Rewrite selection event code for wxListBox.

Remove ifdef for non-native wxCheckListBox.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42469 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/checklst.h

@@ -24,10 +24,6 @@
     #define wxCHECKLBOX_STRING    _T("[ ] ")
 #endif
 
-//Use the native GTK2.0+ checklist?? You should say YYEEESS unless
-//there are like some major bugs or something :)
-#define wxUSE_NATIVEGTKCHECKLIST 1
-
 //-----------------------------------------------------------------------------
 // wxCheckListBox
 // ----------------------------------------------------------------------------
@@ -57,9 +53,7 @@ public:
 
     int GetItemHeight() const;
 
-#if wxUSE_NATIVEGTKCHECKLIST
     void DoCreateCheckList();
-#endif
 
 private:
     DECLARE_DYNAMIC_CLASS(wxCheckListBox)