simple_mvvm 1.0.0

A bold and balanced state management library that pairs MVVM structures with the simplicity of InheritedWidget.

example/lib/main.dart

import 'package:simple_mvvm/simple_mvvm.dart';
import 'package:example/two.dart';
import 'package:flutter/material.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Simple MVVM',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const HomeView(),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return HomeViewModelBuilder(
      builder: (context, model) {
        return Scaffold(
          appBar: AppBar(
            title: Text(model.title),
          ),
          body: Stack(
            children: [
              Center(
                child: Padding(
                  padding: const EdgeInsets.all(24.0),
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      ValueListenableBuilder(
                          valueListenable: model.counter,
                          builder: (context, value, child) => Row(
                                children: [
                                  const Text('ValueListenableBuilder: '),
                                  const SizedBox(width: 8),
                                  Text(value.toString()),
                                ],
                              )),
                      const SeparatedCounter(),
                      const ModelWidgetCounter(),
                      const SizedBox(height: 16),
                      ElevatedButton(
                        onPressed: model.isLoading
                            ? () {}
                            : () async {
                                HomeViewModel().of(context).incrementCounterWithSetState();
                                model.setLoading(false);
                              },
                        child: const Text('Increment using setState'),
                      ),
                      ElevatedButton(
                        onPressed: model.isLoading
                            ? () {}
                            : () {
                                model.incrementCounterWithValueNotifier();
                              },
                        child: const Text('Increment using ValueNotifier'),
                      )
                    ],
                  ),
                ),
              ),
              if (model.isLoading) const ColoredBox(color: Colors.black12, child: Center(child: CircularProgressIndicator()))
            ],
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: () {
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => const ScreenTwoView(),
                ),
              );
            },
            child: const Icon(Icons.navigate_next),
          ),
        );
      },
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        const Text('SeparatedCounter: '),
        const SizedBox(width: 8),
        Text(HomeViewModel().of(context).counter.value.toString()),
      ],
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return ModelWidget<HomeViewModel>(builder: (context, model) {
      return Row(
        children: [
          const Text('ModelWidgetCounter: '),
          const SizedBox(width: 8),
          Text(model.counter.value.toString()),
        ],
      );
    });
  }
}

class HomeViewModelBuilder extends ViewModelBuilder<HomeViewModel> {
  const HomeViewModelBuilder({
    super.key,
    required super.builder,
  });

  @override
  State<StatefulWidget> createState() => HomeViewModel();
}

class HomeViewModel extends ViewModel<HomeViewModel> {
  static HomeViewModel of_(BuildContext context) => getModel<HomeViewModel>(context);

  final String title = 'Home';

  ValueNotifier<int> counter = ValueNotifier(0);

  Future<void> incrementCounterWithSetState() async {
    setState(() {
      counter.value = counter.value + 1;
    });
  }

  void incrementCounterWithValueNotifier() {
    counter.value++;
  }

  @override
  void initState() {
    debugPrint('Initialize');
    super.initState();
  }

  @override
  void dispose() {
    debugPrint('Dispose');
    super.dispose();
  }
}