For golang server.

lib/main.dart

@@ -1,7 +1,8 @@
-import 'package:flutter/material.dart';
-import 'src/utils/key_value_store.dart'
-    if (dart.library.js) 'src/utils/key_value_store_web.dart';
 import 'dart:core';
+
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
 import 'src/basic_sample/basic_sample.dart';
 import 'src/call_sample/call_sample.dart';
 import 'src/call_sample/data_channel_sample.dart';
@@ -21,8 +22,9 @@ enum DialogDemoAction {
 
 class _MyAppState extends State<MyApp> {
   List<RouteItem> items;
-  String _serverAddress = '';
-  KeyValueStore keyValueStore = KeyValueStore();
+  String _server = '';
+  SharedPreferences _prefs;
+
   bool _datachannel = false;
   @override
   initState() {
@@ -60,9 +62,9 @@ class _MyAppState extends State<MyApp> {
   }
 
   _initData() async {
-    await keyValueStore.init();
+    _prefs = await SharedPreferences.getInstance();
     setState(() {
-      _serverAddress = keyValueStore.getString('server') ?? 'demo.cloudwebrtc.com';
+      _server = _prefs.getString('server') ?? 'demo.cloudwebrtc.com';
     });
   }
 
@@ -74,13 +76,13 @@ class _MyAppState extends State<MyApp> {
       // The value passed to Navigator.pop() or null.
       if (value != null) {
         if (value == DialogDemoAction.connect) {
-          keyValueStore.setString('server', _serverAddress);
+          _prefs.setString('server', _server);
           Navigator.push(
               context,
               MaterialPageRoute(
                   builder: (BuildContext context) => _datachannel
-                      ? DataChannelSample(ip: _serverAddress)
-                      : CallSample(ip: _serverAddress)));
+                      ? DataChannelSample(ip: _server)
+                      : CallSample(ip: _server)));
         }
       }
     });
@@ -94,11 +96,11 @@ class _MyAppState extends State<MyApp> {
             content: TextField(
               onChanged: (String text) {
                 setState(() {
-                  _serverAddress = text;
+                  _server = text;
                 });
               },
               decoration: InputDecoration(
-                hintText: _serverAddress,
+                hintText: _server,
               ),
               textAlign: TextAlign.center,
             ),

lib/src/basic_sample/loopback_sample.dart

@@ -151,6 +151,8 @@ class _MyAppState extends State<LoopBackSample> {
       //change for loopback.
       description.type = 'answer';
       _peerConnection.setRemoteDescription(description);
+
+      _localStream.getAudioTracks()[0].setMicrophoneMute(false);
     } catch (e) {
       print(e.toString());
     }

lib/src/call_sample/signaling.dart

@@ -1,12 +1,15 @@
 import 'dart:convert';
 import 'dart:async';
 import 'package:flutter_webrtc/webrtc.dart';
+
 import 'random_string.dart';
 
 import '../utils/device_info.dart'
     if (dart.library.js) '../utils/device_info_web.dart';
 import '../utils/websocket.dart'
     if (dart.library.js) '../utils/websocket_web.dart';
+import '../utils/turn.dart'
+    if (dart.library.js) '../utils/turn_web.dart';
 
 enum SignalingState {
   CallStateNew,
@@ -30,14 +33,17 @@ typedef void DataChannelMessageCallback(
 typedef void DataChannelCallback(RTCDataChannel dc);
 
 class Signaling {
+  JsonEncoder _encoder = new JsonEncoder();
+  JsonDecoder _decoder = new JsonDecoder();
   String _selfId = randomNumeric(6);
   SimpleWebSocket _socket;
   var _sessionId;
   var _host;
-  var _port = 4443;
+  var _port = 8086;
   var _peerConnections = new Map<String, RTCPeerConnection>();
   var _dataChannels = new Map<String, RTCDataChannel>();
   var _remoteCandidates = [];
+  var _turnCredential;
 
   MediaStream _localStream;
   List<MediaStream> _remoteStreams;
@@ -220,7 +226,6 @@ class Signaling {
         break;
       case 'bye':
         {
-          var from = data['from'];
           var to = data['to'];
           var sessionId = data['session_id'];
           print('bye: ' + sessionId);
@@ -259,11 +264,33 @@ class Signaling {
   }
 
   void connect() async {
-    var url = 'wss://$_host:$_port';
+    var url = 'https://$_host:$_port/ws';
     _socket = SimpleWebSocket(url);
 
     print('connect to $url');
 
+    if (_turnCredential == null) {
+      try {
+        _turnCredential = await getTurnCredential(_host, _port);
+        /*{
+            "username": "1584195784:mbzrxpgjys",
+            "password": "isyl6FF6nqMTB9/ig5MrMRUXqZg",
+            "ttl": 86400,
+            "uris": ["turn:127.0.0.1:19302?transport=udp"]
+          }
+        */
+        _iceServers = {
+          'iceServers': [
+            {
+              'url': _turnCredential['uris'][0],
+              'username': _turnCredential['username'],
+              'credential': _turnCredential['password']
+            },
+          ]
+        };
+      } catch (e) {}
+    }
+
     _socket.onOpen = () {
       print('onOpen');
       this?.onStateChange(SignalingState.ConnectionOpen);
@@ -321,6 +348,7 @@ class Signaling {
     pc.onIceCandidate = (candidate) {
       _send('candidate', {
         'to': id,
+        'from': _selfId,
         'candidate': {
           'sdpMLineIndex': candidate.sdpMlineIndex,
           'sdpMid': candidate.sdpMid,
@@ -375,6 +403,7 @@ class Signaling {
       pc.setLocalDescription(s);
       _send('offer', {
         'to': id,
+        'from': _selfId,
         'description': {'sdp': s.sdp, 'type': s.type},
         'session_id': this._sessionId,
         'media': media,
@@ -391,6 +420,7 @@ class Signaling {
       pc.setLocalDescription(s);
       _send('answer', {
         'to': id,
+        'from': _selfId,
         'description': {'sdp': s.sdp, 'type': s.type},
         'session_id': this._sessionId,
       });
@@ -400,8 +430,9 @@ class Signaling {
   }
 
   _send(event, data) {
-    data['type'] = event;
-    JsonEncoder encoder = new JsonEncoder();
-    _socket.send(encoder.convert(data));
+    var request = new Map();
+    request["type"] = event;
+    request["data"] = data;
+    _socket.send(_encoder.convert(request));
   }
 }

lib/src/utils/turn.dart

@@ -0,0 +1,19 @@
+import 'dart:convert';
+import 'dart:async';
+import 'dart:io';
+
+Future<Map> getTurnCredential(String host, int port) async {
+    HttpClient client = HttpClient(context: SecurityContext());
+    client.badCertificateCallback =
+        (X509Certificate cert, String host, int port) {
+      print('getTurnCredential: Allow self-signed certificate => $host:$port. ');
+      return true;
+    };
+    var url = 'https://$host:$port/api/turn?service=turn&username=flutter-webrtc';
+    var request = await client.getUrl(Uri.parse(url));
+    var response = await request.close();
+    var responseBody = await response.transform(Utf8Decoder()).join();
+    print('getTurnCredential:response => $responseBody.');
+    Map data = JsonDecoder().convert(responseBody);
+    return data;
+  }

lib/src/utils/turn_web.dart

@@ -0,0 +1,13 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+
+Future<Map> getTurnCredential(String host, int port) async {
+  var url = 'https://$host:$port/api/turn?service=turn&username=flutter-webrtc';
+    final res = await http.get(url);
+    if (res.statusCode == 200) {
+      var data = json.decode(res.body);
+      print('getTurnCredential:response => $data.');
+      return data;
+    }
+    return {};
+  }

lib/src/utils/websocket.dart

@@ -17,8 +17,8 @@ class SimpleWebSocket {
 
   connect() async {
     try {
-      _socket = await WebSocket.connect(_url);
-      //socket = await _connectForSelfSignedCert(_host, _port);
+      //_socket = await WebSocket.connect(_url);
+      _socket = await _connectForSelfSignedCert(_url);
       this?.onOpen();
       _socket.listen((data) {
         this?.onMessage(data);
@@ -38,23 +38,22 @@ class SimpleWebSocket {
   }
 
   close() {
-    _socket.close();
+    if (_socket != null)
+      _socket.close();
   }
 
-  Future<WebSocket> _connectForSelfSignedCert(String host, int port) async {
+  Future<WebSocket> _connectForSelfSignedCert(url) async {
     try {
       Random r = new Random();
       String key = base64.encode(List<int>.generate(8, (_) => r.nextInt(255)));
-      SecurityContext securityContext = new SecurityContext();
-      HttpClient client = HttpClient(context: securityContext);
+      HttpClient client = HttpClient(context: SecurityContext());
       client.badCertificateCallback =
           (X509Certificate cert, String host, int port) {
-        print('Allow self-signed certificate => $host:$port. ');
+        print('SimpleWebSocket: Allow self-signed certificate => $host:$port. ');
         return true;
       };
 
-      HttpClientRequest request = await client.getUrl(
-          Uri.parse('https://$host:$port/ws')); // form the correct url here
+      HttpClientRequest request = await client.getUrl(Uri.parse(url)); // form the correct url here
       request.headers.add('Connection', 'Upgrade');
       request.headers.add('Upgrade', 'websocket');
       request.headers.add(

lib/src/utils/websocket_web.dart

@@ -11,7 +11,9 @@ class SimpleWebSocket {
   OnMessageCallback onMessage;
   OnCloseCallback onClose;
 
-  SimpleWebSocket(this._url);
+  SimpleWebSocket(this._url) {
+    _url = _url.replaceAll('https:', 'wss:');
+  }
 
   connect() async {
     try {
@@ -28,7 +30,7 @@ class SimpleWebSocket {
         this?.onClose(e.code, e.reason);
       });
     } catch (e) {
-      this?.onClose(e.code, e.reason);
+      this?.onClose(500, e.toString());
     }
   }
 
@@ -42,6 +44,6 @@ class SimpleWebSocket {
   }
 
   close() {
-    _socket.close();
+    if (_socket != null) _socket.close();
   }
 }

pubspec.yaml

@@ -19,9 +19,11 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^0.1.2
-  flutter_webrtc: ^0.2.2
+  flutter_webrtc: ^0.2.6
   shared_preferences:
   shared_preferences_macos:
+  shared_preferences_web:
+  http: ^0.12.0+4
 
   # Required for MediaRecorder example
   path_provider: