Semantics class Null safety

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:

Inheritance
Annotations

Constructors

Semantics({Key? key, 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. [...]
Semantics.fromProperties({Key? key, Widget? child, bool container = false, bool explicitChildNodes = false, bool excludeSemantics = false, required SemanticsProperties properties})
Creates a semantic annotation using SemanticsProperties. [...]
const

Properties

child Widget?
The widget below this widget in the tree. [...]
final, inherited
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. [...]
@nonVirtual, read-only, inherited
key Key?
Controls how one widget replaces another widget in the tree. [...]
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.
read-only, inherited

Methods

createElement() SingleChildRenderObjectElement
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
inherited
createRenderObject(BuildContext context) RenderSemanticsAnnotations
Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget. [...]
override
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
override
didUnmountRenderObject(covariant RenderObject renderObject) → void
A render object previously associated with this widget has been removed from the tree. The given RenderObject will be of the same type as returned by this object's createRenderObject.
@protected, inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent 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}) 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
updateRenderObject(BuildContext context, covariant RenderSemanticsAnnotations renderObject) → void
Copies the configuration described by this RenderObjectWidget to the given RenderObject, which will be of the same type as returned by this object's createRenderObject. [...]
override

Operators

operator ==(Object other) bool
The equality operator. [...]
@nonVirtual, inherited