VoIP: add select answer

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/call/CallListener.kt

@@ -21,6 +21,7 @@ import org.matrix.android.sdk.api.session.room.model.call.CallCandidatesContent
 import org.matrix.android.sdk.api.session.room.model.call.CallHangupContent
 import org.matrix.android.sdk.api.session.room.model.call.CallInviteContent
 import org.matrix.android.sdk.api.session.room.model.call.CallRejectContent
+import org.matrix.android.sdk.api.session.room.model.call.CallSelectAnswerContent
 
 interface CallListener {
     /**
@@ -45,5 +46,10 @@ interface CallListener {
      */
     fun onCallRejectReceived(callRejectContent: CallRejectContent)
 
+    /**
+     * Called when an answer has been selected
+     */
+    fun onCallSelectAnswerReceived(callSelectAnswerContent: CallSelectAnswerContent)
+
     fun onCallManagedByOtherSession(callId: String)
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/call/MxCall.kt

@@ -51,6 +51,11 @@ interface MxCall : MxCallDetail {
      */
     fun accept(sdp: SessionDescription)
 
+    /**
+     * This has to be sent by the caller's client once it has chosen an answer.
+     */
+    fun selectAnswer()
+
     /**
      * Reject an incoming call
      */

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/call/CallHangupContent.kt

@@ -40,7 +40,8 @@ data class CallHangupContent(
         /**
          * Optional error reason for the hangup. This should not be provided when the user naturally ends or rejects the call.
          * When there was an error in the call negotiation, this should be `ice_failed` for when ICE negotiation fails
-         * or `invite_timeout` for when the other party did not answer in time. One of: ["ice_failed", "invite_timeout"]
+         * or `invite_timeout` for when the other party did not answer in time.
+         * One of: ["ice_failed", "invite_timeout"]
          */
         @Json(name = "reason") val reason: Reason? = null
 ) : CallSignallingContent {

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/call/CallListenersDispatcher.kt

@@ -24,6 +24,7 @@ import org.matrix.android.sdk.api.session.room.model.call.CallCandidatesContent
 import org.matrix.android.sdk.api.session.room.model.call.CallHangupContent
 import org.matrix.android.sdk.api.session.room.model.call.CallInviteContent
 import org.matrix.android.sdk.api.session.room.model.call.CallRejectContent
+import org.matrix.android.sdk.api.session.room.model.call.CallSelectAnswerContent
 
 /**
  * Dispatch each method safely to all listeners.
@@ -54,6 +55,10 @@ class CallListenersDispatcher(private val listeners: Set<CallListener>) : CallLi
         it.onCallManagedByOtherSession(callId)
     }
 
+    override fun onCallSelectAnswerReceived(callSelectAnswerContent: CallSelectAnswerContent) = dispatch {
+        it.onCallSelectAnswerReceived(callSelectAnswerContent)
+    }
+
     private fun dispatch(lambda: (CallListener) -> Unit) {
         listeners.toList().forEach {
             tryOrNull {

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/call/DefaultCallSignalingService.kt

@@ -31,6 +31,7 @@ import org.matrix.android.sdk.api.session.room.model.call.CallCandidatesContent
 import org.matrix.android.sdk.api.session.room.model.call.CallHangupContent
 import org.matrix.android.sdk.api.session.room.model.call.CallInviteContent
 import org.matrix.android.sdk.api.session.room.model.call.CallRejectContent
+import org.matrix.android.sdk.api.session.room.model.call.CallSelectAnswerContent
 import org.matrix.android.sdk.api.session.room.model.call.CallSignallingContent
 import org.matrix.android.sdk.api.util.Cancelable
 import org.matrix.android.sdk.api.util.NoOpCancellable
@@ -152,9 +153,31 @@ internal class DefaultCallSignalingService @Inject constructor(
             EventType.CALL_CANDIDATES -> {
                 handleCallCandidatesEvent(event)
             }
+            EventType.CALL_SELECT_ANSWER -> {
+                handleCallSelectAnswerEvent(event)
+            }
         }
     }
 
+    private fun handleCallSelectAnswerEvent(event: Event) {
+        val content = event.getClearContent().toModel<CallSelectAnswerContent>() ?: return
+        val call = content.getCall() ?: return
+        if (call.ourPartyId == content.partyId) {
+            // Ignore remote echo
+            return
+        }
+        if (call.isOutgoing) {
+            Timber.v("Got selectAnswer for an outbound call: ignoring")
+            return
+        }
+        val selectedPartyId = content.selectedPartyId
+        if (selectedPartyId == null) {
+            Timber.w("Got nonsensical select_answer with null selected_party_id: ignoring")
+            return
+        }
+        callListenersDispatcher.onCallSelectAnswerReceived(content)
+    }
+
     private fun handleCallCandidatesEvent(event: Event) {
         val content = event.getClearContent().toModel<CallCandidatesContent>() ?: return
         val call = content.getCall() ?: return
@@ -185,7 +208,7 @@ internal class DefaultCallSignalingService @Inject constructor(
         val content = event.getClearContent().toModel<CallHangupContent>() ?: return
         val call = content.getCall() ?: return
         if (call.state != CallState.Terminated) {
-            // Need to check for party_id? 
+            // Need to check for party_id?
             activeCallHandler.removeCall(content.callId)
             callListenersDispatcher.onCallHangupReceived(content)
         }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/call/model/MxCallImpl.kt

@@ -29,6 +29,7 @@ import org.matrix.android.sdk.api.session.room.model.call.CallCandidatesContent
 import org.matrix.android.sdk.api.session.room.model.call.CallHangupContent
 import org.matrix.android.sdk.api.session.room.model.call.CallInviteContent
 import org.matrix.android.sdk.api.session.room.model.call.CallRejectContent
+import org.matrix.android.sdk.api.session.room.model.call.CallSelectAnswerContent
 import org.matrix.android.sdk.api.util.Optional
 import org.matrix.android.sdk.internal.session.call.DefaultCallSignalingService
 import org.matrix.android.sdk.internal.session.room.send.queue.EventSenderProcessor
@@ -143,6 +144,7 @@ internal class MxCallImpl(
         CallHangupContent(
                 callId = callId,
                 partyId = ourPartyId,
+                reason = CallHangupContent.Reason.USER_HANGUP
         )
                 .let { createEventAndLocalEcho(type = EventType.CALL_HANGUP, roomId = roomId, content = it.toContent()) }
                 .also { eventSenderProcessor.postEvent(it) }
@@ -162,6 +164,19 @@ internal class MxCallImpl(
                 .also { eventSenderProcessor.postEvent(it) }
     }
 
+    override fun selectAnswer() {
+        Timber.v("## VOIP select answer $callId")
+        if (isOutgoing) return
+        state = CallState.Answering
+        CallSelectAnswerContent(
+                callId = callId,
+                partyId = ourPartyId,
+                selectedPartyId = opponentPartyId?.getOrNull()
+        )
+                .let { createEventAndLocalEcho(type = EventType.CALL_SELECT_ANSWER, roomId = roomId, content = it.toContent()) }
+                .also { eventSenderProcessor.postEvent(it) }
+    }
+
     private fun createEventAndLocalEcho(localId: String = LocalEcho.createLocalEchoId(), type: String, roomId: String, content: Content): Event {
         return Event(
                 roomId = roomId,

vector/src/main/java/im/vector/app/features/call/WebRtcPeerConnectionManager.kt

@@ -31,6 +31,7 @@ import io.reactivex.disposables.Disposable
 import io.reactivex.subjects.PublishSubject
 import io.reactivex.subjects.ReplaySubject
 import org.matrix.android.sdk.api.MatrixCallback
+import org.matrix.android.sdk.api.extensions.orFalse
 import org.matrix.android.sdk.api.extensions.tryOrNull
 import org.matrix.android.sdk.api.session.Session
 import org.matrix.android.sdk.api.session.call.CallState
@@ -43,6 +44,7 @@ import org.matrix.android.sdk.api.session.room.model.call.CallCandidatesContent
 import org.matrix.android.sdk.api.session.room.model.call.CallHangupContent
 import org.matrix.android.sdk.api.session.room.model.call.CallInviteContent
 import org.matrix.android.sdk.api.session.room.model.call.CallRejectContent
+import org.matrix.android.sdk.api.session.room.model.call.CallSelectAnswerContent
 import org.webrtc.AudioSource
 import org.webrtc.AudioTrack
 import org.webrtc.Camera1Enumerator
@@ -303,6 +305,10 @@ class WebRtcPeerConnectionManager @Inject constructor(
                 callContext.peerConnection?.setLocalDescription(object : SdpObserverAdapter() {}, p0)
                 // send offer to peer
                 currentCall?.mxCall?.offerSdp(p0)
+
+                if(currentCall?.mxCall?.opponentPartyId?.hasValue().orFalse()){
+                    currentCall?.mxCall?.selectAnswer()
+                }
             }
         }, constraints)
     }
@@ -884,6 +890,21 @@ class WebRtcPeerConnectionManager @Inject constructor(
         endCall(false)
     }
 
+    override fun onCallSelectAnswerReceived(callSelectAnswerContent: CallSelectAnswerContent) {
+        val call = currentCall ?: return
+        if (call.mxCall.callId != callSelectAnswerContent.callId) return Unit.also {
+            Timber.w("onCallSelectAnswerReceived for non active call? ${callSelectAnswerContent.callId}")
+        }
+        val selectedPartyId = callSelectAnswerContent.selectedPartyId
+        if (selectedPartyId != call.mxCall.ourPartyId) {
+            Timber.i("Got select_answer for party ID ${selectedPartyId}: we are party ID ${call.mxCall.ourPartyId}.");
+            // The other party has picked somebody else's answer
+            call.mxCall.state = CallState.Terminated
+            endCall(false)
+        }
+
+    }
+
     override fun onCallManagedByOtherSession(callId: String) {
         Timber.v("## VOIP onCallManagedByOtherSession: $callId")
         currentCall = null