Refactor: move theme prefs to PrefController

app/lib/bloc_util.dart

@@ -1,3 +1,5 @@
+import 'package:flutter_bloc/flutter_bloc.dart';
+
 mixin BlocLogger {
   String? get tag => null;
 
@@ -11,3 +13,15 @@ class StateMessage {
 
   final String value;
 }
+
+extension EmitterExtension<State> on Emitter<State> {
+  Future<void> forEachIgnoreError<T>(
+    Stream<T> stream, {
+    required State Function(T data) onData,
+  }) =>
+      onEach<T>(
+        stream,
+        onData: (data) => call(onData(data)),
+        onError: (_, __) {},
+      );
+}

app/lib/controller/pref_controller.dart

@@ -1,3 +1,6 @@
+// ignore_for_file: deprecated_member_use_from_same_package
+
+import 'package:flutter/material.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/pref.dart';
@@ -141,6 +144,41 @@ class PrefController {
         value: value,
       );
 
+  ValueStream<bool> get isDarkTheme => _isDarkThemeController.stream;
+
+  Future<void> setDarkTheme(bool value) => _set<bool>(
+        controller: _isDarkThemeController,
+        setter: (pref, value) => pref.setDarkTheme(value),
+        value: value,
+      );
+
+  ValueStream<bool> get isFollowSystemTheme =>
+      _isFollowSystemThemeController.stream;
+
+  Future<void> setFollowSystemTheme(bool value) => _set<bool>(
+        controller: _isFollowSystemThemeController,
+        setter: (pref, value) => pref.setFollowSystemTheme(value),
+        value: value,
+      );
+
+  ValueStream<bool> get isUseBlackInDarkTheme =>
+      _isUseBlackInDarkThemeController.stream;
+
+  Future<void> setUseBlackInDarkTheme(bool value) => _set<bool>(
+        controller: _isUseBlackInDarkThemeController,
+        setter: (pref, value) => pref.setUseBlackInDarkTheme(value),
+        value: value,
+      );
+
+  ValueStream<Color?> get seedColor => _seedColorController.stream;
+
+  Future<void> setSeedColor(Color? value) => _setOrRemove<Color>(
+        controller: _seedColorController,
+        setter: (pref, value) => pref.setSeedColor(value.withAlpha(0xFF).value),
+        remover: (pref) => pref.setSeedColor(null),
+        value: value,
+      );
+
   Future<void> _set<T>({
     required BehaviorSubject<T> controller,
     required Future<bool> Function(Pref pref, T value) setter,
@@ -160,6 +198,33 @@ class PrefController {
     }
   }
 
+  Future<void> _setOrRemove<T>({
+    required BehaviorSubject<T?> controller,
+    required Future<bool> Function(Pref pref, T value) setter,
+    required Future<bool> Function(Pref pref) remover,
+    required T? value,
+    T? defaultValue,
+  }) async {
+    final backup = controller.value;
+    controller.add(value ?? defaultValue);
+    try {
+      if (value == null) {
+        if (!await remover(_c.pref)) {
+          throw StateError("Unknown error");
+        }
+      } else {
+        if (!await setter(_c.pref, value)) {
+          throw StateError("Unknown error");
+        }
+      }
+    } catch (e, stackTrace) {
+      _log.severe("[_set] Failed setting preference", e, stackTrace);
+      controller
+        ..addError(e, stackTrace)
+        ..add(backup);
+    }
+  }
+
   static language_util.AppLanguage _langIdToAppLanguage(int langId) {
     try {
       return language_util.supportedLanguages[langId]!;
@@ -168,6 +233,8 @@ class PrefController {
     }
   }
 
+  static const _seedColorDef = 0xFF2196F3;
+
   final DiContainer _c;
   late final _languageController =
       BehaviorSubject.seeded(_langIdToAppLanguage(_c.pref.getLanguageOr(0)));
@@ -197,4 +264,12 @@ class PrefController {
       BehaviorSubject.seeded(_c.pref.isSaveEditResultToServerOr(true));
   late final _enhanceMaxSizeController = BehaviorSubject.seeded(
       SizeInt(_c.pref.getEnhanceMaxWidthOr(), _c.pref.getEnhanceMaxHeightOr()));
+  late final _isDarkThemeController =
+      BehaviorSubject.seeded(_c.pref.isDarkThemeOr(false));
+  late final _isFollowSystemThemeController =
+      BehaviorSubject.seeded(_c.pref.isFollowSystemThemeOr(false));
+  late final _isUseBlackInDarkThemeController =
+      BehaviorSubject.seeded(_c.pref.isUseBlackInDarkThemeOr(false));
+  late final _seedColorController = BehaviorSubject<Color?>.seeded(
+      Color(_c.pref.getSeedColorOr(_seedColorDef)));
 }

app/lib/entity/pref/extension.dart

@@ -101,21 +101,30 @@ extension PrefExtension on Pref {
   Future<bool> setLastVersion(int value) => _set<int>(
       PrefKey.lastVersion, value, (key, value) => provider.setInt(key, value));
 
+  @Deprecated("Use PrefController")
   bool? isDarkTheme() => provider.getBool(PrefKey.darkTheme);
+  @Deprecated("Use PrefController")
   bool isDarkThemeOr(bool def) => isDarkTheme() ?? def;
+  @Deprecated("Use PrefController")
   Future<bool> setDarkTheme(bool value) => _set<bool>(
       PrefKey.darkTheme, value, (key, value) => provider.setBool(key, value));
 
+  @Deprecated("Use PrefController")
   bool? isFollowSystemTheme() => provider.getBool(PrefKey.followSystemTheme);
+  @Deprecated("Use PrefController")
   bool isFollowSystemThemeOr(bool def) => isFollowSystemTheme() ?? def;
+  @Deprecated("Use PrefController")
   Future<bool> setFollowSystemTheme(bool value) => _set<bool>(
       PrefKey.followSystemTheme,
       value,
       (key, value) => provider.setBool(key, value));
 
+  @Deprecated("Use PrefController")
   bool? isUseBlackInDarkTheme() =>
       provider.getBool(PrefKey.useBlackInDarkTheme);
+  @Deprecated("Use PrefController")
   bool isUseBlackInDarkThemeOr(bool def) => isUseBlackInDarkTheme() ?? def;
+  @Deprecated("Use PrefController")
   Future<bool> setUseBlackInDarkTheme(bool value) => _set<bool>(
       PrefKey.useBlackInDarkTheme,
       value,
@@ -249,8 +258,11 @@ extension PrefExtension on Pref {
       value,
       (key, value) => provider.setBool(key, value));
 
+  @Deprecated("Use PrefController")
   int? getSeedColor() => provider.getInt(PrefKey.seedColor);
+  @Deprecated("Use PrefController")
   int getSeedColorOr(int def) => getSeedColor() ?? def;
+  @Deprecated("Use PrefController")
   Future<bool> setSeedColor(int? value) {
     if (value == null) {
       return _remove(PrefKey.seedColor);

app/lib/event/event.dart

@@ -117,8 +117,6 @@ class FavoriteResyncedEvent {
   final Account account;
 }
 
-class ThemeChangedEvent {}
-
 enum MetadataTaskState {
   /// No work is being done
   idle,

app/lib/theme.dart

@@ -1,12 +1,12 @@
 import 'dart:ui';
 
 import 'package:flutter/material.dart';
-import 'package:nc_photos/entity/pref.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
-import 'package:nc_photos/object_extension.dart';
+import 'package:nc_photos/controller/pref_controller.dart';
 import 'package:nc_photos/theme/dimension.dart';
 import 'package:nc_photos/theme/material3.dart';
 
-const defaultSeedColor = 0xFF2196F3;
+const defaultSeedColor = Color(0xFF2196F3);
 
 extension ThemeExtension on ThemeData {
   double get widthLimitedContentMaxWidth => 550.0;
@@ -88,20 +88,20 @@ class DarkModeSwitchTheme extends StatelessWidget {
   final Widget child;
 }
 
-ThemeData buildTheme(Brightness brightness) {
+ThemeData buildTheme(BuildContext context, Brightness brightness) {
   return (brightness == Brightness.light)
-      ? buildLightTheme()
+      ? buildLightTheme(context)
-      : buildDarkTheme();
+      : buildDarkTheme(context);
 }
 
-ThemeData buildLightTheme([ColorScheme? dynamicScheme]) {
+ThemeData buildLightTheme(BuildContext context, [ColorScheme? dynamicScheme]) {
-  final colorScheme = _getColorScheme(dynamicScheme, Brightness.light);
+  final colorScheme = _getColorScheme(context, dynamicScheme, Brightness.light);
   return _applyColorScheme(colorScheme);
 }
 
-ThemeData buildDarkTheme([ColorScheme? dynamicScheme]) {
+ThemeData buildDarkTheme(BuildContext context, [ColorScheme? dynamicScheme]) {
-  final colorScheme = _getColorScheme(dynamicScheme, Brightness.dark);
+  final colorScheme = _getColorScheme(context, dynamicScheme, Brightness.dark);
-  if (Pref().isUseBlackInDarkThemeOr(false)) {
+  if (context.read<PrefController>().isUseBlackInDarkTheme.value) {
     return _applyColorScheme(colorScheme.copyWith(
       background: Colors.black,
       surface: Colors.grey[900],
@@ -111,12 +111,13 @@ ThemeData buildDarkTheme([ColorScheme? dynamicScheme]) {
   }
 }
 
-Color? getSeedColor() {
+Color? getSeedColor(BuildContext context) {
-  return Pref().getSeedColor()?.run((c) => Color(c).withAlpha(0xFF));
+  return context.read<PrefController>().seedColor.value;
 }
 
-ColorScheme _getColorScheme(ColorScheme? dynamicScheme, Brightness brightness) {
+ColorScheme _getColorScheme(
-  var seedColor = Pref().getSeedColor();
+    BuildContext context, ColorScheme? dynamicScheme, Brightness brightness) {
+  var seedColor = getSeedColor(context);
   if (seedColor == null) {
     if (dynamicScheme != null) {
       return dynamicScheme;
@@ -125,7 +126,7 @@ ColorScheme _getColorScheme(ColorScheme? dynamicScheme, Brightness brightness) {
     }
   }
   return ColorScheme.fromSeed(
-    seedColor: Color(seedColor),
+    seedColor: seedColor,
     brightness: brightness,
   );
 }

app/lib/widget/account_picker_dialog.dart

@@ -4,7 +4,6 @@ import 'dart:math';
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:clock/clock.dart';
 import 'package:copy_with/copy_with.dart';
-import 'package:event_bus/event_bus.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:kiwi/kiwi.dart';
@@ -15,15 +14,16 @@ import 'package:nc_photos/api/api_util.dart' as api_util;
 import 'package:nc_photos/app_localizations.dart';
 import 'package:nc_photos/bloc_util.dart';
 import 'package:nc_photos/controller/account_controller.dart';
+import 'package:nc_photos/controller/pref_controller.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/pref.dart';
 import 'package:nc_photos/entity/server_status.dart';
 import 'package:nc_photos/entity/sqlite/database.dart' as sql;
-import 'package:nc_photos/event/event.dart';
 import 'package:nc_photos/exception_event.dart';
 import 'package:nc_photos/exception_util.dart' as exception_util;
 import 'package:nc_photos/help_utils.dart' as help_util;
 import 'package:nc_photos/k.dart' as k;
+import 'package:nc_photos/stream_util.dart';
 import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/toast.dart';
 import 'package:nc_photos/url_launcher_util.dart';
@@ -50,6 +50,7 @@ class AccountPickerDialog extends StatelessWidget {
       create: (context) => _Bloc(
         container: KiwiContainer().resolve(),
         accountController: context.read(),
+        prefController: context.read(),
       ),
       child: const _WrappedAccountPickerDialog(),
     );
@@ -112,13 +113,27 @@ class _WrappedAccountPickerDialog extends StatelessWidget {
                             style: Theme.of(context).textTheme.titleLarge,
                           ),
                         ),
-                        if (!Pref().isFollowSystemThemeOr(false))
+                        ValueStreamBuilder<bool>(
-                          Align(
+                          stream: context
-                            alignment: AlignmentDirectional.centerEnd,
+                              .read<PrefController>()
-                            child: _DarkModeSwitch(
+                              .isFollowSystemTheme,
-                              onChanged: _onDarkModeChanged,
+                          builder: (_, isFollowSystemTheme) {
-                            ),
+                            if (!isFollowSystemTheme.requireData) {
-                          ),
+                              return Align(
+                                alignment: AlignmentDirectional.centerEnd,
+                                child: _DarkModeSwitch(
+                                  onChanged: (value) {
+                                    context
+                                        .read<_Bloc>()
+                                        .add(_SetDarkTheme(value));
+                                  },
+                                ),
+                              );
+                            } else {
+                              return const SizedBox.shrink();
+                            }
+                          },
+                        ),
                       ],
                     ),
                     const SizedBox(height: 8),
@@ -192,12 +207,6 @@ class _WrappedAccountPickerDialog extends StatelessWidget {
       ),
     );
   }
-
-  void _onDarkModeChanged(bool value) {
-    Pref().setDarkTheme(value).then((_) {
-      KiwiContainer().resolve<EventBus>().fire(ThemeChangedEvent());
-    });
-  }
 }
 
 class _DarkModeSwitch extends StatelessWidget {

app/lib/widget/account_picker_dialog.g.dart

@@ -89,6 +89,13 @@ extension _$_DeleteAccountToString on _DeleteAccount {
   }
 }
 
+extension _$_SetDarkThemeToString on _SetDarkTheme {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "_SetDarkTheme {value: $value}";
+  }
+}
+
 extension _$_SetErrorToString on _SetError {
   String _$toString() {
     // ignore: unnecessary_string_interpolations

app/lib/widget/account_picker_dialog/bloc.dart

@@ -5,6 +5,7 @@ class _Bloc extends Bloc<_Event, _State> with BlocLogger {
   _Bloc({
     required DiContainer container,
     required this.accountController,
+    required this.prefController,
   })  : _c = container,
         super(_State.init(
           accounts: container.pref.getAccounts3Or([]),
@@ -12,6 +13,7 @@ class _Bloc extends Bloc<_Event, _State> with BlocLogger {
     on<_ToggleDropdown>(_onToggleDropdown);
     on<_SwitchAccount>(_onSwitchAccount);
     on<_DeleteAccount>(_onDeleteAccount);
+    on<_SetDarkTheme>(_onSetDarkTheme);
 
     on<_SetError>(_onSetError);
   }
@@ -86,6 +88,11 @@ class _Bloc extends Bloc<_Event, _State> with BlocLogger {
     }
   }
 
+  void _onSetDarkTheme(_SetDarkTheme ev, Emitter<_State> emit) {
+    _log.info(ev);
+    prefController.setDarkTheme(ev.value);
+  }
+
   void _onSetError(_SetError ev, Emitter<_State> emit) {
     _log.info(ev);
     emit(state.copyWith(error: ExceptionEvent(ev.error, ev.stackTrace)));
@@ -104,6 +111,7 @@ class _Bloc extends Bloc<_Event, _State> with BlocLogger {
 
   final DiContainer _c;
   final AccountController accountController;
+  final PrefController prefController;
   late final Account activeAccount = accountController.account;
 
   final _prefLock = Mutex();

app/lib/widget/account_picker_dialog/state_event.dart

@@ -60,6 +60,16 @@ class _DeleteAccount implements _Event {
   final Account account;
 }
 
+@toString
+class _SetDarkTheme implements _Event {
+  const _SetDarkTheme(this.value);
+
+  @override
+  String toString() => _$toString();
+
+  final bool value;
+}
+
 @toString
 class _SetError implements _Event {
   const _SetError(this.error, [this.stackTrace]);

app/lib/widget/connect.dart

@@ -73,7 +73,7 @@ class _ConnectState extends State<Connect> {
   @override
   build(BuildContext context) {
     return Theme(
-      data: buildDarkTheme().copyWith(
+      data: buildDarkTheme(context).copyWith(
         scaffoldBackgroundColor: Theme.of(context).nextcloudBlue,
         progressIndicatorTheme: const ProgressIndicatorThemeData(
           color: Colors.white,

app/lib/widget/image_editor.dart

@@ -87,7 +87,7 @@ class _ImageEditorState extends State<ImageEditor> {
 
   @override
   build(BuildContext context) => Theme(
-        data: buildDarkTheme(),
+        data: buildDarkTheme(context),
         child: Scaffold(
           body: Builder(
             builder: _buildContent,

app/lib/widget/image_enhancer.dart

@@ -88,7 +88,7 @@ class _ImageEnhancerState extends State<ImageEnhancer> {
 
   @override
   build(BuildContext context) => Theme(
-        data: buildDarkTheme(),
+        data: buildDarkTheme(context),
         child: Scaffold(
           body: Builder(
             builder: _buildContent,

app/lib/widget/local_file_viewer.dart

@@ -53,7 +53,7 @@ class _LocalFileViewerState extends State<LocalFileViewer> {
   @override
   build(BuildContext context) {
     return Theme(
-      data: buildDarkTheme(),
+      data: buildDarkTheme(context),
       child: Scaffold(
         body: Builder(
           builder: _buildContent,

app/lib/widget/my_app.dart

@@ -1,3 +1,4 @@
+import 'package:copy_with/copy_with.dart';
 import 'package:dynamic_color/dynamic_color.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
@@ -6,18 +7,16 @@ import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:kiwi/kiwi.dart';
 import 'package:logging/logging.dart';
+import 'package:nc_photos/bloc_util.dart';
 import 'package:nc_photos/controller/account_controller.dart';
 import 'package:nc_photos/controller/pref_controller.dart';
 import 'package:nc_photos/di_container.dart';
-import 'package:nc_photos/entity/pref.dart';
-import 'package:nc_photos/event/event.dart';
 import 'package:nc_photos/language_util.dart' as language_util;
 import 'package:nc_photos/legacy/connect.dart' as legacy;
 import 'package:nc_photos/legacy/sign_in.dart' as legacy;
 import 'package:nc_photos/navigation_manager.dart';
 import 'package:nc_photos/session_storage.dart';
 import 'package:nc_photos/snack_bar_manager.dart';
-import 'package:nc_photos/stream_util.dart';
 import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/widget/album_dir_picker.dart';
 import 'package:nc_photos/widget/album_importer.dart';
@@ -51,8 +50,15 @@ import 'package:nc_photos/widget/trashbin_browser.dart';
 import 'package:nc_photos/widget/trashbin_viewer.dart';
 import 'package:nc_photos/widget/viewer.dart';
 import 'package:np_codegen/np_codegen.dart';
+import 'package:to_string/to_string.dart';
 
 part 'my_app.g.dart';
+part 'my_app/bloc.dart';
+part 'my_app/state_event.dart';
+
+typedef _BlocBuilder = BlocBuilder<_Bloc, _State>;
+// typedef _BlocListener = BlocListener<_Bloc, _State>;
+// typedef _BlocSelector<T> = BlocSelector<_Bloc, _State, T>;
 
 class MyApp extends StatelessWidget {
   const MyApp({super.key});
@@ -69,7 +75,12 @@ class MyApp extends StatelessWidget {
           create: (_) => PrefController(_c),
         ),
       ],
-      child: const _WrappedApp(),
+      child: BlocProvider(
+        create: (context) => _Bloc(
+          prefController: context.read(),
+        ),
+        child: const _WrappedApp(),
+      ),
     );
   }
 
@@ -96,43 +107,48 @@ class _WrappedAppState extends State<_WrappedApp>
     super.initState();
     SnackBarManager().registerHandler(this);
     NavigationManager().setHandler(this);
-    _themeChangedListener =
+
-        AppEventListener<ThemeChangedEvent>(_onThemeChangedEvent)..begin();
+    _bloc.add(const _Init());
   }
 
   @override
   Widget build(BuildContext context) {
-    final ThemeMode themeMode;
+    return _BlocBuilder(
-    if (Pref().isFollowSystemThemeOr(false)) {
+      buildWhen: (previous, current) =>
-      themeMode = ThemeMode.system;
+          previous.language != current.language ||
-    } else {
+          previous.isDarkTheme != current.isDarkTheme ||
-      themeMode =
+          previous.isFollowSystemTheme != current.isFollowSystemTheme ||
-          Pref().isDarkThemeOr(false) ? ThemeMode.dark : ThemeMode.light;
+          previous.isUseBlackInDarkTheme != current.isUseBlackInDarkTheme ||
-    }
+          previous.seedColor != current.seedColor,
-    final prefController = context.read<PrefController>();
+      builder: (context, state) => DynamicColorBuilder(
-    return ValueStreamBuilder<language_util.AppLanguage>(
-      stream: prefController.language,
-      builder: (context, snapshot) => DynamicColorBuilder(
         builder: (lightDynamic, darkDynamic) {
           if (lightDynamic != null) {
             SessionStorage().isSupportDynamicColor = true;
           }
+          final ThemeMode themeMode;
+          if (state.isFollowSystemTheme) {
+            themeMode = ThemeMode.system;
+          } else {
+            themeMode = state.isDarkTheme ? ThemeMode.dark : ThemeMode.light;
+          }
           return MaterialApp(
             onGenerateTitle: (context) =>
                 AppLocalizations.of(context)!.appTitle,
-            theme: buildLightTheme(lightDynamic),
+            theme: buildLightTheme(context, lightDynamic),
-            darkTheme: buildDarkTheme(darkDynamic),
+            darkTheme: buildDarkTheme(context, darkDynamic),
             themeMode: themeMode,
             initialRoute: Splash.routeName,
             onGenerateRoute: _onGenerateRoute,
-            navigatorObservers: <NavigatorObserver>[MyApp.routeObserver],
+            navigatorObservers: [
+              MyApp.routeObserver,
+            ],
             navigatorKey: _navigatorKey,
             scaffoldMessengerKey: _scaffoldMessengerKey,
-            locale: snapshot.requireData.locale,
+            locale: state.language.locale,
             localizationsDelegates: AppLocalizations.localizationsDelegates,
-            supportedLocales: const <Locale>[
+            supportedLocales: const [
-              // the order here doesn't matter, except for the first one, which must
+              // the order here doesn't matter, except for the first one, which
-              // be en
+              // must be en
               Locale("en"),
               Locale("el"),
               Locale("es"),
@@ -166,7 +182,6 @@ class _WrappedAppState extends State<_WrappedApp>
     super.dispose();
     SnackBarManager().unregisterHandler(this);
     NavigationManager().unsetHandler(this);
-    _themeChangedListener.end();
   }
 
   @override
@@ -227,10 +242,6 @@ class _WrappedAppState extends State<_WrappedApp>
     return route;
   }
 
-  void _onThemeChangedEvent(ThemeChangedEvent ev) {
-    setState(() {});
-  }
-
   Route<dynamic>? _handleBasicRoute(RouteSettings settings) {
     for (final e in _getRouter().entries) {
       if (e.key == settings.name) {
@@ -578,10 +589,9 @@ class _WrappedAppState extends State<_WrappedApp>
     return null;
   }
 
+  late final _bloc = context.read<_Bloc>();
   final _scaffoldMessengerKey = GlobalKey<ScaffoldMessengerState>();
   final _navigatorKey = GlobalKey<NavigatorState>();
-
-  late AppEventListener<ThemeChangedEvent> _themeChangedListener;
 }
 
 class _ThemedMyApp extends StatelessWidget {

app/lib/widget/my_app.g.dart

@@ -2,6 +2,54 @@
 
 part of 'my_app.dart';
 
+// **************************************************************************
+// CopyWithLintRuleGenerator
+// **************************************************************************
+
+// ignore_for_file: library_private_types_in_public_api, duplicate_ignore
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class $_StateCopyWithWorker {
+  _State call(
+      {language_util.AppLanguage? language,
+      bool? isDarkTheme,
+      bool? isFollowSystemTheme,
+      bool? isUseBlackInDarkTheme,
+      int? seedColor});
+}
+
+class _$_StateCopyWithWorkerImpl implements $_StateCopyWithWorker {
+  _$_StateCopyWithWorkerImpl(this.that);
+
+  @override
+  _State call(
+      {dynamic language,
+      dynamic isDarkTheme,
+      dynamic isFollowSystemTheme,
+      dynamic isUseBlackInDarkTheme,
+      dynamic seedColor = copyWithNull}) {
+    return _State(
+        language: language as language_util.AppLanguage? ?? that.language,
+        isDarkTheme: isDarkTheme as bool? ?? that.isDarkTheme,
+        isFollowSystemTheme:
+            isFollowSystemTheme as bool? ?? that.isFollowSystemTheme,
+        isUseBlackInDarkTheme:
+            isUseBlackInDarkTheme as bool? ?? that.isUseBlackInDarkTheme,
+        seedColor:
+            seedColor == copyWithNull ? that.seedColor : seedColor as int?);
+  }
+
+  final _State that;
+}
+
+extension $_StateCopyWith on _State {
+  $_StateCopyWithWorker get copyWith => _$copyWith;
+  $_StateCopyWithWorker get _$copyWith => _$_StateCopyWithWorkerImpl(this);
+}
+
 // **************************************************************************
 // NpLogGenerator
 // **************************************************************************
@@ -12,3 +60,28 @@ extension _$_WrappedAppStateNpLog on _WrappedAppState {
 
   static final log = Logger("widget.my_app._WrappedAppState");
 }
+
+extension _$_BlocNpLog on _Bloc {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log = Logger("widget.my_app._Bloc");
+}
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$_StateToString on _State {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "_State {language: $language, isDarkTheme: $isDarkTheme, isFollowSystemTheme: $isFollowSystemTheme, isUseBlackInDarkTheme: $isUseBlackInDarkTheme, seedColor: $seedColor}";
+  }
+}
+
+extension _$_InitToString on _Init {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "_Init {}";
+  }
+}

app/lib/widget/my_app/bloc.dart

@@ -0,0 +1,47 @@
+part of '../my_app.dart';
+
+@npLog
+class _Bloc extends Bloc<_Event, _State> with BlocLogger {
+  _Bloc({
+    required this.prefController,
+  }) : super(_State(
+          language: prefController.language.value,
+          isDarkTheme: prefController.isDarkTheme.value,
+          isFollowSystemTheme: prefController.isFollowSystemTheme.value,
+          isUseBlackInDarkTheme: prefController.isUseBlackInDarkTheme.value,
+          seedColor: prefController.seedColor.value?.value,
+        )) {
+    on<_Init>(_onInit);
+  }
+
+  @override
+  String get tag => _log.fullName;
+
+  Future<void> _onInit(_Init ev, Emitter<_State> emit) async {
+    _log.info(ev);
+    await Future.wait([
+      emit.forEachIgnoreError<language_util.AppLanguage>(
+        prefController.language,
+        onData: (data) => state.copyWith(language: data),
+      ),
+      emit.forEachIgnoreError<bool>(
+        prefController.isDarkTheme,
+        onData: (data) => state.copyWith(isDarkTheme: data),
+      ),
+      emit.forEachIgnoreError<bool>(
+        prefController.isFollowSystemTheme,
+        onData: (data) => state.copyWith(isFollowSystemTheme: data),
+      ),
+      emit.forEachIgnoreError<bool>(
+        prefController.isUseBlackInDarkTheme,
+        onData: (data) => state.copyWith(isUseBlackInDarkTheme: data),
+      ),
+      emit.forEachIgnoreError<Color?>(
+        prefController.seedColor,
+        onData: (data) => state.copyWith(seedColor: data?.value),
+      ),
+    ]);
+  }
+
+  final PrefController prefController;
+}

app/lib/widget/my_app/state_event.dart

@@ -0,0 +1,32 @@
+part of '../my_app.dart';
+
+@genCopyWith
+@toString
+class _State {
+  const _State({
+    required this.language,
+    required this.isDarkTheme,
+    required this.isFollowSystemTheme,
+    required this.isUseBlackInDarkTheme,
+    required this.seedColor,
+  });
+
+  @override
+  String toString() => _$toString();
+
+  final language_util.AppLanguage language;
+  final bool isDarkTheme;
+  final bool isFollowSystemTheme;
+  final bool isUseBlackInDarkTheme;
+  final int? seedColor;
+}
+
+abstract class _Event {}
+
+@toString
+class _Init implements _Event {
+  const _Init();
+
+  @override
+  String toString() => _$toString();
+}

app/lib/widget/result_viewer.dart

@@ -61,7 +61,7 @@ class _ResultViewerState extends State<ResultViewer> {
   build(BuildContext context) {
     if (_file == null) {
       return Theme(
-        data: buildDarkTheme(),
+        data: buildDarkTheme(context),
         child: Scaffold(
           appBar: AppBar(
             backgroundColor: Colors.black,

app/lib/widget/settings/theme/bloc.dart

@@ -1,76 +1,68 @@
 part of '../theme_settings.dart';
 
-class _Error {
-  const _Error(this.ev);
-
-  final _Event ev;
-}
-
 @npLog
 class _Bloc extends Bloc<_Event, _State> with BlocLogger {
-  _Bloc(DiContainer c)
+  _Bloc({
-      : assert(require(c)),
+    required this.prefController,
-        _c = c,
+  }) : super(_State(
-        super(_State(
+          isFollowSystemTheme: prefController.isFollowSystemTheme.value,
-          isFollowSystemTheme: c.pref.isFollowSystemThemeOr(false),
+          isUseBlackInDarkTheme: prefController.isUseBlackInDarkTheme.value,
-          isUseBlackInDarkTheme: c.pref.isUseBlackInDarkThemeOr(false),
+          seedColor: prefController.seedColor.value?.value,
-          seedColor: getSeedColor()?.value,
         )) {
+    on<_Init>(_onInit);
     on<_SetFollowSystemTheme>(_onSetFollowSystemTheme);
     on<_SetUseBlackInDarkTheme>(_onSetUseBlackInDarkTheme);
     on<_SetSeedColor>(_onSetSeedColor);
   }
 
-  static bool require(DiContainer c) => DiContainer.has(c, DiType.pref);
-
   @override
   String get tag => _log.fullName;
 
-  Stream<_Error> errorStream() => _errorStream.stream;
+  Future<void> _onInit(_Init ev, Emitter<_State> emit) async {
-
-  Future<void> _onSetFollowSystemTheme(
-      _SetFollowSystemTheme ev, Emitter<_State> emit) async {
     _log.info(ev);
-    final oldValue = state.isFollowSystemTheme;
+    await Future.wait([
-    emit(state.copyWith(isFollowSystemTheme: ev.value));
+      emit.forEach<bool>(
-    if (await _c.pref.setFollowSystemTheme(ev.value)) {
+        prefController.isFollowSystemTheme,
-      KiwiContainer().resolve<EventBus>().fire(ThemeChangedEvent());
+        onData: (data) => state.copyWith(isFollowSystemTheme: data),
-    } else {
+        onError: (e, stackTrace) {
-      _log.severe("[_onSetFollowSystemTheme] Failed writing pref");
+          _log.severe("[_onInit] Uncaught exception", e, stackTrace);
-      _errorStream.add(_Error(ev));
+          return state.copyWith(error: ExceptionEvent(e, stackTrace));
-      emit(state.copyWith(isFollowSystemTheme: oldValue));
+        },
-    }
+      ),
+      emit.forEach<bool>(
+        prefController.isUseBlackInDarkTheme,
+        onData: (data) => state.copyWith(isUseBlackInDarkTheme: data),
+        onError: (e, stackTrace) {
+          _log.severe("[_onInit] Uncaught exception", e, stackTrace);
+          return state.copyWith(error: ExceptionEvent(e, stackTrace));
+        },
+      ),
+      emit.forEach<Color?>(
+        prefController.seedColor,
+        onData: (data) => state.copyWith(seedColor: data?.value),
+        onError: (e, stackTrace) {
+          _log.severe("[_onInit] Uncaught exception", e, stackTrace);
+          return state.copyWith(error: ExceptionEvent(e, stackTrace));
+        },
+      ),
+    ]);
   }
 
-  Future<void> _onSetUseBlackInDarkTheme(
+  void _onSetFollowSystemTheme(_SetFollowSystemTheme ev, Emitter<_State> emit) {
-      _SetUseBlackInDarkTheme ev, Emitter<_State> emit) async {
     _log.info(ev);
-    final oldValue = state.isUseBlackInDarkTheme;
+    prefController.setFollowSystemTheme(ev.value);
-    emit(state.copyWith(isUseBlackInDarkTheme: ev.value));
-    if (await _c.pref.setUseBlackInDarkTheme(ev.value)) {
-      if (ev.theme.brightness == Brightness.dark) {
-        KiwiContainer().resolve<EventBus>().fire(ThemeChangedEvent());
-      }
-    } else {
-      _log.severe("[_onSetUseBlackInDarkTheme] Failed writing pref");
-      _errorStream.add(_Error(ev));
-      emit(state.copyWith(isUseBlackInDarkTheme: oldValue));
-    }
   }
 
-  Future<void> _onSetSeedColor(_SetSeedColor ev, Emitter<_State> emit) async {
+  void _onSetUseBlackInDarkTheme(
+      _SetUseBlackInDarkTheme ev, Emitter<_State> emit) {
     _log.info(ev);
-    final oldValue = state.seedColor;
+    prefController.setUseBlackInDarkTheme(ev.value);
-    emit(state.copyWith(seedColor: ev.value?.value));
-    if (await _c.pref.setSeedColor(ev.value?.withAlpha(0xFF).value)) {
-      KiwiContainer().resolve<EventBus>().fire(ThemeChangedEvent());
-    } else {
-      _log.severe("[_onSetSeedColor] Failed writing pref");
-      _errorStream.add(_Error(ev));
-      emit(state.copyWith(seedColor: oldValue));
-    }
   }
 
-  final DiContainer _c;
+  void _onSetSeedColor(_SetSeedColor ev, Emitter<_State> emit) {
-  final _errorStream = StreamController<_Error>.broadcast();
+    _log.info(ev);
+    prefController.setSeedColor(ev.value);
+  }
+
+  final PrefController prefController;
 }

app/lib/widget/settings/theme/state_event.dart

@@ -7,6 +7,7 @@ class _State {
     required this.isFollowSystemTheme,
     required this.isUseBlackInDarkTheme,
     required this.seedColor,
+    this.error,
   });
 
   @override
@@ -16,12 +17,22 @@ class _State {
   final bool isUseBlackInDarkTheme;
   // workaround analyzer bug where Color type can't be recognized
   final int? seedColor;
+
+  final ExceptionEvent? error;
 }
 
 abstract class _Event {
   const _Event();
 }
 
+@toString
+class _Init implements _Event {
+  const _Init();
+
+  @override
+  String toString() => _$toString();
+}
+
 @toString
 class _SetFollowSystemTheme extends _Event {
   const _SetFollowSystemTheme(this.value);

app/lib/widget/settings/theme_settings.dart

@@ -1,23 +1,23 @@
 import 'dart:async';
 
 import 'package:copy_with/copy_with.dart';
-import 'package:event_bus/event_bus.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_colorpicker/flutter_colorpicker.dart';
-import 'package:kiwi/kiwi.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/app_localizations.dart';
 import 'package:nc_photos/bloc_util.dart';
-import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/controller/pref_controller.dart';
-import 'package:nc_photos/entity/pref.dart';
+import 'package:nc_photos/exception_event.dart';
-import 'package:nc_photos/event/event.dart';
+import 'package:nc_photos/exception_util.dart' as exception_util;
 import 'package:nc_photos/k.dart' as k;
 import 'package:nc_photos/mobile/android/android_info.dart';
+import 'package:nc_photos/object_extension.dart';
 import 'package:nc_photos/platform/k.dart' as platform_k;
 import 'package:nc_photos/session_storage.dart';
 import 'package:nc_photos/snack_bar_manager.dart';
 import 'package:nc_photos/theme.dart';
+import 'package:nc_photos/widget/page_visibility_mixin.dart';
 import 'package:np_codegen/np_codegen.dart';
 import 'package:to_string/to_string.dart';
 
@@ -25,7 +25,9 @@ part 'theme/bloc.dart';
 part 'theme/state_event.dart';
 part 'theme_settings.g.dart';
 
-typedef _BlocBuilder = BlocBuilder<_Bloc, _State>;
+// typedef _BlocBuilder = BlocBuilder<_Bloc, _State>;
+typedef _BlocListener = BlocListener<_Bloc, _State>;
+typedef _BlocSelector<T> = BlocSelector<_Bloc, _State, T>;
 
 class ThemeSettings extends StatelessWidget {
   const ThemeSettings({super.key});
@@ -33,7 +35,9 @@ class ThemeSettings extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return BlocProvider(
-      create: (_) => _Bloc(KiwiContainer().resolve<DiContainer>()),
+      create: (_) => _Bloc(
+        prefController: context.read(),
+      ),
       child: const _WrappedThemeSettings(),
     );
   }
@@ -47,89 +51,86 @@ class _WrappedThemeSettings extends StatefulWidget {
 }
 
 @npLog
-class _WrappedThemeSettingsState extends State<_WrappedThemeSettings> {
+class _WrappedThemeSettingsState extends State<_WrappedThemeSettings>
+    with RouteAware, PageVisibilityMixin {
   @override
   void initState() {
     super.initState();
-    _errorSubscription = _bloc.errorStream().listen((_) {
+    _bloc.add(const _Init());
-      SnackBarManager().showSnackBar(SnackBar(
-        content: Text(L10n.global().writePreferenceFailureNotification),
-        duration: k.snackBarDurationNormal,
-      ));
-    });
-  }
-
-  @override
-  void dispose() {
-    _errorSubscription.cancel();
-    super.dispose();
   }
 
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      body: Builder(
+      body: MultiBlocListener(
-        builder: (context) => _buildContent(context),
+        listeners: [
+          _BlocListener(
+            listenWhen: (previous, current) => previous.error != current.error,
+            listener: (context, state) {
+              if (state.error != null && isPageVisible()) {
+                SnackBarManager().showSnackBar(SnackBar(
+                  content:
+                      Text(exception_util.toUserString(state.error!.error)),
+                  duration: k.snackBarDurationNormal,
+                ));
+              }
+            },
+          ),
+        ],
+        child: CustomScrollView(
+          slivers: [
+            SliverAppBar(
+              pinned: true,
+              title: Text(L10n.global().settingsThemeTitle),
+            ),
+            SliverList(
+              delegate: SliverChildListDelegate(
+                [
+                  const _SeedColorOption(),
+                  if (platform_k.isAndroid &&
+                      AndroidInfo().sdkInt >= AndroidVersion.Q)
+                    _BlocSelector<bool>(
+                      selector: (state) => state.isFollowSystemTheme,
+                      builder: (_, isFollowSystemTheme) {
+                        return SwitchListTile(
+                          title: Text(
+                              L10n.global().settingsFollowSystemThemeTitle),
+                          value: isFollowSystemTheme,
+                          onChanged: (value) {
+                            _bloc.add(_SetFollowSystemTheme(value));
+                          },
+                        );
+                      },
+                    ),
+                  _BlocSelector<bool>(
+                    selector: (state) => state.isUseBlackInDarkTheme,
+                    builder: (context, isUseBlackInDarkTheme) {
+                      return SwitchListTile(
+                        title: Text(
+                            L10n.global().settingsUseBlackInDarkThemeTitle),
+                        subtitle: Text(isUseBlackInDarkTheme
+                            ? L10n.global()
+                                .settingsUseBlackInDarkThemeTrueDescription
+                            : L10n.global()
+                                .settingsUseBlackInDarkThemeFalseDescription),
+                        value: isUseBlackInDarkTheme,
+                        onChanged: (value) {
+                          _bloc.add(_SetUseBlackInDarkTheme(
+                              value, Theme.of(context)));
+                        },
+                      );
+                    },
+                  ),
+                ],
+              ),
+            ),
+          ],
+        ),
       ),
     );
   }
 
-  Widget _buildContent(BuildContext context) {
-    return CustomScrollView(
-      slivers: [
-        SliverAppBar(
-          pinned: true,
-          title: Text(L10n.global().settingsThemeTitle),
-        ),
-        SliverList(
-          delegate: SliverChildListDelegate(
-            [
-              const _SeedColorOption(),
-              if (platform_k.isAndroid &&
-                  AndroidInfo().sdkInt >= AndroidVersion.Q)
-                _BlocBuilder(
-                  buildWhen: (previous, current) =>
-                      previous.isFollowSystemTheme !=
-                      current.isFollowSystemTheme,
-                  builder: (context, state) {
-                    return SwitchListTile(
-                      title: Text(L10n.global().settingsFollowSystemThemeTitle),
-                      value: state.isFollowSystemTheme,
-                      onChanged: (value) {
-                        _bloc.add(_SetFollowSystemTheme(value));
-                      },
-                    );
-                  },
-                ),
-              _BlocBuilder(
-                buildWhen: (previous, current) =>
-                    previous.isUseBlackInDarkTheme !=
-                    current.isUseBlackInDarkTheme,
-                builder: (context, state) {
-                  return SwitchListTile(
-                    title: Text(L10n.global().settingsUseBlackInDarkThemeTitle),
-                    subtitle: Text(state.isUseBlackInDarkTheme
-                        ? L10n.global()
-                            .settingsUseBlackInDarkThemeTrueDescription
-                        : L10n.global()
-                            .settingsUseBlackInDarkThemeFalseDescription),
-                    value: state.isUseBlackInDarkTheme,
-                    onChanged: (value) {
-                      _bloc.add(
-                          _SetUseBlackInDarkTheme(value, Theme.of(context)));
-                    },
-                  );
-                },
-              ),
-            ],
-          ),
-        ),
-      ],
-    );
-  }
-
   late final _bloc = context.read<_Bloc>();
-  late final StreamSubscription _errorSubscription;
 }
 
 class _SeedColorOption extends StatelessWidget {
@@ -137,21 +138,21 @@ class _SeedColorOption extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return _BlocBuilder(
+    return _BlocSelector<int?>(
-      buildWhen: (previous, current) => previous.seedColor != current.seedColor,
+      selector: (state) => state.seedColor,
-      builder: (context, state) {
+      builder: (context, seedColor) {
         if (SessionStorage().isSupportDynamicColor) {
           return ListTile(
             title: Text(L10n.global().settingsSeedColorTitle),
-            subtitle: Text(state.seedColor == null
+            subtitle: Text(seedColor == null
                 ? L10n.global().settingsSeedColorSystemColorDescription
                 : L10n.global().settingsSeedColorDescription),
-            trailing: state.seedColor == null
+            trailing: seedColor == null
                 ? null
                 : Icon(
                     Icons.circle,
                     size: 32,
-                    color: Color(state.seedColor!),
+                    color: Color(seedColor),
                   ),
             onTap: () => _onSeedColorPressed(context),
           );
@@ -162,7 +163,7 @@ class _SeedColorOption extends StatelessWidget {
             trailing: Icon(
               Icons.circle,
               size: 32,
-              color: Color(state.seedColor ?? defaultSeedColor),
+              color: seedColor?.run(Color.new) ?? defaultSeedColor,
             ),
             onTap: () => _onSeedColorPressed(context),
           );
@@ -281,7 +282,7 @@ class _SeedColorCustomPickerState extends State<_SeedColorCustomPicker> {
     );
   }
 
-  late Color _customColor = getSeedColor() ?? const Color(defaultSeedColor);
+  late var _customColor = getSeedColor(context) ?? defaultSeedColor;
 }
 
 class _SeedColorPickerItem extends StatelessWidget {

app/lib/widget/settings/theme_settings.g.dart

@@ -14,7 +14,10 @@ part of 'theme_settings.dart';
 
 abstract class $_StateCopyWithWorker {
   _State call(
-      {bool? isFollowSystemTheme, bool? isUseBlackInDarkTheme, int? seedColor});
+      {bool? isFollowSystemTheme,
+      bool? isUseBlackInDarkTheme,
+      int? seedColor,
+      ExceptionEvent? error});
 }
 
 class _$_StateCopyWithWorkerImpl implements $_StateCopyWithWorker {
@@ -24,14 +27,16 @@ class _$_StateCopyWithWorkerImpl implements $_StateCopyWithWorker {
   _State call(
       {dynamic isFollowSystemTheme,
       dynamic isUseBlackInDarkTheme,
-      dynamic seedColor = copyWithNull}) {
+      dynamic seedColor = copyWithNull,
+      dynamic error = copyWithNull}) {
     return _State(
         isFollowSystemTheme:
             isFollowSystemTheme as bool? ?? that.isFollowSystemTheme,
         isUseBlackInDarkTheme:
             isUseBlackInDarkTheme as bool? ?? that.isUseBlackInDarkTheme,
         seedColor:
-            seedColor == copyWithNull ? that.seedColor : seedColor as int?);
+            seedColor == copyWithNull ? that.seedColor : seedColor as int?,
+        error: error == copyWithNull ? that.error : error as ExceptionEvent?);
   }
 
   final _State that;
@@ -68,7 +73,14 @@ extension _$_BlocNpLog on _Bloc {
 extension _$_StateToString on _State {
   String _$toString() {
     // ignore: unnecessary_string_interpolations
-    return "_State {isFollowSystemTheme: $isFollowSystemTheme, isUseBlackInDarkTheme: $isUseBlackInDarkTheme, seedColor: $seedColor}";
+    return "_State {isFollowSystemTheme: $isFollowSystemTheme, isUseBlackInDarkTheme: $isUseBlackInDarkTheme, seedColor: $seedColor, error: $error}";
+  }
+}
+
+extension _$_InitToString on _Init {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "_Init {}";
   }
 }
 

app/lib/widget/sign_in.dart

@@ -37,7 +37,7 @@ class _SignInState extends State<SignIn> {
   @override
   build(BuildContext context) {
     return Theme(
-      data: buildDarkTheme().copyWith(
+      data: buildDarkTheme(context).copyWith(
         scaffoldBackgroundColor: Colors.transparent,
         progressIndicatorTheme: const ProgressIndicatorThemeData(
           color: Colors.white,

app/lib/widget/slideshow_viewer.dart

@@ -100,7 +100,7 @@ class _SlideshowViewerState extends State<SlideshowViewer>
   @override
   build(BuildContext context) {
     return Theme(
-      data: buildDarkTheme(),
+      data: buildDarkTheme(context),
       child: Scaffold(
         body: Builder(
           builder: _buildContent,

app/lib/widget/trashbin_viewer.dart

@@ -65,7 +65,7 @@ class _TrashbinViewerState extends State<TrashbinViewer> {
   @override
   build(BuildContext context) {
     return Theme(
-      data: buildDarkTheme(),
+      data: buildDarkTheme(context),
       child: Scaffold(
         body: Builder(
           builder: _buildContent,

app/lib/widget/viewer.dart

@@ -120,7 +120,7 @@ class _ViewerState extends State<Viewer>
   build(BuildContext context) {
     final originalBrightness = Theme.of(context).brightness;
     return Theme(
-      data: buildDarkTheme(),
+      data: buildDarkTheme(context),
       child: AnnotatedRegion<SystemUiOverlayStyle>(
         value: const SystemUiOverlayStyle(
           systemNavigationBarColor: Colors.black,
@@ -299,7 +299,7 @@ class _ViewerState extends State<Viewer>
                         }
                       },
                       child: Theme(
-                        data: buildTheme(originalBrightness),
+                        data: buildTheme(context, originalBrightness),
                         child: Builder(
                           builder: (context) {
                             return Container(