import 'package:flutter/material.dart';

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

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String selectedValue = "1";

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              Column(
                spacing: 16.0,
                mainAxisSize: MainAxisSize.min,
                children: [
                  const Text("DropdownMenuCloseBehavior.none"),
                  MenuAnchor(
                    menuChildren: <Widget>[
                      Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: DropdownMenu(
                          closeBehavior: DropdownMenuCloseBehavior.none,
                          label: const Text('Menu'),
                          initialSelection: selectedValue,
                          onSelected: (String? value) {
                            if (value != null) {
                              setState(() {
                                selectedValue = value;
                              });
                            }
                          },
                          dropdownMenuEntries: ["1", "2", "3"]
                              .map(
                                (it) => DropdownMenuEntry(
                                  value: it,
                                  label: it,
                                ),
                              )
                              .toList(),
                        ),
                      )
                    ],
                    child: const Text('Open Menu'),
                    builder: (context, controller, child) {
                      return ElevatedButton(
                        onPressed: () {
                          controller.open();
                        },
                        child: child,
                      );
                    },
                  ),
                ],
              ),
              Column(
                spacing: 16.0,
                mainAxisSize: MainAxisSize.min,
                children: [
                  const Text("DropdownMenuCloseBehavior.self"),
                  MenuAnchor(
                    menuChildren: <Widget>[
                      Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: DropdownMenu(
                          closeBehavior: DropdownMenuCloseBehavior.self,
                          label: const Text('Menu'),
                          initialSelection: selectedValue,
                          onSelected: (String? value) {
                            if (value != null) {
                              setState(() {
                                selectedValue = value;
                              });
                            }
                          },
                          dropdownMenuEntries: ["1", "2", "3"]
                              .map(
                                (it) => DropdownMenuEntry(
                                  value: it,
                                  label: it,
                                ),
                              )
                              .toList(),
                        ),
                      )
                    ],
                    child: const Text('Open Menu'),
                    builder: (context, controller, child) {
                      return ElevatedButton(
                        onPressed: () {
                          controller.open();
                        },
                        child: child,
                      );
                    },
                  ),
                ],
              ),
              Column(
                spacing: 16.0,
                mainAxisSize: MainAxisSize.min,
                children: [
                  const Text("DropdownMenuCloseBehavior.all"),
                  MenuAnchor(
                    menuChildren: <Widget>[
                      Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: DropdownMenu(
                          closeBehavior: DropdownMenuCloseBehavior.all,
                          label: const Text('Menu'),
                          initialSelection: selectedValue,
                          onSelected: (String? value) {
                            if (value != null) {
                              setState(() {
                                selectedValue = value;
                              });
                            }
                          },
                          dropdownMenuEntries: ["1", "2", "3"]
                              .map(
                                (it) => DropdownMenuEntry(
                                  value: it,
                                  label: it,
                                ),
                              )
                              .toList(),
                        ),
                      )
                    ],
                    child: const Text('Open Menu'),
                    builder: (context, controller, child) {
                      return ElevatedButton(
                        onPressed: () {
                          controller.open();
                        },
                        child: child,
                      );
                    },
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}