implement setting of window position.

src/Avalonia.Native.OSX/window.mm

@@ -83,6 +83,38 @@ public:
         [Window performWindowDragWithEvent:lastEvent];
     }
     
+    
+    virtual AvnPoint GetPosition ()
+    {
+        auto frame = [Window frame];
+        
+        AvnPoint bottomLeft;
+        bottomLeft.X = frame.origin.x;
+        bottomLeft.Y = frame.origin.y + frame.size.width;
+        
+        NSRect screen = [NSScreen.screens objectAtIndex:0].frame;
+        
+        auto t = MAX(screen.origin.y, screen.origin.y + screen.size.height);
+        
+        bottomLeft.Y = t - bottomLeft.Y;
+        
+        return bottomLeft;
+    }
+    
+    virtual void SetPosition (AvnPoint point)
+    {
+        NSPoint nspoint;
+        nspoint.x = point.X;
+        nspoint.y = point.Y;
+        
+        NSRect screen = [NSScreen.screens objectAtIndex:0].frame;
+        auto t = MAX(screen.origin.y, screen.origin.y + screen.size.height);
+        
+        nspoint.y = t - nspoint.y;
+        
+        [Window setFrameTopLeftPoint:nspoint];
+    }
+    
 protected:
     virtual NSWindowStyleMask GetStyle()
     {

src/Avalonia.Native/Avalonia.Native.csproj

@@ -12,4 +12,12 @@
         <PackageReference Include="Avalonia" Version="0.6.2-build6248-beta" />
         <SharpGenMapping Include="Mappings.xml" />
     </ItemGroup>
+    <ItemGroup>
+      <Compile Remove="Generated\LocalInterop.cs" />
+      <Compile Remove="Generated\Structures.cs" />
+      <Compile Remove="Generated\Functions.cs" />
+      <Compile Remove="Generated\Interfaces.cs" />
+      <Compile Remove="Generated\LocalInterop.cs" />
+      <Compile Remove="Generated\Structures.cs" />
+    </ItemGroup>
 </Project>

src/Avalonia.Native/Helpers.cs

@@ -0,0 +1,18 @@
+using System;
+using Avalonia.Native.Interop;
+
+namespace Avalonia.Native
+{
+    public static class Helpers
+    {
+        public static Point ToAvaloniaPoint (this AvnPoint pt)
+        {
+            return new Point(pt.X, pt.Y);
+        }
+
+        public static AvnPoint ToAvnPoint (this Point pt)
+        {
+            return new AvnPoint { X = pt.X, Y = pt.Y };
+        }
+    }
+}

src/Avalonia.Native/WindowImplBase.cs

@@ -118,11 +118,11 @@ namespace Avalonia.Native
             switch (type)
             {
                 case AvnRawMouseEventType.Wheel:
-                    Input?.Invoke(new RawMouseWheelEventArgs(_mouse, timeStamp, _inputRoot, new Point(point.X, point.Y), new Vector(delta.X, delta.Y), (InputModifiers)modifiers));
+                    Input?.Invoke(new RawMouseWheelEventArgs(_mouse, timeStamp, _inputRoot, point.ToAvaloniaPoint(), new Vector(delta.X, delta.Y), (InputModifiers)modifiers));
                     break;
 
                 default:
-                    Input?.Invoke(new RawMouseEventArgs(_mouse, timeStamp, _inputRoot, (RawMouseEventType)type, new Point(point.X, point.Y), (InputModifiers)modifiers));
+                    Input?.Invoke(new RawMouseEventArgs(_mouse, timeStamp, _inputRoot, (RawMouseEventType)type, point.ToAvaloniaPoint(), (InputModifiers)modifiers));
                     break;
             }
         }
@@ -164,10 +164,16 @@ namespace Avalonia.Native
         }
 
 
+        public Point Position
+        {
+            get => _native.GetPosition().ToAvaloniaPoint();
+            set => _native.SetPosition(value.ToAvnPoint());
+        }
+
+
         #region Stubs
         public double Scaling => 1;
 
-        public Point Position { get; set; }
         public Action<Point> PositionChanged { get; set; }
         public Action Deactivated { get; set; }
         public Action Activated { get; set; }

src/headers/avalonia-native.h

@@ -73,6 +73,8 @@ AVNCOM(IAvnWindowBase, 02) : virtual IUnknown
     virtual HRESULT Resize(double width, double height) = 0;
     virtual void Invalidate (AvnRect rect) = 0;
     virtual void BeginMoveDrag () = 0;
+    virtual AvnPoint GetPosition () = 0;
+    virtual void SetPosition (AvnPoint point) = 0;
 };
 
 AVNCOM(IAvnPopup, 03) : virtual IAvnWindowBase