[WEBRTC-2963] Flutter SDK - Ice Trickle Support

lib/view/screen/home_screen.dart

@@ -117,11 +117,18 @@ class _HomeScreenState extends State<HomeScreen> {
       case 'Disable Debugging':
         Provider.of<ProfileProvider>(context, listen: false).toggleDebugMode();
         break;
+      case 'Enable Trickle ICE':
+      case 'Disable Trickle ICE':
+        Provider.of<TelnyxClientViewModel>(context, listen: false)
+            .toggleTrickleIce();
+        break;
       case 'Assistant Login':
         _showAssistantLoginDialog();
         break;
       case 'Force ICE Renegotiation':
-        Provider.of<TelnyxClientViewModel>(context, listen: false).forceIceRenegotiation();
+        Provider
+            .of<TelnyxClientViewModel>(context, listen: false)
+            .forceIceRenegotiation();
         break;
     }
   }
@@ -138,33 +145,37 @@ class _HomeScreenState extends State<HomeScreen> {
   @override
   Widget build(BuildContext context) {
     final clientState = context.select<TelnyxClientViewModel, CallStateStatus>(
-      (txClient) => txClient.callState,
+          (txClient) => txClient.callState,
     );
 
     final profileProvider = context.watch<ProfileProvider>();
     final selectedProfile = profileProvider.selectedProfile;
 
+    final clientViewModel = context.watch<TelnyxClientViewModel>();
+    final useTrickleIce = clientViewModel.useTrickleIce;
+
     final errorMessage = context.select<TelnyxClientViewModel, String?>(
-      (viewModel) => viewModel.errorDialogMessage,
+          (viewModel) => viewModel.errorDialogMessage,
     );
 
     if (errorMessage != null) {
       WidgetsBinding.instance.addPostFrameCallback((_) {
         showDialog(
           context: context,
-          builder: (_) => AlertDialog(
-            title: const Text('Error'),
-            content: Text(errorMessage),
-            actions: [
-              TextButton(
-                onPressed: () {
-                  context.read<TelnyxClientViewModel>().clearErrorDialog();
-                  Navigator.of(context).pop();
-                },
-                child: const Text('OK'),
+          builder: (_) =>
+              AlertDialog(
+                title: const Text('Error'),
+                content: Text(errorMessage),
+                actions: [
+                  TextButton(
+                    onPressed: () {
+                      context.read<TelnyxClientViewModel>().clearErrorDialog();
+                      Navigator.of(context).pop();
+                    },
+                    child: const Text('OK'),
+                  ),
+                ],
               ),
-            ],
-          ),
         );
       });
     }
@@ -177,56 +188,64 @@ class _HomeScreenState extends State<HomeScreen> {
             PopupMenuButton<String>(
               onSelected: handleOptionClick,
               itemBuilder: (BuildContext context) {
+                final trickleIceToggleText = useTrickleIce
+                    ? 'Disable Trickle ICE'
+                    : 'Enable Trickle ICE';
                 return {
-          'Audio Codecs',
-          'Export Logs',
-          'Disable Push Notifications',
-          'Force ICE Renegotiation'
-        }.map((
-                  String choice,
-                ) {
-                  return PopupMenuItem<String>(
-                    value: choice,
-                    child: Text(choice),
-                  );
-                }).toList();
-              },
-            )
-          else if (clientState == CallStateStatus.disconnected &&
-              selectedProfile != null)
-            PopupMenuButton<String>(
-              onSelected: handleOptionClick,
-              itemBuilder: (BuildContext context) {
-                final debugToggleText = selectedProfile.isDebug
-                    ? 'Disable Debugging'
-                    : 'Enable Debugging';
-                return {'Export Logs', debugToggleText, 'Assistant Login', 'Force ICE Renegotiation'}
-                    .map((String choice) {
-                  return PopupMenuItem<String>(
-                    value: choice,
-                    child: Text(choice),
-                  );
-                }).toList();
-              },
-            )
-          else if (clientState == CallStateStatus.ongoingCall ||
-                   clientState == CallStateStatus.ringing ||
-                   clientState == CallStateStatus.ongoingInvitation ||
-                   clientState == CallStateStatus.connectingToCall)
-            PopupMenuButton<String>(
-              onSelected: handleOptionClick,
-              itemBuilder: (BuildContext context) {
-                return {
-                  'Force ICE Renegotiation',
+                  'Audio Codecs',
                   'Export Logs',
-                }.map((String choice) {
+                  'Disable Push Notifications',
+                  'Force ICE Renegotiation'
+                }.map((String choice,) {
                   return PopupMenuItem<String>(
                     value: choice,
                     child: Text(choice),
                   );
                 }).toList();
               },
-            ),
+            )
+          else
+            if (clientState == CallStateStatus.disconnected &&
+                selectedProfile != null)
+              PopupMenuButton<String>(
+                onSelected: handleOptionClick,
+                itemBuilder: (BuildContext context) {
+                  final debugToggleText = selectedProfile.isDebug
+                      ? 'Disable Debugging'
+                      : 'Enable Debugging';
+                  return {
+                    'Export Logs',
+                    debugToggleText,
+                    'Assistant Login',
+                    'Force ICE Renegotiation'
+                  }
+                      .map((String choice) {
+                    return PopupMenuItem<String>(
+                      value: choice,
+                      child: Text(choice),
+                    );
+                  }).toList();
+                },
+              )
+            else
+              if (clientState == CallStateStatus.ongoingCall ||
+                  clientState == CallStateStatus.ringing ||
+                  clientState == CallStateStatus.ongoingInvitation ||
+                  clientState == CallStateStatus.connectingToCall)
+                PopupMenuButton<String>(
+                  onSelected: handleOptionClick,
+                  itemBuilder: (BuildContext context) {
+                    return {
+                      'Force ICE Renegotiation',
+                      'Export Logs',
+                    }.map((String choice) {
+                      return PopupMenuItem<String>(
+                        value: choice,
+                        child: Text(choice),
+                      );
+                    }).toList();
+                  },
+                ),
         ],
       ),
       body: SingleChildScrollView(
@@ -249,41 +268,42 @@ class _HomeScreenState extends State<HomeScreen> {
       ),
       bottomNavigationBar: clientState == CallStateStatus.idle
           ? Padding(
-              padding: const EdgeInsets.all(spacingXXL),
-              child: BottomConnectionActionWidget(
-                buttonTitle: 'Disconnect',
-                onPressed: () => {
-                  context.read<TelnyxClientViewModel>().disconnect(),
-                },
-              ),
-            )
+        padding: const EdgeInsets.all(spacingXXL),
+        child: BottomConnectionActionWidget(
+          buttonTitle: 'Disconnect',
+          onPressed: () =>
+          {
+            context.read<TelnyxClientViewModel>().disconnect(),
+          },
+        ),
+      )
           : clientState == CallStateStatus.disconnected
-              ? // Connect Bottom Action widget positioned at the bottom
-              Consumer<TelnyxClientViewModel>(
-                  builder: (context, viewModel, child) {
-                    final profileProvider = context.watch<ProfileProvider>();
-                    final selectedProfile = profileProvider.selectedProfile;
-                    return Padding(
-                      padding: const EdgeInsets.all(spacingXXL),
-                      child: BottomConnectionActionWidget(
-                        buttonTitle: 'Connect',
-                        isLoading: viewModel.loggingIn,
-                        onPressed: selectedProfile != null
-                            ? () async {
-                                final config =
-                                    await selectedProfile.toTelnyxConfig();
-                                if (config is TokenConfig) {
-                                  viewModel.loginWithToken(config);
-                                } else if (config is CredentialConfig) {
-                                  viewModel.login(config);
-                                }
-                              }
-                            : null,
-                      ),
-                    );
-                  },
-                )
-              : null,
+          ? // Connect Bottom Action widget positioned at the bottom
+      Consumer<TelnyxClientViewModel>(
+        builder: (context, viewModel, child) {
+          final profileProvider = context.watch<ProfileProvider>();
+          final selectedProfile = profileProvider.selectedProfile;
+          return Padding(
+            padding: const EdgeInsets.all(spacingXXL),
+            child: BottomConnectionActionWidget(
+              buttonTitle: 'Connect',
+              isLoading: viewModel.loggingIn,
+              onPressed: selectedProfile != null
+                  ? () async {
+                final config =
+                await selectedProfile.toTelnyxConfig();
+                if (config is TokenConfig) {
+                  viewModel.loginWithToken(config);
+                } else if (config is CredentialConfig) {
+                  viewModel.login(config);
+                }
+              }
+                  : null,
+            ),
+          );
+        },
+      )
+          : null,
     );
   }
 }

lib/view/telnyx_client_view_model.dart

@@ -53,6 +53,7 @@ class TelnyxClientViewModel with ChangeNotifier {
   bool _mute = false;
   bool _hold = false;
   bool _isAssistantMode = false;
+  bool _useTrickleIce = false;
   List<AudioCodec> _supportedCodecs = [];
   List<AudioCodec> _preferredCodecs = [];
 
@@ -128,6 +129,13 @@ class TelnyxClientViewModel with ChangeNotifier {
     return _isAssistantMode;
   }
 
+  bool get useTrickleIce => _useTrickleIce;
+
+  void toggleTrickleIce() {
+    _useTrickleIce = !_useTrickleIce;
+    notifyListeners();
+  }
+
   List<AudioCodec> get supportedCodecs => _supportedCodecs;
 
   List<AudioCodec> get preferredCodecs => _preferredCodecs;
@@ -388,6 +396,7 @@ class TelnyxClientViewModel with ChangeNotifier {
     if (config.notificationToken != null) {
       await prefs.setString('notificationToken', config.notificationToken!);
     }
+    await prefs.setBool('forceRelayCandidate', config.forceRelayCandidate);
   }
 
   Future<void> _clearConfigForAutoLogin() async {
@@ -398,6 +407,8 @@ class TelnyxClientViewModel with ChangeNotifier {
     await prefs.remove('sipName');
     await prefs.remove('sipNumber');
     await prefs.remove('notificationToken');
+    await prefs.remove('forceRelayCandidate');
+    await prefs.remove('useTrickleIce');
   }
 
   void observeResponses() {
@@ -791,6 +802,7 @@ class TelnyxClientViewModel with ChangeNotifier {
       customHeaders: {'X-Header-1': 'Value1', 'X-Header-2': 'Value2'},
       preferredCodecs: _preferredCodecs.isNotEmpty ? _preferredCodecs : null,
       debug: true,
+      useTrickleIce: _useTrickleIce,
     );
 
     logger.i(
@@ -907,6 +919,7 @@ class TelnyxClientViewModel with ChangeNotifier {
         'State',
         customHeaders: {},
         debug: true,
+        useTrickleIce: _useTrickleIce,
       );
       observeCurrentCall();
 

packages/telnyx_webrtc/lib/call.dart

@@ -125,8 +125,9 @@ class Call {
   /// - Represents states like: newCall, ringing, connecting, active, held, done, etc.
   late CallState callState;
 
-  /// AudioService instance to handle audio playback
-  final audioService = AudioService();
+  /// AudioService instance to handle audio playback (lazy initialized)
+  AudioService get audioService => _audioService ??= AudioService();
+  AudioService? _audioService;
 
   /// Debug mode flag to enable call quality metrics
   final bool debug;
@@ -249,6 +250,7 @@ class Call {
   /// @param isAttach Whether this is an attach operation
   /// @param customHeaders Optional custom SIP headers
   /// @param debug Whether to enable call quality metrics (default: false)
+  /// @param useTrickleIce Whether to use trickle ICE for faster call setup (default: false)
   Call acceptCall(
     IncomingInviteParams invite,
     String callerName,
@@ -257,6 +259,7 @@ class Call {
     bool isAttach = false,
     Map<String, String> customHeaders = const {},
     bool debug = false,
+    bool useTrickleIce = false,
   }) {
     // Store the session information for later use
     sessionCallerName = callerName;
@@ -276,6 +279,7 @@ class Call {
       customHeaders: customHeaders,
       isAttach: isAttach,
       debug: debug,
+      useTrickleIce: useTrickleIce,
     );
   }
 

packages/telnyx_webrtc/lib/model/pending_ice_candidate.dart

@@ -0,0 +1,31 @@
+/// Represents a pending ICE candidate that needs to be processed
+/// after the remote description is set.
+class PendingIceCandidate {
+  /// The call ID this candidate belongs to
+  final String callId;
+
+  /// The SDP media identifier
+  final String sdpMid;
+
+  /// The SDP media line index
+  final int sdpMLineIndex;
+
+  /// The original candidate string
+  final String candidateString;
+
+  /// The enhanced candidate string (will be set later when ICE parameters are available)
+  final String enhancedCandidateString;
+
+  PendingIceCandidate({
+    required this.callId,
+    required this.sdpMid,
+    required this.sdpMLineIndex,
+    required this.candidateString,
+    required this.enhancedCandidateString,
+  });
+
+  @override
+  String toString() {
+    return 'PendingIceCandidate(callId: $callId, sdpMid: $sdpMid, sdpMLineIndex: $sdpMLineIndex, candidate: $candidateString)';
+  }
+}

packages/telnyx_webrtc/lib/model/socket_method.dart

@@ -15,4 +15,6 @@ class SocketMethod {
   static const attach = 'telnyx_rtc.attach';
   static const disablePush = 'telnyx_rtc.disable_push_notification';
   static const aiConversation = 'ai_conversation';
+  static const candidate = 'telnyx_rtc.candidate';
+  static const endOfCandidates = 'telnyx_rtc.endOfCandidates';
 }