Better Structure

readme.md

Better Structure

Created with <3 with dartpad.dev.

better_structure.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({
    Key? key,
    required this.title,
  }) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final counterGreenNotifier = ValueNotifier<int>(0);
  final counterRedNotifier = ValueNotifier<int>(0);

  void _incrementCounterGreen() {
    counterGreenNotifier.value += 1;
  }

  void _incrementCounterRed() {
    counterRedNotifier.value += 1;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'You have pushed the Green button this many times:',
            ),
            ValueListenableBuilder(
              valueListenable: counterGreenNotifier,
              builder: (context, counterGreen, child) {
                return Text(
                  '$counterGreen',
                  style: Theme.of(context)
                      .textTheme
                      .headlineMedium!
                      .copyWith(color: Colors.green),
                );
              },
            ),
            const Text(
              'You have pushed the Red button this many times:',
            ),
            ValueListenableBuilder(
              valueListenable: counterRedNotifier,
              builder: (context, counterRed, child) {
                return Text(
                  '$counterRed',
                  style: Theme.of(context)
                      .textTheme
                      .headlineMedium!
                      .copyWith(color: Colors.red),
                );
              },
            ),
          ],
        ),
      ),
      floatingActionButton: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          FloatingActionButton(
            onPressed: _incrementCounterGreen,
            tooltip: 'Increment Green',
            backgroundColor: Colors.green,
            child: const Icon(Icons.add),
          ),
          FloatingActionButton(
            onPressed: _incrementCounterRed,
            tooltip: 'Increment Red',
            backgroundColor: Colors.red,
            child: const Icon(Icons.add),
          ),
        ],
      ),
    );
  }
}

main.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({
    Key? key,
    required this.title,
  }) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final counterGreenNotifier = ValueNotifier<int>(0);
  final counterRedNotifier = ValueNotifier<int>(0);

  void _incrementCounterGreen() {
    counterGreenNotifier.value += 1;
  }

  void _incrementCounterRed() {
    counterRedNotifier.value += 1;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'You have pushed the Green button this many times:',
            ),
            ValueListenableBuilder(
              valueListenable: counterGreenNotifier,
              builder: (context, counterGreen, child) {
                return Text(
                  '$counterGreen',
                  style: Theme.of(context)
                      .textTheme
                      .headlineMedium!
                      .copyWith(color: Colors.green),
                );
              },
            ),
            const Text(
              'You have pushed the Red button this many times:',
            ),
            ValueListenableBuilder(
              valueListenable: counterRedNotifier,
              builder: (context, counterRed, child) {
                return Text(
                  '$counterRed',
                  style: Theme.of(context)
                      .textTheme
                      .headlineMedium!
                      .copyWith(color: Colors.red),
                );
              },
            ),
          ],
        ),
      ),
      floatingActionButton: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          FloatingActionButton(
            onPressed: _incrementCounterGreen,
            tooltip: 'Increment Green',
            backgroundColor: Colors.green,
            child: const Icon(Icons.add),
          ),
          FloatingActionButton(
            onPressed: _incrementCounterRed,
            tooltip: 'Increment Red',
            backgroundColor: Colors.red,
            child: const Icon(Icons.add),
          ),
        ],
      ),
    );
  }
}