/*
  span-arpeggio-engraver.cc -- implement Span_arpeggio_engraver

  source file of the GNU LilyPond music typesetter

  (c) 2000--2004 Jan Nieuwenhuizen <janneke@gnu.org>

  Han-Wen Nienhuys <hanwen@xs4all.nl>
*/

#include "engraver.hh"
#include "lily-guile.hh"
#include "item.hh"
#include "arpeggio.hh"
#include "group-interface.hh"
#include "side-position-interface.hh"
#include "staff-symbol-referencer.hh"


/** 
  Make arpeggios that span multiple staves.  Catch arpeggios, and span a
  Span_arpeggio over them if we find more than two arpeggios.
  */
class Span_arpeggio_engraver : public Engraver
{
public:
  TRANSLATOR_DECLARATIONS (Span_arpeggio_engraver);
  
protected:
  virtual void acknowledge_grob (Grob_info);
  virtual void process_acknowledged_grobs ();
  virtual void stop_translation_timestep ();

private:
  Item *span_arpeggio_;
  Link_array<Grob> arpeggios_;
};


Span_arpeggio_engraver::Span_arpeggio_engraver ()
{
  span_arpeggio_ = 0;
}

void
Span_arpeggio_engraver::acknowledge_grob (Grob_info info)
{
  if (Arpeggio::has_interface (info.grob_)
      && info.origin_contexts (this).size ()) // huh? what's this test for? 
    {
      arpeggios_.push (info.grob_);
    }
}

void
Span_arpeggio_engraver::process_acknowledged_grobs ()
{
  /*
    connectArpeggios is slightly brusque; we should really read a grob
    property of the caught non-span arpeggios. That way, we can have

    both non-connected and connected arps in one pianostaff.

  */
  if (!span_arpeggio_ && arpeggios_.size () > 1
      && to_boolean (get_property ("connectArpeggios")))
    {
      span_arpeggio_ = make_item ("Arpeggio", SCM_EOL);
            
    }
}

void
Span_arpeggio_engraver::stop_translation_timestep ()
{
  if (span_arpeggio_) 
    {
      /*
	we do this very late, to make sure we also catch `extra'
	side-pos support like accidentals.
       */
      for (int i=0; i < arpeggios_.size (); i ++)
	{
	  for (SCM s = arpeggios_[i]->get_property ("stems");
	       ly_c_pair_p (s); s = ly_cdr (s))
	    Group_interface::add_thing (span_arpeggio_, ly_symbol2scm ("stems"), ly_car (s));
	  for (SCM s = arpeggios_[i]->get_property ("side-support-elements");
	       ly_c_pair_p (s); s = ly_cdr (s))
	    Group_interface::add_thing (span_arpeggio_, ly_symbol2scm ("side-support-elements"), ly_car (s));

	  /*
	    we can't kill the children, since we don't want to the
	    previous note to bump into the span arpeggio; so we make
	    it transparent.  */
	  arpeggios_[i]->set_property ("print-function", SCM_EOL);
	}
      
      span_arpeggio_ = 0;
    }
  arpeggios_.clear ();
}



ENTER_DESCRIPTION (Span_arpeggio_engraver,
/* descr */       "",
/* creats*/       "Arpeggio",
/* accepts */     "",
/* acks  */      "arpeggio-interface",
/* reads */       "connectArpeggios",
/* write */       "");
