IndexedSemantics class Null safety

A widget that annotates the child semantics with an index.

Semantic indexes are used by TalkBack/Voiceover to make announcements about the current scroll state. Certain widgets like the ListView will automatically provide a child index for building semantics. A user may wish to manually provide semantic indexes if not all child of the scrollable contribute semantics.

The example below handles spacers in a scrollable that don't contribute semantics. The automatic indexes would give the spaces a semantic index, causing scroll announcements to erroneously state that there are four items visible.
  addSemanticIndexes: false,
  semanticChildCount: 2,
  children: const <Widget>[
    IndexedSemantics(index: 0, child: Text('First')),
    IndexedSemantics(index: 1, child: Text('Second')),

See also:



IndexedSemantics({Key? key, required int index, Widget? child})
Creates a widget that annotated the first child semantics node with an index.


child Widget?
The widget below this widget in the tree.
final, inherited
hashCode int
The hash code for this object.
@nonVirtual, read-only, inherited
index int
The index used to annotate the first child semantics node.
key Key?
Controls how one widget replaces another widget in the tree.
final, inherited
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) RenderIndexedSemantics
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
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 RenderIndexedSemantics 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