Rx Example - RxDart

main.dart

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

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) => const MaterialApp(
        debugShowCheckedModeBanner: false,
        home: MyHomePage(),
      );
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final name = BehaviorSubject.seeded('Jane');
  final surname = BehaviorSubject.seeded('Doe');

  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: const Text('RxDart Example'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              StreamBuilder<String>(
                stream: Rx.combineLatest2(
                  name,
                  surname,
                  (name, surname) => '$name $surname',
                ),
                builder: (context, snapshot) => Text(
                  snapshot.data ?? '',
                  style: Theme.of(context).textTheme.headlineMedium,
                ),
              ),
              ElevatedButton(
                onPressed: () =>
                    name.add(name.value == 'Jane' ? 'John' : 'Jane'),
                child: const Text('Change First Name'),
              ),
              ElevatedButton(
                onPressed: () =>
                    surname.add(surname.value == 'Doe' ? 'Dop' : 'Doe'),
                child: const Text('Change Surname'),
              ),
            ],
          ),
        ),
      );

  @override
  Future<void> dispose() async {
    await name.close();
    await surname.close();
    super.dispose();
  }
}