Added rtcSetSignalingStateChangeCallback() to C API

include/rtc/rtc.h

@@ -100,6 +100,7 @@ typedef void (RTC_API *rtcDescriptionCallbackFunc)(int pc, const char *sdp, cons
 typedef void (RTC_API *rtcCandidateCallbackFunc)(int pc, const char *cand, const char *mid, void *ptr);
 typedef void (RTC_API *rtcStateChangeCallbackFunc)(int pc, rtcState state, void *ptr);
 typedef void (RTC_API *rtcGatheringStateCallbackFunc)(int pc, rtcGatheringState state, void *ptr);
+typedef void (RTC_API *rtcSignalingStateCallbackFunc)(int pc, rtcSignalingState state, void *ptr);
 typedef void (RTC_API *rtcDataChannelCallbackFunc)(int pc, int dc, void *ptr);
 typedef void (RTC_API *rtcTrackCallbackFunc)(int pc, int tr, void *ptr);
 typedef void (RTC_API *rtcOpenCallbackFunc)(int id, void *ptr);
@@ -124,6 +125,7 @@ RTC_EXPORT int rtcSetLocalDescriptionCallback(int pc, rtcDescriptionCallbackFunc
 RTC_EXPORT int rtcSetLocalCandidateCallback(int pc, rtcCandidateCallbackFunc cb);
 RTC_EXPORT int rtcSetStateChangeCallback(int pc, rtcStateChangeCallbackFunc cb);
 RTC_EXPORT int rtcSetGatheringStateChangeCallback(int pc, rtcGatheringStateCallbackFunc cb);
+RTC_EXPORT int rtcSetSignalingStateChangeCallback(int pc, rtcSignalingStateCallbackFunc cb);
 
 RTC_EXPORT int rtcSetLocalDescription(int pc, const char *type);
 RTC_EXPORT int rtcSetRemoteDescription(int pc, const char *sdp, const char *type);

src/capi.cpp

@@ -468,6 +468,19 @@ int rtcSetGatheringStateChangeCallback(int pc, rtcGatheringStateCallbackFunc cb)
 	});
 }
 
+int rtcSetSignalingStateChangeCallback(int pc, rtcSignalingStateCallbackFunc cb) {
+	return WRAP({
+		auto peerConnection = getPeerConnection(pc);
+		if (cb)
+			peerConnection->onSignalingStateChange([pc, cb](PeerConnection::SignalingState state) {
+				if (auto ptr = getUserPointer(pc))
+					cb(pc, static_cast<rtcSignalingState>(state), *ptr);
+			});
+		else
+			peerConnection->onGatheringStateChange(nullptr);
+	});
+}
+
 int rtcSetDataChannelCallback(int pc, rtcDataChannelCallbackFunc cb) {
 	return WRAP({
 		auto peerConnection = getPeerConnection(pc);