riscait

import 'package:flutter/material.dart';

class AwaitableIconButton extends StatefulWidget {
  const AwaitableIconButton({
    Key? key,
    required this.onPressed,
    required this.icon,
    this.indicatorWidget,
    this.buttonStyle,
  }) : super(key: key);

riscait

import 'package:intl/intl.dart';

void main() {
  final now = DateTime.now();
  print('isUTC: ${now.isUtc}'); // <- false
  print('now: $now'); // <- now: 2021-12-16 07:58:03.661
  final hms = DateFormat.Hms().format(now);
  print('hms: $hms'); // <- hms: 07:58:03
}

riscait

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

class AsyncValueBuilder<R> extends StatelessWidget {
  const AsyncValueBuilder({
    Key? key,
    required this.asyncValue,
    required this.builder,
  }) : super(key: key);

riscait

import 'package:flutter/material.dart';

enum AppForm {
  first,
  second,
  third,
}

extension AppFormExt on AppForm {
  

riscait

class Cat {
  const Cat(this.name);
  final String name;
}

void f<T>(T arg) {
  if (arg is String) {
    print('This is String!');
  }

riscait

/// Factory Constructorを使ったシングルトンクラスの定義方法
class FactorySinglton {
  /// 初めてインスタンス化するときにfactoryコンストラクタから使用する、Privateなコンストラクタ
  FactorySinglton._() {
    print('FactorySingleton Constructed');
  }

  /// シングルトンを実現するインスタンスを提供
  factory FactorySinglton.instance() => _instance;

riscait

enum Sport {
  baseball,
  football,
  tennis,
  swimming,
}

void main() {
  final list = [Sport.baseball,Sport.football, Sport.tennis];
  final hasTennis = list.contains(Sport.tennis);

riscait

void main() {
  final items = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k'];
  final chunkedItems = [];
  final chunkSize = 3;

  for (var i = 0; i < items.length; i += chunkSize) {
    final isLast = i + chunkSize >= items.length;
    final end = isLast ? items.length : i + chunkSize;
    chunkedItems.add(items.sublist(i, end));
  }

riscait

void main() {
  final items = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k'];
  final chunkedItems = [];
  final chunkSize = 3;
  var count = 0;

  do {
    chunkedItems.add(items.skip(count).take(chunkSize).toList());
    count += chunkSize;
  } while (count < items.length);

riscait

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(