feat: add bluetooth enabled state to viewmodel

app/src/main/java/com/example/tvcontroller/BluetoothService.kt

@@ -16,12 +16,13 @@ class BluetoothService(private val context: Context) {
         getSystemService(context, BluetoothManager::class.java)!!;
     private var bluetoothAdapter: BluetoothAdapter = bluetoothManager.adapter
     private var bluetoothStateReceiver: BroadcastReceiver? = null
+    private var bluetoothStateChangedCallbacks: MutableList<(Int) -> Unit> = mutableListOf()
 
     init {
         registerBluetoothStateReceiver()
     }
 
-    fun isEnabled(): Boolean {
+    fun isBluetoothEnabled(): Boolean {
         return bluetoothAdapter.isEnabled ?: false
     }
 
@@ -29,6 +30,7 @@ class BluetoothService(private val context: Context) {
         bluetoothStateReceiver = object : BroadcastReceiver() {
             override fun onReceive(context: Context, intent: Intent) {
                 val state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR)
+                bluetoothStateChangedCallbacks.forEach { it(state) }
                 when (state) {
                     BluetoothAdapter.STATE_ON -> {
                         // Handle Bluetooth turned on
@@ -53,6 +55,14 @@ class BluetoothService(private val context: Context) {
         context.registerReceiver(bluetoothStateReceiver, IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED))
     }
 
+    fun onBluetoothStateChanged(callback: (Int) -> Unit) {
+        bluetoothStateChangedCallbacks.add(callback)
+    }
+
+    fun offBluetoothStateChanged(callback: (Int) -> Unit) {
+        bluetoothStateChangedCallbacks.remove(callback)
+    }
+
     fun cleanUp() {
         context.unregisterReceiver(bluetoothStateReceiver)
     }

app/src/main/java/com/example/tvcontroller/MainActivity.kt

@@ -1,11 +1,13 @@
 package com.example.tvcontroller
 
+import android.bluetooth.BluetoothAdapter
 import android.content.ContentValues.TAG
 import android.os.Bundle
 import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
+import androidx.activity.viewModels
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
@@ -34,14 +36,17 @@ import com.example.tvcontroller.ui.AppViewModel
 
 class MainActivity : ComponentActivity() {
     private lateinit var bluetoothService: BluetoothService
+    private val appViewModel by viewModels<AppViewModel>()
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         bluetoothService = BluetoothService(this.applicationContext)
+        bluetoothService.onBluetoothStateChanged { state -> appViewModel.setBluetoothEnabled(state == BluetoothAdapter.STATE_ON) }
+        appViewModel.setBluetoothEnabled(bluetoothService.isBluetoothEnabled())
         enableEdgeToEdge()
         setContent {
             TVControllerTheme {
-                TvControllerApp()
+                TvControllerApp(appViewModel = appViewModel, bluetoothService = bluetoothService)
             }
         }
     }
@@ -55,7 +60,8 @@ class MainActivity : ComponentActivity() {
 @Composable
 fun TvControllerApp(
     navController: NavHostController = rememberNavController(),
-    appViewModel: AppViewModel = viewModel()
+    appViewModel: AppViewModel = viewModel(),
+    bluetoothService: BluetoothService? = null
 ) {
     val backStackEntry by navController.currentBackStackEntryAsState()
     val currentScreen = Screen.valueOf(backStackEntry?.destination?.route ?: Screen.Camera.name)
@@ -112,7 +118,7 @@ fun TvControllerApp(
                     RemoteScreen()
                 }
                 composable(route = Screen.Settings.name) {
-                    SettingsScreen()
+                    SettingsScreen(appViewModel = appViewModel)
                 }
             }
         }
@@ -147,13 +153,17 @@ fun RemoteScreen(modifier: Modifier = Modifier) {
 }
 
 @Composable
-fun SettingsScreen(modifier: Modifier = Modifier) {
+fun SettingsScreen(modifier: Modifier = Modifier, appViewModel: AppViewModel = viewModel()) {
     Column(
         modifier = modifier
             .fillMaxSize(),
         horizontalAlignment = Alignment.CenterHorizontally,
         verticalArrangement = Arrangement.Center
     ) {
-        Text(text = "Settings Screen", modifier = modifier)
+        if (appViewModel.isBluetoothEnabled()) {
+            Text(text = "Settings Screen", modifier = modifier)
+        }else{
+            Text(text = "Bluetooth is disabled. Please enable it in settings.", modifier = modifier)
+        }
     }
 }

app/src/main/java/com/example/tvcontroller/ui/AppViewModel.kt

@@ -1,6 +1,9 @@
 package com.example.tvcontroller.ui
 
 import android.content.Context
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
 import com.example.tvcontroller.BluetoothService
 import com.example.tvcontroller.Screen
@@ -9,5 +12,14 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 
-class AppViewModel(private val bluetoothService: BluetoothService) : ViewModel() {
+class AppViewModel() : ViewModel() {
+    private var isBluetoothEnabled = mutableStateOf(false)
+
+    fun setBluetoothEnabled(enabled: Boolean) {
+        isBluetoothEnabled.value = enabled
+    }
+
+    fun isBluetoothEnabled(): Boolean {
+        return isBluetoothEnabled.value
+    }
 }