MinimumTextContrastGuideline class Null safety

A guideline which verifies that all nodes that contribute semantics via text meet minimum contrast levels.

The guidelines are defined by the Web Content Accessibility Guidelines, http://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html.

See also:

Inheritance
Annotations

Constructors

MinimumTextContrastGuideline()
Create a new MinimumTextContrastGuideline.
const

Properties

description → String
A description of the policy restrictions and criteria.
read-onlyoverride
hashCode → int
The hash code for this object.
read-onlyinherited
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited

Methods

evaluate(WidgetTester tester) → Future<Evaluation>
Evaluate whether the current state of the tester conforms to the rule.
override
isNodeOffScreen(Rect paintBounds, FlutterView window) → bool
Returns if a rectangle of node is off the screen.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
shouldSkipNode(SemanticsData data) → bool
Returns whether node should be skipped.
targetContrastRatio(double? fontSize, {required bool bold}) → double
Returns the required contrast ratio for the fontSize and bold setting.
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Constants

kBoldTextMinimumSize → const int
The minimum text size for bold text to be considered large for contrast checking.
14
kLargeTextMinimumSize → const int
The minimum text size considered large for contrast checking.
18
kMinimumRatioLargeText → const double
The minimum contrast ratio for large text.
3.0
kMinimumRatioNormalText → const double
The minimum contrast ratio for normal text.
4.5