ColorContrast class abstract final

WCAG 2.x color math: relative luminance and contrast ratio.

See https://www.w3.org/TR/WCAG21/#dfn-relative-luminance and https://www.w3.org/TR/WCAG21/#dfn-contrast-ratio.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

compositeOver(Color foreground, Color background) → Color

Alpha-composites foreground over an opaque background, returning the resulting opaque color. Returns foreground unchanged if it is already opaque.

contrastRatio(Color a, Color b) → double

The WCAG contrast ratio between a and b, in the range [1, 21]. Order of arguments does not matter.

relativeLuminance(Color color) → double

The relative luminance of color, in the range [0, 1].

Constants

aaaLargeText → const double

WCAG AAA minimum contrast ratio for large-scale text.

aaaNormalText → const double

WCAG AAA minimum contrast ratio for normal-size text.

aaLargeText → const double

WCAG AA minimum contrast ratio for large-scale text (>=18pt, or

aaNormalText → const double

WCAG AA minimum contrast ratio for normal-size text.