lily/grace-engraver.cc

   1 /*
   2   grace-engraver.cc -- implement Grace_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2004--2005 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "engraver.hh"
  10 #include "context.hh"
  11 #include "warn.hh"
  12
  13 class Grace_engraver : public Engraver
  14 {
  15   void consider_change_grace_settings ();
  16 protected:
  17   virtual void start_translation_timestep ();
  18   virtual void derived_mark () const;
  19   virtual void initialize ();
  20
  21   TRANSLATOR_DECLARATIONS (Grace_engraver);
  22   Moment last_moment_;
  23   SCM grace_settings_;
  24 public:
  25 };
  26
  27 Grace_engraver::Grace_engraver ()
  28 {
  29   grace_settings_ = SCM_EOL;
  30   last_moment_ = Moment (Rational (-1,1));
  31 }
  32
  33 void
  34 Grace_engraver::initialize ()
  35 {
  36   consider_change_grace_settings ();
  37 }
  38
  39 void
  40 Grace_engraver::consider_change_grace_settings ()
  41 {
  42   Moment now = now_mom ();
  43   if (last_moment_.grace_part_ && !now.grace_part_)
  44     {
  45       for (SCM s = grace_settings_; scm_is_pair (s); s = scm_cdr (s))
  46         {
  47           SCM context = scm_caar (s);
  48           SCM entry = scm_cdar (s);
  49           SCM grob = scm_cadr (entry);
  50           SCM sym = scm_caddr (entry);
  51
  52           execute_pushpop_property (unsmob_context (context),
  53                                     grob, sym, SCM_UNDEFINED);
  54         }
  55
  56       grace_settings_ = SCM_EOL;
  57     }
  58   else if (!last_moment_.grace_part_ && now.grace_part_)
  59     {
  60       SCM settings = get_property ("graceSettings");
  61
  62       grace_settings_ = SCM_EOL;
  63       for (SCM s = settings; scm_is_pair (s); s = scm_cdr (s))
  64         {
  65           SCM entry = scm_car (s);
  66           SCM context_name = scm_car (entry);
  67           SCM grob = scm_cadr (entry);
  68           SCM sym = scm_caddr (entry);
  69           SCM val = scm_cadr (scm_cddr (entry));
  70
  71           Context *c = context ();
  72           while (c
  73                  && c->context_name_symbol () != context_name)
  74             {
  75               c = c->get_parent_context ();
  76             }
  77
  78           if (c)
  79             {
  80               execute_pushpop_property (c,
  81                                         grob, sym, val);
  82               grace_settings_
  83                 = scm_cons (scm_cons (c->self_scm (), entry), grace_settings_);
  84             }
  85           else
  86             {
  87               programming_error ("can't find context");
  88               scm_display (context_name, scm_current_error_port ());
  89             }
  90         }
  91     }
  92
  93   last_moment_ = now_mom();
  94 }
  95
  96 void
  97 Grace_engraver::derived_mark () const
  98 {
  99   scm_gc_mark (grace_settings_);
 100   Engraver::derived_mark ();
 101 }
 102
 103 void
 104 Grace_engraver::start_translation_timestep ()
 105 {
 106   consider_change_grace_settings ();
 107 }
 108
 109 ADD_TRANSLATOR (Grace_engraver,
 110                 /* descr */ "Set font size and other properties for grace notes.",
 111                 /* creats*/ "",
 112                 /* accepts */ "",
 113                 /* acks  */ "",
 114                 /* reads */ "graceSettings",
 115                 /* write */ "");