show method
Implementation
Future<void> show(bool animation) {
if (isPersistentCallbacks) {
final Completer<Future> completer = Completer<Future>();
SchedulerBinding.instance.addPostFrameCallback((_) => completer
.complete(_animationController.forward(from: animation ? 0 : 1)));
return completer.future;
} else {
return _animationController.forward(from: animation ? 0 : 1);
}
}