import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      theme: ThemeData(
        popupMenuTheme: const PopupMenuThemeData(
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.all(
              Radius.circular(40),
            ),
          ),
        ),
      ),
      home: Scaffold(
        body: Center(
          child: PopupMenuButton(
            itemBuilder: (BuildContext context) {
              return [PopupMenuItem(child: Text('Some action'))];
            },
          ),
        ),
      ),
    );
  }
}