Add wxDataViewCtrl::SetHeaderAttr() too

This is currently only implemented in the generic version but could be
implemented at least for GTK+ native one as well in the future.

include/wx/dataview.h

@@ -29,6 +29,7 @@
 #include "wx/systhemectrl.h"
 
 class WXDLLIMPEXP_FWD_CORE wxImageList;
+class WXDLLIMPEXP_FWD_CORE wxItemAttr;
 
 #if !(defined(__WXGTK20__) || defined(__WXOSX__) ) || defined(__WXUNIVERSAL__)
 // #if !(defined(__WXOSX__)) || defined(__WXUNIVERSAL__)
@@ -128,7 +129,7 @@ private:
 // wxDataViewItemAttr: a structure containing the visual attributes of an item
 // ----------------------------------------------------------------------------
 
-// TODO: this should be renamed to wxItemAttr or something general like this
+// TODO: Merge with wxItemAttr somehow.
 
 class WXDLLIMPEXP_ADV wxDataViewItemAttr
 {
@@ -732,6 +733,10 @@ public:
     // define control visual attributes
     // --------------------------------
 
+    // Header attributes: only implemented in the generic version currently.
+    virtual bool SetHeaderAttr(const wxItemAttr& WXUNUSED(attr))
+        { return false; }
+
     virtual wxVisualAttributes GetDefaultAttributes() const wxOVERRIDE
     {
         return GetClassDefaultAttributes(GetWindowVariant());

include/wx/generic/dataview.h

@@ -256,6 +256,8 @@ public:
 
     virtual void EditItem(const wxDataViewItem& item, const wxDataViewColumn *column) wxOVERRIDE;
 
+    virtual bool SetHeaderAttr(const wxItemAttr& attr) wxOVERRIDE;
+
     // These methods are specific to generic wxDataViewCtrl implementation and
     // should not be used in portable code.
     wxColour GetAlternateRowColour() const { return m_alternateRowColour; }