improved readability on BluetoothStateReceiver

and renamed `intent` to `intentFilter` to properly reflect type

app/src/main/java/com/geeksville/mesh/MainActivity.kt

@@ -371,7 +371,7 @@ class MainActivity : AppCompatActivity(), Logging,
         updateBluetoothEnabled()
 
         /// We now want to be informed of bluetooth state
-        registerReceiver(btStateReceiver, btStateReceiver.intent)
+        registerReceiver(btStateReceiver, btStateReceiver.intentFilter)
 
         // if (!isInTestLab) - very important - even in test lab we must request permissions because we need location perms for some of our tests to pass
         requestPermission()

app/src/main/java/com/geeksville/mesh/service/BluetoothStateReceiver.kt

@@ -10,23 +10,21 @@ import com.geeksville.util.exceptionReporter
 /**
  * A helper class to call onChanged when bluetooth is enabled or disabled
  */
-class BluetoothStateReceiver(val onChanged: (Boolean) -> Unit) : BroadcastReceiver() {
-    val intent =
-        IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED) // Can be used for registering
+class BluetoothStateReceiver(
+    private val onChanged: (Boolean) -> Unit
+) : BroadcastReceiver() {
 
-    override fun onReceive(context: Context, intent: Intent) =
-        exceptionReporter {
-            if (intent.action == BluetoothAdapter.ACTION_STATE_CHANGED) {
-                when (intent.getIntExtra(
-                    BluetoothAdapter.EXTRA_STATE,
-                    -1
-                )) {
-                    // Simulate a disconnection if the user disables bluetooth entirely
-                    BluetoothAdapter.STATE_OFF -> onChanged(
-                        false
-                    )
-                    BluetoothAdapter.STATE_ON -> onChanged(true)
-                }
+    val intentFilter get() = IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED) // Can be used for registering
+
+    override fun onReceive(context: Context, intent: Intent) = exceptionReporter {
+        if (intent.action == BluetoothAdapter.ACTION_STATE_CHANGED) {
+            when (intent.bluetoothAdapterState) {
+                // Simulate a disconnection if the user disables bluetooth entirely
+                BluetoothAdapter.STATE_OFF -> onChanged(false)
+                BluetoothAdapter.STATE_ON -> onChanged(true)
             }
         }
+    }
+
+    private val Intent.bluetoothAdapterState: Int get() = getIntExtra(BluetoothAdapter.EXTRA_STATE, -1)
 }

app/src/main/java/com/geeksville/mesh/service/RadioInterfaceService.kt

@@ -195,7 +195,7 @@ class RadioInterfaceService : Service(), Logging {
     override fun onCreate() {
         runningService = this
         super.onCreate()
-        registerReceiver(bluetoothStateReceiver, bluetoothStateReceiver.intent)
+        registerReceiver(bluetoothStateReceiver, bluetoothStateReceiver.intentFilter)
     }
 
     override fun onDestroy() {