dashboard_bloc.dart

import 'dart:async';

import 'package:bloc/bloc.dart';
import 'package:bloc_concurrency/bloc_concurrency.dart';
import 'package:equatable/equatable.dart';
import 'package:file_selector/file_selector.dart';

part 'dashboard_event.dart';
part 'dashboard_state.dart';

/// Handles selecting and removing files.
class DashboardBloc extends Bloc<DashboardEvent, DashboardState> {
  DashboardBloc() : super(DashboardState(files: [], alreadyPresent: false)) {
    on<DashboardEvent>(_onEvent, transformer: sequential());
  }
  FutureOr<void> _onEvent(
      DashboardEvent event, Emitter<DashboardState> emit) async {
    // TODO: logic goes here...
    if (event is NewFileAdded) {
      List<XFile> finalEventList = List.from(event.files);
      bool alreadyPresent = false;
      // create your own wrapper around the third party class as use EquatableMixin
      for (var stateFile in state.files) {
        for (var eventFile in event.files) {
          if (eventFile.path == stateFile.path) {
            alreadyPresent = true;
            finalEventList.remove(eventFile);
          }
        }
      }
      if (alreadyPresent) {
        emit(state.copyWith(
            files: List.from(state.files)..addAll(finalEventList),
            alreadyPresent: true));
      } else {
        emit(state.copyWith(
            files: List.from(state.files)..addAll(event.files),
            alreadyPresent: false));
        ;
      }
    } else if (event is FileRemoved) {
      emit(state.copyWith(
          files: List.from(state.files)..remove(event.file),
          alreadyPresent: false));
    } else if (event is RemoveAllFiles) {
      emit(state.copyWith(files: [], alreadyPresent: false));
    }
  }
}