showCupertinoProgressDialog<T> function

Future<ProgressDialogResult<T>> showCupertinoProgressDialog<T>({ required BuildContext context, required Task<T> future, WidgetBuilder? builder, Offset? anchorPoint, String? barrierLabel, bool useRootNavigator = true, Color? barrierColor, bool? requestFocus, })

Shows a Cupertino-styled progress dialog while executing an asynchronous task.

Displays a modal progress dialog with iOS-style appearance that remains visible until future completes.

Parameters:

• context - The build context used to show the dialog
• future - The async task to execute while showing the progress dialog
• builder - Optional custom widget builder for the progress dialog UI
• useRootNavigator - Whether to show dialog above all screens, defaults to true
• anchorPoint - Optional anchor point for the dialog position
• barrierLabel - Semantic label used for the modal barrier
• barrierColor - Color of the modal barrier behind the dialog
• requestFocus - Whether the dialog should request focus when opened

Returns a ProgressDialogResult: Success with the value, Failure with the error details if the future fails, or Cancelled if the dialog is dismissed before the task delivers a result — for example by the Android back button, or by a custom builder that calls Navigator.pop. The task itself is not interrupted in that case; it runs to completion and its result is discarded.

Example:

final result = await showCupertinoProgressDialog(
  context: context,
  future: () => myAsyncTask(),
);

switch (result) {
  case Success(value: final value):
    print('Task completed successfully: $value');
    break;
  case Failure(error: final error):
    print('Task failed: $error');
    break;
  case Cancelled():
    print('Dialog dismissed before the task finished');
    break;
}

Implementation

Future<ProgressDialogResult<T>> showCupertinoProgressDialog<T>({
  required c.BuildContext context,
  required Task<T> future,
  c.WidgetBuilder? builder,
  c.Offset? anchorPoint,
  String? barrierLabel,
  bool useRootNavigator = true,
  c.Color? barrierColor,
  bool? requestFocus,
}) async {
  final navigator = c.Navigator.of(context, rootNavigator: useRootNavigator);

  late final c.CupertinoDialogRoute<ProgressDialogResult<T>> route;
  final outcome = _Outcome<T>();

  route = c.CupertinoDialogRoute<ProgressDialogResult<T>>(
    builder: (context) => ExactlyOnce(
      callback: () => _callback(navigator, future, route, outcome.settle),
      onDispose: () => outcome.settle(Cancelled<T>()),
      child: builder?.call(context) ?? const CupertinoProgressBarDialog(),
    ),
    context: context,
    barrierDismissible: false,
    barrierLabel: barrierLabel,
    barrierColor: barrierColor,
    anchorPoint: anchorPoint,
    requestFocus: requestFocus,
  );
  return outcome.track(navigator, route);
}