cancelIf method
Register whetherToCancel
to later decide whether to cancel. It is
expected that whatever async processing required to determine whether to
cancel the action is started by the action receiver. The resolved value
will only be looked at once the action broadcaster has attempted to
execute.
If whetherToContinue
returns true, the action will be cancelled.
Implementation
@override
void cancelIf(Future<bool> whetherToCancel) =>
delegate.cancelIf(whetherToCancel);