/*
  staff-symbol.cc -- implement Staff_symbol

  source file of the GNU LilyPond music typesetter

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

#include "lookup.hh"
#include "dimensions.hh"
#include "output-def.hh"
#include "stencil.hh"
#include "warn.hh"
#include "item.hh"
#include "staff-symbol.hh"
#include "staff-symbol-referencer.hh"
#include "spanner.hh"



MAKE_SCHEME_CALLBACK (Staff_symbol,print,1);

SCM
Staff_symbol::print (SCM smob)
{
  Grob *me = unsmob_grob (smob);
  Spanner* sp = dynamic_cast<Spanner*> (me);
  Grob * common
    = sp->get_bound (LEFT)->common_refpoint (sp->get_bound (RIGHT), X_AXIS);
  
  Interval span_points (0,0);
  

  /*
    For raggedright without ragged staffs, simply set width to the linewidth.

    (ok -- lousy UI, since width is in staff spaces)

    --hwn.
   */
  Real t = me->get_paper ()->get_dimension (ly_symbol2scm ("linethickness"));
  t *= robust_scm2double (me->get_property ("thickness"), 1.0);
  
  Direction d = LEFT;
  do
    {
      SCM width_scm = me->get_property ("width");
      if (d == RIGHT && scm_is_number (width_scm))
	{
	  /*
	    don't multiply by Staff_symbol_referencer::staff_space (me),
	    since that would make aligning staff symbols of different sizes to
	    one right margin hell.
	  */      
	  span_points[RIGHT] = scm_to_double (width_scm);
	}
      else
	{
	  Item * x = sp->get_bound (d);

	  span_points[d] = x->relative_coordinate (common , X_AXIS);
	  if (!x->break_status_dir ()
	      && !x->extent (x, X_AXIS).is_empty ())
	    span_points[d] += x->extent (x, X_AXIS)[d];
	}

      span_points[d] -= d* t/2;
    }
  while (flip (&d) !=LEFT);


  int l = Staff_symbol::line_count (me);
  
  Real height = (l-1) * staff_space (me) /2;
  Stencil a =
    Lookup::horizontal_line (span_points
			     -me->relative_coordinate (common, X_AXIS),
			     t);

  Stencil m;
  for (int i=0; i < l; i++)
    {
      Stencil b(a);
      b.translate_axis (height - i * staff_space (me), Y_AXIS);
      m.add_stencil (b);
    }
  return m.smobbed_copy ();
}

int
Staff_symbol::get_steps (Grob*me) 
{
  return line_count (me) * 2;
}

int
Staff_symbol::line_count (Grob*me) 
{
  SCM c = me->get_property ("line-count");
  if (scm_is_number (c))
    return scm_to_int (c);
  else
    return 0;
}

Real
Staff_symbol::staff_space (Grob*me)
{
  return robust_scm2double (me->get_property ("staff-space"), 1.0);
}

Real
Staff_symbol::get_line_thickness (Grob* me)
{
  Real lt =  me->get_paper ()->get_dimension (ly_symbol2scm ("linethickness"));

  return robust_scm2double (me->get_property ("thickness"), 1.0) * lt;
}

Real
Staff_symbol::get_ledger_line_thickness (Grob * me)
{
  SCM lt_pair = me->get_property ("ledger-line-thickness");
  Offset z = robust_scm2offset (lt_pair, Offset (1.0, 0.1));
  
  return z[X_AXIS] * get_line_thickness (me) + z[Y_AXIS]* staff_space (me);
}


ADD_INTERFACE (Staff_symbol,"staff-symbol-interface",
	       "This spanner draws the lines of a staff. "
	       "A staff symbol definines a vertical unit, the staff space. "
	       "Quantities that go by a half staff space are called positions "
	       "The center (i.e. middle line "
	       "or space) is position 0. The length of the symbol may be set by hand "
	       "through the @code{width} property. ",
	       
  "ledger-line-thickness width staff-space thickness line-count");
