Fixed bug that prevented wxTreeCtrl.OnCompareItems from being called.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10090 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/src/msw/controls2.cpp

@@ -164,6 +164,7 @@ public:
 };
 
 class wxPyTreeCtrl : public wxTreeCtrl {
+    DECLARE_ABSTRACT_CLASS(wxPyTreeCtrl);
 public:
     wxPyTreeCtrl(wxWindow *parent, wxWindowID id,
                  const wxPoint& pos,
@@ -173,7 +174,6 @@ public:
                  char* name) :
         wxTreeCtrl(parent, id, pos, size, style, validator, name) {}
 
-
     int OnCompareItems(const wxTreeItemId& item1,
                        const wxTreeItemId& item2) {
         int rval = 0;
@@ -191,6 +191,8 @@ public:
     PYPRIVATE;
 };
 
+IMPLEMENT_ABSTRACT_CLASS(wxPyTreeCtrl, wxTreeCtrl);
+
 #ifdef __cplusplus
 extern "C" {
 #endif