MainActivity.kt

Surface(
       modifier = Modifier
                  .fillMaxSize()
                  .padding(10.dp),
       color = MaterialTheme.colors.background
       ) {
            val deviceScanningState by viewModel.viewState.observeAsState()

            val deviceConnectionState by ChatServer.deviceConnection.observeAsState()

            var isChatOpen by remember {
                 mutableStateOf(false)
            }

            Box(
                contentAlignment = Alignment.TopCenter,
                modifier = Modifier.fillMaxSize()
            ) {
               if (deviceScanningState != null && !isChatOpen || deviceConnectionState == DeviceConnectionState.Disconnected) {
                  Column {
                       Text(
                          text = "Choose a device to chat with:",
                          fontSize = 20.sp,
                          fontWeight = FontWeight.Bold
                       )
                       Spacer(modifier = Modifier.height(10.dp))
                       DeviceScanCompose.DeviceScan(deviceScanViewState = deviceScanningState!!) {
                           isChatOpen = true
                  }
              }

        } else {
           ChatCompose.Chats()
       }
    }
}