Index: extobj.h
===================================================================
--- extobj.h	(revision 11151)
+++ extobj.h	(revision 11152)
@@ -47,8 +47,17 @@
 RND_INLINE void csch_extrobj_attr_edit_pre(csch_cgrp_t *grp, const char *key);
 RND_INLINE void csch_extrobj_attr_edit_post(csch_cgrp_t *grp, const char *key);
 
+/*** for implementing extended objects ***/
 
-/* internal, do not call */
+/* return the extobj-gfx group within grp or NULL if not found */
+csch_cgrp_t *csch_extobj_gfx_lookup(csch_cgrp_t *grp);
+
+/* return the extobj-gfx group within grp after making sure it is empty
+   (creating or clearing it) */
+csch_cgrp_t *csch_extobj_gfx_clear(csch_sheet_t *sheet, csch_cgrp_t *grp);
+
+
+/*** internal, do not call ***/
 void csch_extobj_init(void);
 void csch_extobj_uninit(void);
 const csch_extobj_impl_t *csch_extobj_lookup(const char *name);