addListener method
Register a closure to be called when the object notifies its listeners.
Implementation
@override
VoidCallback addListener(VoidCallback listener) {
_listeners.add(listener);
return () => _listeners.remove(listener);
}
Register a closure to be called when the object notifies its listeners.
@override
VoidCallback addListener(VoidCallback listener) {
_listeners.add(listener);
return () => _listeners.remove(listener);
}