/*
  clef-engraver.cc -- implement Clef_engraver

  source file of the GNU LilyPond music typesetter

  (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>,

  Mats Bengtsson <matsb@s3.kth.se>
*/

#include <ctype.h>

#include "context.hh"
#include "bar-line.hh"
#include "staff-symbol-referencer.hh"
#include "engraver.hh"
#include "direction.hh"
#include "side-position-interface.hh"
#include "item.hh"

class Clef_engraver : public  Engraver
{
public:
  TRANSLATOR_DECLARATIONS (Clef_engraver);

  Direction octave_dir_;

protected:
  virtual void stop_translation_timestep ();
  virtual void process_music ();
  virtual void acknowledge_grob (Grob_info);
private:
  Item * clef_;
  Item * octavate_;

  SCM prev_glyph_;
  SCM prev_cpos_;
  SCM prev_octavation_;
  void create_clef ();
  void set_glyph ();
  void inspect_clef_properties ();
};

Clef_engraver::Clef_engraver ()
{
  clef_ = 0;
  octave_dir_ = CENTER;
  octavate_ = 0;

  /*
    will trigger a clef at the start since #f != ' ()
   */
  prev_cpos_ = prev_glyph_ = SCM_BOOL_F;
}

void
Clef_engraver::set_glyph ()
{
  SCM glyph_sym = ly_symbol2scm ("glyph-name");
  SCM glyph = get_property ("clefGlyph");

  SCM basic = ly_symbol2scm ("Clef");
  
  execute_pushpop_property (context (), basic, glyph_sym, SCM_UNDEFINED);
  execute_pushpop_property (context (), basic, glyph_sym, glyph);
}

/** 
  Generate a clef at the start of a measure. (when you see a Bar,
  ie. a breakpoint) 
  */
void
Clef_engraver::acknowledge_grob (Grob_info info)
{
  Item * item =dynamic_cast <Item *> (info.grob_);
  if (item)
    {
      if (Bar_line::has_interface (info.grob_)
	  && scm_is_string (get_property ("clefGlyph")))
	create_clef ();
    } 
}

void
Clef_engraver::create_clef ()
{
  if (!clef_)
    {
      Item *c = make_item ("Clef", SCM_EOL);
      

      clef_ = c;
      SCM cpos = get_property ("clefPosition");

      if (scm_is_number (cpos))
	clef_->set_property ("staff-position", cpos);

      SCM oct =  get_property ("clefOctavation");
      if (scm_is_number (oct) && scm_to_int (oct))
	{
	  Item * g = make_item ("OctavateEight", SCM_EOL);

	  int abs_oct = scm_to_int (oct) ;
	  int dir = sign (abs_oct);
	  abs_oct = abs (abs_oct)  + 1;

	  SCM txt = scm_number_to_string (scm_int2num (abs_oct),
					  scm_from_int (10));

	  g->set_property ("text",
			   scm_list_n (ly_scheme_function ("vcenter-markup"),
				       txt,  SCM_UNDEFINED));
	  Side_position_interface::add_support (g,clef_);      

	  g->set_parent (clef_, Y_AXIS);
	  g->set_parent (clef_, X_AXIS);
	  g->set_property ("direction", scm_int2num (dir));
	  octavate_ = g;
	  
	}
    }
}
void
Clef_engraver::process_music ()
{
  inspect_clef_properties ();
}

void
Clef_engraver::inspect_clef_properties ()
{
  SCM glyph = get_property ("clefGlyph");
  SCM clefpos = get_property ("clefPosition");
  SCM octavation = get_property ("clefOctavation");
  SCM force_clef = get_property ("forceClef");
  
  if (clefpos == SCM_EOL
      || scm_equal_p (glyph, prev_glyph_) == SCM_BOOL_F
      || scm_equal_p (clefpos, prev_cpos_) == SCM_BOOL_F
      || scm_equal_p (octavation, prev_octavation_) == SCM_BOOL_F
      || to_boolean (force_clef))
    {
      set_glyph ();
      create_clef ();

      clef_->set_property ("non-default", SCM_BOOL_T);

      prev_cpos_ = clefpos;
      prev_glyph_ = glyph;
      prev_octavation_ = octavation;
    }

  if (to_boolean (force_clef))
    {
      Context * w = context ()->where_defined (ly_symbol2scm ("forceClef"));
      w->set_property ("forceClef", SCM_EOL);
    }
}


void
Clef_engraver::stop_translation_timestep ()
{
  if (clef_)
    {
      SCM vis = 0; 
      if (to_boolean (clef_->get_property ("non-default")))
	{
	  vis = get_property ("explicitClefVisibility");
	}

      if (vis)
	{
	  clef_->set_property ("break-visibility", vis);
	  if (octavate_)
	    {
	      octavate_->set_property ("break-visibility", vis);

	    }
	}
      
      clef_ =0;

      octavate_ = 0;
    }
}



ENTER_DESCRIPTION (Clef_engraver,
/* descr */       "Determine and set reference point for pitches",
/* creats*/       "Clef OctavateEight",
/* accepts */     "",
/* acks  */      "bar-line-interface",
/* reads */       "clefPosition clefGlyph middleCPosition clefOctavation explicitClefVisibility forceClef",
/* write */       "");
