--- a/Framework/Widgets/IWorldSceneMouseTracker.h	Wed Oct 17 15:18:48 2018 +0200
+++ b/Framework/Widgets/IWorldSceneMouseTracker.h	Wed Oct 17 19:38:39 2018 +0200
@@ -32,15 +32,20 @@
   class IWorldSceneMouseTracker : public boost::noncopyable
   {
   public:
-    virtual ~IWorldSceneMouseTracker() {
+    virtual ~IWorldSceneMouseTracker()
+    {
     }
 
+    virtual bool HasRender() const = 0;
+
     virtual void Render(CairoContext& context,
                         double zoom) = 0;
 
     virtual void MouseUp() = 0;
 
-    virtual void MouseMove(double x,
-                           double y) = 0;
+    virtual void MouseMove(int displayX,
+                           int displayY,
+                           double sceneX,
+                           double sceneY) = 0;
   };
 }