showOkCancelAlertDialog function Null safety

Future<OkCancelResult> showOkCancelAlertDialog(
  1. {required BuildContext context,
  2. String? title,
  3. String? message,
  4. String? okLabel,
  5. String? cancelLabel,
  6. OkCancelAlertDefaultType? defaultType,
  7. bool isDestructiveAction = false,
  8. bool barrierDismissible = true,
  9. AdaptiveStyle alertStyle = AdaptiveStyle.adaptive,
  10. bool useActionSheetForCupertino = false,
  11. bool useRootNavigator = true,
  12. VerticalDirection actionsOverflowDirection = VerticalDirection.up,
  13. bool fullyCapitalizedForMaterial = true}

Show OK/Cancel alert dialog, whose appearance is adaptive according to platform

This is convenient wrapper of showAlertDialog. barrierDismissible (default: true) only works for material style, and if it is set to false, pressing OK or Cancel buttons is only way to close alert. defaultType only works for cupertino style and if it is specified OK or Cancel button label will be changed to bold. actionsOverflowDirection works only for Material style currently.


Future<OkCancelResult> showOkCancelAlertDialog({
  required BuildContext context,
  String? title,
  String? message,
  String? okLabel,
  String? cancelLabel,
  OkCancelAlertDefaultType? defaultType,
  bool isDestructiveAction = false,
  bool barrierDismissible = true,
  AdaptiveStyle alertStyle = AdaptiveStyle.adaptive,
  bool useActionSheetForCupertino = false,
  bool useRootNavigator = true,
  VerticalDirection actionsOverflowDirection = VerticalDirection.up,
  bool fullyCapitalizedForMaterial = true,
}) async {
  final isCupertinoStyle = Theme.of(context).isCupertinoStyle;
  String defaultCancelLabel() {
    final label = MaterialLocalizations.of(context).cancelButtonLabel;
    return isCupertinoStyle ? label.capitalizedForce : label;

  final result = await showAlertDialog<OkCancelResult>(
    context: context,
    title: title,
    message: message,
    barrierDismissible: barrierDismissible,
    style: alertStyle,
    useActionSheetForCupertino: useActionSheetForCupertino,
    useRootNavigator: useRootNavigator,
    actionsOverflowDirection: actionsOverflowDirection,
    fullyCapitalizedForMaterial: fullyCapitalizedForMaterial,
    actions: [
        label: cancelLabel ?? defaultCancelLabel(),
        key: OkCancelResult.cancel,
        isDefaultAction: defaultType == OkCancelAlertDefaultType.cancel,
        label: okLabel ?? MaterialLocalizations.of(context).okButtonLabel,
        key: OkCancelResult.ok,
        isDefaultAction: defaultType == OkCancelAlertDefaultType.ok,
        isDestructiveAction: isDestructiveAction,
  return result ?? OkCancelResult.cancel;