Support showing connected device in repeater tile

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

@@ -22,8 +22,9 @@ class RepeaterTileService : KillableTileService() {
 
     override fun onStartListening() {
         super.onStartListening()
-        if (!RepeaterService.supported) updateTile()
-        else bindService(Intent(this, RepeaterService::class.java), this, Context.BIND_AUTO_CREATE)
+        if (RepeaterService.supported) {
+            bindService(Intent(this, RepeaterService::class.java), this, Context.BIND_AUTO_CREATE)
+        } else updateTile()
     }
 
     override fun onStopListening() {
@@ -57,6 +58,7 @@ class RepeaterTileService : KillableTileService() {
 
     private fun updateTile(group: WifiP2pGroup? = binder?.group) {
         qsTile?.run {
+            subtitle(null)
             when ((binder ?: return).service.status) {
                 RepeaterService.Status.IDLE -> {
                     state = Tile.STATE_INACTIVE
@@ -65,6 +67,9 @@ class RepeaterTileService : KillableTileService() {
                 RepeaterService.Status.ACTIVE -> {
                     state = Tile.STATE_ACTIVE
                     label = group?.networkName
+                    val size = group?.clientList?.size ?: 0
+                    if (size > 0) subtitle(resources.getQuantityString(
+                            R.plurals.quick_settings_hotspot_secondary_label_num_devices, size, size))
                 }
                 else -> {   // STARTING or DESTROYED, which should never occur
                     state = Tile.STATE_UNAVAILABLE

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

@@ -2,7 +2,9 @@ package be.mygod.vpnhotspot.util
 
 import android.content.ComponentName
 import android.content.ServiceConnection
+import android.os.Build
 import android.os.IBinder
+import android.service.quicksettings.Tile
 import android.service.quicksettings.TileService
 import androidx.annotation.RequiresApi
 
@@ -10,6 +12,13 @@ import androidx.annotation.RequiresApi
 abstract class KillableTileService : TileService(), ServiceConnection {
     protected var tapPending = false
 
+    /**
+     * Compat helper for setSubtitle.
+     */
+    protected fun Tile.subtitle(value: CharSequence?) {
+        if (Build.VERSION.SDK_INT >= 29) subtitle = value
+    }
+
     override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
         if (tapPending) {
             tapPending = false

mobile/src/main/res/values/strings.xml

@@ -11,6 +11,8 @@
     * @string/wifi_ap_choose_2G
     * @string/wifi_ap_choose_5G
     * @string/wifi_hidden_network
+    * https://android.googlesource.com/platform/frameworks/base/+/f41fdc9/packages/SystemUI/res/values/strings.xml#874
+    * @plurals/quick_settings_hotspot_secondary_label_num_devices
   -->
 <resources>
     <string name="app_name">VPN Hotspot</string>
@@ -150,6 +152,10 @@
         <item quantity="other">%d interfaces</item>
     </plurals>
     <string name="notification_interfaces_inactive">Inactive: %s</string>
+    <plurals name="quick_settings_hotspot_secondary_label_num_devices">
+        <item quantity="one">%d device</item>
+        <item quantity="other">%d devices</item>
+    </plurals>
 
     <string name="failure_reason_unknown">unknown #%d</string>
     <string name="exception_interface_not_found">Fatal: Downstream interface not found</string>