// define hierachy
virtual wxDataViewItem GetParent( const wxDataViewItem &item ) const = 0;
virtual bool IsContainer( const wxDataViewItem &item ) const = 0;
+ // Is the container just a header or an item with all columns
+ virtual bool HasContainerColumns( const wxDataViewItem &item ) const { return false; }
virtual unsigned int GetChildren( const wxDataViewItem &item, wxDataViewItemArray &children ) const = 0;
// delegated notifiers