ContrastRule class

Flags Text widgets whose resolved color has insufficient contrast against the nearest solid background behind them.

Background is detected by walking up from the text's element to the first ancestor widget that paints an opaque color — ColoredBox, Container, DecoratedBox (with a BoxDecoration color), Material, or Scaffold. If none is found, the widget is skipped rather than guessed at, to avoid false positives.

Inheritance

• Object
• A11yRule
• ContrastRule

Constructors

ContrastRule({A11yContrastLevel level = A11yContrastLevel.aa, double? minimumRatio})

minimumRatio, if set, overrides the WCAG-derived threshold for every text size — the hook for teams enforcing a brand contrast minimum stricter than WCAG.

const

Properties

description → String

Short human-readable description of what this rule checks.

no setter, override

hashCode → int

The hash code for this object.

no setter, inherited

id → String

Stable identifier used in A11yViolation.ruleId and reports.

no setter, override

level → A11yContrastLevel

final

minimumRatio → double?

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

check(List<A11yElementInfo> elements) → List<A11yViolation>

Inspects elements — a snapshot of the tree captured by the ElementTreeWalker — and returns any violations found.

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