import 'package:flutter/material.dart';

enum Fruits { mango, apple, banana, straberry }

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key, this.dark = true}) : super(key: key);

  final bool dark;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Material App',
      theme: dark ? ThemeData.dark() : ThemeData.light(),
      home: const PopupMenuButtonSample(),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text(' PopupMenuButton Sample'),
        actions: <Widget>[
          PopupMenuButton<Fruits>(
            position: MenuPosition.under,
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(8),
            ),
            onSelected: (Fruits result) {
              print('selected fruit: ${result.name}');
            },
            onCanceled: () {
              print('onCanceled');
            },
            color: Colors.red[700],
            itemBuilder: (BuildContext context) => <PopupMenuEntry<Fruits>>[
              const PopupMenuItem<Fruits>(
                value: Fruits.mango,
                child: Text('Mango'),
              ),
              const PopupMenuItem<Fruits>(
                value: Fruits.apple,
                child: Text('Apple'),
              ),
              const PopupMenuItem<Fruits>(
                value: Fruits.banana,
                child: Text('Banana'),
              ),
              const PopupMenuItem<Fruits>(
                value: Fruits.straberry,
                child: Text('Strawberry'),
              ),
            ],
          )
        ],
      ),
      body: Center(
        child: Stack(
          children: [
            Positioned(
              bottom: 25,
              right: 10,
              child: PopupMenuButton<Fruits>(
                position: MenuPosition.under,
                icon: const Icon(Icons.apple),
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(8),
                ),
                onSelected: (Fruits result) {
                  print('selected fruit: ${result.name}');
                },
                onCanceled: () {
                  print('onCanceled');
                },
                color: Colors.red[700],
                itemBuilder: (BuildContext context) => <PopupMenuEntry<Fruits>>[
                  const PopupMenuItem<Fruits>(
                    value: Fruits.mango,
                    child: Text('Mango'),
                  ),
                  const PopupMenuItem<Fruits>(
                    value: Fruits.apple,
                    child: Text('Apple'),
                  ),
                  const PopupMenuItem<Fruits>(
                    value: Fruits.banana,
                    child: Text('Banana'),
                  ),
                  const PopupMenuItem<Fruits>(
                    value: Fruits.straberry,
                    child: Text('Strawberry'),
                  ),
                ],
              ),
            ),
            Positioned.fill(
              child: Center(
                child: PopupMenuButton<Fruits>(
                  position: MenuPosition.under,
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(8),
                  ),
                  onSelected: (Fruits result) {
                    print('selected fruit: ${result.name}');
                  },
                  onCanceled: () {
                    print('onCanceled');
                  },
                  color: Colors.red[700],
                  itemBuilder: (BuildContext context) =>
                      <PopupMenuEntry<Fruits>>[
                    const PopupMenuItem<Fruits>(
                      value: Fruits.mango,
                      child: Text('Mango'),
                    ),
                    const PopupMenuItem<Fruits>(
                      value: Fruits.apple,
                      child: Text('Apple'),
                    ),
                    const PopupMenuItem<Fruits>(
                      value: Fruits.banana,
                      child: Text('Banana'),
                    ),
                    const PopupMenuItem<Fruits>(
                      value: Fruits.straberry,
                      child: Text('Strawberry'),
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}