ColorDef Class

An immutable integer representation of a color.

A color consists of 4 components: Red, Blue, Green, and Transparency. Each component is an 8-bit unsigned integer in the range [0..255]. A value of zero means that component contributes nothing to the color: e.g., a color with Red=0 contains no shade of red, and a color with Transparency=0 is fully opaque. A value of 255 means that component contributes its maximum value to the color: e.g., a color with Red=255 is as red as it is possible to be, and a color with Transparency=255 is fully transparent.

Internally, these 4 components are combined into a single 32-bit unsigned integer as represented by ColorDefProps. This representation can result in some confusion regarding:

1. The ordering of the individual components; and
2. Whether to specify transparency or opacity (sometimes referred to as "alpha").

ColorDef uses 0xTTBBGGRR internally, which uses Transparency and puts Red in the low byte and Transparency in the high byte. It can be converted to 0xRRGGBB format (blue in the low byte) using getRgb and `0xAABBGGRRx format (red in the low byte, using opacity instead of transparency) using getAbgr.

A ColorDef can be created from a numeric ColorDefProps, from a string in one of the common HTML formats (e.g., fromString), or by specifying values for the individual components (e.g., from).

ColorDef is immutable. To obtain a modified copy of a ColorDef, use methods like adjustedForContrast, inverse, or withTransparency. For example:

 const semiTransparentBlue = ColorDef.blue.withTransparency(100);

Methods

Name	Description
adjustedForContrast(other: ColorDef, alpha?: number): ColorDef	Create a new ColorDef that is adjusted from this ColorDef for maximum contrast against another color.
equals(other: ColorDef): boolean	True if the value of this ColorDef is the same as another ColorDef.
getAbgr(): number	Get the value of the color as a number in 0xAABBGGRR format (i.e.
getAlpha(): number	Get the alpha value for this ColorDef.
getRgb(): number	Get the RGB value of the color as a number in 0xRRGGBB format (i.e blue is in the low byte).
getTransparency(): number	Get the transparency value for this ColorDef (inverse of alpha).
inverse(): ColorDef	Create a new ColorDef that is the inverse (all colors set to 255 - this) of this color.
lerp(color2: ColorDef, weight: number): ColorDef	Create a ColorDef that is the linear interpolation of this ColorDef and another ColorDef, using a weighting factor.
toHexString(): string	Convert this ColorDef to a string in the form "#rrggbb" where values are hex digits of the respective colors
toHSL(): HSLColor	Create an HSLColor from this ColorDef
toHSV(): HSVColor	Create an HSVColor from this ColorDef
toJSON(): number	Convert this ColorDef to a 32 bit number representing the 0xTTBBGGRR value
toRgbaString(): string	Convert this ColorDef to a string in the form "rgba(r,g,b,a)" where color values are decimal digits and a is a fraction
toRgbString(): string	Convert this ColorDef to a string in the form "rgb(r,g,b)" where values are decimal digits of the respective colors.
withAlpha(alpha: number): ColorDef	Return a copy of this ColorDef with the specified alpha component.
withTransparency(transparency: number): ColorDef	Create a copy of this ColorDef with the specified transparency.
computeTbgr(val?: string | number): number Static	Compute the 0xTTBBGGRR value corresponding to the specified representation of a color.
computeTbgrFromComponents(red: number, green: number, blue: number, transparency?: number): number Static	Compute the 0xTTBBGGRR value corresponding to the specified Red, Green, Blue, Transparency components.
computeTbgrFromHSL(h: number, s: number, l: number, transparency: number0): number Static	Compute the 0xTTBBGGRR color corresponding to the specified hue, saturation, lightness values.
computeTbgrFromString(val: string): number Static	Compute the 0xTTBBGGRR value corresponding to a string representation of a color.
create(val?: string | number): ColorDef Static	Create a new ColorDef.
from(red: number, green: number, blue: number, transparency?: number): ColorDef Static	Create a ColorDef from Red, Green, Blue, Transparency values.
fromAbgr(abgr: number): ColorDef Static	Create a ColorDef from its 0xAABBGGRR representation.
fromHSL(h: number, s: number, l: number, transparency: number0): ColorDef Static	Create a ColorDef from hue, saturation, lightness values
fromHSV(hsv: HSVColor, transparency: number0): ColorDef Static	Create a ColorDef from an HSVColor
fromJSON(json?: number): ColorDef Static	Create a new ColorDef from a json object.
fromString(val: string): ColorDef Static	Create a ColorDef from a string representation.
fromTbgr(tbgr: number): ColorDef Static	Create a ColorDef from its 0xTTBBGGRR representation.
getAbgr(tbgr: number): number Static	Get the value of a 0xTTBBGGRR color as a number in 0xAABBGGRR format (i.e.
getAlpha(tbgr: number): number Static	Extract the alpha value from a 0xTTBBGGRR color.
getColors(tbgr: number): { b: number, g: number, r: number, t: number } Static	Get the r,g,b,t values encoded in an 0xTTBBGGRR value.
getName(tbgr: number): undefined | string Static	Obtain the name of the color in the ColorByName list associated with the specified 0xTTBBGGRR value, or undefined if no such named color exists.
getRgb(tbgr: number): number Static	Get the RGB value of the 0xTTBBGGRR color as a number in 0xRRGGBB format (i.e blue is in the low byte).
getTransparency(tbgr: number): number Static	Extract the transparency component from a 0xTTBBGGRR color as an integer between 0-255..
inverse(tbgr: number): number Static	Return a 0xTTBBGGRR color whose color components are the inverse of the input color.
isOpaque(tbgr: number): boolean Static	True if the specified 0xTTBBGGRR color is fully opaque.
isValidColor(val: string | number): boolean Static	Determine whether the input is a valid representation of a ColorDef.
lerp(tbgr1: number, tbgr2: number, weight: number): number Static	Interpolate between two 0xTTBBGGRR colors using a weighting factor.
toHexString(tbgr: number): string Static	Convert the 0xTTBBGGRR value to a string in the form "#rrggbb".
toRgbaString(tbgr: number): string Static	Convert the 0xTTBBGGRR color to a string of the form "rgba(r,g,b,a)" where the color components are specified in decimal and the alpha component is a fraction.
toRgbString(tbgr: number): string Static	Convert the 0xTTBBGGRR color to a string in the form "rgb(r,g,b)" where each component is specified in decimal.
tryComputeTbgrFromString(val: string): undefined | number Static	Try to compute the 0xTTBBGGRR value corresponding to a string representation of a ColorDef.
withAlpha(tbgr: number, alpha: number): number Static	Return a color equivalent to the specified 0xTTBBGGRR but with modified alpha component.
withTransparency(tbgr: number, transparency: number): number Static	Compute the 0xTTBBGGRR value of the specified color and transparency.

Properties

Name	Type	Description
black Static Readonly	ColorDef	pure black
blue Static Readonly	ColorDef	pure blue
colors Accessor ReadOnly	{ b: number, g: number, r: number, t: number }	Get the red, green, blue, and transparency values from this ColorDef.
green Static Readonly	ColorDef	pure green
isOpaque Accessor ReadOnly	boolean	True if this ColorDef is fully opaque.
name Accessor ReadOnly	undefined | string	The "known name" for this ColorDef.
red Static Readonly	ColorDef	pure red
tbgr Accessor ReadOnly	number	The color value of this ColorDef as an integer in the form 0xTTBBGGRR (red in the low byte)
white Static Readonly	ColorDef	pure white

Defined in

• core/common/src/ColorDef.ts Line 50