lily/grob-closure.cc

   1 #include "grob.hh"
   2 #include "simple-closure.hh"
   3
   4 SCM
   5 axis_offset_symbol (Axis a)
   6 {
   7   return a == X_AXIS
   8     ? ly_symbol2scm ("X-offset")
   9     : ly_symbol2scm ("Y-offset");
  10 }
  11
  12 SCM
  13 axis_parent_positioning (Axis a)
  14 {
  15   return (a == X_AXIS)
  16     ? Grob::x_parent_positioning_proc
  17     : Grob::y_parent_positioning_proc;
  18 }
  19
  20
  21
  22 /*
  23   Replace
  24
  25   (orig-proc GROB)
  26
  27   by
  28
  29   (+ (PROC GROB) (orig-proc GROB))
  30
  31 */
  32 void
  33 add_offset_callback (Grob *g, SCM proc, Axis a)
  34 {
  35   SCM data = g->get_property_data (axis_offset_symbol (a));
  36   if (!scm_is_number (data)
  37       && !ly_is_procedure (data)
  38       && !is_simple_closure (data))
  39     {
  40       g->set_property (axis_offset_symbol (a), proc);
  41       return ;
  42     }
  43
  44   if (ly_is_procedure (data))
  45     data = ly_make_simple_closure (scm_list_1  (data));
  46   else if (is_simple_closure (data))
  47     data = simple_closure_expression (data);
  48
  49   SCM plus = ly_lily_module_constant ("+");
  50
  51   if (ly_is_procedure (proc))
  52     proc = ly_make_simple_closure (scm_list_1 (proc));
  53
  54   SCM expr = scm_list_3 (plus, proc, data);
  55   g->set_property (axis_offset_symbol (a), ly_make_simple_closure (expr));
  56 }
  57
  58
  59 /*
  60   replace
  61
  62   (orig-proc GROB)
  63
  64   by
  65
  66   (PROC GROB (orig-proc GROB))
  67
  68 */
  69 void
  70 chain_callback (Grob *g, SCM proc, SCM sym)
  71 {
  72   SCM data = g->get_property_data (sym);
  73
  74   if (ly_is_procedure (data))
  75     data = ly_make_simple_closure (scm_list_1  (data));
  76   else if (is_simple_closure (data))
  77     data = simple_closure_expression (data);
  78   else
  79     /*
  80       Data may be nonnumber. In that case, it is assumed to be
  81       undefined.
  82     */
  83
  84     data = SCM_UNDEFINED;
  85
  86   SCM expr = scm_list_2 (proc, data);
  87   g->set_property (sym,
  88
  89                    // twice: one as a wrapper for grob property routines,
  90                    // once for the actual delayed binding.
  91                    ly_make_simple_closure (ly_make_simple_closure (expr)));
  92 }
  93
  94 void
  95 chain_offset_callback (Grob *g, SCM proc, Axis a)
  96 {
  97   chain_callback (g, proc, axis_offset_symbol (a));
  98 }