SemanticsOwner class

Owns SemanticsNode objects and notifies listeners of changes to the render tree semantics.

To listen for semantic updates, call SemanticsBinding.ensureSemantics or PipelineOwner.ensureSemantics to obtain a SemanticsHandle. This will create a SemanticsOwner if necessary.

Inheritance

Constructors

SemanticsOwner({required SemanticsUpdateCallback onSemanticsUpdate})
Creates a SemanticsOwner that manages zero or more SemanticsNode objects.

Properties

hashCode → int
The hash code for this object.
no setterinherited
hasListeners → bool
Whether any listeners are currently registered.
no setterinherited
onSemanticsUpdate → SemanticsUpdateCallback
The onSemanticsUpdate callback is expected to dispatch SemanticsUpdates to the FlutterView that is associated with this PipelineOwner and/or SemanticsOwner.
final
rootSemanticsNode → SemanticsNode?
The root node of the semantics tree, if any.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

addListener(VoidCallback listener) → void
Register a closure to be called when the object changes.
inherited
dispose() → void
Discards any resources used by the object.
override
getSemanticsNode(int id) → SemanticsNode?
Returns the SemanticsNode with the given id, if any.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notifyListeners() → void
Call all the registered listeners.
inherited
performAction(int id, SemanticsAction action, [Object? args]) → void
Asks the SemanticsNode with the given id to perform the given action.
performActionAt(Offset position, SemanticsAction action, [Object? args]) → void
Asks the SemanticsNode at the given position to perform the given action.
removeListener(VoidCallback listener) → void
Remove a previously registered closure from the list of closures that are notified when the object changes.
inherited
sendSemanticsUpdate() → void
Update the semantics using onSemanticsUpdate.
toString() → String
A string representation of this object.
override

Operators

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