/*
  mark-engraver.cc -- implement Mark_engraver

  source file of the GNU LilyPond music typesetter

  (c) 1998--2006 Jan Nieuwenhuizen <janneke@gnu.org>
*/

#include <cctype>
using namespace std;

#include "engraver.hh"

#include "axis-group-interface.hh"
#include "bar-line.hh"
#include "context.hh"
#include "grob-array.hh"
#include "international.hh"
#include "item.hh"
#include "stream-event.hh"
#include "text-interface.hh"
#include "warn.hh"

#include "translator.icc"

/**
   put stuff over or next to  bars.  Examples: bar numbers, marginal notes,
   rehearsal marks.
*/
class Mark_engraver : public Engraver
{

  void create_items (Stream_event *);
  Item *text_;
  Stream_event *mark_ev_;

public:
  TRANSLATOR_DECLARATIONS (Mark_engraver);

protected:
  void process_music ();
  void stop_translation_timestep ();

  DECLARE_TRANSLATOR_LISTENER (mark);
  DECLARE_ACKNOWLEDGER (break_alignment);
  DECLARE_ACKNOWLEDGER (break_aligned);
};

Mark_engraver::Mark_engraver ()
{
  text_ = 0;
  mark_ev_ = 0;
}

/*
  This is a flawed approach, since various break-aligned objects may
  not appear depending on key signature etc.

   We keep it in case someone puts the engraver in a lower context than score.
 */
void
Mark_engraver::acknowledge_break_aligned (Grob_info inf)
{
  Grob *s = inf.grob ();
  if (text_
      && !text_->get_parent (X_AXIS)
      && (text_->get_property_data (ly_symbol2scm ("break-align-symbol"))
	  == s->get_property_data (ly_symbol2scm ("break-align-symbol")))
      && Axis_group_interface::has_interface (s))
    {
      /*
	RehearsalMark cannot be break-aligned, since the width of the
	object should not be taken into alignment considerations.
      */
      text_->set_parent (s, X_AXIS);
    }
}

void
Mark_engraver::acknowledge_break_alignment (Grob_info inf)
{
  Grob *s = inf.grob ();
  if (text_
      && dynamic_cast<Item *> (s))
    {
      text_->set_parent (s, X_AXIS);
    }
}


void
Mark_engraver::stop_translation_timestep ()
{
  if (text_)
    {
      text_->set_object ("side-support-elements",
			 grob_list_to_grob_array (get_property ("stavesFound")));
      text_ = 0;
    }
  mark_ev_ = 0;
}

void
Mark_engraver::create_items (Stream_event *ev)
{
  if (text_)
    return;

  text_ = make_item ("RehearsalMark", ev->self_scm ());
}

IMPLEMENT_TRANSLATOR_LISTENER (Mark_engraver, mark);
void
Mark_engraver::listen_mark (Stream_event *ev)
{
  ASSIGN_EVENT_ONCE (mark_ev_, ev);
}

/*
  TODO: make the increment function in Scheme.
*/
void
Mark_engraver::process_music ()
{
  if (mark_ev_)
    {
      create_items (mark_ev_);

      /*
	automatic marks.
      */

      SCM m = mark_ev_->get_property ("label");
      SCM proc = get_property ("markFormatter");
      if (!Text_interface::is_markup (m)
	  && ly_is_procedure (proc))
	{
	  if (!scm_is_number (m))
	    m = get_property ("rehearsalMark");

	  if (scm_integer_p (m) == SCM_BOOL_T
	      && scm_exact_p (m) == SCM_BOOL_T)
	    {
	      int mark_count = scm_to_int (m);
	      mark_count++;
	      context ()->set_property ("rehearsalMark",
					scm_from_int (mark_count));
	    }

	  if (scm_is_number (m))
	    m = scm_call_2 (proc, m, context ()->self_scm ());
	  else
	    /* FIXME: constant error message.  */
	    warning (_ ("rehearsalMark must have integer value"));
	}

      if (Text_interface::is_markup (m))
	text_->set_property ("text", m);
      else
	warning (_ ("mark label must be a markup object"));
    }
}

ADD_ACKNOWLEDGER (Mark_engraver, break_aligned);
ADD_ACKNOWLEDGER (Mark_engraver, break_alignment);

ADD_TRANSLATOR (Mark_engraver,
		/* doc */ "This engraver will create RehearsalMark objects. "
		"It puts them on top of all staves (which is taken from "
		"the property @code{stavesFound}). If moving this engraver "
		"to a different context, "
		"@ref{Staff_collecting_engraver} must move along, otherwise all marks"
		"end up on the same Y-location",
		
		/* create */ "RehearsalMark",
		/* accept */ "mark-event",
		/* read */
		"markFormatter "
		"rehearsalMark "
		"stavesFound ",
		
		/* write */ "");
