pubspec.yaml

name: galmoji
description: "ギャル文字"
# The following line prevents the package from being accidentally published to
# pub.dev using `flutter pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number is used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
# In Windows, build-name is used as the major, minor, and patch parts
# of the product and file versions while build-number is used as the build suffix.
version: 1.0.1+2

environment:
  sdk: ^3.8.0-148.0.dev

# Dependencies specify other packages that your package needs in order to work.
# To automatically upgrade your package dependencies to the latest versions
# consider running `flutter pub upgrade --major-versions`. Alternatively,
# dependencies can be manually updated by changing the version numbers below to
# the latest version available on pub.dev. To see which dependencies have newer
# versions available, run `flutter pub outdated`.
dependencies:
  flutter:
    sdk: flutter
  share_plus: ^7.0.2

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.8
  package_info_plus: ^8.3.0
  shared_preferences: ^2.0.17
  google_mobile_ads: ^5.3.1
  just_audio: ^0.9.36
  fluttertoast: ^8.2.4

dev_dependencies:
  flutter_test:
    sdk: flutter

  flutter_launcher_icons: ^0.14.3    #flutter pub run flutter_launcher_icons
  flutter_native_splash: ^2.3.5     #flutter pub run flutter_native_splash:create

  # The "flutter_lints" package below contains a set of recommended lints to
  # encourage good coding practices. The lint set provided by the package is
  # activated in the `analysis_options.yaml` file located at the root of your
  # package. See that file for information about deactivating specific lint
  # rules and activating additional ones.
  flutter_lints: ^5.0.0

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

flutter_launcher_icons:
  android: "launcher_icon"
  ios: true
  image_path: "assets/icon/icon.png"
  adaptive_icon_background: "assets/icon/icon_back.png"
  adaptive_icon_foreground: "assets/icon/icon_fore.png"

flutter_native_splash:
  color: '#c80064'
  image: 'assets/image/splash.png'
  color_dark: '#c80064'
  image_dark: 'assets/image/splash.png'
  fullscreen: true
  android_12:
    icon_background_color: '#c80064'
    image: 'assets/image/splash.png'
    icon_background_color_dark: '#c80064'
    image_dark: 'assets/image/splash.png'

# The following section is specific to Flutter packages.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #   - images/a_dot_burr.jpeg
  #   - images/a_dot_ham.jpeg
  assets:
    - assets/image/
    - assets/sound/

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/to/resolution-aware-images

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/to/asset-from-package

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/to/font-from-package

ad_manager.dart

///
/// @author akira ohmachi
/// @copyright ao-system, Inc.
/// @date 2023-02-06
///
library;

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

import 'package:galmoji/ad_unit_id.dart';

class AdManager {

  BannerAd? _bannerAd;
  BannerAd? get bannerAd => _bannerAd;

  Future<void> loadBannerAd(VoidCallback onAdLoaded) async {
    try {
      BannerAd bannerAd = BannerAd(
        adUnitId: AdUnitId.bannerAdUnitId,
        request: AdRequest(),
        size: AdSize.banner,
        listener: BannerAdListener(
          onAdLoaded: (ad) {
            _bannerAd = ad as BannerAd;
            onAdLoaded();
          },
          onAdFailedToLoad: (ad, err) {
            ad.dispose();
            onAdLoaded();
            //debugPrint('Failed to load a banner ad: $err');
          },
        ),
      );
      await bannerAd.load();
    } catch (e) {
      onAdLoaded();
      //debugPrint('Error loading banner ad: $e');
    }
  }

  Widget widget() {
    if (_bannerAd != null) {
      return Padding(
          padding: const EdgeInsets.only(top: 10, left: 0, right: 0, bottom: 0),
          child: Align(
            alignment: Alignment.topCenter,
            child: SizedBox(
              width: _bannerAd!.size.width.toDouble(),
              height: _bannerAd!.size.height.toDouble(),
              child: AdWidget(ad: _bannerAd!),
            ),
          )
      );
    } else {
      return Container();
    }
  }

  void dispose() {
    _bannerAd?.dispose();
  }

}

ad_unit_id.dart

///
/// @author akira ohmachi
/// @copyright ao-system, Inc.
/// @date 2023-02-06
///
library;

import 'dart:io';

class AdUnitId {

  static String get bannerAdUnitId {
    if (Platform.isAndroid) {
      //return 'ca-app-pub-3940256099942544/6300978111';  //test
      return '<YOUR_ANDROID_INTERSTITIAL_AD_UNIT_ID>';
    } else if (Platform.isIOS) {
      //return 'ca-app-pub-3940256099942544/2934735716';  //test
      return '<YOUR_ANDROID_INTERSTITIAL_AD_UNIT_ID>';
    } else {
      throw UnsupportedError('Unsupported platform');
    }
  }

  static String get interstitialAdUnitId {
    if (Platform.isAndroid) {
      //return 'ca-app-pub-3940256099942544/1033173712';  //test
      return '<YOUR_ANDROID_INTERSTITIAL_AD_UNIT_ID>';
    } else if (Platform.isIOS) {
      //return 'ca-app-pub-3940256099942544/4411468910';  //test
      return '<YOUR_IOS_INTERSTITIAL_AD_UNIT_ID>';
    } else {
      throw UnsupportedError('Unsupported platform');
    }
  }

  static String get rewardedAdUnitId {
    if (Platform.isAndroid) {
      //return 'ca-app-pub-3940256099942544/5224354917';  //test
      return '<YOUR_ANDROID_REWARDED_AD_UNIT_ID>';
    } else if (Platform.isIOS) {
      //return 'ca-app-pub-3940256099942544/1712485313';  //test
      return '<YOUR_IOS_REWARDED_AD_UNIT_ID>';
    } else {
      throw UnsupportedError('Unsupported platform');
    }
  }
}

audio_play.dart

///
/// @author akira ohmachi
/// @copyright ao-system, Inc.
/// @date 2023-01-27
///
library;

import 'package:just_audio/just_audio.dart';

import 'package:galmoji/const_value.dart';

class AudioPlay {
  //音を重ねて連続再生できるようにインスタンスを用意しておき、順繰りに使う。
  static final List<AudioPlayer> _player01 = [
    AudioPlayer(),
    AudioPlayer(),
    AudioPlayer(),
    AudioPlayer(),
    AudioPlayer(),
    AudioPlayer(),  //6個
  ];
  int _player01Ptr = 0;

  double _soundVolume = 0.0;

  //constructor
  AudioPlay() {
    constructor();
  }
  void constructor() async {
    for (int i = 0; i < _player01.length; i++) {
      await _player01[i].setVolume(0);
      await _player01[i].setAsset(ConstValue.audioHiyokos[i]);
    }
    playZero();
  }
  void dispose() {
    for (int i = 0; i < _player01.length; i++) {
      _player01[i].dispose();
    }
  }
  //getter
  double get soundVolume {
    return _soundVolume;
  }
  //setter
  set soundVolume(double vol) {
    _soundVolume = vol;
  }
  //最初に音が鳴らないのを回避する方法
  void playZero() async {
    AudioPlayer ap = AudioPlayer();
    await ap.setAsset(ConstValue.audioZero);
    await ap.load();
    await ap.play();
  }
  //
  void play01() async {
    if (_soundVolume == 0) {
      return;
    }
    _player01Ptr += 1;
    if (_player01Ptr >= _player01.length) {
      _player01Ptr = 0;
    }
    await _player01[_player01Ptr].setVolume(_soundVolume);
    await _player01[_player01Ptr].pause();
    await _player01[_player01Ptr].seek(Duration.zero);
    await _player01[_player01Ptr].play();
  }
}

main.dart

///
/// @author akira ohmachi
/// @copyright ao-system, Inc.
/// @date 2023-11-17
///
library;

import 'dart:math';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_mobile_ads/google_mobile_ads.dart';
import 'package:package_info_plus/package_info_plus.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:share_plus/share_plus.dart';

//自身で作成したclassを読み込む
import 'package:galmoji/const_value.dart';
import 'package:galmoji/version_state.dart';
import 'package:galmoji/setting.dart';
import 'package:galmoji/ad_manager.dart';
import 'package:galmoji/preferences.dart';
import 'package:galmoji/audio_play.dart';


void main() {
  runApp(const MainApp());
}

class MainApp extends StatefulWidget {    //statefulに変更して言語変更に対応
  const MainApp({super.key});
  @override
  State<MainApp> createState() => _MainAppState();
}

class _MainAppState extends State<MainApp> {
  @override
  Widget build(BuildContext context) {
    if (kIsWeb == false) {
      MobileAds.instance.initialize();
    }
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      home: MainHomePage(),
    );
  }
}

class MainHomePage extends StatefulWidget {
  const MainHomePage({super.key});
  @override
  State<MainHomePage> createState() => _MainHomePageState();
}

class _MainHomePageState extends State<MainHomePage> with SingleTickerProviderStateMixin {
  final AdManager _adManager = AdManager();
  final AudioPlay _audioPlay = AudioPlay();
  bool _isInitialized = false;
  bool _backImageFlag = true;
  final TextEditingController _textEditingController = TextEditingController();
  late AnimationController _animationController;
  late Animation<double> _opacityAnimation;
  int _backImageNumber = 0;
  int _lastBackImageNumber = 0;
  bool _convertKana = true;
  bool _convertAlphabet = false;
  Color _buttonBackColorRegeneration = ConstValue.colorButtonBack;
  Color _buttonBackColorCopyClipboard = ConstValue.colorButtonBack;
  Color _buttonBackColorShare = ConstValue.colorButtonBack;
  late Random _random;
  String _inputText = '';
  String _convertedText = '';

  //アプリのバージョン取得
  void _getVersion() async {
    PackageInfo packageInfo = await PackageInfo.fromPlatform();
    setState(() {
      VersionState.versionSave(packageInfo.version);
    });
  }
  //ページ起動開始時に一度だけ呼ばれる
  @override
  void initState() {
    super.initState();
    _initializeAsync();
    _adManager.loadBannerAd(() {
      setState(() {});
    });
  }

  void _initializeAsync() async {
    _getVersion();
    _audioPlay.playZero();
    int seed = (DateTime.now()).millisecondsSinceEpoch;
    _random = Random(seed);
    //background animation
    _animationController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 500),
    );
    _opacityAnimation = Tween<double>(begin: 0, end: 1).animate(_animationController);
    _animationController.addListener(() {
      setState(() {});
    });
    //
    await Preferences.initial();
    _backImageFlag = Preferences.backImageFlag;
    _audioPlay.soundVolume = Preferences.soundVolume;
    setState(() {
      _isInitialized = true;
    });
  }
  //ページ終了時に一度だけ呼ばれる
  @override
  void dispose() {
    _adManager.dispose();
    _textEditingController.dispose();
    _animationController.dispose();
    super.dispose();
  }
  Widget _textFieldInput() {
    return Container(
      decoration: BoxDecoration(
        color: ConstValue.colorButtonBack,
        borderRadius: BorderRadius.circular(10.0),
      ),
      child: Padding(
        padding: const EdgeInsets.all(8.0),
        child: TextField(
          controller: _textEditingController,
          keyboardType: TextInputType.multiline,
          maxLines: null,
          onChanged: (text) {
            _inputText = text;
            _conversion();
          },
          decoration: const InputDecoration(
            labelText: '文章を入力',
            border: OutlineInputBorder(),
          )
        )
      )
    );
  }
  Widget _toggleKana() {
    return Expanded(
      child: Container(
        decoration: BoxDecoration(
          color: ConstValue.colorButtonBack,
          borderRadius: BorderRadius.circular(10.0),
        ),
        child: Padding(
          padding: const EdgeInsets.only(top: 1, left: 8, right: 8, bottom: 1),
          child: Row(children:<Widget>[
            const Expanded(
              child: Text('かなカナ漢字を変換',style: TextStyle(fontSize: 12)),
            ),
            Switch(
              value: _convertKana,
              onChanged: (bool value) {
                _audioPlay.play01();
                _backImageChange();
                setState(() {
                  _convertKana = value;
                  _conversion();
                });
              },
              activeColor: ConstValue.colorUiActiveColor,
              inactiveThumbColor: ConstValue.colorUiInactiveColor,
            ),
          ]),
        )
      )
    );
  }
  Widget _toggleAlphabet() {
    return Expanded(
      child: Container(
        decoration: BoxDecoration(
          color: ConstValue.colorButtonBack,
          borderRadius: BorderRadius.circular(10.0),
        ),
        child: Padding(
          padding: const EdgeInsets.only(top: 1, left: 8, right: 8, bottom: 1),
          child: Row(children:<Widget>[
            const Expanded(
              child: Text('英大文字を変換',style: TextStyle(fontSize: 12)),
            ),
            Switch(
              value: _convertAlphabet,
              onChanged: (bool value) {
                _audioPlay.play01();
                _backImageChange();
                setState(() {
                  _convertAlphabet = value;
                  _conversion();
                });
              },
              activeColor: ConstValue.colorUiActiveColor,
              inactiveThumbColor: ConstValue.colorUiInactiveColor,
            ),
          ]),
        )
      )
    );
  }
  Widget _textFieldResult() {
    return Container(
      decoration: BoxDecoration(
        color: ConstValue.colorButtonBack,
        borderRadius: BorderRadius.circular(10.0),
      ),
      child: Padding(
        padding: const EdgeInsets.all(8.0),
        child: TextField(
          readOnly: true,
          keyboardType: TextInputType.multiline,
          maxLines: null,
          controller: TextEditingController(
            text: _convertedText,
          ),
          decoration: const InputDecoration(
            labelText: '変換後',
            border: OutlineInputBorder(),
          ),
        )
      )
    );
  }
  //再生成
  Widget _regenerationButton() {
    return Expanded(
      child: Container(
        padding: const EdgeInsets.fromLTRB(0, 0, 0, 0),
        child: GestureDetector(
          onTap: () {
            _audioPlay.play01();
            _conversion();
            _backImageChange();
          },
          onTapDown: (TapDownDetails details) {
            setState(() {
              _buttonBackColorRegeneration = ConstValue.colorButtonBackOn;
            });
          },
          onTapUp: (TapUpDetails details) {
            setState(() {
              _buttonBackColorRegeneration = ConstValue.colorButtonBack;
            });
          },
          child: Container(
            padding: const EdgeInsets.fromLTRB(0, 12, 0, 12),
            color: _buttonBackColorRegeneration,
            child: const Center(
              child: Text('再生成',
                style: TextStyle(
                  fontSize: 12,
                )
              )
            )
          )
        )
      )
    );
  }
  //クリップボードにコピーボタン
  Widget _copyClipboardButton() {
    return Expanded(
      child: Container(
        padding: const EdgeInsets.fromLTRB(3, 0, 0, 0),
        child: GestureDetector(
          onTap: () {
            _audioPlay.play01();
            if (_convertedText.isNotEmpty) {
              FocusScope.of(context).unfocus();
              Clipboard.setData(ClipboardData(text: _convertedText));
              showToast('コピーしました');
            }
          },
          onTapDown: (TapDownDetails details) {
            setState(() {
              _buttonBackColorCopyClipboard = ConstValue.colorButtonBackOn;
            });
          },
          onTapUp: (TapUpDetails details) {
            setState(() {
              _buttonBackColorCopyClipboard = ConstValue.colorButtonBack;
            });
          },
          child: Container(
            padding: const EdgeInsets.fromLTRB(0, 12, 0, 12),
            color: _buttonBackColorCopyClipboard,
            child: const Center(
              child: Text('コピー',
                style: TextStyle(
                  fontSize: 12,
                )
              )
            )
          )
        )
      )
    );
  }
  //送るボタン
  Widget _shareButton() {
    return Expanded(
      child: Container(
        padding: const EdgeInsets.fromLTRB(3,0,0,0),
        child: GestureDetector(
          onTap: () {
            _audioPlay.play01();
            if (_convertedText.isNotEmpty) {
              Share.share(_convertedText);
            }
          },
          onTapDown: (TapDownDetails details) {
            setState(() {
              _buttonBackColorShare = ConstValue.colorButtonBackOn;
            });
          },
          onTapUp: (TapUpDetails details) {
            setState(() {
              _buttonBackColorShare = ConstValue.colorButtonBack;
            });
          },
          child: Container(
            padding: const EdgeInsets.fromLTRB(0, 12, 0, 12),
            color: _buttonBackColorShare,
            child: const Center(
              child: Text('送る',
                style: TextStyle(
                  fontSize: 12,
                )
              )
            )
          )
        )
      )
    );
  }
  //画面全体
  @override
  Widget build(BuildContext context) {
    if (!_isInitialized) {
      return const Center(
          child: CircularProgressIndicator() //初期化中のローディングインジケーターを表示
      );
    }
    return Container(
      decoration: const BoxDecoration(
        color: Color.fromRGBO(240,240,240,1)
      ),
      child: Container(
        decoration: _decoration2(),
        child: Container(
          decoration: _decoration1(),
          child: Scaffold(
            backgroundColor: Colors.transparent,
            appBar: AppBar(
              //タイトル表示
              title: const Text('ギャル文字',
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 15.0,
                )
              ),
              foregroundColor: const Color.fromRGBO(255,255,255,1),
              backgroundColor: ConstValue.colorHeader,
              actions: <Widget>[
                TextButton(
                  onPressed: () async {
                    bool? ret = await Navigator.of(context).push(
                      MaterialPageRoute<bool>(
                        builder: (context) => const SettingPage(),
                      ),
                    );
                    //awaitで呼び出しているので、settingから戻ったら以下が実行される。
                    if (ret!) { //設定で適用だった場合
                      _backImageFlag = Preferences.backImageFlag;
                      _audioPlay.soundVolume = Preferences.soundVolume;
                      setState(() {});
                    }
                  },
                  child: const Text('設定',
                    style: TextStyle(
                      color: Colors.white,
                    )
                  )
                )
              ]
            ),
            body: SafeArea(
              child: Stack(children:[
                Column(children:[
                  Expanded(
                    child: GestureDetector(
                      onTap: () => FocusScope.of(context).unfocus(),  //背景タップでキーボードを仕舞う
                      child: SingleChildScrollView(
                        child: Padding(
                          padding: const EdgeInsets.all(4.0),
                          child: Column(children:[
                            _textFieldInput(),
                            const SizedBox(height:5),
                            Row(children:[
                              _toggleKana(),
                              const SizedBox(width:8),
                              _toggleAlphabet(),
                            ]),
                            const SizedBox(height:5),
                            _textFieldResult(),
                            const SizedBox(height:5),
                            Row(children:[
                              _regenerationButton(),
                              _copyClipboardButton(),
                              _shareButton(),
                            ])
                          ]),
                        )
                      )
                    )
                  ),
                  //広告
                  _adManager.widget()
                ])
              ])
            )
          )
        )
      )
    );
  }
  //背景画像前側
  Decoration _decoration1() {
    if (_backImageFlag) {
      return BoxDecoration(
        image: DecorationImage(
          image: AssetImage(ConstValue.imageBackGrounds[_backImageNumber]),
          fit: BoxFit.cover,
          colorFilter: ColorFilter.mode(
            Color.alphaBlend(
              Colors.black.withAlpha((_opacityAnimation.value * 255).toInt()),
              Colors.transparent,
            ),
            BlendMode.dstATop,
          ),
        )
      );
    } else {
      return const BoxDecoration();
    }
  }
  //背景画像後ろ側
  Decoration _decoration2() {
    if (_backImageFlag) {
      return BoxDecoration(
        image: DecorationImage(
          image: AssetImage(ConstValue.imageBackGrounds[_lastBackImageNumber]),
          fit: BoxFit.cover,
        ),
      );
    } else {
      return const BoxDecoration();
    }
  }
  void _backImageChange() {
    final int second = (DateTime.now()).millisecondsSinceEpoch ~/ 1000 ~/ 3;  //3秒ごとに変化
    _backImageNumber = second % ConstValue.imageBackGrounds.length;
    _animationController.forward();
    Future.delayed(const Duration(milliseconds: 600), () {
      _lastBackImageNumber = _backImageNumber;
      _animationController.reverse();
    });
  }
  void _conversion() {
    String text = _inputText;
    Map<String, String> stock = {};
    int stockP = 1;
    if (_convertKana) {
      for (String key in ConstValue.galCharKana.keys) {
        String proxy = '#%%1$stockP%%#';
        text = text.replaceAll(key, proxy);
        List<String> valuesForKey = ConstValue.galCharKana[key]!;
        int p = _random.nextInt(valuesForKey.length);
        String to = valuesForKey[p];
        stock[proxy] = to;
        stockP += 1;
      }
    }
    if (_convertAlphabet) {
      for (String key in ConstValue.galCharAlphabet.keys) {
        String proxy = '#%%2$stockP%%#';
        text = text.replaceAll(key, proxy);
        List<String> valuesForKey = ConstValue.galCharAlphabet[key]!;
        int p = _random.nextInt(valuesForKey.length);
        String to = valuesForKey[p];
        stock[proxy] = to;
        stockP += 1;
      }
    }
    for (String key in stock.keys) {
      text = text.replaceAll(key, stock[key]!);
    }
    setState(() {
      _convertedText = text;
    });
  }
  void showToast(String message) {
    Fluttertoast.showToast(
      msg: message,
      toastLength: Toast.LENGTH_SHORT, // または Toast.LENGTH_LONG
      gravity: ToastGravity.BOTTOM, // トーストの表示位置
      timeInSecForIosWeb: 1, // iOSおよびWebの場合の表示時間
      backgroundColor: Colors.black87, // 背景色
      textColor: Colors.white, // テキスト色
      fontSize: 16.0, // テキストサイズ
    );
  }
}

preferences.dart

///
/// @author akira ohmachi
/// @copyright ao-system, Inc.
/// @date 2023-10-26
///
library;

import 'package:shared_preferences/shared_preferences.dart';

import 'package:galmoji/const_value.dart';

//デバイスに情報を保存
class Preferences {

  static bool ready = false;

  //この値は常に最新にしておく
  static bool _backImageFlag = true;
  static double _soundVolume = 0.3;

  static bool get backImageFlag {
    return _backImageFlag;
  }
  static double get soundVolume {
    return _soundVolume;
  }

  static Future<void> initial() async {
    _backImageFlag = await getBackImageFlag();
    _soundVolume = await getSoundVolume();
    ready = true;
  }

  //----------------------------

  //背景画像On/Off
  static Future<void> setBackImageFlag(bool flag) async {
    _backImageFlag = flag;
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    await prefs.setBool(ConstValue.prefBackImageFlag, flag);
  }
  static Future<bool> getBackImageFlag() async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    final bool flag = prefs.getBool(ConstValue.prefBackImageFlag) ?? true;
    return flag;
  }

  //----------------------------

  //効果音音量
  static Future<void> setSoundVolume(double num) async {
    _soundVolume = num;
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    await prefs.setDouble(ConstValue.prefSoundVolume, num);
  }
  static Future<double> getSoundVolume() async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    final double num = prefs.getDouble(ConstValue.prefSoundVolume) ?? 0.3;
    return num;
  }

  //----------------------------

}

setting.dart

///
/// @author akira ohmachi
/// @copyright ao-system, Inc.
/// @date 2023-11-17
///
library;

import 'package:flutter/material.dart';

import 'package:galmoji/const_value.dart';
import 'package:galmoji/preferences.dart';
import 'package:galmoji/version_state.dart';
import 'package:galmoji/ad_manager.dart';

class SettingPage extends StatefulWidget {
  const SettingPage({super.key});

  @override
  State<SettingPage> createState() => _SettingPageState();
}

class _SettingPageState extends State<SettingPage> {
  final AdManager _adManager = AdManager();
  bool _isInitialized = false;
  //これら変数はUIへの表示や入力の為に一時的に使用される。
  bool _backImageFlag = true;
  double _soundVolume = 0.0;

  //ページ起動時に一度だけ実行される
  @override
  void initState() {
    super.initState();
    _initializeAsync();
    _adManager.loadBannerAd(() {
      setState(() {});
    });
  }
  void _initializeAsync() async {
    await Preferences.initial();
    _backImageFlag = Preferences.backImageFlag;
    _soundVolume = Preferences.soundVolume;
    setState(() {
      _isInitialized = true;
    });
  }
  //ページ終了時に一度だけ実行される
  @override
  void dispose() {
    _adManager.dispose();
    super.dispose();
  }
  //ページ描画
  @override
  Widget build(BuildContext context) {
    if (!_isInitialized) {
      return const Center(
          child: CircularProgressIndicator() //初期化中のローディングインジケーターを表示
      );
    }
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        elevation: 0,
        //設定キャンセルボタン
        leading: IconButton(
          icon: const Icon(Icons.close),
          onPressed: () {
            Navigator.of(context).pop(false); //falseを返す
          },
        ),
        title: const Text('設定'),
        foregroundColor: const Color.fromRGBO(255,255,255,1),
        backgroundColor: ConstValue.colorSettingAccent,
        actions: [
          //設定OKボタン
          IconButton(
            icon: const Icon(Icons.check),
            onPressed: () async {
              await Preferences.setBackImageFlag(_backImageFlag);
              await Preferences.setSoundVolume(_soundVolume);
              if (!mounted) {
                return;
              }
              Navigator.of(context).pop(true);  //trueを返す
            },
          ),
        ],
      ),
      body: SafeArea(
        child: Column(children:[
          Expanded(
            child: GestureDetector(
              onTap: () => FocusScope.of(context).unfocus(),  //背景タップでキーボードを仕舞う
              child: SingleChildScrollView(
                child: Padding(
                  padding: const EdgeInsets.all(20),
                  child: Column(children: [
                    Padding(
                      padding: const EdgeInsets.only(top: 16, left: 16, right: 16, bottom: 16),
                      child: Row(children:<Widget>[
                        const Expanded(
                          child: Text('背景画像表示',style: TextStyle(fontSize: 16)),
                        ),
                        Switch(
                          value: _backImageFlag,
                          onChanged: (bool value) {
                            setState(() {
                              _backImageFlag = value;
                            });
                          },
                          activeColor: ConstValue.colorUiActiveColor,
                          inactiveThumbColor: ConstValue.colorUiInactiveColor,
                        ),
                      ]),
                    ),
                    _border(),
                    const Padding(
                      padding: EdgeInsets.only(top: 18, left: 16, right: 16, bottom: 0),
                      child: Row(children: [
                        Text('効果音量',style: TextStyle(fontSize: 16)),
                        Spacer(),
                      ])
                    ),
                    Padding(
                      padding: const EdgeInsets.only(top: 0, left: 16, right: 16, bottom: 6),
                      child: Row(children: <Widget>[
                        Text(_soundVolume.toString()),
                        Expanded(
                          child: Slider(
                            value: _soundVolume,
                            min: 0.0,
                            max: 1.0,
                            divisions: 10,
                            onChanged: (double value) {
                              setState(() {
                                _soundVolume = value;
                              });
                            },
                            activeColor: ConstValue.colorUiActiveColor,
                            inactiveColor: ConstValue.colorUiInactiveColor,
                          )
                        )
                      ])
                    ),
                    _border(),
                    const Padding(
                      padding: EdgeInsets.only(top: 24, left: 0, right: 0, bottom: 24),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children:[
                          Text('ギャル文字変換'),
                          SizedBox(height:15),
                          Text('日本語文字列を入力欄に入力またはペーストします。ギャル文字への変換結果がリアルタイムに表示されます。'),
                          SizedBox(height:15),
                          Text('かなカナ漢字は適宜変換されます。英字は大文字のみです。'),
                          SizedBox(height:15),
                          Text('ギャル文字とは、2002年～2005年ぐらいに女子中学生や女子高生の間で流行となった文字遊び。'),
                        ]
                      ),
                    ),
                    _border(),
                    Padding(
                      padding: const EdgeInsets.only(top: 24, left: 0, right: 0, bottom: 36),
                      child: SizedBox(
                        child: Text('version  ${VersionState.versionLoad()}',
                          style: const TextStyle(
                            fontSize: 10,
                          ),
                        ),
                      ),
                    ),
                  ]),
                ),
              ),
            ),
          ),
          //広告
          _adManager.widget()
        ]),
      )
    );
  }
  //UIの仕切り用ボーダーライン
  Widget _border() {
    return Container(
      decoration: BoxDecoration(
        border: Border(
          top: BorderSide(
            color: Colors.grey.shade300,
            width: 1,
          ),
        ),
      ),
    );
  }

}

version_state.dart

///
/// @author akira ohmachi
/// @copyright ao-system, Inc.
/// @date 2023-01-27
///
library;

class VersionState {

  static String _version = '';

  //バージョンを記録
  static void versionSave(String str) {
    _version = str;
  }
  //バージョンを返す
  static String versionLoad() {
    return _version;
  }

}