Paired devices list was added

app/src/main/java/com/helible/pilot/BluetoothAdapterStateReceiver.kt

@@ -9,29 +9,13 @@ import android.content.Intent
 import android.location.LocationManager
 import android.os.Build
 
-class BluetoothIntentReceiver(
+class BluetoothAdapterStateReceiver(
-    private val onDeviceFound: (device: BluetoothDevice, rssi: Short) -> Unit,
     private val onBluetoothEnabledChanged: (isBluetoothEnabled: Boolean) -> Unit,
     private val onDiscoveryRunningChanged: (isDiscoveryRunning: Boolean) -> Unit,
     private val onLocationEnabledChanged: () -> Unit
 ) : BroadcastReceiver() {
     override fun onReceive(context: Context?, intent: Intent?) {
         when (intent?.action) {
-            BluetoothDevice.ACTION_FOUND -> {
-                val device = if (Build.VERSION.SDK_INT >= 33) {
-                    intent.getParcelableExtra(
-                        BluetoothDevice.EXTRA_DEVICE,
-                        BluetoothDevice::class.java
-                    )
-                } else {
-                    @Suppress("DEPRECATION") intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE)
-                }
-
-                val rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI, Short.MIN_VALUE)
-                @SuppressLint("MissingPermission") if (device?.name != null)
-                    onDeviceFound(device, rssi)
-            }
-
             BluetoothAdapter.ACTION_STATE_CHANGED -> {
                 when (intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, -1)) {
                     BluetoothAdapter.STATE_ON -> {
@@ -57,3 +41,32 @@ class BluetoothIntentReceiver(
         }
     }
 }
+
+class BluetoothStateReceiver(
+    private val onDeviceFound: (device: BluetoothDevice, rssi: Short) -> Unit,
+    private val onConnectedStateChanged: (isConnected: Boolean, BluetoothDevice) -> Unit
+) : BroadcastReceiver() {
+    override fun onReceive(context: Context?, intent: Intent?) {
+        val device = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            intent?.getParcelableExtra(
+                BluetoothDevice.EXTRA_DEVICE,
+                BluetoothDevice::class.java
+            )
+        } else {
+            @Suppress("DEPRECATION") intent?.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE)
+        }
+        when(intent?.action) {
+            BluetoothDevice.ACTION_FOUND -> {
+                val rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI, Short.MIN_VALUE)
+                @SuppressLint("MissingPermission") if (device?.name != null)
+                    onDeviceFound(device, rssi)
+            }
+            BluetoothDevice.ACTION_ACL_CONNECTED -> {
+                onConnectedStateChanged(true, device ?: return)
+            }
+            BluetoothDevice.ACTION_ACL_DISCONNECTED -> {
+                onConnectedStateChanged(false, device ?: return)
+            }
+        }
+    }
+}

app/src/main/java/com/helible/pilot/BluetoothController.kt

@@ -14,6 +14,7 @@ import android.os.Build
 import android.util.Log
 import android.widget.Toast
 import androidx.activity.ComponentActivity
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
@@ -22,15 +23,20 @@ import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.emitAll
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onCompletion
+import kotlinx.coroutines.flow.toSet
 import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
 import java.io.IOException
 import java.util.UUID
 
 sealed interface ConnectionResult {
     object ConnectionEstablished: ConnectionResult
+    data class TransferSucceded(val message: KMessage): ConnectionResult
     data class Error(val message: String) : ConnectionResult
 }
 
@@ -40,12 +46,13 @@ interface BluetoothController {
     val isConnected: StateFlow<Boolean>
     val isScanning: StateFlow<Boolean>
     val scannedDevices: StateFlow<List<Device>>
-    val pairedDevices: StateFlow<Set<BluetoothDevice>>
+    val pairedDevices: StateFlow<List<Device>>
     val errors: SharedFlow<String>
 
     fun startDiscovery()
     fun cancelDiscovery()
     fun connectToDevice(device: Device?): Flow<ConnectionResult>
+    suspend fun trySendMessage(message: KMessage): KMessage?
     fun closeConnection()
     fun onDestroy()
 }
@@ -64,6 +71,8 @@ class AndroidBluetoothController(private val context: Context) : BluetoothContro
         context.getSystemService(ComponentActivity.LOCATION_SERVICE) as LocationManager
     }
 
+    private var dataTransferService: BluetoothDataTransferService? = null
+
     private val _isConnected: MutableStateFlow<Boolean> = MutableStateFlow(false)
     override val isConnected: StateFlow<Boolean>
         get() = _isConnected.asStateFlow()
@@ -84,8 +93,8 @@ class AndroidBluetoothController(private val context: Context) : BluetoothContro
     override val isLocationEnabled: StateFlow<Boolean>
         get() = _isLocationEnabled.asStateFlow()
 
-    private val _pairedDevices = MutableStateFlow<Set<BluetoothDevice>>(emptySet())
+    private val _pairedDevices = MutableStateFlow<List<Device>>(emptyList())
-    override val pairedDevices: StateFlow<Set<BluetoothDevice>>
+    override val pairedDevices: StateFlow<List<Device>>
         get() = _pairedDevices.asStateFlow()
 
     private val _scannedDevices: MutableStateFlow<List<Device>> = MutableStateFlow(emptyList())
@@ -94,20 +103,8 @@ class AndroidBluetoothController(private val context: Context) : BluetoothContro
 
     private var currentClientSocket: BluetoothSocket? = null
 
-
     @SuppressLint("MissingPermission")
-    private val bluetoothIntentReceiver = BluetoothIntentReceiver(
+    private val bluetoothAdapterStateReceiver = BluetoothAdapterStateReceiver(
-        onDeviceFound = {device, rssi ->
-            if(!hasAllPermissions()) return@BluetoothIntentReceiver
-            val newDevice = Device(device, rssi)
-            _scannedDevices.update { devices ->
-                if(newDevice in devices) devices else devices + newDevice
-            }
-            Log.i(
-                "ScanActivity",
-                "Found new device: ${device.name} ${device.address} $rssi"
-            )
-        },
         onBluetoothEnabledChanged = { isEnabled ->
             _isEnabled.update { _ -> isEnabled }
             startDiscovery()
@@ -125,6 +122,30 @@ class AndroidBluetoothController(private val context: Context) : BluetoothContro
         }
     )
 
+    @SuppressLint("MissingPermission")
+    private val bluetoothStateReceiver = BluetoothStateReceiver(
+        onDeviceFound = { device, rssi ->
+            if(!hasAllPermissions()) return@BluetoothStateReceiver
+            val newDevice = Device(device, rssi)
+            _scannedDevices.update { devices ->
+                if(newDevice in devices) devices else devices + newDevice
+            }
+            Log.i(
+                "ScanActivity",
+                "Found new device: ${device.name} ${device.address} $rssi"
+            )
+        },
+        onConnectedStateChanged = { isConnected, device ->
+            if(bluetoothAdapter?.bondedDevices?.contains(device) == true) {
+                _isConnected.update { isConnected }
+            } else {
+                CoroutineScope(Dispatchers.IO).launch {
+                    _errors.emit("Can't connect to a non-paired device.")
+                }
+            }
+        }
+    )
+
     companion object {
         const val SERVICE_UUID = "af7cc14b-cffa-4a3d-b677-01b0ff0a93d7"
     }
@@ -133,13 +154,26 @@ class AndroidBluetoothController(private val context: Context) : BluetoothContro
         updatePairedDevices()
         _isEnabled.update { bluetoothAdapter.isEnabled }
         _isLocationEnabled.update { locationManager?.isLocationEnabled == true }
-        context.registerReceiver(bluetoothIntentReceiver, IntentFilter(BluetoothDevice.ACTION_FOUND))
+        context.registerReceiver(
-        context.registerReceiver(bluetoothIntentReceiver, IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED))
+            bluetoothAdapterStateReceiver,
-        context.registerReceiver(bluetoothIntentReceiver, IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED))
+            IntentFilter().apply {
-        context.registerReceiver(bluetoothIntentReceiver, IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED))
+                addAction(BluetoothAdapter.ACTION_STATE_CHANGED)
-        if(Build.VERSION.SDK_INT <= Build.VERSION_CODES.R) {
+                addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED)
-            context.registerReceiver(bluetoothIntentReceiver, IntentFilter(LocationManager.PROVIDERS_CHANGED_ACTION))
+                addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED)
-        }
+                if(Build.VERSION.SDK_INT <= Build.VERSION_CODES.R) {
+                    addAction(LocationManager.PROVIDERS_CHANGED_ACTION)
+                }
+            }
+        )
+        context.registerReceiver(
+            bluetoothStateReceiver,
+            IntentFilter().apply {
+                addAction(BluetoothDevice.ACTION_ACL_CONNECTED)
+                addAction(BluetoothDevice.ACTION_ACL_DISCONNECTED)
+                addAction(BluetoothDevice.ACTION_FOUND)
+            }
+        )
+
     }
 
     @SuppressLint("MissingPermission")
@@ -185,6 +219,13 @@ class AndroidBluetoothController(private val context: Context) : BluetoothContro
                 try {
                     socket.connect()
                     emit(ConnectionResult.ConnectionEstablished)
+                    BluetoothDataTransferService(socket).also { it ->
+                        dataTransferService = it
+                        emitAll(
+                            it.listenForIncomingMessages()
+                                .map {ConnectionResult.TransferSucceded(it)}
+                        )
+                    }
                 } catch (e: IOException) {
                     closeConnection()
                     emit(ConnectionResult.Error("Connection was interrupted"))
@@ -193,22 +234,40 @@ class AndroidBluetoothController(private val context: Context) : BluetoothContro
         }.onCompletion { closeConnection() }.flowOn(Dispatchers.IO)
     }
 
+    override suspend fun trySendMessage(message: KMessage): KMessage? {
+        if(!hasAllPermissions()){
+            return null
+        }
+        if(dataTransferService == null) {
+            return null
+        }
+        dataTransferService?.sendMessage(message.toByteArray())
+        return message
+    }
+
     override fun closeConnection() {
         currentClientSocket?.close()
         currentClientSocket = null
     }
 
     override fun onDestroy() {
-        context.unregisterReceiver(bluetoothIntentReceiver)
+        context.unregisterReceiver(bluetoothAdapterStateReceiver)
+        context.unregisterReceiver(bluetoothStateReceiver)
         closeConnection()
     }
 
     @SuppressLint("MissingPermission")
     private fun updatePairedDevices() {
         if(!hasAllPermissions()) return
-        bluetoothAdapter?.bondedDevices.also { devices ->
+        Log.i("ScanActivity", "${bluetoothAdapter?.bondedDevices}")
-            if(devices != null) {
+        bluetoothAdapter?.bondedDevices?.onEach { device ->
-                _pairedDevices.update { devices }
+            _pairedDevices.update {
+                val currentDevice = Device(bluetoothDevice = device, rssi=0, isPaired = true)
+                if (currentDevice in pairedDevices.value) {
+                    pairedDevices.value
+                } else {
+                    _pairedDevices.value + currentDevice
+                }
             }
         }
     }

app/src/main/java/com/helible/pilot/BluetoothDataTransferService.kt

@@ -0,0 +1,48 @@
+package com.helible.pilot
+
+import android.bluetooth.BluetoothSocket
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.withContext
+
+import java.io.IOException
+
+class TransferFailedException : IOException("Reading incoming data failed")
+
+class BluetoothDataTransferService(
+    private val socket: BluetoothSocket
+) {
+    fun listenForIncomingMessages(): Flow<KMessage> {
+        return flow {
+            if(!socket.isConnected)
+                return@flow
+            val buffer = ByteArray(128)
+            while(true) {
+                val byteCount: Int = try {
+                    socket.inputStream.read(buffer)
+                } catch (e: IOException) {
+                    throw TransferFailedException()
+                }
+                emit(
+                    buffer.decodeToString(
+                        endIndex = byteCount
+                    ).toKMessage()
+                )
+            }
+        }.flowOn(Dispatchers.IO)
+    }
+
+    suspend fun sendMessage(bytes: ByteArray): Boolean {
+        return withContext(Dispatchers.IO) {
+            try {
+                socket.outputStream.write(bytes)
+            } catch (e: IOException) {
+                e.printStackTrace()
+                return@withContext false
+            }
+            true
+        }
+    }
+}

app/src/main/java/com/helible/pilot/BluetoothUiState.kt

@@ -0,0 +1,13 @@
+package com.helible.pilot
+
+import android.bluetooth.BluetoothDevice
+data class BluetoothUiState(
+    val isEnabled: Boolean = false,
+    val isLocationEnabled: Boolean = false,
+    val isDiscovering: Boolean = false,
+    val isConnected: Boolean = false,
+    val isConnecting: Boolean = false,
+    val errorMessage: String? = null,
+    val scannedDevices: List<Device> = emptyList(),
+    val pairedDevices: List<Device> = emptyList(),
+)

app/src/main/java/com/helible/pilot/BluetoothViewModel.kt

@@ -1,7 +1,6 @@
 package com.helible.pilot
 
 import android.bluetooth.BluetoothDevice
-import android.util.Log
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Job
@@ -16,18 +15,6 @@ import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
-
-data class BluetoothUiState(
-    val isEnabled: Boolean = false,
-    val isLocationEnabled: Boolean = false,
-    val isDiscovering: Boolean = false,
-    val isConnected: Boolean = false,
-    val isConnecting: Boolean = false,
-    val errorMessage: String? = null,
-    val scannedDevices: List<Device> = emptyList(),
-    val pairedDevices: List<BluetoothDevice> = emptyList(),
-)
-
 class BluetoothViewModel(
     private val bluetoothController: BluetoothController
 ) : ViewModel() {
@@ -41,7 +28,7 @@ class BluetoothViewModel(
     { scannedDevices, pairedDevices, state ->
         state.copy(
             scannedDevices = scannedDevices.toList(),
-            pairedDevices = pairedDevices.toList()
+            pairedDevices = pairedDevices
         )
     }.stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), _state.value)
 
@@ -83,6 +70,9 @@ class BluetoothViewModel(
                         )
                     }
                 }
+                is ConnectionResult.TransferSucceded -> {
+                    TODO("Telemetry not implemented")
+                }
                 is ConnectionResult.Error -> {
                     _state.update { it.copy(
                         isConnected = false,

app/src/main/java/com/helible/pilot/Kproto.kt

@@ -0,0 +1,23 @@
+package com.helible.pilot
+
+// Todo: add checksum
+// Todo: add arguments names
+
+data class KMessage(
+    val r1: UShort,
+    val r2: UShort,
+    val r3: UShort,
+    val emergStop: Boolean,
+    val alarm: Boolean
+)
+
+fun KMessage.toByteArray(): ByteArray {
+    return "$$r1;$r2;$r3;$emergStop;$alarm\r\n".encodeToByteArray()
+}
+
+fun String.toKMessage(): KMessage {
+    // TODO: implement
+    return KMessage(
+        0u, 0u, 0u, emergStop = false, alarm = false
+    )
+}

app/src/main/java/com/helible/pilot/MainViewModel.kt

@@ -1,27 +1,15 @@
 package com.helible.pilot
 
 import android.bluetooth.BluetoothDevice
-import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.mutableStateListOf
-import androidx.compose.runtime.mutableStateOf
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.viewModelScope
 import com.helible.pilot.components.SavedPreferences
 import com.helible.pilot.components.SavedPreferencesCache
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
-import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.catch
-import kotlinx.coroutines.flow.launchIn
-import kotlinx.coroutines.flow.onEach
-import kotlinx.coroutines.flow.stateIn
-import kotlinx.coroutines.flow.update
 
 data class Device(
     val bluetoothDevice: BluetoothDevice,
     val rssi: Short,
+    val isPaired: Boolean = false
 )
 
 class PermissionDialogViewModel: ViewModel() {

app/src/main/java/com/helible/pilot/PermissionsRequest.kt

@@ -6,7 +6,6 @@ import android.content.Intent
 import android.content.pm.PackageManager
 import android.net.Uri
 import android.provider.Settings
-import android.util.Log
 import androidx.activity.compose.ManagedActivityResultLauncher
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.snapshots.SnapshotStateList

app/src/main/java/com/helible/pilot/components/BluetoothScannerScreen.kt

@@ -45,7 +45,7 @@ fun BluetoothScannerScreen(
             val (title, devicesList, controls) = createRefs()
 
             Title(
-                text = "Поиск устройств",
+                text = "Устройства поблизости",
                 modifier = Modifier
                     .fillMaxWidth()
                     .padding(vertical = 10.dp)
@@ -53,7 +53,7 @@ fun BluetoothScannerScreen(
             )
 
             DiscoveredDevicesList(
-                devices = bluetoothState.scannedDevices,
+                bluetoothState = bluetoothState,
                 selectedDevice = selectedDevice,
                 choiceDevice = choiceDevice,
                 modifier = Modifier

app/src/main/java/com/helible/pilot/components/DeviceItem.kt

@@ -29,36 +29,51 @@ import com.helible.pilot.R
 
 @SuppressLint("MissingPermission")
 @Composable
-fun DeviceItem(deviceInfo: Device, selectedDevice: Device?, choiceDevice: (device: Device?) -> Unit, modifier: Modifier) {
+fun DeviceItem(
+    deviceInfo: Device,
+    selectedDevice: Device?,
+    choiceDevice: (device: Device?) -> Unit,
+    modifier: Modifier,
+) {
     ElevatedCard(
-        modifier=modifier.clickable {
+        modifier = modifier.clickable {
             choiceDevice(deviceInfo)
         },
-        colors = CardDefaults.elevatedCardColors(containerColor = if (deviceInfo.bluetoothDevice == selectedDevice?.bluetoothDevice)
+        colors = CardDefaults.elevatedCardColors(
-            MaterialTheme.colorScheme.secondaryContainer
+            containerColor = if (deviceInfo.bluetoothDevice == selectedDevice?.bluetoothDevice)
+                MaterialTheme.colorScheme.secondaryContainer
             else MaterialTheme.colorScheme.surface
         )
     ) {
-        Row(modifier=Modifier.padding(8.dp)) {
+        Row(modifier = Modifier.padding(8.dp)) {
             Column(verticalArrangement = Arrangement.Center) {
-                Text(text=deviceInfo.bluetoothDevice.name, fontWeight = FontWeight.Bold, softWrap = true)
+                Text(
-                Text(text="MAC: ${deviceInfo.bluetoothDevice.address}", fontWeight = FontWeight.Thin)
+                    text = deviceInfo.bluetoothDevice.name,
-            }
+                    fontWeight = FontWeight.Bold,
-            Box(contentAlignment = Alignment.CenterEnd, modifier = Modifier.fillMaxSize()) {
+                    softWrap = true
-                Icon(
-                    painterResource(id = getSignalIconForRssiValue(deviceInfo.rssi)),
-                    contentDescription = null,
-                    modifier = Modifier
-                        .fillMaxHeight()
-                        .padding(10.dp),
-                    tint = MaterialTheme.colorScheme.primary
                 )
+                Text(
+                    text = "MAC: ${deviceInfo.bluetoothDevice.address}",
+                    fontWeight = FontWeight.Thin
+                )
+            }
+            if (!deviceInfo.isPaired) {
+                Box(contentAlignment = Alignment.CenterEnd, modifier = Modifier.fillMaxSize()) {
+                    Icon(
+                        painterResource(id = getSignalIconForRssiValue(deviceInfo.rssi)),
+                        contentDescription = null,
+                        modifier = Modifier
+                            .fillMaxHeight()
+                            .padding(10.dp),
+                        tint = MaterialTheme.colorScheme.primary
+                    )
+                }
             }
         }
     }
 }
 
-fun getSignalIconForRssiValue(rssi: Short): Int{
+fun getSignalIconForRssiValue(rssi: Short): Int {
     if (rssi >= -80) return R.drawable.signal_icon4
     else if (rssi >= -90) return R.drawable.signal_icon3
     else if (rssi >= -100) return R.drawable.signal_icon2

app/src/main/java/com/helible/pilot/components/DiscoveredDevicesList.kt

@@ -1,18 +1,36 @@
 package com.helible.pilot.components
 
+import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
+import com.helible.pilot.BluetoothUiState
 import com.helible.pilot.Device
 
 @Composable
-fun DiscoveredDevicesList(devices: List<Device>, selectedDevice: Device?, choiceDevice: (device: Device?) -> Unit, modifier: Modifier = Modifier) {
+fun DiscoveredDevicesList(
+    bluetoothState: BluetoothUiState,
+    selectedDevice: Device?,
+    choiceDevice: (device: Device?) -> Unit,
+    modifier: Modifier = Modifier
+) {
     LazyColumn(modifier = modifier) {
-        items(devices) { device ->
+        item {
+            Text(
+                text = "Ранее подключенные устройства",
+                textAlign = TextAlign.Left,
+                fontWeight = FontWeight.Bold,
+                modifier = Modifier.padding(10.dp)
+            )
+        }
+        items(bluetoothState.pairedDevices) { device ->
             DeviceItem(
                 deviceInfo = device,
                 selectedDevice = selectedDevice,
@@ -24,5 +42,44 @@ fun DiscoveredDevicesList(devices: List<Device>, selectedDevice: Device?, choice
                     )
             )
         }
+        if(bluetoothState.pairedDevices.isEmpty()){
+            item {
+                Text(
+                    text = "Нет элементов для отображения",
+                    textAlign = TextAlign.Center,
+                    modifier = Modifier.fillMaxSize()
+                )
+            }
+        }
+        
+        item {
+            Text(
+                text = "Доступные устройства",
+                textAlign = TextAlign.Left,
+                fontWeight = FontWeight.Bold,
+                modifier = Modifier.padding(10.dp)
+            )
+        }
+
+        items(bluetoothState.scannedDevices) { device ->
+            DeviceItem(
+                deviceInfo = device,
+                selectedDevice = selectedDevice,
+                choiceDevice = choiceDevice,
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(
+                        5.dp
+                    )
+            )
+        }
+        if(bluetoothState.pairedDevices.isEmpty() && !bluetoothState.isDiscovering) {
+            item {
+                Text(
+                    text = "Устройства поблизости не обнаружены.",
+                    modifier = Modifier.fillMaxSize()
+                )
+            }
+        }
     }
 }