lily/key-signature-interface.cc

   1 /*
   2   key-item.cc -- implement Key_signature_interface
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1996--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7
   8   keyplacement by Mats Bengtsson
   9 */
  10
  11 #include "accidental-interface.hh"
  12 #include "font-interface.hh"
  13 #include "international.hh"
  14 #include "item.hh"
  15 #include "lookup.hh"
  16 #include "output-def.hh"
  17 #include "staff-symbol-referencer.hh"
  18 #include "rational.hh"
  19
  20 struct Key_signature_interface
  21 {
  22   DECLARE_SCHEME_CALLBACK (print, (SCM));
  23   DECLARE_GROB_INTERFACE ();
  24 };
  25
  26
  27 /*
  28   TODO
  29   - space the `natural' signs wider
  30 */
  31 MAKE_SCHEME_CALLBACK (Key_signature_interface, print, 1);
  32 SCM
  33 Key_signature_interface::print (SCM smob)
  34 {
  35   Item *me = dynamic_cast<Item *> (unsmob_grob (smob));
  36
  37   Real inter = Staff_symbol_referencer::staff_space (me) / 2.0;
  38
  39   SCM scm_style = me->get_property ("style");
  40   string style;
  41   if (scm_is_symbol (scm_style))
  42     style = ly_symbol2string (scm_style);
  43   else
  44     style = "";
  45
  46   Stencil mol;
  47
  48   SCM c0s = me->get_property ("c0-position");
  49
  50   bool is_cancellation = me->internal_has_interface
  51     (ly_symbol2scm ("key-cancellation-interface"));
  52
  53   /*
  54     SCM lists are stacks, so we work from right to left, ending with
  55     the cancellation signature.
  56   */
  57
  58   int last_pos = -1000;
  59   SCM last_glyph_name = SCM_BOOL_F;
  60   SCM padding_pairs = me->get_property ("padding-pairs");
  61
  62   Font_metric *fm = Font_interface::get_default_font (me);
  63   SCM alist = me->get_property ("glyph-name-alist");
  64
  65   for (SCM s = me->get_property ("alteration-alist"); scm_is_pair (s); s = scm_cdr (s))
  66     {
  67       SCM alt = is_cancellation
  68         ? scm_from_int (0)
  69         : scm_cdar (s);
  70
  71       SCM glyph_name_scm = ly_assoc_get (alt, alist, SCM_BOOL_F);
  72       if (!scm_is_string (glyph_name_scm))
  73         {
  74           me->warning (_f ("No glyph found for alteration: %s",
  75                            ly_scm2rational (alt).to_string ().c_str ()));
  76           continue;
  77         }
  78
  79       string glyph_name = ly_scm2string (glyph_name_scm);
  80
  81       Stencil acc (fm->find_by_name (glyph_name));
  82
  83       if (acc.is_empty ())
  84         me->warning (_ ("alteration not found"));
  85       else
  86         {
  87           SCM what = scm_caar (s);
  88
  89           SCM proc = ly_lily_module_constant ("key-signature-interface::alteration-position");
  90
  91           int pos = scm_to_int (scm_call_3 (proc, what, scm_cdar (s), c0s));
  92           acc.translate_axis (pos * inter, Y_AXIS);
  93
  94           /*
  95             The natural sign (unlike flat & sharp)
  96             has vertical edges on both sides. A little padding is
  97             needed to prevent collisions.
  98           */
  99           Real padding = robust_scm2double (me->get_property ("padding"),
 100                                             0.0);
 101           SCM handle = scm_assoc (scm_cons (glyph_name_scm, last_glyph_name),
 102                                   padding_pairs);
 103           if (scm_is_pair (handle))
 104             padding = robust_scm2double (scm_cdr (handle), 0.0);
 105           else if (glyph_name ==  "accidentals.natural"
 106               && last_pos < pos + 2
 107               && last_pos > pos - 6)
 108             padding += 0.3;
 109
 110           mol.add_at_edge (X_AXIS, LEFT, acc, padding);
 111
 112           last_pos = pos;
 113           last_glyph_name = glyph_name_scm;
 114         }
 115     }
 116
 117   mol.align_to (X_AXIS, LEFT);
 118
 119   return mol.smobbed_copy ();
 120 }
 121
 122 ADD_INTERFACE (Key_signature_interface,
 123                "A group of accidentals, to be printed as signature sign.",
 124
 125                /* properties */
 126                "alteration-alist "
 127                "c0-position "
 128                "glyph-name-alist "
 129                "padding "
 130                "padding-pairs "
 131                "style "
 132                );