feat: Working VoIP calling implementation (Flutter + Android)

Working video and audio calls, as well as android integration

lib/liblinphone_flutter.dart

@@ -0,0 +1,70 @@
+import 'package:flutter/services.dart' show EventChannel;
+
+import 'liblinphone_flutter_platform_interface.dart';
+import 'models/call_type.dart';
+import 'models/registration_state.dart';
+import 'models/call_state.dart';
+
+class LiblinphoneFlutter {
+  final _registrationEventsStream = EventChannel(
+    'liblinphone_flutter.nuark.xyz/registration_events',
+  );
+
+  final _callEventsStream = EventChannel(
+    'liblinphone_flutter.nuark.xyz/call_events',
+  );
+
+  Stream<RegistrationState> get registrationEvents =>
+      _registrationEventsStream.receiveBroadcastStream().map((dynamic event) {
+        return RegistrationState.fromOrdinal(event);
+      });
+
+  Stream<CallState> get callEvents =>
+      _callEventsStream.receiveBroadcastStream().map((dynamic event) {
+        print("call event: $event");
+        return CallState.fromOrdinal(event);
+      });
+
+  Future<bool> checkPermissions() async =>
+      LiblinphoneFlutterPlatform.instance.checkPermissions();
+
+  Future<bool> initialize() async =>
+      LiblinphoneFlutterPlatform.instance.initialize();
+
+  Future<bool> register(
+    String username,
+    String password,
+    String serverIp,
+    int serverPort,
+  ) async => LiblinphoneFlutterPlatform.instance.register(
+    username,
+    password,
+    serverIp,
+    serverPort,
+  );
+
+  Future<bool> unregister() async =>
+      LiblinphoneFlutterPlatform.instance.unregister();
+
+  Future<bool> makeCall(String callTo, bool isVideoEnabled) async =>
+      LiblinphoneFlutterPlatform.instance.makeCall(callTo, isVideoEnabled);
+
+  Future<bool> answerCall() async =>
+      LiblinphoneFlutterPlatform.instance.answerCall();
+
+  Future<bool> hangupCall() async =>
+      LiblinphoneFlutterPlatform.instance.hangupCall();
+
+  Future<bool> inCall() async => LiblinphoneFlutterPlatform.instance.inCall();
+
+  Future<CallType> callType() async =>
+      LiblinphoneFlutterPlatform.instance.callType();
+
+  Future<bool> toggleVideo() async =>
+      LiblinphoneFlutterPlatform.instance.toggleVideo();
+
+  Future<bool> toggleMicrophone() async =>
+      LiblinphoneFlutterPlatform.instance.toggleMicrophone();
+
+  Future<bool> stop() async => LiblinphoneFlutterPlatform.instance.stop();
+}