+ (c) 2002--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
+*/
+#include "grob-interface.hh"
+#include "lily-proto.hh"
+
+#ifndef SPACING_INTERFACE_HH
+#define SPACING_INTERFACE_HH
+
+struct Spacing_interface
+{
+ static Real minimum_distance (Grob *me, Grob *right_col);
+ static vector<Item*> right_note_columns (Grob *me);
+ static vector<Item*> left_note_columns (Grob *me);
+ static Item* right_column (Grob *me);
+ static Item* left_column (Grob *me);
+ static Drul_array<Skyline> skylines (Grob *me, Grob *right_col);
+ static Grob* extremal_break_aligned_grob (Grob *me, Direction, Direction, Interval*);
+
+ DECLARE_GROB_INTERFACE();