[flutter] 랜덤숫자 생성기

1) 

2) component/number_row.dart

import 'package:flutter/material.dart';

class NumberRow extends StatelessWidget {
  final int number;

  const NumberRow({
    Key? key,
    required this.number,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Row(
      children: number
          .toInt()
          .toString()
          .split('')
          .map((e) => Image.asset(
                'asset/img/$e.png',
                width: 50.0,
                height: 70.0,
              ))
          .toList(),
    );
  }
}

3) constant/color.dart

import 'package:flutter/material.dart';

const Color PRIMARY_COLOR = Color(0xFF2D2D33);
const Color RED_COLOR= Color(0xFFEA4955);
const Color BLUE_COLOR = Color(0xFF549FBF);

4) screen/

home_screen.dart

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:random_number_generator/constant/color.dart';
import 'package:random_number_generator/screen/settings_screen.dart';

import '../component/number_row.dart';

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

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  int maxNumber = 1000;
  List<int> randomNumbers = [
    123,
    456,
    789,
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: PRIMARY_COLOR,
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.symmetric(
            horizontal: 16.0,
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              _Header(
                onPressed: onSettingsPop,
              ),
              _Body(
                randomNumbers: randomNumbers,
              ),
              _Footer(
                onPressed: onRandomNumberGenerate,
              ),
            ],
          ),
        ),
      ),
    );
  }

  void onRandomNumberGenerate() {
    final rand = Random();

    final Set<int> newNumbers = {};

    while (newNumbers.length != 3) {
      final number = rand.nextInt(maxNumber);

      newNumbers.add(number);
    }

    setState(() {
      randomNumbers = newNumbers.toList();
    });
  }

  void onSettingsPop() async {
    // list - add
    // [HomeScreen(), SettingsScreen()]
    final int? result = await Navigator.of(context).push<int>(
      MaterialPageRoute(
        builder: (BuildContext context) {
          return SettingsScreen();
        },
      ),
    );
    if (result != null) {
      setState(() {
        maxNumber = result;
      });
    }
  }
}

class _Header extends StatelessWidget {
  final VoidCallback onPressed;

  const _Header({
    Key? key,
    required this.onPressed,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Text(
          '랜덤숫자 생성기',
          style: TextStyle(
            color: Colors.white,
            fontSize: 30.0,
            fontWeight: FontWeight.w700,
          ),
        ),
        IconButton(
          onPressed: onPressed,
          icon: Icon(
            Icons.settings,
            color: RED_COLOR,
          ),
        ),
      ],
    );
  }
}

class _Body extends StatelessWidget {
  final List<int> randomNumbers;

  const _Body({
    required this.randomNumbers,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: randomNumbers
            .asMap()
            .entries
            .map(
              (x) => Padding(
                padding: EdgeInsets.only(bottom: x.key == 2 ? 0 : 16.0),
                child: NumberRow(
                  number: x.value,
                ),
              ),
            )
            .toList(),
      ),
    );
  }
}

class _Footer extends StatelessWidget {
  final VoidCallback onPressed;

  const _Footer({
    required this.onPressed,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: double.infinity,
      child: ElevatedButton(
        style: ElevatedButton.styleFrom(
          primary: RED_COLOR,
        ),
        onPressed: onPressed,
        child: Text(
          '생성하기',
        ),
      ),
    );
  }
}

settings_screen.dart

import 'package:flutter/material.dart';
import 'package:random_number_generator/component/number_row.dart';
import 'package:random_number_generator/constant/color.dart';

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

  @override
  State<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends State<SettingsScreen> {
  double maxNumber = 1000;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: PRIMARY_COLOR,
      body: Center(
        child: SafeArea(
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 16.0),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                _Body(maxNumber: maxNumber),
                _Footer(
                  maxNumber: maxNumber,
                  onSliderChanged: onSliderChanged,
                  onButtonPressed: onButtonPressed,
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  void onSliderChanged(double val) {
    setState(
      () {
        maxNumber = val;
      },
    );
  }

  void onButtonPressed() {
    Navigator.of(context).pop(maxNumber.toInt());
  }
}

class _Body extends StatelessWidget {
  final double maxNumber;

  const _Body({
    Key? key,
    required this.maxNumber,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: NumberRow(
        number: maxNumber.toInt(),
      ),
    );
  }
}

class _Footer extends StatelessWidget {
  final double maxNumber;
  final ValueChanged<double>? onSliderChanged;
  final VoidCallback onButtonPressed;

  const _Footer({
    Key? key,
    required this.maxNumber,
    this.onSliderChanged,
    required this.onButtonPressed,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        Slider(
            value: maxNumber,
            min: 1000,
            max: 100000,
            onChanged: onSliderChanged),
        ElevatedButton(
          onPressed: onButtonPressed,
          style: ElevatedButton.styleFrom(
            primary: RED_COLOR,
          ),
          child: Text(
            '저장!',
          ),
        )
      ],
    );
  }
}

5)

home_screen

settings_screen