カテゴリー: ニュース

  flutter_hooks: ^0.17.0
  hooks_riverpod: ^0.14.0+4
  state_notifier: ^0.7.0

import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:gap/gap.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';

final viewModel = StateNotifierProvider((_) => ViewModel());

class ViewModel extends StateNotifier<int> {
  ViewModel() : super(0);
  void increment() => state++;
  void decrement() => state--;
}

void main() {
  runApp(
    ProviderScope(
      child: CounterApp(),
    ),
  );
}

class CounterApp extends HookWidget {
  @override
  Widget build(BuildContext context) {
    final _viewModel = useProvider(viewModel);

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('CounterApp')),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text(
                'You have pushed the button this many times:',
              ),
              Text(
                _viewModel.toString(),
                style: Theme.of(context).textTheme.headline4,
              ),
            ],
          ),
        ),
        floatingActionButton: Column(
          mainAxisAlignment: MainAxisAlignment.end,
          children: [
            FloatingActionButton(
              heroTag: 'increment',
              onPressed: () => context.read(viewModel.notifier).increment(),
              child: Icon(Icons.add),
            ),
            Gap(15),
            FloatingActionButton(
              heroTag: 'decrement',
              onPressed: () => context.read(viewModel.notifier).decrement(),
              child: Icon(Icons.remove_circle_outline),
            ),
          ],
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:gap/gap.dart';

void main() {
  runApp(MyApp());
}

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

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

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    String dropdownValue = 'One';
    return Scaffold(
      backgroundColor: Colors.grey,
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            ClipRRect(
              borderRadius: BorderRadius.all(Radius.circular(30)),
              child: Container(
                width: 200,
                height: 100,
                color: Colors.yellow,
                child: Padding(
                  padding: const EdgeInsets.all(8),
                  child: const TextField(
                    obscureText: true,
                    decoration: InputDecoration(
                      border: InputBorder.none,
                      labelText: 'Pass',
                    ),
                  ),
                ),
              ),
            ),
            Gap(20),
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 5),
              width: 200,
              decoration: BoxDecoration(
                border: Border.all(color: Colors.blue),
                borderRadius: BorderRadius.circular(20),
              ),
              child: const TextField(
                obscureText: true,
                decoration: InputDecoration(
                  border: InputBorder.none,
                  labelText: 'Pass',
                ),
              ),
            ),
            Gap(20),
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 5),
              width: 200,
              decoration: BoxDecoration(
                border: Border.all(color: Colors.blue),
                borderRadius: BorderRadius.circular(20),
              ),
              child: DropdownButton<String>(
                value: dropdownValue,
                icon: const Icon(Icons.arrow_downward),
                iconSize: 24,
                elevation: 16,
                style: const TextStyle(color: Colors.deepPurple),
                onChanged: (String? newValue) {},
                items: <String>['One', 'Two', 'Free', 'Four']
                    .map<DropdownMenuItem<String>>((String value) {
                  return DropdownMenuItem<String>(
                    value: value,
                    child: Text(value),
                  );
                }).toList(),
              ),
            ),
            Gap(20),
            Text(
              'You have pushed the button this many times:',
              style: TextStyle(color: Colors.white),
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(
        key: null,
        child: Scaffold(
          appBar: AppBar(
            title: Text("Inherited Widget Sample"),
          ),
          body: Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                WidgetNumText(),
                WidgetCenterText(
                  key: null,
                ),
              ],
            ),
          ),
          floatingActionButton: WidgetIncrementBtn(),
        ),
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({required Key? key, required this.child}) : super(key: key);

  final Widget child;

  @override
  _MyHomePageState createState() => _MyHomePageState();

  static _MyHomePageState of(BuildContext context, {bool rebuild = true}) {
    return rebuild
        ? (context.dependOnInheritedWidgetOfExactType<_InheritedWidget>()
                as _InheritedWidget)
            .data
        : (context
                .getElementForInheritedWidgetOfExactType<_InheritedWidget>()!
                .widget as _InheritedWidget)
            .data;
  }
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return _InheritedWidget(
      child: widget.child,
      data: this,
    );
  }
}

class WidgetIncrementButton extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final _MyHomePageState state = MyHomePage.of(context, rebuild: false);
    return FloatingActionButton(
      onPressed: () => state._incrementCounter(),
      tooltip: 'Increment',
      child: Icon(Icons.add),
    );
  }
}

class _InheritedWidget extends InheritedWidget {
  _InheritedWidget({
    Key? key,
    required Widget child,
    required this.data,
  }) : super(key: key, child: child);

  final _MyHomePageState data;

  @override
  bool updateShouldNotify(InheritedWidget oldWidget) => true;
}

class WidgetNumText extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final _MyHomePageState state = MyHomePage.of(context);
    return Text(
      '${state._counter}',
      style: Theme.of(context).textTheme.headline4,
    );
  }
}

class WidgetIncrementBtn extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final _MyHomePageState state = MyHomePage.of(context, rebuild: false);
    return FloatingActionButton(
      onPressed: () => state._incrementCounter(),
      tooltip: 'Increment',
      child: Icon(Icons.add),
    );
  }
}

class WidgetCenterText extends StatelessWidget {
  const WidgetCenterText({required Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Text('You have pushed the button this many times:');
  }
}

Google Pixelを有効にするためのコマンド
echo "SUBSYSTEM==\"usb\", ATTRS{idVendor}==\"18d1\", MODE=\"0666\", GROUP=\"plugdev\"" > /tmp/51-android.rules
sudo cp /tmp/51-android.rules /etc/udev/rules.d/51-android.rules

Flutterのインストール
git clone https://github.com/flutter/flutter
sudo mv flutter /usr/local/
sudo apt install clang curl pkg-config ninja-sudo apt install clang curl pkg-config ninja-build cmake libgtk-3-dev libblkid-dev liblzma-dev unzipbuild cmake libgtk-3-dev libblkid-dev liblzma-dev unzip
flutter config --enable-linux-desktop
flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel master, 2.5.0-7.0.pre.182, on Ubuntu 20.04.3 LTS
    5.4.0-83-generic, locale ja_JP.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
[✓] Chrome - develop for the web
[✓] Linux toolchain - develop for Linux desktop
[✓] Android Studio (version 2020.3)
[✓] Android Studio
[✓] VS Code (version 1.59.1)
[✓] Connected device (4 available)