Bloc (State Management) Check Connectivity Example using Cubit

 import 'dart:async';

import 'package:connectivity/connectivity.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

enum InternetState { Initial, Lost, Gained }

/// Difference between Cubit and Bloc is that Cubit is based on Function and
/// Bloc is based on Event
/// In short, Cubit is Function based and Bloc is Event based

class InternetCubit extends Cubit<InternetState>
{
  final Connectivity _connectivity = Connectivity();
  StreamSubscription? connectivitySubscription;

  InternetCubit() : super(InternetState.Initial) {
    connectivitySubscription = _connectivity.onConnectivityChanged.listen((result) {
      if(result == ConnectivityResult.mobile || result == ConnectivityResult.wifi)
        {
          emit(InternetState.Gained);
        }
      else
        {
          emit(InternetState.Lost);
        }
    },);
  }

  @override
  Future<void> close()
  {
    connectivitySubscription?.cancel();
    return super.close();
  }
}

import "package:firebase/Stateless_Component_UI/cubits/internet_cubit.dart";
import "package:flutter/material.dart";
import "package:flutter_bloc/flutter_bloc.dart";

/// Difference between Cubit and Bloc is that Cubit is based on Function and
/// Bloc is based on Event
/// In short, Cubit is Function based and Bloc is Event based

void main()
{
  runApp(const MyApp());
}
class MyApp extends StatelessWidget
{
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) {
        return InternetCubit();
      },
      child: MaterialApp(
        title: "Bloc Internet Connectivity",
        debugShowCheckedModeBanner: false,
        theme: ThemeData(
          primarySwatch: Colors.grey,
        ),
        home: const HomeScreen3(),
      ),
    );
  }
}
class HomeScreen3 extends StatelessWidget
{
  const HomeScreen3({super.key});
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Check Connectivity"),
        centerTitle: true,
        backgroundColor: Colors.grey,
      ),
      body: Center(
        child: BlocConsumer<InternetCubit, InternetState>(
          listener: (context, state) {
            if(state == InternetState.Gained)
              {
                ScaffoldMessenger.of(context).showSnackBar(
                  const SnackBar(content: Text("Internet Connected!"),),
                );
              }
            else if(state == InternetState.Lost)
              {
                ScaffoldMessenger.of(context).showSnackBar(
                  const SnackBar(content: Text("Internet not Connected!"),),
                );
              }
          },
          builder: (context, state) {
            if(state == InternetState.Gained)
              {
                return const Text("Connected!");
              }
            else if(state == InternetState.Lost)
              {
                return const Text("Not Connected!");
              }
            else
              {
                return const Text("Loading...");
              }
          },
        ),
      ),
    );
  }
}