lily/output-property-engraver.cc

   1 /*
   2   output-property-engraver.cc --  implement Output_property_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "engraver.hh"
  11 #include "grob.hh"
  12 #include "output-property-music-iterator.hh"
  13 #include "translator-group.hh"
  14
  15 class Output_property_engraver : public Engraver
  16 {
  17 TRANSLATOR_DECLARATIONS(Output_property_engraver);
  18 protected:
  19   Link_array<Music> props_;
  20
  21   virtual void stop_translation_timestep ();
  22   virtual void acknowledge_grob (Grob_info);
  23   virtual bool try_music (Music*);
  24 };
  25
  26
  27 bool
  28 Output_property_engraver::try_music (Music* m)
  29 {
  30   if (m->is_mus_type ("layout-instruction"))
  31     {
  32       props_.push (m);
  33       return true;
  34     }
  35   return false;
  36 }
  37
  38 void
  39 Output_property_engraver::acknowledge_grob (Grob_info inf)
  40 {
  41   for (int i=props_.size (); i--;)
  42     {
  43       Music * o = props_[i];
  44       SCM pred = o->get_mus_property ("predicate");
  45
  46
  47
  48       if (gh_procedure_p (pred))
  49         {
  50           /*
  51             should typecheck pred.
  52           */
  53           SCM result=scm_call_1 (pred, inf.grob_->self_scm ());
  54           if (to_boolean (result))
  55             {
  56               SCM sym = o->get_mus_property ("grob-property");
  57               SCM val = o->get_mus_property ("grob-value");
  58               inf.grob_->internal_set_grob_property (sym, val);
  59             }
  60         }
  61       else
  62         {
  63           Translator_group * d =
  64             dynamic_cast<Translator_group*> (inf.origin_trans_);
  65
  66           if (!d)
  67             d = dynamic_cast<Translator_group*> (inf.origin_trans_->daddy_trans_);
  68
  69           SCM proc = o->get_mus_property ("procedure");
  70           scm_call_3 (proc,
  71                       inf.grob_->self_scm(),
  72                       d->self_scm(),
  73                       daddy_trans_->self_scm());
  74         }
  75     }
  76 }
  77
  78 void
  79 Output_property_engraver::stop_translation_timestep ()
  80 {
  81   props_.clear ();
  82 }
  83
  84 Output_property_engraver::Output_property_engraver()
  85 {
  86 }
  87
  88 ENTER_DESCRIPTION(Output_property_engraver,
  89 /* descr */       "Interpret Music of Output_property type, and apply a function "
  90 " to any Graphic objects that satisfies the predicate.",
  91 /* creats*/       "",
  92 /* accepts */     "layout-instruction",
  93 /* acks  */       "grob-interface",
  94 /* reads */       "",
  95 /* write */       "");