Semantics class

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

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

See also:



Semantics({Key? key, Widget? child, bool container = false, bool explicitChildNodes = false, bool excludeSemantics = false, bool blockUserActions = false, bool? enabled, bool? checked, bool? mixed, 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, bool? expanded, int? maxValueLength, int? currentValueLength, String? identifier, String? label, AttributedString? attributedLabel, String? value, AttributedString? attributedValue, String? increasedValue, AttributedString? attributedIncreasedValue, String? decreasedValue, AttributedString? attributedDecreasedValue, String? hint, AttributedString? attributedHint, String? tooltip, 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, bool blockUserActions = false, required SemanticsProperties properties})
Creates a semantic annotation using SemanticsProperties.


blockUserActions bool
Whether to block user interactions for the rendering subtree.
child Widget?
The widget below this widget in the tree.
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).
excludeSemantics bool
Whether to replace all child semantics with this node.
explicitChildNodes bool
Whether descendants of this widget are allowed to add semantic information to the SemanticsNode annotated by this widget.
hashCode int
The hash code for this object.
no setterinherited
key Key?
Controls how one widget replaces another widget in the tree.
properties SemanticsProperties
Contains properties used by assistive technologies to make the application more accessible.
runtimeType Type
A representation of the runtime type of the object.
no setterinherited


createElement() SingleChildRenderObjectElement
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
createRenderObject(BuildContext context) RenderSemanticsAnnotations
Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
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.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toString({DiagnosticLevel minLevel =}) String
A string representation of this object.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A short, textual description of this widget.
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.


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