SemanticsModifier class

A widget that annotates the widget tree with a description of the meaning of the widgets.

Used by accessibility tools, search engines, and other semantic analysis software to determine the meaning of the application.

See also:

• MergeSemantics, which marks a subtree as being a single node for accessibility purposes.
• ExcludeSemantics, which excludes a subtree from the semantics tree (which might be useful if it is, e.g., totally decorative and not important to the user).
• RenderObject.describeSemanticsConfiguration, the rendering library API through which the Semantics widget is actually implemented.
• SemanticsNode, the object used by the rendering library to represent semantics in the semantics tree.
• SemanticsDebugger, an overlay to help visualize the semantics tree. Can be enabled using WidgetsApp.showSemanticsDebugger or MaterialApp.showSemanticsDebugger.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• SingleChildStatelessModifier
• SemanticsModifier

Available extensions

• ModifierTransformer

Annotations

• @immutable

Constructors

SemanticsModifier({Key? key, Key? modifierKey, Widget? child, bool container = false, bool explicitChildNodes = false, bool excludeSemantics = false, bool? enabled, bool? checked, bool? selected, bool? toggled, bool? button, bool? slider, bool? keyboardKey, bool? link, bool? header, bool? textField, bool? readOnly, bool? focusable, bool? focused, bool? inMutuallyExclusiveGroup, bool? obscured, bool? multiline, bool? scopesRoute, bool? namesRoute, bool? hidden, bool? image, bool? liveRegion, int? maxValueLength, int? currentValueLength, String? label, AttributedString? attributedLabel, String? value, AttributedString? attributedValue, String? increasedValue, AttributedString? attributedIncreasedValue, String? decreasedValue, AttributedString? attributedDecreasedValue, String? hint, AttributedString? attributedHint, String? onTapHint, String? onLongPressHint, TextDirection? textDirection, SemanticsSortKey? sortKey, SemanticsTag? tagForChildren, VoidCallback? onTap, VoidCallback? onLongPress, VoidCallback? onScrollLeft, VoidCallback? onScrollRight, VoidCallback? onScrollUp, VoidCallback? onScrollDown, VoidCallback? onIncrease, VoidCallback? onDecrease, VoidCallback? onCopy, VoidCallback? onCut, VoidCallback? onPaste, VoidCallback? onDismiss, MoveCursorHandler? onMoveCursorForwardByCharacter, MoveCursorHandler? onMoveCursorBackwardByCharacter, SetSelectionHandler? onSetSelection, SetTextHandler? onSetText, VoidCallback? onDidGainAccessibilityFocus, VoidCallback? onDidLoseAccessibilityFocus, Map<CustomSemanticsAction, VoidCallback>? customSemanticsActions})

Creates a semantic annotation.

SemanticsModifier.fromProperties({Key? key, Widget? child, Key? modifierKey, bool container = false, bool explicitChildNodes = false, bool excludeSemantics = false, required SemanticsProperties properties})

Creates a semantic annotation using SemanticsProperties.

const

Properties

container → bool

If container is true, this widget will introduce a new node in the semantics tree. Otherwise, the semantics will be merged with the semantics of any ancestors (if the ancestor allows that).

final

excludeSemantics → bool

Whether to replace all child semantics with this node.

final

explicitChildNodes → bool

Whether descendants of this widget are allowed to add semantic information to the SemanticsNode annotated by this widget.

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

modifierKey → Key?

The actual key of the widget, which Modifier wrapped

final, inherited

properties → SemanticsProperties

Contains properties used by assistive technologies to make the application more accessible.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

build(BuildContext context) → Widget

Describes the part of the user interface represented by this widget.

inherited

buildWithChild(BuildContext context, Widget? child) → Widget

A build method that receives an extra child parameter.

override

createElement() → SingleChildStatelessElement

Create a SingleChildStatelessElement

inherited

debugDescribeChildren() → List<DiagnosticsNode>

Returns a list of DiagnosticsNode objects describing this node's children.

inherited

debugFillProperties(DiagnosticPropertiesBuilder properties) → void

Add additional properties associated with the node.

inherited

modified() → Modifier

Available on Widget, provided by the ModifierTransformer extension

Transform normal widget to Modifier

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode

Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.

inherited

toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String

A string representation of this object.

inherited

toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String

Returns a string representation of this node and its descendants.

inherited

toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String

Returns a one-line detailed description of the object.

inherited

toStringShort() → String

A short, textual description of this widget.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited