Remove Bluetooth tethering if unsupported

mobile/src/main/java/be/mygod/vpnhotspot/manage/BluetoothTethering.kt

@@ -3,7 +3,6 @@ package be.mygod.vpnhotspot.manage
 import android.annotation.SuppressLint
 import android.annotation.TargetApi
 import android.bluetooth.BluetoothAdapter
-import android.bluetooth.BluetoothManager
 import android.bluetooth.BluetoothProfile
 import android.content.BroadcastReceiver
 import android.content.Context
@@ -11,7 +10,6 @@ import android.content.Intent
 import android.content.IntentFilter
 import android.os.Build
 import androidx.annotation.RequiresApi
-import androidx.core.content.getSystemService
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.net.TetheringManager
 import be.mygod.vpnhotspot.util.broadcastReceiver
@@ -20,7 +18,7 @@ import be.mygod.vpnhotspot.widget.SmartSnackbar
 import timber.log.Timber
 import java.lang.reflect.InvocationTargetException
 
-class BluetoothTethering(context: Context, val stateListener: () -> Unit) :
+class BluetoothTethering(context: Context, private val adapter: BluetoothAdapter, val stateListener: () -> Unit) :
         BluetoothProfile.ServiceListener, AutoCloseable {
     companion object : BroadcastReceiver() {
         /**
@@ -30,7 +28,6 @@ class BluetoothTethering(context: Context, val stateListener: () -> Unit) :
         private val clazz by lazy { Class.forName("android.bluetooth.BluetoothPan") }
         private val isTetheringOn by lazy { clazz.getDeclaredMethod("isTetheringOn") }
 
-        private val adapter = app.getSystemService<BluetoothManager>()?.adapter
         private val BluetoothProfile.isTetheringOn get() = isTetheringOn(this) as Boolean
 
         private fun registerBluetoothStateListener(receiver: BroadcastReceiver) =
@@ -67,7 +64,7 @@ class BluetoothTethering(context: Context, val stateListener: () -> Unit) :
         val pan = pan ?: return null
         if (!connected) return null
         activeFailureCause = null
-        val on = adapter?.state == BluetoothAdapter.STATE_ON && try {
+        val on = adapter.state == BluetoothAdapter.STATE_ON && try {
             pan.isTetheringOn
         } catch (e: InvocationTargetException) {
             activeFailureCause = e.cause ?: e
@@ -84,7 +81,6 @@ class BluetoothTethering(context: Context, val stateListener: () -> Unit) :
     private val receiver = broadcastReceiver { _, _ -> stateListener() }
 
     fun ensureInit(context: Context) {
-        val adapter = adapter ?: return
         activeFailureCause = null
         if (!proxyCreated) try {
             check(adapter.getProfileProxy(context, this, PAN))
@@ -116,7 +112,7 @@ class BluetoothTethering(context: Context, val stateListener: () -> Unit) :
     @RequiresApi(24)
     fun start(callback: TetheringManager.StartTetheringCallback) {
         if (pendingCallback == null) try {
-            if (adapter?.state == BluetoothAdapter.STATE_OFF) {
+            if (adapter.state == BluetoothAdapter.STATE_OFF) {
                 registerBluetoothStateListener(BluetoothTethering)
                 pendingCallback = callback
                 adapter.enable()
@@ -134,6 +130,6 @@ class BluetoothTethering(context: Context, val stateListener: () -> Unit) :
 
     override fun close() {
         app.unregisterReceiver(receiver)
-        adapter!!.closeProfileProxy(PAN, pan)
+        adapter.closeProfileProxy(PAN, pan)
     }
 }

mobile/src/main/java/be/mygod/vpnhotspot/manage/TetherManager.kt

@@ -2,6 +2,7 @@ package be.mygod.vpnhotspot.manage
 
 import android.Manifest
 import android.annotation.TargetApi
+import android.bluetooth.BluetoothAdapter
 import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
@@ -306,8 +307,9 @@ sealed class TetherManager(protected val parent: TetheringFragment) : Manager(),
         override fun stop() = TetheringManager.stopTethering(TetheringManager.TETHERING_USB, this::onException)
     }
     @RequiresApi(24)
-    class Bluetooth(parent: TetheringFragment) : TetherManager(parent), DefaultLifecycleObserver {
+    class Bluetooth(parent: TetheringFragment, adapter: BluetoothAdapter) :
-        private val tethering = BluetoothTethering(parent.requireContext()) { data.notifyChange() }
+        TetherManager(parent), DefaultLifecycleObserver {
+        private val tethering = BluetoothTethering(parent.requireContext(), adapter) { data.notifyChange() }
 
         init {
             parent.viewLifecycleOwner.lifecycle.addObserver(this)

mobile/src/main/java/be/mygod/vpnhotspot/manage/TetheringFragment.kt

@@ -3,6 +3,7 @@
 package be.mygod.vpnhotspot.manage
 
 import android.annotation.TargetApi
+import android.bluetooth.BluetoothManager
 import android.content.*
 import android.os.Build
 import android.os.Bundle
@@ -15,6 +16,7 @@ import androidx.activity.result.contract.ActivityResultContracts
 import androidx.annotation.RequiresApi
 import androidx.appcompat.widget.Toolbar
 import androidx.core.content.ContextCompat
+import androidx.core.content.getSystemService
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.DefaultItemAnimator
@@ -49,12 +51,18 @@ class TetheringFragment : Fragment(), ServiceConnection, Toolbar.OnMenuItemClick
         @get:RequiresApi(26)
         internal val localOnlyHotspotManager by lazy @TargetApi(26) { LocalOnlyHotspotManager(this@TetheringFragment) }
         @get:RequiresApi(24)
-        internal val bluetoothManager by lazy @TargetApi(24) { TetherManager.Bluetooth(this@TetheringFragment) }
+        internal val bluetoothManager by lazy {
+            if (Build.VERSION.SDK_INT >= 24) requireContext().getSystemService<BluetoothManager>()?.adapter?.let {
+                TetherManager.Bluetooth(this@TetheringFragment, it)
+            } else null
+        }
         @get:RequiresApi(24)
         private val tetherManagers by lazy @TargetApi(24) {
-            listOf(TetherManager.Wifi(this@TetheringFragment),
+            listOfNotNull(
+                TetherManager.Wifi(this@TetheringFragment),
                 TetherManager.Usb(this@TetheringFragment),
-                    bluetoothManager)
+                bluetoothManager,
+            )
         }
         @get:RequiresApi(30)
         private val tetherManagers30 by lazy @TargetApi(30) {
@@ -139,7 +147,7 @@ class TetheringFragment : Fragment(), ServiceConnection, Toolbar.OnMenuItemClick
     }
     @RequiresApi(31)
     val requestBluetooth = registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted ->
-        if (granted) adapter.bluetoothManager.ensureInit(requireContext())
+        if (granted) adapter.bluetoothManager!!.ensureInit(requireContext())
     }
 
     var ifaceLookup: Map<String, NetworkInterface> = emptyMap()

mobile/src/main/java/be/mygod/vpnhotspot/manage/TetheringTileService.kt

@@ -1,5 +1,6 @@
 package be.mygod.vpnhotspot.manage
 
+import android.bluetooth.BluetoothManager
 import android.content.ComponentName
 import android.content.Context
 import android.content.Intent
@@ -11,6 +12,7 @@ import android.service.quicksettings.Tile
 import android.widget.Toast
 import androidx.annotation.RequiresApi
 import androidx.core.content.ContextCompat
+import androidx.core.content.getSystemService
 import be.mygod.vpnhotspot.R
 import be.mygod.vpnhotspot.TetheringService
 import be.mygod.vpnhotspot.net.TetherType
@@ -158,7 +160,9 @@ sealed class TetheringTileService : IpNeighbourMonitoringTileService(), Tetherin
         }
 
         override fun onStartListening() {
-            tethering = BluetoothTethering(this) { updateTile() }
+            tethering = getSystemService<BluetoothManager>()?.adapter?.let {
+                BluetoothTethering(this, it) { updateTile() }
+            }
             super.onStartListening()
         }
         override fun onStopListening() {