pubspec.yaml

name: barcodereader
description: "barcodereader"
# 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: 2.1.0+33

environment:
  sdk: ">=3.3.0 <4.0.0"

# 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# versions available, run `flutter pub outdated`.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
  flutter_localizations:
    sdk: flutter

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  mobile_scanner: ^7.0.1
  shared_preferences: ^2.0.15
  flutter_toastr: ^1.0.3
  url_launcher: ^6.1.5
  share_plus: ^12.0.0
  google_mobile_ads: ^6.0.0
  provider: ^6.0.3
  clipboard: ^2.0.2
  intl: ^0.20.2
  audioplayers: ^6.0.0

dev_dependencies:
  flutter_test:
    sdk: flutter

  flutter_launcher_icons: ^0.14.4    #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: ^6.0.0

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

flutter_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: '#9da9f5'
  image: 'assets/image/splash.png'
  color_dark: '#9da9f5'
  image_dark: 'assets/image/splash.png'
  fullscreen: true
  android_12:
    icon_background_color: '#9da9f5'
    image: 'assets/image/splash.png'
    icon_background_color_dark: '#9da9f5'
    image_dark: 'assets/image/splash.png'

# The following section is specific to Flutter packages.
flutter:
  generate: true # Add this line

  # 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

  assets:
    - assets/image/
    - assets/sound/

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

  # 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

lib/ad_banner_widget.dart

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

import 'package:barcodereader/ad_manager.dart';

class AdBannerWidget extends StatefulWidget {
  final AdManager adManager;
  const AdBannerWidget({super.key, required this.adManager});
  @override
  State<AdBannerWidget> createState() => _AdBannerWidgetState();
}

class _AdBannerWidgetState extends State<AdBannerWidget> {
  int _lastBannerWidthDp = 0;
  bool _isAdLoaded = false;
  bool _isLoading = false;
  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: LayoutBuilder(
        builder: (context, constraints) {
          final int width = constraints.maxWidth.isFinite ? constraints.maxWidth.truncate() : MediaQuery.of(context).size.width.truncate();
          final bannerAd = widget.adManager.bannerAd;
          if (width > 0) {
            WidgetsBinding.instance.addPostFrameCallback((_) {
              if (mounted) {
                final bannerAd = widget.adManager.bannerAd;
                final bool widthChanged = _lastBannerWidthDp != width;
                final bool sizeMismatch = bannerAd == null || bannerAd.size.width != width;
                if ((widthChanged || !_isAdLoaded || sizeMismatch) && !_isLoading) {
                  _lastBannerWidthDp = width;
                  setState(() { _isAdLoaded = false; _isLoading = true; });
                  widget.adManager.loadAdaptiveBannerAd(width, () {
                    if (mounted) {
                      setState(() { _isAdLoaded = true; _isLoading = false; });
                    }
                  });
                }
              }
            });
          }
          if (_isAdLoaded && bannerAd != null) {
            return Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                SizedBox(
                  width: bannerAd.size.width.toDouble(),
                  height: bannerAd.size.height.toDouble(),
                  child: AdWidget(ad: bannerAd),
                ),
              ],
            );
          } else {
            return const SizedBox.shrink();
          }
        },
      ),
    );
  }
}

lib/ad_manager.dart

import 'dart:async';
import 'dart:io' show Platform;
import 'dart:ui';
import 'package:google_mobile_ads/google_mobile_ads.dart';

class AdManager {
  // Test IDs
  // static const String _androidAdUnitId = "ca-app-pub-3940256099942544/6300978111";
  // static const String _iosAdUnitId     = "ca-app-pub-3940256099942544/2934735716";

  // Production IDs
  static const String _androidAdUnitId = "ca-app-pub-000/000";
  static const String _iosAdUnitId     = "ca-app-pub-000/000";

  static String get _adUnitId => Platform.isIOS ? _iosAdUnitId : _androidAdUnitId;

  BannerAd? _bannerAd;
  int _lastWidthPx = 0;
  VoidCallback? _onLoadedCb;
  Timer? _retryTimer;
  int _retryAttempt = 0;

  BannerAd? get bannerAd => _bannerAd;

  Future<void> loadAdaptiveBannerAd(int widthPx, VoidCallback onAdLoaded) async {
    _onLoadedCb = onAdLoaded;
    _lastWidthPx = widthPx;
    _retryAttempt = 0;
    _retryTimer?.cancel();
    _startLoad(widthPx);
  }

  Future<void> _startLoad(int widthPx) async {
    _bannerAd?.dispose();

    AnchoredAdaptiveBannerAdSize? adaptiveSize;
    try {
      adaptiveSize = await AdSize.getCurrentOrientationAnchoredAdaptiveBannerAdSize(widthPx);
    } catch (_) {
      adaptiveSize = null;
    }
    final AdSize size = adaptiveSize ?? AdSize.fullBanner;

    _bannerAd = BannerAd(
      adUnitId: _adUnitId,
      request: const AdRequest(),
      size: size,
      listener: BannerAdListener(
        onAdLoaded: (ad) {
          _retryTimer?.cancel();
          _retryAttempt = 0;
          final cb = _onLoadedCb;
          if (cb != null) {
            cb();
          }
        },
        onAdFailedToLoad: (ad, err) {
          ad.dispose();
          _scheduleRetry();
        },
      ),
    )..load();
  }

  void _scheduleRetry() {
    _retryTimer?.cancel();
    // Exponential backoff: 3s, 6s, 12s, max 30s
    _retryAttempt = (_retryAttempt + 1).clamp(1, 5);
    final seconds = _retryAttempt >= 4 ? 30 : (3 << (_retryAttempt - 1));
    _retryTimer = Timer(Duration(seconds: seconds), () {
      _startLoad(_lastWidthPx > 0 ? _lastWidthPx : 320);
    });
  }

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

}

lib/home_page.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:provider/provider.dart';
import 'package:share_plus/share_plus.dart';
import 'package:url_launcher/url_launcher.dart';
import 'l10n/app_localizations.dart';

import 'package:barcodereader/ad_manager.dart';
import 'package:barcodereader/ad_banner_widget.dart';
import 'package:barcodereader/scan_list_page.dart';
import 'package:barcodereader/scan_provider.dart';
import 'package:barcodereader/scanner_page.dart';
import 'package:barcodereader/settings_page.dart';

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

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  late AdManager _adManager;
  final _textController = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  late ScanProvider _scanProvider;

  @override
  void initState() {
    super.initState();
    _adManager = AdManager();
    _scanProvider = context.read<ScanProvider>();
    _scanProvider.loadScanResults().then((_) {
      _updateTextField();
    });
    _scanProvider.addListener(_updateTextField);
  }

  @override
  void dispose() {
    _scanProvider.removeListener(_updateTextField);
    _textController.dispose();
    _scrollController.dispose();
    _adManager.dispose();
    super.dispose();
  }

  Future<void> _scanBarcode() async {
    await Navigator.of(context).push(
      MaterialPageRoute(
        builder: (context) => ScannerPage(
          onScan: (result) async {
            await _scanProvider.addScanResult(result);
          },
        ),
      ),
    );
  }

  void _updateTextField() {
    _textController.text = _scanProvider.getFormattedResults();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (_scrollController.hasClients) {
        _scrollController.animateTo(
          _scrollController.position.maxScrollExtent,
          duration: const Duration(milliseconds: 300),
          curve: Curves.easeOut,
        );
      }
    });
  }

  void _copyToClipboard(String text) {
    if (text.isEmpty) return;
    Clipboard.setData(ClipboardData(text: text));
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(AppLocalizations.of(context)!.copiedToClipboard),
        duration: const Duration(seconds: 1),
      ),
    );
  }

  void _shareText(String text) {
    if (text.isEmpty) {
      return;
    }
    SharePlus.instance.share(ShareParams(text: text));
  }

  void _launchUrlOrShare(String text) async {
    if (text.isEmpty) return;
    Uri uri;
    final parsedUri = Uri.tryParse(text);
    if (parsedUri != null &&
        (parsedUri.scheme == 'http' || parsedUri.scheme == 'https')) {
      uri = parsedUri;
    } else {
      uri = Uri.parse(
        'https://www.google.com/search?q=${Uri.encodeComponent(text)}',
      );
    }
    try {
      if (!await launchUrl(uri)) {
        if (!mounted) return;
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(
              AppLocalizations.of(context)!.couldNotLaunchBrowserFor(
                uri.toString(),
              ),
            ),
          ),
        );
      }
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(
        SnackBar(
          content: Text(
            AppLocalizations.of(context)!.errorLaunchingBrowser(
              e.toString(),
            ),
          ),
        ),
      );
    }
  }

  Future<bool> _showConfirmDialog(String title) async {
    return await showDialog<bool>(
          context: context,
          builder: (context) => AlertDialog(
            title: Text(title),
            actions: [
              TextButton(
                onPressed: () => Navigator.of(context).pop(false),
                child: Text(AppLocalizations.of(context)!.cancel),
              ),
              TextButton(
                onPressed: () => Navigator.of(context).pop(true),
                child: Text(AppLocalizations.of(context)!.ok),
              ),
            ],
          ),
        ) ??
        false;
  }

  Future<void> _showMessageDialog({String? title, required List<String> messages}) async {
    await showDialog<void>(
      context: context,
      builder: (context) => AlertDialog(
        title: title != null ? Text(title) : null,
        content: messages.length == 1
            ? Text(messages.first)
            : Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  for (var i = 0; i < messages.length; i++)
                    Padding(
                      padding: EdgeInsets.only(bottom: i == messages.length - 1 ? 0 : 8.0),
                      child: Text(messages[i]),
                    ),
                ],
              ),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(context).pop(),
            child: Text(AppLocalizations.of(context)!.ok),
          ),
        ],
      ),
    );
  }

  Future<void> _handleDeleteDuplicates() async {
    if (!await _showConfirmDialog(
      AppLocalizations.of(context)!.deleteDuplicatesConfirmation,
    )) {
      return;
    }

    final results = await _scanProvider.removeDuplicateScanResults();
    if (!mounted) return;

    if (results.isEmpty) {
      await _showMessageDialog(
        title: AppLocalizations.of(context)!.deleteDuplicates,
        messages: [AppLocalizations.of(context)!.noDuplicateDataFound],
      );
      return;
    }

    await _showMessageDialog(
      title: AppLocalizations.of(context)!.duplicateRemovalResultTitle,
      messages: results
          .map(
            (entry) => AppLocalizations.of(context)!.duplicateRemovalEntry(
              entry.removedCount,
              entry.data,
            ),
          )
          .toList(),
    );
  }

  Widget _buildFullWidthButton(
    String text,
    VoidCallback onPressed, {
    Color? backgroundColor,
    double height = 38.0,
  }) {
    final isDark = Theme.of(context).brightness == Brightness.dark;
    final defaultBgColor = isDark ? Colors.grey[800] : Colors.blueGrey[400];
    return Container(
      height: height,
      decoration: BoxDecoration(
        color: backgroundColor ?? defaultBgColor,
        border: Border(
          bottom: BorderSide(
            color: isDark ? Colors.black : Colors.white,
            width: 1.0,
          ),
        ),
      ),
      child: SizedBox.expand(
        child: TextButton(onPressed: onPressed, child: Text(text)),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final isDark = Theme.of(context).brightness == Brightness.dark;
    const otherButtonHeight = 40.0;

    return Scaffold(
      appBar: AppBar(
        title: const Text(''),
        elevation: 0,
        actions: [
          IconButton(
            icon: const Icon(Icons.list),
            onPressed: () => Navigator.of(context).push(
              MaterialPageRoute(builder: (context) => const ScanListPage()),
            ),
          ),
          IconButton(
            icon: const Icon(Icons.settings),
            onPressed: () => Navigator.of(context).push(
              MaterialPageRoute(builder: (context) => const SettingsPage()),
            ),
          ),
        ],
      ),
      body: SafeArea(
        child: Column(
          children: [
            Divider(height: 1, color: isDark ? Colors.black : Colors.white),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.scan,
              _scanBarcode,
              backgroundColor:
                  isDark ? const Color(0xFF3E309E) : const Color(0xFF9DA0FC),
              height: 76.0,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.copy,
              () async {
                if (await _showConfirmDialog(
                  AppLocalizations.of(context)!.copyAll,
                )) {
                  _copyToClipboard(_scanProvider.toCsv());
                }
              },
              backgroundColor:
                  isDark ? const Color(0xFF372A8B) : const Color(0xFF909FFF),
              height: otherButtonHeight,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.send,
              () async {
                if (await _showConfirmDialog(
                  AppLocalizations.of(context)!.sendAll,
                )) {
                  _shareText(_scanProvider.toCsv());
                }
              },
              backgroundColor:
                  isDark ? const Color(0xFF372A8B) : const Color(0xFF909FFF),
              height: otherButtonHeight,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.deleteDuplicates,
              () {
                unawaited(_handleDeleteDuplicates());
              },
              backgroundColor:
                  isDark ? const Color(0xFF372A8B) : const Color(0xFF909FFF),
              height: otherButtonHeight,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.deleteAll,
              () async {
                if (await _showConfirmDialog(
                  AppLocalizations.of(context)!.deleteAll,
                )) {
                  _scanProvider.deleteAllScanResults();
                }
              },
              backgroundColor:
                  isDark ? const Color(0xFF372A8B) : const Color(0xFF909FFF),
              height: otherButtonHeight,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.copyLast,
              () => _copyToClipboard(_scanProvider.getLastScanContent()),
              backgroundColor:
                  isDark ? const Color(0xFF32277C) : const Color(0xFF9FADFF),
              height: otherButtonHeight,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.sendLast,
              () => _shareText(_scanProvider.getLastScanContent()),
              backgroundColor:
                  isDark ? const Color(0xFF32277C) : const Color(0xFF9FADFF),
              height: otherButtonHeight,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.browserLast,
              () => _launchUrlOrShare(_scanProvider.getLastScanContent()),
              backgroundColor:
                  isDark ? const Color(0xFF32277C) : const Color(0xFF9FADFF),
              height: otherButtonHeight,
            ),
            _buildFullWidthButton(
              AppLocalizations.of(context)!.deleteLast,
              () async {
                if (await _showConfirmDialog(
                  AppLocalizations.of(context)!.deleteLastConfirmation,
                )) {
                  _scanProvider.deleteLastScanResult();
                }
              },
              backgroundColor:
                  isDark ? const Color(0xFF32277C) : const Color(0xFF9FADFF),
              height: otherButtonHeight,
            ),
            Expanded(
              child: Padding(
                padding: const EdgeInsets.fromLTRB(8.0, 8.0, 8.0, 8.0),
                child: TextField(
                  controller: _textController,
                  scrollController: _scrollController,
                  readOnly: true,
                  maxLines: null,
                  expands: true,
                  textAlignVertical: TextAlignVertical.top,
                  decoration: const InputDecoration(border: InputBorder.none),
                ),
              ),
            ),
          ],
        ),
      ),
      bottomNavigationBar: AdBannerWidget(adManager: _adManager),
    );
  }

}

lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_mobile_ads/google_mobile_ads.dart';
import 'package:provider/provider.dart';
import 'l10n/app_localizations.dart';

import 'package:barcodereader/home_page.dart';
import 'package:barcodereader/scan_provider.dart';
import 'package:barcodereader/settings_provider.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  MobileAds.instance.initialize();
  runApp(
    MultiProvider(
      providers: [
        ChangeNotifierProvider(create: (context) => ScanProvider()),
        ChangeNotifierProvider(create: (context) => SettingsProvider()),
      ],
      child: const MyApp(),
    ),
  );
}

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

  @override
  Widget build(BuildContext context) {
    return Consumer<SettingsProvider>(
      builder: (context, settings, child) {
        return MaterialApp(
          onGenerateTitle: (context) {
            return AppLocalizations.of(context)!.appName;
          },
          debugShowCheckedModeBanner: false,
          theme: ThemeData(
            brightness: Brightness.light,
            scaffoldBackgroundColor: const Color(0xFFEEEEEE),
            appBarTheme: const AppBarTheme(
              backgroundColor: Color(0xFF9FADFF),
              foregroundColor: Colors.black,
              systemOverlayStyle: SystemUiOverlayStyle.dark,
            ),
            inputDecorationTheme: const InputDecorationTheme(
              filled: true,
              fillColor: Colors.white,
              border: OutlineInputBorder(),
            ),
            textButtonTheme: TextButtonThemeData(
              style: TextButton.styleFrom(
                foregroundColor: Colors.black87,
                shape: const RoundedRectangleBorder(
                  borderRadius: BorderRadius.zero,
                ),
              ),
            ),
          ),
          darkTheme: ThemeData(
            brightness: Brightness.dark,
            scaffoldBackgroundColor: const Color(0xFF222222),
            appBarTheme: const AppBarTheme(
              backgroundColor: Color(0xFF32277C),
              foregroundColor: Colors.white,
              systemOverlayStyle: SystemUiOverlayStyle.light,
            ),
            inputDecorationTheme: const InputDecorationTheme(
              filled: true,
              fillColor: Colors.black,
              border: OutlineInputBorder(),
            ),
            textButtonTheme: TextButtonThemeData(
              style: TextButton.styleFrom(
                foregroundColor: Colors.white,
                shape: const RoundedRectangleBorder(
                  borderRadius: BorderRadius.zero,
                ),
              ),
            ),
          ),
          themeMode: settings.themeMode,
          locale: settings.appLocale,
          localizationsDelegates: AppLocalizations.localizationsDelegates,
          supportedLocales: AppLocalizations.supportedLocales,
          home: const HomePage(),
        );
      },
    );
  }
}

lib/scan_list_page.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:google_mobile_ads/google_mobile_ads.dart';
import 'package:provider/provider.dart';
import 'package:share_plus/share_plus.dart';
import 'l10n/app_localizations.dart';

import 'package:barcodereader/scan_provider.dart';
import 'package:barcodereader/ad_manager.dart';

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

class _ScanListPageState extends State<ScanListPage> {
  final ScrollController _scrollController = ScrollController();
  late AdManager _adManager;
  bool _isAdLoaded = false;
  int? _lastBannerWidthDp;

  @override
  void initState() {
    super.initState();
    _adManager = AdManager();
    // buildが完了した直後に実行
    WidgetsBinding.instance.addPostFrameCallback((_) {
      // 遅延させてからスクロールを実行
      Timer(const Duration(milliseconds: 50), _scrollToBottom);
    });
  }

  @override
  void dispose() {
    _scrollController.dispose();
    _adManager.dispose();
    super.dispose();
  }

  void _scrollToBottom() {
    // scrollControllerがListViewに紐付いていて、スクロール可能な場合
    if (_scrollController.hasClients) {
      _scrollController.animateTo(
        _scrollController.position.maxScrollExtent,
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeOut,
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    final l = AppLocalizations.of(context)!;
    return Consumer<ScanProvider>(
      builder: (context, scanProvider, child) {
        // スキャン結果が空の場合の表示
        if (scanProvider.scanResults.isEmpty) {
          return Scaffold(
            appBar: AppBar(
              backgroundColor: Colors.transparent,
              title: Text(l.scanHistory),
              centerTitle: true,
            ),
            body: Center(
              child: Text(l.noScanHistory),
            ),
          );
        }
        // スキャン結果をリスト表示
        return Scaffold(
          appBar: AppBar(
            backgroundColor: Colors.transparent,
            title: Text(l.scanHistory),
            centerTitle: true,
          ),
          body: SafeArea(
            child: ListView.builder(
              controller: _scrollController, // コントローラーを紐付け
              padding: const EdgeInsets.all(8.0),
              itemCount: scanProvider.scanResults.length,
              itemBuilder: (context, index) {
                // 古いものが上、新しいものが下になるようにそのままのindexを使用
                final result = scanProvider.scanResults[index];
                final parts = result.split(',');
                // データのパース
                final timestamp =
                    parts.isNotEmpty
                        ? parts[0]
                        : l.noDate;
                final format = parts.length > 1
                    ? parts[1].split('.').last
                    : l.unknownFormat;
                final content = parts.length > 2
                    ? parts.sublist(2).join(',')
                    : l.noContent;

                // デフォルトのテキストスタイルを取得
                final textTheme = Theme.of(context).textTheme;
                final titleStyle = textTheme.titleMedium;

                return Card(
                  margin: const EdgeInsets.symmetric(vertical: 4.0),
                  child: Dismissible(
                    key: Key(result + index.toString()), // ユニークなキー
                    direction: DismissDirection.endToStart,
                    background: Container(
                      color: Colors.red,
                      alignment: Alignment.centerRight,
                      padding: const EdgeInsets.symmetric(horizontal: 20.0),
                      child: const Icon(Icons.delete, color: Colors.white),
                    ),
                    onDismissed: (direction) {
                      // Provider経由でデータを削除
                      scanProvider.deleteScanResult(index);
                      ScaffoldMessenger.of(context).showSnackBar(
                        SnackBar(
                          content: Text(
                            l.resultDeleted,
                          ),
                          duration: const Duration(seconds: 1),
                        ),
                      );
                    },
                    child: ListTile(
                      title: Text('$timestamp - $format'),
                      subtitle: Text(content, style: titleStyle),
                      onTap: () {
                        // Send / Delete のオプションダイアログを表示
                        showDialog(
                          context: context,
                          builder: (context) => AlertDialog(
                            title: Text(content),
                            actions: <Widget>[
                              TextButton(
                                child: Text(
                                  l.sendAction,
                                ),
                                onPressed: () {
                                  Navigator.of(context).pop();
                                  SharePlus.instance.share(ShareParams(text: content));
                                },
                              ),
                              TextButton(
                                child: Text(
                                  l.deleteAction,
                                ),
                                onPressed: () {
                                  Navigator.of(context).pop();
                                  scanProvider.deleteScanResult(index);
                                  ScaffoldMessenger.of(
                                    context,
                                  ).showSnackBar(
                                    SnackBar(
                                      content: Text(
                                        l
                                            .resultDeleted,
                                      ),
                                      duration: const Duration(seconds: 1),
                                    ),
                                  );
                                },
                              ),
                              TextButton(
                                child: Text(
                                  l.cancel,
                                ),
                                onPressed: () {
                                  Navigator.of(context).pop();
                                },
                              ),
                            ],
                          ),
                        );
                      },
                    ),
                  ),
                );
              },
            ),
          ),
          bottomNavigationBar: _buildAdBanner()
        );
      },
    );
  }

  Widget _buildAdBanner() {
    return SafeArea(
        child: LayoutBuilder(
          builder: (context, constraints) {
            final int width = constraints.maxWidth.isFinite ? constraints.maxWidth.truncate() : MediaQuery.of(context).size.width.truncate();
            if (width > 0) {
              WidgetsBinding.instance.addPostFrameCallback((_) {
                if (mounted) {
                  _updateAdBannerForWidth(width);
                }
              });
            }
            return _isAdLoaded && _adManager.bannerAd != null
              ? Row(mainAxisAlignment: MainAxisAlignment.center, children: [
                SizedBox(
                  width: _adManager.bannerAd!.size.width.toDouble(),
                  height: _adManager.bannerAd!.size.height.toDouble(),
                  child: AdWidget(ad: _adManager.bannerAd!),
                )
              ])
              : const SizedBox.shrink();
          },
        )
    );
  }

  void _updateAdBannerForWidth(int widthDp) {
    if (widthDp <= 0) {
      return;
    }
    if (_lastBannerWidthDp == widthDp && _isAdLoaded && _adManager.bannerAd != null && _adManager.bannerAd!.size.width == widthDp) {
      return;
    }
    _lastBannerWidthDp = widthDp;
    _adManager.loadAdaptiveBannerAd(widthDp, () {
      if (mounted) {
        setState(() => _isAdLoaded = true);
      }
    });
  }

}

lib/scan_provider.dart

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

class DuplicateRemovalEntry {
  const DuplicateRemovalEntry({required this.data, required this.removedCount});

  final String data;
  final int removedCount;
}

class ScanProvider extends ChangeNotifier {
  List<String> _scanResults = [];
  static const String _scanResultsKey = 'scan_results';
  List<String> get scanResults => _scanResults;

  Future<void> loadScanResults() async {
    final prefs = await SharedPreferences.getInstance();
    _scanResults = prefs.getStringList(_scanResultsKey) ?? [];
    notifyListeners();
  }

  Future<void> addScanResult(String result) async {
    _scanResults.add(result);
    await _saveResults();
  }

  Future<void> deleteScanResult(int index) async {
    if (index >= 0 && index < _scanResults.length) {
      _scanResults.removeAt(index);
      await _saveResults();
    }
  }

  Future<void> deleteLastScanResult() async {
    if (_scanResults.isNotEmpty) {
      _scanResults.removeLast();
      await _saveResults();
    }
  }

  Future<void> deleteAllScanResults() async {
    _scanResults.clear();
    await _saveResults();
  }

  Future<List<DuplicateRemovalEntry>> removeDuplicateScanResults() async {
    final seenKeys = <String>{};
    final removalCounts = <String, int>{};
    final displayTexts = <String, String>{};
    final indexesToRemove = <int>[];

    for (var i = 0; i < _scanResults.length; i++) {
      final entry = _scanResults[i];
      final parts = entry.split(',');

      final hasContent = parts.length >= 3;
      final format = hasContent ? parts[1] : '';
      final content = hasContent ? parts.sublist(2).join(',') : entry;
      final key = hasContent ? '$format::$content' : entry;

      displayTexts.putIfAbsent(key, () => content);

      if (!seenKeys.add(key)) {
        removalCounts.update(key, (value) => value + 1, ifAbsent: () => 1);
        indexesToRemove.add(i);
      }
    }

    if (indexesToRemove.isEmpty) {
      return const <DuplicateRemovalEntry>[];
    }

    indexesToRemove.sort((a, b) => b.compareTo(a));
    for (final index in indexesToRemove) {
      _scanResults.removeAt(index);
    }

    await _saveResults();

    return removalCounts.entries
        .map(
          (entry) => DuplicateRemovalEntry(
            data: displayTexts[entry.key] ?? entry.key,
            removedCount: entry.value,
          ),
        )
        .toList();
  }

  Future<void> _saveResults() async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setStringList(_scanResultsKey, _scanResults);
    notifyListeners();
  }

  String getFormattedResults() {
    return _scanResults.map((res) {
      final parts = res.split(',');
      if (parts.length >= 2) {
        parts[1] = parts[1].split('.').last;
        return parts.join(',');
      }
      return res;
    }).join('\n');
  }

  String getLastScanContent() {
    if (_scanResults.isEmpty) return '';
    final parts = _scanResults.last.split(',');
    if (parts.length >= 3) {
      return parts.sublist(2).join(',');
    }
    return _scanResults.last;
  }

  String toCsv() {
    return _scanResults
        .map((line) {
          final parts = line.split(',');
          if (parts.length >= 3) {
            final timestamp = parts[0];
            final format = parts[1];
            final content =
                '"${parts.sublist(2).join(',').replaceAll('"', '""')}"';
            return '"$timestamp","$format",$content';
          }
          return line;
        })
        .join('\n');
  }
}

lib/scanner_page.dart

import 'dart:async';
import 'package:audioplayers/audioplayers.dart';
import 'package:barcodereader/settings_provider.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:mobile_scanner/mobile_scanner.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import 'l10n/app_localizations.dart';

class ScannerPage extends StatefulWidget {
  final Function(String result) onScan;
  const ScannerPage({super.key, required this.onScan});
  @override
  State<ScannerPage> createState() => _ScannerPageState();
}

class _ScannerPageState extends State<ScannerPage> {
  final MobileScannerController _scannerController = MobileScannerController();
  bool _isScanPaused = false;
  bool _isFlashing = false;

  @override
  void initState() {
    super.initState();
    _setOrientation();
  }

  void _setOrientation() {
    final settings = context.read<SettingsProvider>();
    if (settings.lockOrientation) {
      SystemChrome.setPreferredOrientations([
        DeviceOrientation.portraitUp,
        DeviceOrientation.portraitDown,
      ]);
    }
  }

  @override
  void dispose() {
    _scannerController.dispose();
    SystemChrome.setPreferredOrientations([
      DeviceOrientation.portraitUp,
      DeviceOrientation.portraitDown,
      DeviceOrientation.landscapeLeft,
      DeviceOrientation.landscapeRight,
    ]);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final settings = context.watch<SettingsProvider>();
    return Scaffold(
      appBar: AppBar(
        backgroundColor: _isFlashing ? Colors.yellow : null,
        foregroundColor: _isFlashing ? Colors.black : null,
        actions: [
          IconButton(
            icon: ValueListenableBuilder<MobileScannerState>(
              valueListenable: _scannerController,
              builder: (context, state, child) {
                switch (state.torchState) {
                  case TorchState.off:
                    return Icon(
                      Icons.flash_off,
                      color: _isFlashing ? Colors.grey : Colors.white,
                    );
                  case TorchState.on:
                    return const Icon(Icons.flash_on, color: Colors.yellow);
                  default:
                    return const Icon(Icons.no_flash, color: Colors.grey);
                }
              },
            ),
            onPressed: () => _scannerController.toggleTorch(),
          ),
          IconButton(
            icon: const Icon(Icons.flip_camera_ios),
            onPressed: () => _scannerController.switchCamera(),
          ),
        ],
      ),
      body: MobileScanner(
        controller: _scannerController,
        onDetect: (capture) {
          if (_isScanPaused) return;

          final List<Barcode> barcodes = capture.barcodes;
          if (barcodes.isNotEmpty) {
            if (mounted) {
              setState(() {
                _isScanPaused = true;
              });
            }

            final String code =
                barcodes.first.rawValue ?? AppLocalizations.of(context)!.noData;
            final String format = barcodes.first.format.name;
            final String result =
                '${DateFormat('yyyyMMdd_HHmmss').format(DateTime.now())},$format,$code';
            widget.onScan(result);

            if (settings.beepOnScan) {
              final soundId = settings.selectedBeepSound;
              AudioPlayer().play(AssetSource('sound/beep$soundId.mp3'));
            }

            if (settings.flashOnScan) {
              if (mounted) {
                setState(() {
                  _isFlashing = true;
                });
              }
            }

            if (settings.continuousScan) {
              if (settings.flashOnScan) {
                Timer(const Duration(milliseconds: 200), () {
                  if (mounted) {
                    setState(() {
                      _isFlashing = false;
                    });
                  }
                });
              }
              final interval = (settings.scanInterval * 1000).toInt();
              Timer(Duration(milliseconds: interval), () {
                if (mounted) {
                  setState(() {
                    _isScanPaused = false;
                  });
                }
              });
            } else {
              final popDelay = settings.flashOnScan ? 200 : 50;
              Timer(Duration(milliseconds: popDelay), () {
                if (mounted) {
                  Navigator.of(context).pop();
                }
              });
            }
          }
        },
      ),
    );
  }
}

lib/settings_page.dart

import 'package:audioplayers/audioplayers.dart';
import 'package:flutter/material.dart';
import 'package:google_mobile_ads/google_mobile_ads.dart';
import 'package:provider/provider.dart';
import 'l10n/app_localizations.dart';

import 'package:barcodereader/ad_manager.dart';
import 'package:barcodereader/ad_banner_widget.dart';
import 'package:barcodereader/settings_provider.dart';

// 設定画面のUI (StatefulWidget)
class SettingsPage extends StatefulWidget {
  const SettingsPage({super.key});

  @override
  State<SettingsPage> createState() => _SettingsPageState();
}

class _SettingsPageState extends State<SettingsPage> {
  late AdManager _adManager;
  // 画面内でのみ変更を保持する一時的な変数
  late bool _tempContinuousScan;
  late bool _tempBeepOnScan;
  late bool _tempFlashOnScan;
  late bool _tempLockOrientation;
  late ThemeMode _tempThemeMode;
  late double _tempScanInterval;
  late int _tempSelectedBeepSound; // 一時変数
  late Locale? _tempAppLocale;

  final Map<String, String> languages = {
    'en': 'English',
    'bg': 'Български',
    'cs': 'Čeština',
    'da': 'Dansk',
    'de': 'Deutsch',
    'el': 'Ελληνικά',
    'es': 'Español',
    'et': 'Eesti',
    'fi': 'Suomi',
    'fr': 'Français',
    'hu': 'Magyar',
    'it': 'Italiano',
    'ja': '日本語',
    'lt': 'Lietuvių',
    'lv': 'Latviešu',
    'nl': 'Nederlands',
    'pl': 'Polski',
    'pt': 'Português',
    'ro': 'Română',
    'ru': 'Русский',
    'sk': 'Slovenčina',
    'sv': 'Svenska',
    'zh': '中文',
  };

  @override
  void initState() {
    super.initState();
    _adManager = AdManager();
    // Providerから初期値を取得して一時変数にセット
    final settings = context.read<SettingsProvider>();
    _tempContinuousScan = settings.continuousScan;
    _tempBeepOnScan = settings.beepOnScan;
    _tempFlashOnScan = settings.flashOnScan;
    _tempLockOrientation = settings.lockOrientation;
    _tempThemeMode = settings.themeMode;
    _tempScanInterval = settings.scanInterval;
    _tempSelectedBeepSound = settings.selectedBeepSound; // 初期値
    _tempAppLocale = settings.appLocale;
  }

  @override
  void dispose() {
    _adManager.dispose();
    super.dispose();
  }

  void _applyChanges() {
    // Provider経由で変更を保存
    final settings = context.read<SettingsProvider>();
    settings.setContinuousScan(_tempContinuousScan);
    settings.setBeepOnScan(_tempBeepOnScan);
    settings.setFlashOnScan(_tempFlashOnScan);
    settings.setLockOrientation(_tempLockOrientation);
    settings.setThemeMode(_tempThemeMode);
    settings.setScanInterval(_tempScanInterval);
    settings.setSelectedBeepSound(_tempSelectedBeepSound); // 保存
    settings.setAppLocale(_tempAppLocale);
    if (mounted) {
      Navigator.of(context).pop();
    }
  }

  @override
  Widget build(BuildContext context) {
    final l = AppLocalizations.of(context)!;
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        title: Text(l.settings),
        centerTitle: true,
        leading: IconButton(
          icon: const Icon(Icons.close),
          onPressed: () => Navigator.of(context).pop(),
        ),
        actions: [
          IconButton(icon: const Icon(Icons.check), onPressed: _applyChanges),
          const SizedBox(width: 24),
        ],
      ),
      body: ListView(
        children: [
          SwitchListTile(
            title: Text(l.continuousScan),
            value: _tempContinuousScan,
            onChanged: (value) => setState(() => _tempContinuousScan = value),
          ),
          Padding(
            padding: const EdgeInsets.symmetric(
              horizontal: 16.0,
              vertical: 8.0,
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  l.scanInterval(
                    _tempScanInterval.toStringAsFixed(1),
                  ),
                ),
                Slider(
                  value: _tempScanInterval,
                  min: 0.0,
                  max: 3.0,
                  divisions: 15,
                  label: '${_tempScanInterval.toStringAsFixed(1)}s',
                  onChanged: (value) {
                    setState(() {
                      _tempScanInterval = value;
                    });
                  },
                ),
              ],
            ),
          ),
          const Divider(),
          SwitchListTile(
            title: Text(l.beepOnScan),
            value: _tempBeepOnScan,
            onChanged: (value) => setState(() => _tempBeepOnScan = value),
          ),
          // --- ビープ音選択 ---
          ListTile(
            title: Text(l.beepSound),
            trailing: DropdownButton<int>(
              value: _tempSelectedBeepSound,
              items: List.generate(14, (index) {
                final soundNum = index + 1;
                return DropdownMenuItem(
                  value: soundNum,
                  child: Text(
                    l.beepSoundName(
                      soundNum.toString(),
                    ),
                  ),
                );
              }),
              onChanged: (value) {
                if (value != null) {
                  setState(() => _tempSelectedBeepSound = value);
                  AudioPlayer().play(AssetSource('sound/beep$value.mp3'));
                }
              },
            ),
          ),
          SwitchListTile(
            title: Text(l.flashOnScan),
            value: _tempFlashOnScan,
            onChanged: (value) => setState(() => _tempFlashOnScan = value),
          ),
          const Divider(),
          SwitchListTile(
            title: Text(l.lockOrientation),
            value: _tempLockOrientation,
            onChanged: (value) => setState(() => _tempLockOrientation = value),
          ),
          const Divider(),
          ListTile(
            title: Text(l.language),
            trailing: DropdownButton<String>(
              value: _tempAppLocale?.languageCode,
              hint: Text(l.systemDefault),
              items: [
                DropdownMenuItem<String>(
                  value: null,
                  child: Text(l.systemDefault),
                ),
                ...languages.entries.map((entry) {
                  return DropdownMenuItem<String>(
                    value: entry.key,
                    child: Text(entry.value),
                  );
                }),
              ],
              onChanged: (value) {
                setState(() {
                  if (value == null) {
                    _tempAppLocale = null;
                  } else {
                    _tempAppLocale = Locale(value);
                  }
                });
              },
            ),
          ),
          ListTile(
            title: Text(l.theme),
            trailing: DropdownButton<ThemeMode>(
              value: _tempThemeMode,
              items: [
                DropdownMenuItem(
                  value: ThemeMode.system,
                  child: Text(l.systemDefault),
                ),
                DropdownMenuItem(
                  value: ThemeMode.light,
                  child: Text(l.lightTheme),
                ),
                DropdownMenuItem(
                  value: ThemeMode.dark,
                  child: Text(l.darkTheme),
                ),
              ],
              onChanged: (value) {
                if (value != null) {
                  setState(() => _tempThemeMode = value);
                }
              },
            ),
          ),
          const Divider(),
        ],
      ),
      bottomNavigationBar: AdBannerWidget(adManager: _adManager),
    );
  }

}

lib/settings_provider.dart

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

// 設定値を管理するためのProvider
class SettingsProvider extends ChangeNotifier {
  bool _continuousScan = false;
  bool _beepOnScan = true;
  bool _flashOnScan = true;
  bool _lockOrientation = false;
  ThemeMode _themeMode = ThemeMode.system;
  double _scanInterval = 1.0;
  int _selectedBeepSound = 1; // ビープ音の選択値
  Locale? _appLocale;

  bool get continuousScan => _continuousScan;
  bool get beepOnScan => _beepOnScan;
  bool get flashOnScan => _flashOnScan;
  bool get lockOrientation => _lockOrientation;
  ThemeMode get themeMode => _themeMode;
  double get scanInterval => _scanInterval;
  int get selectedBeepSound => _selectedBeepSound; // getter
  Locale? get appLocale => _appLocale;

  static const String _continuousScanKey = 'continuousScan';
  static const String _beepOnScanKey = 'beepOnScan';
  static const String _flashOnScanKey = 'flashOnScan';
  static const String _lockOrientationKey = 'lockOrientation';
  static const String _themeModeKey = 'themeMode';
  static const String _scanIntervalKey = 'scanInterval';
  static const String _selectedBeepSoundKey = 'selectedBeepSound'; // キー
  static const String _appLocaleKey = 'appLocale';

  SettingsProvider() {
    _loadSettings();
  }

  // 設定をSharedPreferencesから読み込む
  Future<void> _loadSettings() async {
    final prefs = await SharedPreferences.getInstance();
    _continuousScan = prefs.getBool(_continuousScanKey) ?? false;
    _beepOnScan = prefs.getBool(_beepOnScanKey) ?? true;
    _flashOnScan = prefs.getBool(_flashOnScanKey) ?? true;
    _lockOrientation = prefs.getBool(_lockOrientationKey) ?? false;
    final themeIndex = prefs.getInt(_themeModeKey) ?? 0;
    _themeMode = ThemeMode.values[themeIndex];
    _scanInterval = prefs.getDouble(_scanIntervalKey) ?? 1.0;
    _selectedBeepSound = prefs.getInt(_selectedBeepSoundKey) ?? 1; // 読み込み
    final languageCode = prefs.getString(_appLocaleKey);
    if (languageCode != null) {
      _appLocale = Locale(languageCode);
    }
    notifyListeners();
  }

  // 各設定値を更新し、SharedPreferencesに保存
  Future<void> setContinuousScan(bool value) async {
    _continuousScan = value;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_continuousScanKey, value);
    notifyListeners();
  }

  Future<void> setBeepOnScan(bool value) async {
    _beepOnScan = value;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_beepOnScanKey, value);
    notifyListeners();
  }

  Future<void> setFlashOnScan(bool value) async {
    _flashOnScan = value;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_flashOnScanKey, value);
    notifyListeners();
  }

  Future<void> setLockOrientation(bool value) async {
    _lockOrientation = value;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_lockOrientationKey, value);
    notifyListeners();
  }

  Future<void> setThemeMode(ThemeMode value) async {
    _themeMode = value;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setInt(_themeModeKey, value.index);
    notifyListeners();
  }

  Future<void> setScanInterval(double value) async {
    _scanInterval = value;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setDouble(_scanIntervalKey, value);
    notifyListeners();
  }

  Future<void> setSelectedBeepSound(int value) async {
    // setter
    _selectedBeepSound = value;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setInt(_selectedBeepSoundKey, value);
    notifyListeners();
  }

  Future<void> setAppLocale(Locale? locale) async {
    _appLocale = locale;
    final prefs = await SharedPreferences.getInstance();
    if (locale == null) {
      await prefs.remove(_appLocaleKey);
    } else {
      await prefs.setString(_appLocaleKey, locale.languageCode);
    }
    notifyListeners();
  }
}