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 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "output-property.hh"
  11 #include "engraver.hh"
  12 #include "score-element.hh"
  13
  14 class Output_property_engraver : public Engraver
  15 {
  16 public:
  17   VIRTUAL_COPY_CONS(Translator);
  18 protected:
  19
  20   Link_array<Output_property> props_;
  21
  22   virtual void do_pre_move_processing ();
  23   virtual void acknowledge_element (Score_element_info);
  24   virtual bool do_try_music (Music*);
  25 };
  26
  27
  28 bool
  29 Output_property_engraver::do_try_music (Music* m)
  30 {
  31   if (Output_property * o = dynamic_cast<Output_property*> (m))
  32     {
  33       props_.push (o);
  34       return true;
  35     }
  36   return false;
  37 }
  38
  39 void
  40 Output_property_engraver::acknowledge_element (Score_element_info inf)
  41 {
  42   for (int i=props_.size (); i--; )
  43     {
  44       Output_property * o = props_[i];
  45       SCM pred = gh_car (o->pred_sym_val_list_);
  46
  47       /*
  48         should typecheck pred.
  49        */
  50       SCM result=gh_apply (pred,
  51                            gh_list (inf.elem_l_->self_scm_, SCM_UNDEFINED));
  52       if (to_boolean (result))
  53         {
  54           inf.elem_l_->set_elt_property (gh_cadr (o->pred_sym_val_list_),
  55                                          gh_caddr (o->pred_sym_val_list_));
  56         }
  57     }
  58 }
  59
  60 void
  61 Output_property_engraver::do_pre_move_processing ()
  62 {
  63   props_.clear ();
  64 }
  65
  66 ADD_THIS_TRANSLATOR(Output_property_engraver);