dependencies:
  flutter:
    sdk: flutter
  flutter_bloc: ^8.0.0
  equatable: ^2.0.0

import 'package:equatable/equatable.dart';

abstract class CounterEvent extends Equatable {
  const CounterEvent();
}

class IncrementEvent extends CounterEvent {
  @override
  List<Object> get props => [];
}

class DecrementEvent extends CounterEvent {
  @override
  List<Object> get props => [];
}

import 'package:equatable/equatable.dart';

abstract class CounterState extends Equatable {
  const CounterState();
}

class CounterInitial extends CounterState {
  @override
  List<Object> get props => [];
}

class CounterValue extends CounterState {
  final int value;

  const CounterValue(this.value);

  @override
  List<Object> get props => [value];
}

import 'package:flutter_bloc/flutter_bloc.dart';

class CounterBloc extends Bloc<CounterEvent, CounterState> {
  CounterBloc() : super(CounterInitial()) {
    on<IncrementEvent>((event, emit) {
      if (state is CounterValue) {
        final currentValue = (state as CounterValue).value;
        emit(CounterValue(currentValue + 1));
      } else {
        emit(CounterValue(1));
      }
    });

    on<DecrementEvent>((event, emit) {
      if (state is CounterValue) {
        final currentValue = (state as CounterValue).value;
        emit(CounterValue(currentValue - 1));
      } else {
        emit(CounterValue(-1));
      }
    });
  }
}

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: BlocProvider(
        create: (context) => CounterBloc(),
        child: CounterPage(),
      ),
    );
  }
}

class CounterPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Counter with Bloc')),
      body: Center(
        child: BlocBuilder<CounterBloc, CounterState>(
          builder: (context, state) {
            int counterValue = 0;
            if (state is CounterValue) {
              counterValue = state.value;
            }
            return Text('Counter Value: $counterValue');
          },
        ),
      ),
      floatingActionButton: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          FloatingActionButton(
            onPressed: () {
              context.read<CounterBloc>().add(IncrementEvent());
            },
            child: Icon(Icons.add),
          ),
          SizedBox(height: 10),
          FloatingActionButton(
            onPressed: () {
              context.read<CounterBloc>().add(DecrementEvent());
            },
            child: Icon(Icons.remove),
          ),
        ],
      ),
    );
  }
}