/*
  This file is part of LilyPond, the GNU music typesetter.

  Copyright (C) 1996--2020 Jan Nieuwenhuizen <janneke@gnu.org>

  LilyPond is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  LilyPond is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "performer.hh"
#include "audio-item.hh"
#include "audio-column.hh"
#include "global-context.hh"
#include "stream-event.hh"
#include "warn.hh"

#include "translator.icc"

class Beam_performer : public Performer
{
public:
  TRANSLATOR_DECLARATIONS (Beam_performer);

protected:
  void start_translation_timestep ();
  void process_music ();
  void set_melisma (bool);
  void listen_beam (Stream_event *);
private:
  Stream_event *start_ev_;
  Stream_event *now_stop_ev_;
  bool beam_;
};

Beam_performer::Beam_performer (Context *c)
  : Performer (c)
{
  beam_ = false;
  start_ev_ = 0;
  now_stop_ev_ = 0;
}

void
Beam_performer::process_music ()
{
  if (now_stop_ev_)
    {
      beam_ = false;
      set_melisma (false);
    }

  if (start_ev_)
    {
      beam_ = true;
      set_melisma (true);
    }
}

void
Beam_performer::set_melisma (bool ml)
{
  SCM b = get_property (this, "autoBeaming");
  if (!from_scm<bool> (b))
    set_property (context (), "beamMelismaBusy", ml ? SCM_BOOL_T : SCM_BOOL_F);
}

void
Beam_performer::start_translation_timestep ()
{
  start_ev_ = 0;
  now_stop_ev_ = 0;
}

void
Beam_performer::listen_beam (Stream_event *ev)
{
  Direction d = from_scm<Direction> (get_property (ev, "span-direction"));

  if (d == START)
    start_ev_ = ev;
  else if (d == STOP)
    now_stop_ev_ = ev;
}

void
Beam_performer::boot ()
{
  ADD_LISTENER (Beam_performer, beam);
}

ADD_TRANSLATOR (Beam_performer,
                /* doc */
                "",

                /* create */
                "",

                /* read */
                "",

                /* write */
                ""
               );

