implement Cursor=None for OSX.

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

@@ -144,6 +144,7 @@ enum AvnStandardCursorType
     CursorDragMove,
     CursorDragCopy,
     CursorDragLink,
+    CursorNone
 };
 
 enum AvnWindowEdge

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

@@ -11,18 +11,24 @@ class Cursor : public ComSingleObject<IAvnCursor, &IID_IAvnCursor>
 {
 private:
     NSCursor * _native;
-
+    bool _isHidden;
 public:
     FORWARD_IUNKNOWN()
-    Cursor(NSCursor * cursor)
+    Cursor(NSCursor * cursor, bool isHidden = false)
     {
         _native = cursor;
+        _isHidden = isHidden;
     }
 
     NSCursor* GetNative()
     {
         return _native;
     }
+    
+    bool IsHiden ()
+    {
+        return _isHidden;
+    }
 };
 
 extern std::map<AvnStandardCursorType, Cursor*> s_cursorMap;

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

@@ -21,6 +21,7 @@ class CursorFactory : public ComSingleObject<IAvnCursorFactory, &IID_IAvnCursorF
     Cursor* resizeRightCursor = new Cursor([NSCursor resizeRightCursor]);
     Cursor* resizeWestEastCursor = new Cursor([NSCursor resizeLeftRightCursor]);
     Cursor* operationNotAllowedCursor = new Cursor([NSCursor operationNotAllowedCursor]);
+    Cursor* noCursor = new Cursor([NSCursor arrowCursor], true);
 
     std::map<AvnStandardCursorType, Cursor*> s_cursorMap =
     {
@@ -46,11 +47,13 @@ class CursorFactory : public ComSingleObject<IAvnCursorFactory, &IID_IAvnCursorF
         { CursorIbeam, IBeamCursor },
         { CursorLeftSide, resizeLeftCursor },
         { CursorRightSide, resizeRightCursor },
-        { CursorNo, operationNotAllowedCursor }
+        { CursorNo, operationNotAllowedCursor },
+        { CursorNone, noCursor }
     };
 
 public:
     FORWARD_IUNKNOWN()
+    
     virtual HRESULT GetCursor (AvnStandardCursorType cursorType, IAvnCursor** retOut) override
     {
         *retOut = s_cursorMap[cursorType];

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

@@ -353,6 +353,16 @@ public:
             Cursor* avnCursor = dynamic_cast<Cursor*>(cursor);
             this->cursor = avnCursor->GetNative();
             UpdateCursor();
+            
+            if(avnCursor->IsHiden())
+            {
+                [NSCursor hide];
+            }
+            else
+            {
+                [NSCursor unhide];
+            }
+            
             return S_OK;
         }
     }