Route AudioSwitch calls through main thread (#120)

@@ -2,6 +2,8 @@ package io.livekit.android.audio
 
 
 import android.content.Context
 import android.content.Context
 import android.media.AudioManager
 import android.media.AudioManager
+import android.os.Handler
+import android.os.Looper
 import com.twilio.audioswitch.AudioDevice
 import com.twilio.audioswitch.AudioDevice
 import com.twilio.audioswitch.AudioDeviceChangeListener
 import com.twilio.audioswitch.AudioDeviceChangeListener
 import com.twilio.audioswitch.AudioSwitch
 import com.twilio.audioswitch.AudioSwitch
@@ -19,8 +21,13 @@ constructor(private val context: Context) : AudioHandler {
 
 
     private var audioSwitch: AudioSwitch? = null
     private var audioSwitch: AudioSwitch? = null
 
 
+    // AudioSwitch is not threadsafe, so all calls should be done on the main thread.
+    private val handler = Handler(Looper.getMainLooper())
+
     override fun start() {
     override fun start() {
         if (audioSwitch == null) {
         if (audioSwitch == null) {
+            handler.removeCallbacksAndMessages(null)
+            handler.post {
                 val switch = AudioSwitch(
                 val switch = AudioSwitch(
                     context = context,
                     context = context,
                     loggingEnabled = loggingEnabled,
                     loggingEnabled = loggingEnabled,
@@ -32,11 +39,15 @@ constructor(private val context: Context) : AudioHandler {
                 switch.activate()
                 switch.activate()
             }
             }
         }
         }
+    }
 
 
     override fun stop() {
     override fun stop() {
+        handler.removeCallbacksAndMessages(null)
+        handler.post {
             audioSwitch?.stop()
             audioSwitch?.stop()
             audioSwitch = null
             audioSwitch = null
         }
         }
+    }
 
 
     val selectedAudioDevice: AudioDevice?
     val selectedAudioDevice: AudioDevice?
         get() = audioSwitch?.selectedAudioDevice
         get() = audioSwitch?.selectedAudioDevice

@@ -19,21 +19,23 @@ import io.livekit.android.room.participant.Participant
 import io.livekit.android.room.participant.RemoteParticipant
 import io.livekit.android.room.participant.RemoteParticipant
 import io.livekit.android.room.track.*
 import io.livekit.android.room.track.*
 import io.livekit.android.util.flow
 import io.livekit.android.util.flow
-import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.*
 import kotlinx.coroutines.flow.*
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.launch
 import livekit.LivekitRtc
 import livekit.LivekitRtc
 
 
-@OptIn(ExperimentalCoroutinesApi::class)
 class CallViewModel(
 class CallViewModel(
     val url: String,
     val url: String,
     val token: String,
     val token: String,
     application: Application
     application: Application
 ) : AndroidViewModel(application) {
 ) : AndroidViewModel(application) {
 
 
+    val audioHandler = AudioSwitchHandler(application)
     val room = LiveKit.create(
     val room = LiveKit.create(
         appContext = application,
         appContext = application,
         options = RoomOptions(adaptiveStream = true, dynacast = true),
         options = RoomOptions(adaptiveStream = true, dynacast = true),
+        overrides = LiveKitOverrides(
+            audioHandler = audioHandler
+        )
     )
     )
 
 
     val participants = room::remoteParticipants.flow
     val participants = room::remoteParticipants.flow
@@ -73,7 +75,6 @@ class CallViewModel(
     private val mutablePermissionAllowed = MutableStateFlow(true)
     private val mutablePermissionAllowed = MutableStateFlow(true)
     val permissionAllowed = mutablePermissionAllowed.hide()
     val permissionAllowed = mutablePermissionAllowed.hide()
 
 
-    val audioHandler = AudioSwitchHandler(application)
     init {
     init {
         viewModelScope.launch {
         viewModelScope.launch {
             launch {
             launch {