Flutter BLoC combine rxdart.dart

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

class AppBloc extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      darkTheme: ThemeData.dark(),
      theme: ThemeData.light(),
      home: const HomePage(),
      debugShowCheckedModeBanner: false,
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage();

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {

  @override
  void dispose() {
    myBloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter Bloc'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(20.0),
        child: Center(
          child: StreamBuilder<PasswordField>(
            stream: myBloc.passwordForm,
            builder: (_, snapshot) {
              final isShow = snapshot.data?.showPassword ?? false;
              return TextField(
                onChanged: myBloc.changePassword,
                obscureText: isShow,
                decoration: InputDecoration(
                  label: Text('Password'),
                  suffixIcon: IconButton(
                    onPressed: myBloc.toggleShowPassword,
                    icon: Icon(
                      isShow ? Icons.abc : Icons.remove_red_eye_outlined,
                    ),
                  ),
                ),
              );
            },
          ),
        ),
      ),
      floatingActionButton: StreamBuilder<bool>(
        stream: myBloc.showPassword,
        builder: (_, snapshot) {
          final isShow = snapshot.data ?? false;
          return FloatingActionButton(
            onPressed: () {
              myBloc.toggleShowPassword();
            },
            child: Icon(
              isShow ? Icons.abc : Icons.remove_red_eye_outlined,
            ),
          );
        },
      ),
    );
  }
}

// model
class PasswordField {
  PasswordField({
    required this.password,
    required this.showPassword,
  });

  final String password;
  final bool showPassword;
}

// bloc
class MyBloC {
  bool _showPassword = false;

  final _passwordCtrl = BehaviorSubject<String>();
  Stream<String> get password => _passwordCtrl.stream;

  final _showPasswordCtrl = BehaviorSubject<bool>()..add(false);
  Stream<bool> get showPassword => _showPasswordCtrl.stream;

  // use cambine 2 types
  Stream<PasswordField> get passwordForm => Rx.combineLatest2(
        password,
        showPassword,
        (String a, bool b) => PasswordField(
          password: a,
          showPassword: b,
        ),
      );

  void changePassword(String val) {
    print(val);
    _passwordCtrl.sink.add(val);
  }

  void toggleShowPassword() {
    _showPassword = !_showPassword;
    _showPasswordCtrl.sink.add(_showPassword);
  }

  void dispose() {
    _passwordCtrl.close();
    _showPasswordCtrl.close();
  }
}

final myBloc = MyBloC();