FIX: transfer input events to children of PopupWindow

Change-Id: I2ff9ba91a548402d77308aa88de34976a146a571
Jira: STUDIO-8942
(cherry picked from commit 23e30c7227474adf4efe5ee93f985e1140da9b6f)

src/slic3r/GUI/Widgets/PopupWindow.hpp

@@ -12,10 +12,15 @@ public:
 
     PopupWindow(wxWindow *parent, int style = wxBORDER_NONE)
         { Create(parent, style); }
-    
+
     bool Create(wxWindow *parent, int flags = wxBORDER_NONE);
 
 private:
+#ifdef __WXOSX__
+    void OnMouseEvent2(wxMouseEvent &evt);
+    wxEvtHandler * hovered { this };
+#endif
+
 #ifdef __WXGTK__
     void topWindowActiavate(wxActivateEvent &event);
 #endif