ContrastRule class

Flags text whose contrast against its background is below the WCAG minimum.

Reads the samples gathered by the raster collector; a pure-Dart snapshot has none and the rule yields nothing. Normal text needs a ratio of at least 4.5:1 and large text at least 3:1. Disabled controls are exempt (WCAG 1.4.3 excludes them), and ratios just below the threshold are downgraded to a warning because pixel sampling over gradients and images is false-positive prone.

Implemented types

• Rule

Constructors

ContrastRule()

Creates a ContrastRule.

const

Properties

confidence → Confidence

How much to trust this rule's findings.

no setter, override

criterion → Criterion

The standard clause this rule enforces.

no setter, override

defaultSeverity → Severity

The severity findings get unless configuration overrides it.

no setter, override

hashCode → int

The hash code for this object.

no setter, inherited

id → String

The stable rule id, e.g. attest/interactive-name.

no setter, override

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

evaluate(SemanticsSnapshot snapshot, RuleContext context) → Iterable<Finding>

Inspects snapshot and yields zero or more findings.

override

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