fix state not being recomputed when track is attached (#61)

@@ -7,7 +7,7 @@ import kotlinx.coroutines.test.runTest
 import org.junit.Rule
 import org.mockito.junit.MockitoJUnit
 
-@ExperimentalCoroutinesApi
+@OptIn(ExperimentalCoroutinesApi::class)
 abstract class BaseTest {
     // Uncomment to enable logging in tests.
     //@get:Rule
@@ -19,6 +19,6 @@ abstract class BaseTest {
     @get:Rule
     var coroutineRule = TestCoroutineRule()
 
-    @ExperimentalCoroutinesApi
+    @OptIn(ExperimentalCoroutinesApi::class)
     fun runTest(testBody: suspend TestScope.() -> Unit) = coroutineRule.scope.runTest(testBody = testBody)
 }

 package io.livekit.android.room.participant
 
-import io.livekit.android.coroutines.TestCoroutineRule
+import io.livekit.android.BaseTest
 import io.livekit.android.room.SignalClient
+import io.livekit.android.room.track.TrackPublication
+import io.livekit.android.util.flow
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.launch
 import livekit.LivekitModels
 import org.junit.Assert.*
 import org.junit.Before
-import org.junit.Rule
 import org.junit.Test
 import org.mockito.Mockito
 
-class RemoteParticipantTest {
+@OptIn(ExperimentalCoroutinesApi::class)
+class RemoteParticipantTest : BaseTest() {
 
-    @get:Rule
-    var coroutineRule = TestCoroutineRule()
 
     lateinit var signalClient: SignalClient
     lateinit var participant: RemoteParticipant
@@ -50,7 +52,6 @@ class RemoteParticipantTest {
         val newTrackInfo = LivekitModels.ParticipantInfo.newBuilder(INFO)
             .addTracks(TRACK_INFO)
             .build()
-
         participant.updateFromInfo(newTrackInfo)
 
         assertEquals(1, participant.tracks.values.size)
@@ -58,6 +59,54 @@ class RemoteParticipantTest {
     }
 
     @Test
+    fun tracksFlow() = runTest {
+
+        val newTrackInfo = LivekitModels.ParticipantInfo.newBuilder(INFO)
+            .addTracks(TRACK_INFO)
+            .build()
+
+        val emissions = mutableListOf<Map<String, TrackPublication>>()
+        val job = launch {
+            participant::tracks.flow.collect {
+                emissions.add(it)
+            }
+        }
+
+        assertEquals(1, emissions.size)
+        assertEquals(emptyMap<String, TrackPublication>(), emissions.first())
+
+        participant.updateFromInfo(newTrackInfo)
+
+        job.cancel()
+        assertEquals(2, emissions.size)
+        assertEquals(1, emissions[1].size)
+    }
+
+    @Test
+    fun audioTracksFlow() = runTest {
+
+        val newTrackInfo = LivekitModels.ParticipantInfo.newBuilder(INFO)
+            .addTracks(TRACK_INFO)
+            .build()
+
+        val emissions = mutableListOf<Map<String, TrackPublication>>()
+        val job = launch {
+            participant::audioTracks.flow.collect {
+                emissions.add(it)
+            }
+        }
+
+        assertEquals(1, emissions.size)
+        assertEquals(emptyMap<String, TrackPublication>(), emissions.first())
+
+        participant.updateFromInfo(newTrackInfo)
+
+        job.cancel()
+        assertEquals(2, emissions.size)
+        assertEquals(1, emissions[1].size)
+    }
+
+    @Test
     fun updateFromInfoRemovesTrack() {
         val newTrackInfo = LivekitModels.ParticipantInfo.newBuilder(INFO)
             .addTracks(TRACK_INFO)

@@ -2,7 +2,6 @@ package io.livekit.android.composesample
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
-import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material.Icon
 import androidx.compose.material.Surface
 import androidx.compose.material.Text
@@ -21,8 +20,6 @@ import io.livekit.android.composesample.ui.theme.NoVideoBackground
 import io.livekit.android.room.Room
 import io.livekit.android.room.participant.ConnectionQuality
 import io.livekit.android.room.participant.Participant
-import io.livekit.android.room.track.Track
-import io.livekit.android.room.track.VideoTrack
 import io.livekit.android.util.flow
 
 /**
@@ -50,33 +47,20 @@ fun ParticipantItem(
                 }
             }
     ) {
-        val (videoCamOff, identityBar, identityText, muteIndicator, connectionIndicator) = createRefs()
-        val videoTrack = participant.getTrackPublication(Track.Source.SCREEN_SHARE)?.track as? VideoTrack
-            ?: participant.getTrackPublication(Track.Source.CAMERA)?.track as? VideoTrack
-            ?: videoTracks.values.firstOrNull()?.track as? VideoTrack
+        val (videoItem, identityBar, identityText, muteIndicator, connectionIndicator) = createRefs()
 
-
-        if (videoTrack != null && videoTrack.enabled) {
         VideoItemTrackSelector(
             room = room,
             participant = participant,
-                modifier = Modifier.fillMaxSize()
-            )
-        } else {
-            Icon(
-                painter = painterResource(id = R.drawable.outline_videocam_off_24),
-                contentDescription = null,
-                tint = Color.White,
-                modifier = Modifier.constrainAs(videoCamOff) {
+            modifier = Modifier.constrainAs(videoItem) {
                 top.linkTo(parent.top)
                 bottom.linkTo(parent.bottom)
                 start.linkTo(parent.start)
                 end.linkTo(parent.end)
-                    width = Dimension.wrapContent
-                    height = Dimension.wrapContent
+                width = Dimension.fillToConstraints
+                height = Dimension.fillToConstraints
             }
         )
-        }
 
         Surface(
             color = Color(0x80000000),

 package io.livekit.android.composesample
 
+import androidx.compose.foundation.layout.Box
+import androidx.compose.material.Icon
 import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.viewinterop.AndroidView
+import com.github.ajalt.timberkt.Timber
 import io.livekit.android.renderer.TextureViewRenderer
 import io.livekit.android.room.Room
 import io.livekit.android.room.participant.Participant
@@ -12,7 +18,7 @@ import io.livekit.android.room.track.Track
 import io.livekit.android.room.track.VideoTrack
 import io.livekit.android.room.track.video.ComposeVisibility
 import io.livekit.android.util.flow
-import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.*
 
 /**
  * Widget for displaying a VideoTrack. Handles the Compose <-> AndroidView interop needed to use
@@ -24,6 +30,7 @@ fun VideoItem(
     videoTrack: VideoTrack,
     modifier: Modifier = Modifier
 ) {
+
     val videoSinkVisibility = remember(room, videoTrack) { ComposeVisibility() }
     var boundVideoTrack by remember { mutableStateOf<VideoTrack?>(null) }
     var view: TextureViewRenderer? by remember { mutableStateOf(null) }
@@ -91,9 +98,21 @@ fun VideoItemTrackSelector(
     val subscribedVideoTracksFlow by remember(participant) {
         mutableStateOf(
             participant::videoTracks.flow
-                .map { tracks -> tracks.values.filter { pub -> pub.subscribed } }
+                .flatMapLatest { videoTracks ->
+                    combine(
+                        videoTracks.values
+                            .map { trackPublication ->
+                                // Re-emit when track changes
+                                trackPublication::track.flow
+                                    .map { trackPublication }
+                            }
+                    ) { trackPubs ->
+                        trackPubs.toList().filter { trackPublication -> trackPublication.track != null }
+                    }
+                }
         )
     }
+
     val videoTracks by subscribedVideoTracksFlow.collectAsState(initial = emptyList())
     val videoTrack = videoTracks.firstOrNull { pub -> pub.source == Track.Source.SCREEN_SHARE }?.track as? VideoTrack
         ?: videoTracks.firstOrNull { pub -> pub.source == Track.Source.CAMERA }?.track as? VideoTrack
@@ -105,5 +124,14 @@ fun VideoItemTrackSelector(
             videoTrack = videoTrack,
             modifier = modifier
         )
+    } else {
+        Box(modifier = modifier) {
+            Icon(
+                painter = painterResource(id = R.drawable.outline_videocam_off_24),
+                contentDescription = null,
+                tint = Color.White,
+                modifier = Modifier.align(Alignment.Center)
+            )
+        }
     }
 }
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