Lazily start IpNeighbourMonitor in qs tiles

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

@@ -1,6 +1,7 @@
 package be.mygod.vpnhotspot.manage
 
 import android.service.quicksettings.Tile
+import androidx.annotation.CallSuper
 import androidx.annotation.RequiresApi
 import be.mygod.vpnhotspot.R
 import be.mygod.vpnhotspot.net.IpNeighbour
@@ -11,15 +12,28 @@ import java.net.Inet4Address
 @RequiresApi(24)
 abstract class IpNeighbourMonitoringTileService : KillableTileService(), IpNeighbourMonitor.Callback {
     private var neighbours: Collection<IpNeighbour> = emptyList()
+    private var canRegister = false
     abstract fun updateTile()
 
+    @CallSuper
     override fun onStartListening() {
         super.onStartListening()
-        IpNeighbourMonitor.registerCallback(this)
+        synchronized(this) { canRegister = true }
     }
 
+    /**
+     * Lazily start [IpNeighbourMonitor], which could invoke root.
+     */
+    protected fun listenForClients() = synchronized(this) {
+        if (canRegister) IpNeighbourMonitor.registerCallback(this)
+    }
+
+    @CallSuper
     override fun onStopListening() {
-        IpNeighbourMonitor.unregisterCallback(this)
+        synchronized(this) {
+            canRegister = false
+            IpNeighbourMonitor.unregisterCallback(this)
+        }
         super.onStopListening()
     }
 

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

@@ -40,6 +40,7 @@ class LocalOnlyHotspotTileService : IpNeighbourMonitoringTileService() {
                 state = Tile.STATE_ACTIVE
                 label = binder.configuration?.ssid ?: getText(R.string.tethering_temp_hotspot)
                 subtitleDevices { it == iface }
+                listenForClients()
             }
             updateTile()
         }

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

@@ -92,6 +92,7 @@ sealed class TetheringTileService : IpNeighbourMonitoringTileService(), Tetherin
                     state = Tile.STATE_ACTIVE
                     icon = if (interested.all(binder::isActive)) tileOn else tileOff
                     subtitleDevices(interested::contains)
+                    listenForClients()
                 }
             }
             label = getText(labelString)
@@ -179,6 +180,7 @@ sealed class TetheringTileService : IpNeighbourMonitoringTileService(), Tetherin
                         state = Tile.STATE_ACTIVE
                         icon = if (interested.isNotEmpty() && interested.all(binder::isActive)) tileOn else tileOff
                         subtitleDevices(interested::contains)
+                        listenForClients()
                     }
                     false -> {
                         state = Tile.STATE_INACTIVE

mobile/src/main/java/be/mygod/vpnhotspot/util/KillableTileService.kt

@@ -6,6 +6,7 @@ import android.os.Build
 import android.os.IBinder
 import android.service.quicksettings.Tile
 import android.service.quicksettings.TileService
+import androidx.annotation.CallSuper
 import androidx.annotation.RequiresApi
 
 @RequiresApi(24)
@@ -19,6 +20,7 @@ abstract class KillableTileService : TileService(), ServiceConnection {
         if (Build.VERSION.SDK_INT >= 29) subtitle = value
     }
 
+    @CallSuper
     override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
         if (tapPending) {
             tapPending = false