SemanticsOwner class Null safety

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

To listen for semantic updates, call 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.
read-onlyinherited
hasListeners bool
Whether any listeners are currently registered.
read-onlyinherited
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.
read-only
runtimeType Type
A representation of the runtime type of the object.
read-onlyinherited

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. After this is called, the object is not in a usable state and should be discarded (calls to addListener will throw after the object is disposed).
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent 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