X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fstaff-symbol-referencer.cc;h=dec5000b2a944e299345ba9c74321544de2bfeff;hb=d02e96479e11bc7e3714ab92a460a08d8a68f54f;hp=e63efa1b309298e08b67bafce0cd9cd3674ded59;hpb=8d7a55721e3305f745c0b24c367de002dd197825;p=lilypond.git

diff --git a/lily/staff-symbol-referencer.cc b/lily/staff-symbol-referencer.cc
index e63efa1b30..dec5000b2a 100644
--- a/lily/staff-symbol-referencer.cc
+++ b/lily/staff-symbol-referencer.cc
@@ -3,7 +3,7 @@
   
   source file of the GNU LilyPond music typesetter
   
-  (c) 1999--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c) 1999--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
  */
 
 #include <math.h>
@@ -11,25 +11,20 @@
 #include "staff-symbol-referencer.hh"
 #include "staff-symbol.hh"
 #include "paper-def.hh"
- 
-bool
-Staff_symbol_referencer::has_interface (Grob*e)
-{
-  return unsmob_grob (e->get_grob_property ("staff-symbol"))
-    || gh_number_p (e->get_grob_property ("staff-position"));
-}
+#include "libc-extension.hh" 
+
 
 int
 Staff_symbol_referencer::line_count (Grob*me) 
 {
-  Grob *st = staff_symbol_l (me);
+  Grob *st = get_staff_symbol (me);
   return st  ?  Staff_symbol::line_count (st) : 0;
 }
 
 bool
 Staff_symbol_referencer::on_staffline (Grob*me)
 {
-  return on_staffline (me, (int) rint (position_f (me)));
+  return on_staffline (me, (int) rint (get_position (me)));
 }
 
 bool
@@ -40,7 +35,7 @@ Staff_symbol_referencer::on_staffline (Grob*me, int pos)
 }
 
 Grob*
-Staff_symbol_referencer::staff_symbol_l (Grob*me) 
+Staff_symbol_referencer::get_staff_symbol (Grob*me) 
 {
   SCM st = me->get_grob_property ("staff-symbol");
   return unsmob_grob (st);
@@ -49,20 +44,18 @@ Staff_symbol_referencer::staff_symbol_l (Grob*me)
 Real
 Staff_symbol_referencer::staff_space (Grob*me) 
 {
-  Grob * st = staff_symbol_l (me);
+  Grob * st = get_staff_symbol (me);
   if (st)
     return Staff_symbol::staff_space (st);
 
-  
   return 1.0;
 }
 
-
 Real
-Staff_symbol_referencer::position_f (Grob*me) 
+Staff_symbol_referencer::get_position (Grob*me) 
 {
   Real p =0.0;
-  Grob * st = staff_symbol_l (me);
+  Grob * st = get_staff_symbol (me);
   Grob * c = st ? me->common_refpoint (st, Y_AXIS) : 0;
   if (st && c)
     {
@@ -82,6 +75,22 @@ Staff_symbol_referencer::position_f (Grob*me)
 }
 
 
+LY_DEFINE(ly_grob_staff_position,
+	  "ly:grob-staff-position",
+	  1, 0,0, (SCM sg),
+	  "Return the Y-position of this grob relative to the staff.")
+{
+  Grob * g = unsmob_grob (sg);
+
+  SCM_ASSERT_TYPE (g, sg, SCM_ARG1, __FUNCTION__, "grob");
+  Real pos = Staff_symbol_referencer::get_position (g);
+
+  if (fabs (rint (pos) -pos) < 1e-6) // ugh.
+    return gh_int2scm ((int) my_round (pos));
+  else
+    return gh_double2scm (pos);
+}
+
 
 /*
   should use offset callback!
@@ -99,7 +108,7 @@ Staff_symbol_referencer::callback (SCM element_smob, SCM)
     {
       Real space = Staff_symbol_referencer::staff_space (me);
       off = gh_scm2double (pos) * space/2.0;
-      me->set_grob_property ("staff-position", gh_double2scm (0.0));
+      me->set_grob_property ("staff-position", gh_int2scm (0));
     }
 
   return gh_double2scm (off);
@@ -123,10 +132,10 @@ Staff_symbol_referencer::callback (SCM element_smob, SCM)
 void
 Staff_symbol_referencer::set_position (Grob*me,Real p)
 {
-  Grob * st = staff_symbol_l (me);
+  Grob * st = get_staff_symbol (me);
   if (st && me->common_refpoint (st, Y_AXIS))
     {
-      Real oldpos = position_f (me);
+      Real oldpos = get_position (me);
       me->set_grob_property ("staff-position", gh_double2scm (p - oldpos));
     }
   else
@@ -143,26 +152,25 @@ Staff_symbol_referencer::set_position (Grob*me,Real p)
 }
 
 /*
-  half  of the height, in staff space.
- */
+  Half of the height, in staff space, i.e. 2.0 for a normal staff. 
+*/
 Real
 Staff_symbol_referencer::staff_radius (Grob*me)
 {
-  return (line_count (me) -1) / 2;
+  return (line_count (me) -1) / 2.0;
 }
 
 
 int
 compare_position (Grob *const  &a, Grob * const &b)
 {
-  return sign (Staff_symbol_referencer::position_f ((Grob*)a) - 
-    Staff_symbol_referencer::position_f ((Grob*)b));
-}
-
-
-void
-Staff_symbol_referencer::set_interface (Grob * e)
-{
-  e->add_offset_callback (Staff_symbol_referencer::callback_proc, Y_AXIS);
+  return sign (Staff_symbol_referencer::get_position ((Grob*)a) - 
+    Staff_symbol_referencer::get_position ((Grob*)b));
 }
 
+ADD_INTERFACE (Staff_symbol_referencer,"staff-symbol-referencer-interface",
+  "Object whose Y position is meaning with reference to a staff "
+"symbol. Objects that have this interface should include "
+"Staff_symbol_referencer::callback in their Y-offset-callback. "
+,
+  "staff-position");