Semantics 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:

  • @immutable


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 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, String value, String increasedValue, String decreasedValue, String hint, String onTapHint, String onLongPressHint, TextDirection textDirection, SemanticsSortKey sortKey, VoidCallback onTap, VoidCallback onLongPress, VoidCallback onScrollLeft, VoidCallback onScrollRight, VoidCallback onScrollUp, VoidCallback onScrollDown, VoidCallback onIncrease, VoidCallback onDecrease, VoidCallback onCopy, VoidCallback onCut, VoidCallback onPaste, VoidCallback onDismiss, void onMoveCursorForwardByCharacter(bool extendSelection), void onMoveCursorBackwardByCharacter(bool extendSelection), void onSetSelection(TextSelection selection), 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. [...]


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). [...]
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. [...]
@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.
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited


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. [...]
@protected, inherited
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.
@protected, inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent 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
Returns 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. [...]
@nonVirtual, inherited