Helper function for showing an adaptive alert dialog (Material, Cupertino)

show_alert_dialog.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

/// Helper function for showing an adaptive alert dialog
/// Returns:
/// - true if the default action was selected
/// - false if the cancel action was selected
/// - null if the dialog was dismissed
Future<bool?> showAlertDialog({
  required BuildContext context,
  required String title,
  required String content,
  String? cancelActionText,
  required String defaultActionText,
  bool barrierDismissible = true,
  bool isDestructive = false,
}) {
  return showAdaptiveDialog<bool?>(
    context: context,
    barrierDismissible: barrierDismissible,
    builder:
        (BuildContext context) => AlertDialog.adaptive(
          title: Text(title),
          content: Text(content),
          actions: <Widget>[
            if (cancelActionText != null)
              _adaptiveAction(
                context: context,
                onPressed: () => Navigator.pop(context, false),
                child: Text(cancelActionText),
              ),
            _adaptiveAction(
              context: context,
              isDestructive: isDestructive,
              onPressed: () => Navigator.pop(context, true),
              child: Text(defaultActionText),
            ),
          ],
        ),
  );
}

/// Helper function for showing an adaptive action
/// Returns:
/// - TextButton if the platform is not iOS or macOS
/// - CupertinoDialogAction if the platform is iOS or macOS
Widget _adaptiveAction({
  required BuildContext context,
  required VoidCallback onPressed,
  required Widget child,
  bool isDestructive = false,
}) {
  final platform = Theme.of(context).platform;
  if (platform != TargetPlatform.iOS && platform != TargetPlatform.macOS) {
    return TextButton(onPressed: onPressed, child: child);
  } else {
    return CupertinoDialogAction(
      onPressed: onPressed,
      isDestructiveAction: isDestructive,
      child: child,
    );
  }
}