add method
Notifies the Bloc of a new event
If close has already been called, any subsequent calls to add will
be ignored and will not result in any subsequent state changes.
Implementation
@override
void add(Event event) {
if (_eventController.isClosed) return;
try {
onEvent(event);
_eventController.add(event);
} catch (error, stackTrace) {
onError(error, stackTrace);
}
}