enum_widget.dart

enum_widget.dart

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,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatefulWidget {
  const MyWidget({Key? key}) : super(key: key);

  @override
  State<MyWidget> createState() => MyState();
}

enum EnumWidget {
  one(
    title: 'one',
    description: 'one is the first item',
    color: Colors.amber,
  ),
  two(
    title: 'two',
    description: 'two is the second item',
    color: Colors.cyan,
  ),
  three(
    title: 'three',
    description: 'three is the third item',
    color: Colors.lime,
  );

  const EnumWidget({
    required this.title,
    required this.description,
    required this.color,
  });

  final String title;
  final String description;
  final Color color;

  Widget build(BuildContext context) {
    return ColoredBox(
      key: ValueKey(this),
      color: color,
      child: Column(children: [
        Text(title, style: const TextStyle(fontSize: 16.0)),
        Text(description),
      ]),
    );
  }
}

class MyState extends State<MyWidget> {
  EnumWidget value = EnumWidget.one;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        DropdownButton<EnumWidget>(
          value: value,
          icon: const Icon(Icons.arrow_downward),
          underline: Container(
            height: 2,
            color: Colors.deepPurpleAccent,
          ),
          onChanged: (EnumWidget? newValue) {
            setState(() {
              value = newValue!;
            });
          },
          items: EnumWidget.values.map((EnumWidget value) {
            return DropdownMenuItem<EnumWidget>(
              value: value,
              child: Text(value.name),
            );
          }).toList(),
        ),
        const Text('Content:'),
        value.build(context),
      ],
    );
  }
}