streams_channel3 1.0.1 streams_channel3: ^1.0.1 copied to clipboard
StreamsChannel is inspired from EventChannel. It allows to create streams of events between Flutter and platform side.
// Copyright (c) 2021 Kfir Matityahu
// Licensed under Apache License v2.0
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:streams_channel3/streams_channel3.dart';
void main() => runApp(MyApp());
final StreamsChannel streamsChannel = StreamsChannel('streams_channel_example');
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
StreamSubscription<dynamic>? _subscriptionA;
StreamSubscription<dynamic>? _subscriptionB;
void _start(bool a) {
// ignore: cancel_subscriptions
StreamSubscription<dynamic>? subscription =
a ? _subscriptionA : _subscriptionB;
if (subscription != null) {
subscription.cancel();
subscription = null;
} else {
final streamId = 'Stream ${a ? 'A' : 'B'}';
subscription = streamsChannel
.receiveBroadcastStream(streamId)
.listen((data) => debugPrint('Received from $streamId: $data'));
subscription.onDone(() {
setState(() {
if (a) {
_subscriptionA = null;
} else {
_subscriptionB = null;
}
});
});
}
setState(() {
if (a) {
_subscriptionA = subscription;
} else {
_subscriptionB = subscription;
}
});
}
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('Demo'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
FlatButton(
onPressed: () => _start(true),
child: Text(_subscriptionA != null ? 'Stop A' : 'Start A'),
),
FlatButton(
onPressed: () => _start(false),
child: Text(_subscriptionB != null ? 'Stop B' : 'Start B'),
),
],
),
),
),
);
}
}