Remove ListServicesAsync usage

- Uses Reflection underneath
- It's faster to just fail than receiving all available services first

src/Avalonia.FreeDesktop/DBusMenuExporter.cs

@@ -98,16 +98,21 @@ namespace Avalonia.FreeDesktop
                 Connection.AddMethodHandler(this);
                 if (!_appMenu)
                     return;
-                var services = await Connection.ListServicesAsync();
-                if (!services.Contains("com.canonical.AppMenu.Registrar"))
-                    return;
+
                 _registrar = new ComCanonicalAppMenuRegistrar(Connection, "com.canonical.AppMenu.Registrar", "/com/canonical/AppMenu/Registrar");
-                if (!_disposed)
-                    await _registrar.RegisterWindowAsync(_xid, Path);
-                // It's not really important if this code succeeds,
-                // and it's not important to know if it succeeds
-                // since even if we register the window it's not guaranteed that
-                // menu will be actually exported
+                try
+                {
+                    if (!_disposed)
+                        await _registrar.RegisterWindowAsync(_xid, Path);
+                }
+                catch
+                {
+                    // It's not really important if this code succeeds,
+                    // and it's not important to know if it succeeds
+                    // since even if we register the window it's not guaranteed that
+                    // menu will be actually exported
+                    _registrar = null;
+                }
             }
 
             public void Dispose()
@@ -286,7 +291,7 @@ namespace Avalonia.FreeDesktop
                 return null;
             }
 
-            private Dictionary<string, DBusVariantItem> GetProperties((NativeMenuItemBase? item, NativeMenu? menu) i, string[] names)
+            private static Dictionary<string, DBusVariantItem> GetProperties((NativeMenuItemBase? item, NativeMenu? menu) i, string[] names)
             {
                 if (names.Length == 0)
                     names = s_allProperties;

src/Avalonia.FreeDesktop/DBusSystemDialog.cs

@@ -17,20 +17,28 @@ namespace Avalonia.FreeDesktop
         {
             if (DBusHelper.Connection is null)
                 return null;
-            var services = await DBusHelper.Connection.ListServicesAsync();
-            return services.Contains("org.freedesktop.portal.Desktop", StringComparer.Ordinal)
-                ? new DBusSystemDialog(DBusHelper.Connection, handle)
-                : null;
+
+            var dbusFileChooser = new OrgFreedesktopPortalFileChooser(DBusHelper.Connection, "org.freedesktop.portal.Desktop", "/org/freedesktop/portal/desktop");
+            try
+            {
+                await dbusFileChooser.GetVersionAsync();
+            }
+            catch
+            {
+                return null;
+            }
+
+            return new DBusSystemDialog(DBusHelper.Connection, handle, dbusFileChooser);
         }
 
         private readonly Connection _connection;
         private readonly OrgFreedesktopPortalFileChooser _fileChooser;
         private readonly IPlatformHandle _handle;
 
-        private DBusSystemDialog(Connection connection, IPlatformHandle handle)
+        private DBusSystemDialog(Connection connection, IPlatformHandle handle, OrgFreedesktopPortalFileChooser fileChooser)
         {
             _connection = connection;
-            _fileChooser = new OrgFreedesktopPortalFileChooser(connection, "org.freedesktop.portal.Desktop", "/org/freedesktop/portal/desktop");
+            _fileChooser = fileChooser;
             _handle = handle;
         }
 
@@ -137,7 +145,6 @@ namespace Avalonia.FreeDesktop
             if (fileTypes is null)
                 return null;
 
-            var any = false;
             var filters = new DBusArrayItem(DBusType.Struct, new List<DBusItem>());
 
             foreach (var fileType in fileTypes)
@@ -154,7 +161,6 @@ namespace Avalonia.FreeDesktop
                 else
                     continue;
 
-                any = true;
                 filters.Add(new DBusStructItem(
                     new DBusItem[]
                     {
@@ -163,7 +169,7 @@ namespace Avalonia.FreeDesktop
                     }));
             }
 
-            return any ? new DBusVariantItem("a(sa(us))", filters) : null;
+            return filters.Count > 0 ? new DBusVariantItem("a(sa(us))", filters) : null;
         }
     }
 }

src/Avalonia.FreeDesktop/DBusTrayIconImpl.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Diagnostics;
-using System.Linq;
 using Avalonia.Controls.Platform;
 using Avalonia.Logging;
 using Avalonia.Platform;
@@ -66,13 +65,18 @@ namespace Avalonia.FreeDesktop
 
         private async void WatchAsync()
         {
-            var services = await _connection!.ListServicesAsync();
-            if (!services.Contains("org.kde.StatusNotifierWatcher", StringComparer.Ordinal))
-                return;
-
-            _serviceWatchDisposable = await _dBus!.WatchNameOwnerChangedAsync((_, x) => OnNameChange(x.Item2) );
-            var nameOwner = await _dBus.GetNameOwnerAsync("org.kde.StatusNotifierWatcher");
-            OnNameChange(nameOwner);
+            try
+            {
+                _serviceWatchDisposable = await _dBus!.WatchNameOwnerChangedAsync((_, x) => OnNameChange(x.Item2));
+                var nameOwner = await _dBus.GetNameOwnerAsync("org.kde.StatusNotifierWatcher");
+                OnNameChange(nameOwner);
+            }
+            catch
+            {
+                _serviceWatchDisposable = null;
+                Logger.TryGet(LogEventLevel.Error, "DBUS")
+                    ?.Log(this, "Interface 'org.kde.StatusNotifierWatcher' is unavailable.");
+            }
         }
 
         private void OnNameChange(string? newOwner)
@@ -99,7 +103,7 @@ namespace Avalonia.FreeDesktop
 
         private async void CreateTrayIcon()
         {
-            if (_connection is null || !_serviceConnected || _isDisposed)
+            if (_connection is null || !_serviceConnected || _isDisposed || _statusNotifierWatcher is null)
                 return;
 
 #if NET5_0_OR_GREATER
@@ -114,7 +118,7 @@ namespace Avalonia.FreeDesktop
 
             _connection.AddMethodHandler(_statusNotifierItemDbusObj);
             await _dBus!.RequestNameAsync(_sysTrayServiceName, 0);
-            await _statusNotifierWatcher!.RegisterStatusNotifierItemAsync(_sysTrayServiceName);
+            await _statusNotifierWatcher.RegisterStatusNotifierItemAsync(_sysTrayServiceName);
 
             _statusNotifierItemDbusObj.SetTitleAndTooltip(_tooltipText);
             _statusNotifierItemDbusObj.SetIcon(_icon);

src/tools/Tmds.DBus.SourceGenerator

@@ -1 +1 @@
-Subproject commit 86e0ded07fc8622e216f93f8fc01e8c1b3ef29b1
+Subproject commit 309159609e09f3f0ae77f0abd761360049761700