2 staff-symbol-referencer.cc -- implement Staff_symbol_referencer
4 source file of the GNU LilyPond music typesetter
6 (c) 1999--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
9 #include "staff-symbol-referencer.hh"
11 #include "staff-symbol.hh"
13 #include "output-def.hh"
14 #include "libc-extension.hh"
17 Staff_symbol_referencer::line_count (Grob *me)
19 Grob *st = get_staff_symbol (me);
20 return st ? Staff_symbol::line_count (st) : 0;
24 Staff_symbol_referencer::on_line (Grob *me)
26 return on_line (me, (int) rint (get_position (me)));
30 Staff_symbol_referencer::on_staff_line (Grob *me)
32 return on_staff_line (me, (int) rint (get_position (me)));
36 Staff_symbol_referencer::on_line (Grob *me, int pos)
38 return Staff_symbol::on_line (me, pos);
42 Staff_symbol_referencer::on_staff_line (Grob *me, int pos)
44 return on_line (me, pos) && abs (pos) <= 2 * staff_radius (me);
48 Staff_symbol_referencer::get_staff_symbol (Grob *me)
50 if (Staff_symbol::has_interface (me))
53 SCM st = me->get_object ("staff-symbol");
54 return unsmob_grob (st);
58 Staff_symbol_referencer::staff_space (Grob *me)
60 Grob *st = get_staff_symbol (me);
62 return Staff_symbol::staff_space (st);
67 Staff_symbol_referencer::line_thickness (Grob *me)
69 Grob *st = get_staff_symbol (me);
71 return Staff_symbol::get_line_thickness (st);
72 return me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
76 Staff_symbol_referencer::get_position (Grob *me)
79 Grob *st = get_staff_symbol (me);
80 Grob *c = st ? me->common_refpoint (st, Y_AXIS) : 0;
83 Real y = me->relative_coordinate (c, Y_AXIS)
84 - st->relative_coordinate (c, Y_AXIS);
86 p += 2.0 * y / Staff_symbol::staff_space (st);
90 return me->relative_coordinate (me->get_parent (Y_AXIS), Y_AXIS) * 2;
91 return robust_scm2double (me->get_property ("staff-position"), p);
96 Staff_symbol_referencer::extent_in_staff (Grob *me)
98 Grob *st = get_staff_symbol (me);
99 Grob *c = st ? me->common_refpoint (st, Y_AXIS) : 0;
104 retval = me->extent (c, Y_AXIS)
105 - st->relative_coordinate (c, Y_AXIS);
114 Staff_symbol_referencer::get_rounded_position (Grob *me)
116 return int (rint (get_position (me)));
119 MAKE_SCHEME_CALLBACK (Staff_symbol_referencer, callback, 1);
121 Staff_symbol_referencer::callback (SCM smob)
123 Grob *me = unsmob_grob (smob);
125 SCM pos = me->get_property ("staff-position");
127 if (scm_is_number (pos))
129 Real space = Staff_symbol_referencer::staff_space (me);
130 off = scm_to_double (pos) * space / 2.0;
133 return scm_from_double (off);
136 /* This sets the position relative to the center of the staff symbol.
138 The function is hairy, because it can be called in two situations:
140 1. There is no staff yet; we must set staff-position
142 2. There is a staff, and perhaps someone even applied a
143 translate_axis (). Then we must compensate for the translation
145 In either case, we set a callback to be sure that our new position
146 will be extracted from staff-position */
149 Staff_symbol_referencer::set_position (Grob *me, Real p)
151 Grob *st = get_staff_symbol (me);
153 if (st && me->common_refpoint (st, Y_AXIS))
155 oldpos = get_position (me);
159 Real ss = Staff_symbol_referencer::staff_space (me);
160 me->translate_axis ((p - oldpos) * ss * 0.5, Y_AXIS);
163 /* Half of the height, in staff space, i.e. 2.0 for a normal staff. */
165 Staff_symbol_referencer::staff_radius (Grob *me)
167 return (line_count (me) - 1) / 2.0;
171 compare_position (Grob *const &a, Grob *const &b)
173 return sign (Staff_symbol_referencer::get_position ((Grob *)a)
174 - Staff_symbol_referencer::get_position ((Grob *) b));
178 position_less (Grob *const &a, Grob *const &b)
180 return Staff_symbol_referencer::get_position (a)
181 < Staff_symbol_referencer::get_position (b);
184 ADD_INTERFACE (Staff_symbol_referencer,
185 "An object whose Y@tie{}position is meant relative to a staff"
186 " symbol. These usually"
187 " have @code{Staff_symbol_referencer::callback} in their"
188 " @code{Y-offset-callbacks}.",