an object implementing the Paint interface.

Specified by:

createContext in interface Paint

See Also:

Paint, PaintContext, Graphics2D.setPaint(java.awt.Paint)

getTransparency

public int getTransparency()

Return the transparency mode for this Color. This is required in to implement the Paint interface.

See Also:

Paint, Transparency, createContext(java.awt.image.ColorModel, java.awt.Rectangle, java.awt.geom.Rectangle2D, java.awt.geom.AffineTransform, java.awt.RenderingHints)