special treatment for toplevel items in nativemenus.

native/Avalonia.Native/inc/avalonia-native.h

@@ -190,7 +190,7 @@ public:
     virtual HRESULT CreateCursorFactory(IAvnCursorFactory** ppv) = 0;
     virtual HRESULT ObtainGlDisplay(IAvnGlDisplay** ppv) = 0;
     virtual HRESULT SetAppMenu(IAvnMenu* menu) = 0;
-    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv) = 0;
+    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv, bool isTopLevel) = 0;
     virtual HRESULT CreateMenuItem (IAvnMenuItem** ppv) = 0;
     virtual HRESULT CreateMenuItemSeperator (IAvnMenuItem** ppv) = 0;
 };

native/Avalonia.Native/src/OSX/common.h

@@ -15,7 +15,7 @@ extern IAvnScreens* CreateScreens();
 extern IAvnClipboard* CreateClipboard();
 extern IAvnCursorFactory* CreateCursorFactory();
 extern IAvnGlDisplay* GetGlDisplay();
-extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* events);
+extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* events, bool isTopLevel);
 extern IAvnMenuItem* CreateAppMenuItem();
 extern IAvnMenuItem* CreateAppMenuItemSeperator();
 extern void SetAppMenu (NSString* appName, IAvnMenu* appMenu);

native/Avalonia.Native/src/OSX/main.mm

@@ -227,9 +227,9 @@ public:
         return S_OK;
     }
     
-    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv) override
+    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv, bool isTopLevel) override
     {
-        *ppv = ::CreateAppMenu(cb);
+        *ppv = ::CreateAppMenu(cb, isTopLevel);
         return S_OK;
     }
     

native/Avalonia.Native/src/OSX/menu.h

@@ -59,11 +59,12 @@ class AvnAppMenu : public ComSingleObject<IAvnMenu, &IID_IAvnMenu>
 private:
     AvnMenu* _native;
     ComPtr<IAvnMenuEvents> _baseEvents;
+    bool _isTopLevel;
     
 public:
     FORWARD_IUNKNOWN()
     
-    AvnAppMenu(IAvnMenuEvents* events);
+    AvnAppMenu(IAvnMenuEvents* events, bool isTopLevel);
         
     AvnMenu* GetNative();
     

native/Avalonia.Native/src/OSX/menu.mm

@@ -169,11 +169,18 @@ void AvnAppMenuItem::RaiseOnClicked()
     }
 }
 
-AvnAppMenu::AvnAppMenu(IAvnMenuEvents* events)
+AvnAppMenu::AvnAppMenu(IAvnMenuEvents* events, bool isTopLevel)
 {
+    _isTopLevel = isTopLevel;
     _baseEvents = events;
     id del = [[AvnMenuDelegate alloc] initWithParent: this];
     _native = [[AvnMenu alloc] initWithDelegate: del];
+    
+    
+    if(_isTopLevel)
+    {
+        [_native insertItem: [NSMenuItem new] atIndex:0];
+    }
 }
 
 
@@ -194,6 +201,11 @@ HRESULT AvnAppMenu::InsertItem(int index, IAvnMenuItem *item)
 {
     @autoreleasepool
     {
+        if(_isTopLevel)
+        {
+            index++;
+        }
+        
         auto avnMenuItem = dynamic_cast<AvnAppMenuItem*>(item);
         
         if(avnMenuItem != nullptr)
@@ -272,11 +284,11 @@ HRESULT AvnAppMenu::Clear()
 
 @end
 
-extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* cb)
+extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* cb, bool isTopLevel)
 {
     @autoreleasepool
     {
-        return new AvnAppMenu(cb);
+        return new AvnAppMenu(cb, isTopLevel);
     }
 }
 

src/Avalonia.Native/AvaloniaNativeMenuExporter.cs

@@ -84,9 +84,11 @@ namespace Avalonia.Native
 
                 if (appMenu == null)
                 {
-                    appMenu = CreateDefaultAppMenu();
-                    SetMenu(appMenu);
+                    appMenu = CreateDefaultAppMenu();           
+                    NativeMenu.SetMenu(Application.Current, appMenu);         
                 }
+
+                SetMenu(appMenu);
             }
             else
             {
@@ -131,7 +133,7 @@ namespace Avalonia.Native
 
             if (_nativeMenu is null)
             {
-                _nativeMenu = IAvnMenu.Create(_factory);
+                _nativeMenu = IAvnMenu.Create(_factory, false);
 
                 _nativeMenu.Initialise(this, appMenuHolder, "");
 
@@ -150,7 +152,7 @@ namespace Avalonia.Native
         {
             if (_nativeMenu is null)
             {
-                _nativeMenu = IAvnMenu.Create(_factory);
+                _nativeMenu = IAvnMenu.Create(_factory, true);
 
                 _nativeMenu.Initialise(this, menu, "");                
             }

src/Avalonia.Native/IAvnMenu.cs

@@ -39,11 +39,11 @@ namespace Avalonia.Native.Interop
 
         internal NativeMenu ManagedMenu { get; private set; }
 
-        public static IAvnMenu Create(IAvaloniaNativeFactory factory)
+        public static IAvnMenu Create(IAvaloniaNativeFactory factory, bool isTopLevel)
         {
             var events = new MenuEvents();
 
-            var menu = factory.CreateMenu(events);
+            var menu = factory.CreateMenu(events, isTopLevel);
 
             events.Initialise(menu);
 

src/Avalonia.Native/IAvnMenuItem.cs

@@ -114,7 +114,7 @@ namespace Avalonia.Native.Interop
             {
                 if (_subMenu == null)
                 {
-                    _subMenu = IAvnMenu.Create(factory);
+                    _subMenu = IAvnMenu.Create(factory, false);
 
                     _subMenu.Initialise(exporter, item.Menu, item.Header);