SettingsScope with InheritedModel

inherited_model_sample.dart

/*
 * https://gist.github.com/PlugFox/320d051c5a393f56f60c3cf080d6171a
 * https://dartpad.dev/320d051c5a393f56f60c3cf080d6171a?null_safety=true
 */

import 'package:flutter/widgets.dart';

@immutable
class SettingsScope extends StatefulWidget {
  final Widget child;
  const SettingsScope({
    required this.child,
    Key? key,
  }) : super(key: key);

  static SettingsBLoC _blocOf(BuildContext context) => _InheritedSettings.stateOf(context).settingsBLoC;

  /// Обновить настройки приложения
  static void updateOf(BuildContext context, {required UserSettings settings}) => _blocOf(context).add(
        SettingsEvent.update(
          Provider.of<UserEntity>(
            context,
            listen: false,
          ),
          settings,
        ),
      );

  /// Получить текущие настройки приложения
  static UserSettings settingsOf(BuildContext context, {bool listen = false}) =>
      _InheritedSettings.of(context, listen: listen).settings;

  /// Получить и подписаться на текущую локаль приложения
  static String localeOf(BuildContext context) => _InheritedSettings.aspectOf(context, 'locale').locale;

  /// Получить и подписаться на текущую тему приложения
  static String themeOf(BuildContext context) => _InheritedSettings.aspectOf(context, 'theme').theme;

  @override
  State<StatefulWidget> createState() => _SettingsScopeState();
}

class _SettingsScopeState extends State<SettingsScope> {
  UserEntity? _lastUserSettings;
  late SettingsBLoC settingsBLoC;

  @override
  void initState() {
    super.initState();
    settingsBLoC = SettingsBLoC(
      repository: Provider.of<RepositoryStore>(context, listen: false).settingsRepository,
    );
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    final user = Provider.of<UserEntity>(context, listen: true);
    if (_lastUserSettings != user) {
      _lastUserSettings = user;
      settingsBLoC.add(SettingsEvent.getFromServer(user));
    }
  }

  @override
  void dispose() {
    settingsBLoC.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => BlocBuilder<SettingsBLoC, SettingsState>(
        bloc: settingsBLoC,
        builder: (context, state) => _InheritedSettings(
          state: this,
          settings: state.settings,
          child: widget.child,
        ),
      );
}

class _InheritedSettings extends InheritedModel<String> {
  final _SettingsScopeState state;
  final UserSettings settings;
  const _InheritedSettings({
    required this.state,
    required this.settings,
    required Widget child,
    Key? key,
  }) : super(child: child, key: key);

  @override
  bool updateShouldNotify(covariant _InheritedSettings oldWidget) => oldWidget.settings != settings;

  @override
  bool updateShouldNotifyDependent(covariant _InheritedSettings oldWidget, Set<String> dependencies) =>
      oldWidget.settings != settings &&
      ((dependencies.contains('locale') && oldWidget.settings.locale != settings.locale) ||
          (dependencies.contains('theme') && oldWidget.settings.theme != settings.theme));

  static _InheritedSettings of(BuildContext context, {bool listen = false}) => listen
      ? context.dependOnInheritedWidgetOfExactType<_InheritedSettings>()!
      : (context.getElementForInheritedWidgetOfExactType<_InheritedSettings>()!.widget as _InheritedSettings);

  static UserSettings aspectOf(BuildContext context, String aspect) =>
      InheritedModel.inheritFrom<_InheritedSettings>(context, aspect: aspect)!.settings;

  static _SettingsScopeState stateOf(BuildContext context) => of(context, listen: false).state;
}