Refactor: extract collection settings

app/lib/controller/pref_controller.dart

@@ -108,6 +108,15 @@ class PrefController {
         value: value,
       );
 
+  ValueStream<bool> get isAlbumBrowserShowDate =>
+      _isAlbumBrowserShowDateController.stream;
+
+  Future<void> setAlbumBrowserShowDate(bool value) => _set<bool>(
+        controller: _isAlbumBrowserShowDateController,
+        setter: (pref, value) => pref.setAlbumBrowserShowDate(value),
+        value: value,
+      );
+
   Future<void> _set<T>({
     required BehaviorSubject<T> controller,
     required Future<bool> Function(Pref pref, T value) setter,
@@ -162,4 +171,6 @@ class PrefController {
       BehaviorSubject.seeded(_c.pref.isViewerForceRotationOr(false));
   late final _gpsMapProviderController = BehaviorSubject.seeded(
       GpsMapProvider.fromValue(_c.pref.getGpsMapProviderOr(0)));
+  late final _isAlbumBrowserShowDateController =
+      BehaviorSubject.seeded(_c.pref.isAlbumBrowserShowDateOr(false));
 }

app/lib/widget/settings.dart

@@ -18,6 +18,7 @@ import 'package:nc_photos/snack_bar_manager.dart';
 import 'package:nc_photos/stream_util.dart';
 import 'package:nc_photos/url_launcher_util.dart';
 import 'package:nc_photos/widget/list_tile_center_leading.dart';
+import 'package:nc_photos/widget/settings/collection_settings.dart';
 import 'package:nc_photos/widget/settings/developer_settings.dart';
 import 'package:nc_photos/widget/settings/expert_settings.dart';
 import 'package:nc_photos/widget/settings/language_settings.dart';
@@ -117,7 +118,7 @@ class _SettingsState extends State<Settings> {
               _SubPageItem(
                 leading: const Icon(Icons.grid_view_outlined),
                 label: L10n.global().collectionsTooltip,
-                pageBuilder: () => _AlbumSettings(),
+                pageBuilder: () => const CollectionSettings(),
               ),
               _SubPageItem(
                 leading: const Icon(Icons.view_carousel_outlined),
@@ -290,72 +291,6 @@ class _SubPageItem extends StatelessWidget {
   final Widget Function() pageBuilder;
 }
 
-class _AlbumSettings extends StatefulWidget {
-  @override
-  createState() => _AlbumSettingsState();
-}
-
-@npLog
-class _AlbumSettingsState extends State<_AlbumSettings> {
-  @override
-  initState() {
-    super.initState();
-    _isBrowserShowDate = Pref().isAlbumBrowserShowDateOr();
-  }
-
-  @override
-  build(BuildContext context) {
-    return Scaffold(
-      body: Builder(
-        builder: (context) => _buildContent(context),
-      ),
-    );
-  }
-
-  Widget _buildContent(BuildContext context) {
-    return CustomScrollView(
-      slivers: [
-        SliverAppBar(
-          pinned: true,
-          title: Text(L10n.global().collectionsTooltip),
-        ),
-        SliverList(
-          delegate: SliverChildListDelegate(
-            [
-              SwitchListTile(
-                title: Text(L10n.global().settingsShowDateInAlbumTitle),
-                subtitle:
-                    Text(L10n.global().settingsShowDateInAlbumDescription),
-                value: _isBrowserShowDate,
-                onChanged: (value) => _onBrowserShowDateChanged(value),
-              ),
-            ],
-          ),
-        ),
-      ],
-    );
-  }
-
-  Future<void> _onBrowserShowDateChanged(bool value) async {
-    final oldValue = _isBrowserShowDate;
-    setState(() {
-      _isBrowserShowDate = value;
-    });
-    if (!await Pref().setAlbumBrowserShowDate(value)) {
-      _log.severe("[_onBrowserShowDateChanged] Failed writing pref");
-      SnackBarManager().showSnackBar(SnackBar(
-        content: Text(L10n.global().writePreferenceFailureNotification),
-        duration: k.snackBarDurationNormal,
-      ));
-      setState(() {
-        _isBrowserShowDate = oldValue;
-      });
-    }
-  }
-
-  late bool _isBrowserShowDate;
-}
-
 class EnhancementSettings extends StatefulWidget {
   static const routeName = "/enhancement-settings";
 

app/lib/widget/settings.g.dart

@@ -13,13 +13,6 @@ extension _$_SettingsStateNpLog on _SettingsState {
   static final log = Logger("widget.settings._SettingsState");
 }
 
-extension _$_AlbumSettingsStateNpLog on _AlbumSettingsState {
-  // ignore: unused_element
-  Logger get _log => log;
-
-  static final log = Logger("widget.settings._AlbumSettingsState");
-}
-
 extension _$_EnhancementSettingsStateNpLog on _EnhancementSettingsState {
   // ignore: unused_element
   Logger get _log => log;

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

@@ -0,0 +1,35 @@
+part of '../collection_settings.dart';
+
+@npLog
+class _Bloc extends Bloc<_Event, _State> with BlocLogger {
+  _Bloc({
+    required this.prefController,
+  }) : super(_State(
+          isBrowserShowDate: prefController.isAlbumBrowserShowDate.value,
+        )) {
+    on<_Init>(_onInit);
+    on<_SetBrowserShowDate>(_onSetBrowserShowDate);
+  }
+
+  @override
+  String get tag => _log.fullName;
+
+  Future<void> _onInit(_Init ev, Emitter<_State> emit) async {
+    _log.info(ev);
+    return emit.forEach<bool>(
+      prefController.isAlbumBrowserShowDate,
+      onData: (data) => state.copyWith(isBrowserShowDate: data),
+      onError: (e, stackTrace) {
+        _log.severe("[_onInit] Uncaught exception", e, stackTrace);
+        return state.copyWith(error: ExceptionEvent(e, stackTrace));
+      },
+    );
+  }
+
+  void _onSetBrowserShowDate(_SetBrowserShowDate ev, Emitter<_State> emit) {
+    _log.info(ev);
+    prefController.setAlbumBrowserShowDate(ev.value);
+  }
+
+  final PrefController prefController;
+}

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

@@ -0,0 +1,39 @@
+part of '../collection_settings.dart';
+
+@genCopyWith
+@toString
+class _State {
+  const _State({
+    required this.isBrowserShowDate,
+    this.error,
+  });
+
+  @override
+  String toString() => _$toString();
+
+  final bool isBrowserShowDate;
+
+  final ExceptionEvent? error;
+}
+
+abstract class _Event {
+  const _Event();
+}
+
+@toString
+class _Init implements _Event {
+  const _Init();
+
+  @override
+  String toString() => _$toString();
+}
+
+@toString
+class _SetBrowserShowDate implements _Event {
+  const _SetBrowserShowDate(this.value);
+
+  @override
+  String toString() => _$toString();
+
+  final bool value;
+}

app/lib/widget/settings/collection_settings.dart

@@ -0,0 +1,104 @@
+import 'package:copy_with/copy_with.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/app_localizations.dart';
+import 'package:nc_photos/bloc_util.dart';
+import 'package:nc_photos/controller/pref_controller.dart';
+import 'package:nc_photos/exception_event.dart';
+import 'package:nc_photos/exception_util.dart' as exception_util;
+import 'package:nc_photos/k.dart' as k;
+import 'package:nc_photos/snack_bar_manager.dart';
+import 'package:nc_photos/widget/page_visibility_mixin.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:to_string/to_string.dart';
+
+part 'collection/bloc.dart';
+part 'collection/state_event.dart';
+part 'collection_settings.g.dart';
+
+typedef _BlocListener = BlocListener<_Bloc, _State>;
+typedef _BlocSelector<T> = BlocSelector<_Bloc, _State, T>;
+
+class CollectionSettings extends StatelessWidget {
+  const CollectionSettings({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return BlocProvider(
+      create: (_) => _Bloc(
+        prefController: context.read(),
+      ),
+      child: const _WrappedAlbumSettings(),
+    );
+  }
+}
+
+class _WrappedAlbumSettings extends StatefulWidget {
+  const _WrappedAlbumSettings();
+
+  @override
+  State<StatefulWidget> createState() => _WrappedAlbumSettingsState();
+}
+
+@npLog
+class _WrappedAlbumSettingsState extends State<_WrappedAlbumSettings>
+    with RouteAware, PageVisibilityMixin {
+  @override
+  void initState() {
+    super.initState();
+    _bloc.add(const _Init());
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: MultiBlocListener(
+        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().settingsViewerTitle),
+            ),
+            SliverList(
+              delegate: SliverChildListDelegate(
+                [
+                  _BlocSelector<bool>(
+                    selector: (state) => state.isBrowserShowDate,
+                    builder: (context, state) {
+                      return SwitchListTile(
+                        title: Text(L10n.global().settingsShowDateInAlbumTitle),
+                        subtitle: Text(
+                            L10n.global().settingsShowDateInAlbumDescription),
+                        value: state,
+                        onChanged: (value) {
+                          _bloc.add(_SetBrowserShowDate(value));
+                        },
+                      );
+                    },
+                  ),
+                ],
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  late final _bloc = context.read<_Bloc>();
+}

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

@@ -0,0 +1,79 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'collection_settings.dart';
+
+// **************************************************************************
+// CopyWithLintRuleGenerator
+// **************************************************************************
+
+// ignore_for_file: library_private_types_in_public_api, duplicate_ignore
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class $_StateCopyWithWorker {
+  _State call({bool? isBrowserShowDate, ExceptionEvent? error});
+}
+
+class _$_StateCopyWithWorkerImpl implements $_StateCopyWithWorker {
+  _$_StateCopyWithWorkerImpl(this.that);
+
+  @override
+  _State call({dynamic isBrowserShowDate, dynamic error = copyWithNull}) {
+    return _State(
+        isBrowserShowDate: isBrowserShowDate as bool? ?? that.isBrowserShowDate,
+        error: error == copyWithNull ? that.error : error as ExceptionEvent?);
+  }
+
+  final _State that;
+}
+
+extension $_StateCopyWith on _State {
+  $_StateCopyWithWorker get copyWith => _$copyWith;
+  $_StateCopyWithWorker get _$copyWith => _$_StateCopyWithWorkerImpl(this);
+}
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$_WrappedAlbumSettingsStateNpLog on _WrappedAlbumSettingsState {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log =
+      Logger("widget.settings.collection_settings._WrappedAlbumSettingsState");
+}
+
+extension _$_BlocNpLog on _Bloc {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log = Logger("widget.settings.collection_settings._Bloc");
+}
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$_StateToString on _State {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "_State {isBrowserShowDate: $isBrowserShowDate, error: $error}";
+  }
+}
+
+extension _$_InitToString on _Init {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "_Init {}";
+  }
+}
+
+extension _$_SetBrowserShowDateToString on _SetBrowserShowDate {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "_SetBrowserShowDate {value: $value}";
+  }
+}