feature-theme

Feature: Theme

Purpose: Persist and restore the user's chosen IosThemeData (light or dark) across sessions using SharedPreferences, and expose a reactive ThemeStateNotifier that the app root widget watches to re-theme the entire app.

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Layer Map

lib/src/features/theme/
├── domain/
│   ├── repositories/theme_repository.dart          # abstract ThemeRepository
│   └── usecases/
│       ├── get_theme_data_usecase.dart              # GetThemeDataUsecase + provider
│       ├── set_theme_data_usecase.dart              # SetThemeDataUsecase + provider
│       └── remove_theme_data_usecase.dart           # RemoveThemeDataUsecase + provider
├── data/
│   └── repositories/theme_repository.dart          # ThemeRepositoryImpl + provider
└── presentation/
    └── notifiers/
        └── theme_state_notifier.dart               # ThemeStateNotifier + provider

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Domain

Repository Interface

abstract class ThemeRepository {
  IosThemeData? getThemeData();                               // sync, nullable
  Future<bool> setThemeData({required IosThemeData iosThemeData});
  Future<bool> removeThemeData();
}

Use Cases

Class	Provider	Signature
GetThemeDataUsecase	getThemeDataUsecaseProvider	IosThemeData? call()
SetThemeDataUsecase	setThemeDataUsecaseProvider	Future<bool> call({required IosThemeData iosThemeData})
RemoveThemeDataUsecase	removeThemeDataUsecaseProvider	Future<bool> call()

All providers are Provider.autoDispose.

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Data

ThemeRepositoryImpl

File: lib/src/features/theme/data/repositories/theme_repository.dart

Stores the theme as a String (runtime type name) in SharedPreferences:

IosLightThemeData → stored as 'IosLightThemeData'
IosDarkThemeData  → stored as 'IosDarkThemeData'

Key: DatabaseKeys.iosThemeData.key → 'iosThemeData' (prod) / 'iosThemeDataDebug' (debug)

// Read: pattern-matches on the stored string to reconstruct the correct subclass
IosThemeData? getThemeData() => switch (_sharedPreferences.getString(key)) {
  null => null,
  final v when v == IosLightThemeData().runtimeType.toString() => IosLightThemeData(),
  final v when v == IosDarkThemeData().runtimeType.toString()  => IosDarkThemeData(),
  _ => null,
};