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
-
- Object
- ChangeNotifier
- SemanticsOwner
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. 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 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