feat: make sure bluetooth is enabled

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

@@ -1,5 +1,14 @@
 package com.example.sensortestingapp
 
+import android.Manifest
+import android.annotation.SuppressLint
+import android.app.Activity
+import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothManager
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.os.Build
 import android.os.Bundle
 import com.google.android.material.snackbar.Snackbar
 import androidx.appcompat.app.AppCompatActivity
@@ -10,13 +19,21 @@ import androidx.navigation.ui.navigateUp
 import androidx.navigation.ui.setupActionBarWithNavController
 import android.view.Menu
 import android.view.MenuItem
+import androidx.core.content.ContextCompat
 import com.example.sensortestingapp.databinding.ActivityMainBinding
 
+private const val ENABLE_BLUETOOTH_REQUEST_CODE = 1
+
 class MainActivity : AppCompatActivity() {
 
     private lateinit var appBarConfiguration: AppBarConfiguration
     private lateinit var binding: ActivityMainBinding
 
+    private val bluetoothAdapter: BluetoothAdapter by lazy {
+        val bluetoothManager = getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
+        bluetoothManager.adapter
+    }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         WindowCompat.setDecorFitsSystemWindows(window, false)
         super.onCreate(savedInstanceState)
@@ -58,4 +75,31 @@ class MainActivity : AppCompatActivity() {
         return navController.navigateUp(appBarConfiguration)
                 || super.onSupportNavigateUp()
     }
+
+    override fun onResume() {
+        super.onResume()
+        if (!bluetoothAdapter.isEnabled) {
+            promptEnableBluetooth()
+        }
+    }
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
+        super.onActivityResult(requestCode, resultCode, data)
+        when (requestCode) {
+            ENABLE_BLUETOOTH_REQUEST_CODE -> {
+                if (resultCode != Activity.RESULT_OK) {
+                    promptEnableBluetooth()
+                }
+            }
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun promptEnableBluetooth() {
+        if (!bluetoothAdapter.isEnabled) {
+            val enableBtIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
+            startActivityForResult(enableBtIntent, ENABLE_BLUETOOTH_REQUEST_CODE)
+        }
+    }
+
 }