Fixed primarySpeaker videoTrack, mute observer (#98)

* Add private keyword

* Set primarySpeaker muteIndicator visibility

* Fixed primarySpeaker videoTrack, mute observer

@@ -77,33 +77,19 @@ class CallActivity : AppCompatActivity() {
                     // Observe primary speaker changes
                     emitAll(viewModel.primarySpeaker)
                 }.flatMapLatest { primarySpeaker ->
-                    // Update new primary speaker identity
-                    binding.identityText.text = primarySpeaker?.identity
-
-                    if (primarySpeaker != null) {
-                        primarySpeaker::audioTracks.flow
-                            .flatMapLatest { tracks ->
-                                val audioTrack = tracks.firstOrNull()?.first
-                                if (audioTrack != null) {
-                                    audioTrack::muted.flow
-                                } else {
-                                    flowOf(true)
-                                }
-                            }
-                            .collect { muted ->
-                                binding.muteIndicator.visibility = if (muted) View.VISIBLE else View.INVISIBLE
-                            }
-                    }
-
-                    // observe videoTracks changes.
                     if (primarySpeaker != null) {
-                        primarySpeaker::videoTracks.flow
-                            .map { primarySpeaker to it }
+                        flowOf(primarySpeaker)
                     } else {
                         emptyFlow()
                     }
-                }.flatMapLatest { (participant, videoTracks) ->
+                }.collect { participant ->
+                    // Update new primary speaker identity
+                    binding.identityText.text = participant.identity
 
+                    // observe videoTracks changes.
+                    val videoTrackFlow = participant::videoTracks.flow
+                        .map { participant to it }
+                        .flatMapLatest { (participant, videoTracks) ->
                             // Prioritize any screenshare streams.
                             val trackPublication = participant.getTrackPublication(Track.Source.SCREEN_SHARE)
                                 ?: participant.getTrackPublication(Track.Source.CAMERA)
@@ -111,7 +97,22 @@ class CallActivity : AppCompatActivity() {
                                 ?: return@flatMapLatest emptyFlow()
 
                             trackPublication::track.flow
-                }.collect { videoTrack ->
+                        }
+
+                    // observe audioTracks changes.
+                    val mutedFlow = participant::audioTracks.flow
+                        .flatMapLatest { tracks ->
+                            val audioTrack = tracks.firstOrNull()?.first
+                            if (audioTrack != null) {
+                                audioTrack::muted.flow
+                            } else {
+                                flowOf(true)
+                            }
+                        }
+
+                    combine(videoTrackFlow, mutedFlow) { videoTrack, muted ->
+                        videoTrack to muted
+                    }.collect { (videoTrack, muted) ->
                         // Cleanup old video track
                         val oldVideoTrack = binding.speakerVideoView.tag as? VideoTrack
                         oldVideoTrack?.removeRenderer(binding.speakerVideoView)
@@ -124,6 +125,9 @@ class CallActivity : AppCompatActivity() {
                             binding.speakerVideoView.visibility = View.INVISIBLE
                         }
                         binding.speakerVideoView.tag = videoTrack
+
+                        binding.muteIndicator.visibility = if (muted) View.VISIBLE else View.INVISIBLE
+                    }
                 }
         }