SpinnerScheduler typedef
SpinnerScheduler =
void Function() Function(Duration period, void onTick())
Schedules onTick to be called every period, returning a callback that
cancels the scheduled ticking.
Exposed primarily so tests can drive the spinner animation deterministically instead of relying on a real periodic timer.
Implementation
typedef SpinnerScheduler =
void Function() Function(Duration period, void Function() onTick);