yokutango-mobile-reader/lib/service/theme_bloc.dart

import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter/services.dart';
import 'package:get_it/get_it.dart';
import 'package:meta/meta.dart';
import 'package:shared_preferences/shared_preferences.dart';

export 'package:flutter_bloc/flutter_bloc.dart';

@immutable
class SetTheme {
  final bool isDark;
  const SetTheme(this.isDark);
}

class ThemeBloc extends Bloc<SetTheme, Brightness> {
  ThemeBloc({
    required Brightness init,
  }) : super(init) {
    on<SetTheme>((event, emit) {
      GetIt.instance
          .get<SharedPreferences>()
          .setBool('darkTheme', event.isDark);
      emit(event.isDark ? Brightness.dark : Brightness.light);
    });
  }
}