lily/auto-change-iterator.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1999--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "context.hh"
  21 #include "direction.hh"
  22 #include "international.hh"
  23 #include "music.hh"
  24 #include "music-wrapper-iterator.hh"
  25
  26 class Auto_change_iterator : public Music_wrapper_iterator
  27 {
  28 public:
  29   DECLARE_SCHEME_CALLBACK (constructor, ());
  30
  31   Auto_change_iterator ();
  32
  33 protected:
  34   virtual void do_quit ();
  35   virtual void construct_children ();
  36   virtual void process (Moment);
  37   vector<Pitch> pending_pitch (Moment) const;
  38 private:
  39   SCM split_list_;
  40   Direction where_dir_;
  41   void change_to (Music_iterator *, SCM, string);
  42   Moment start_moment_;
  43
  44   Context_handle up_;
  45   Context_handle down_;
  46 };
  47
  48 void
  49 Auto_change_iterator::change_to (Music_iterator *it, SCM to_type_sym,
  50                                  string to_id)
  51 {
  52   Context *current = it->get_outlet ();
  53   Context *last = 0;
  54
  55   /*
  56     Cut & Paste from Change_iterator (ugh).
  57
  58     TODO: abstract this function
  59   */
  60
  61   /* find the type  of translator that we're changing.
  62
  63   If \translator Staff = bass, then look for Staff = *
  64   */
  65   while (current && !current->is_alias (to_type_sym))
  66     {
  67       last = current;
  68       current = current->get_parent_context ();
  69     }
  70
  71   if (current && current->id_string () == to_id)
  72     {
  73       string msg;
  74       msg += _f ("cannot change, already in translator: %s", to_id);
  75     }
  76
  77   if (current)
  78     {
  79       if (last)
  80         {
  81           Context *dest
  82             = it->get_outlet ()->find_create_context (to_type_sym, to_id, SCM_EOL);
  83
  84           send_stream_event (last, "ChangeParent", get_music ()->origin (),
  85                                ly_symbol2scm ("context"), dest->self_scm ());
  86         }
  87       else
  88         {
  89           /*
  90             We could change the current translator's id, but that would make
  91             errors hard to catch
  92
  93           */
  94           ;
  95         }
  96     }
  97 }
  98
  99 void
 100 Auto_change_iterator::process (Moment m)
 101 {
 102   Music_wrapper_iterator::process (m);
 103
 104   Moment now = get_outlet ()->now_mom ();
 105   Moment *splitm = 0;
 106   if (start_moment_.main_part_.is_infinity () && start_moment_ < 0)
 107     start_moment_ = now;
 108
 109   for (; scm_is_pair (split_list_); split_list_ = scm_cdr (split_list_))
 110     {
 111       splitm = unsmob_moment (scm_caar (split_list_));
 112       if ((*splitm + start_moment_) > now)
 113         break;
 114
 115       SCM tag = scm_cdar (split_list_);
 116       Direction d = to_dir (tag);
 117
 118       if (d && d != where_dir_)
 119         {
 120           where_dir_ = d;
 121           string to_id = (d >= 0) ? "up" : "down";
 122           change_to (child_iter_,
 123                      ly_symbol2scm ("Staff"),
 124                      to_id);
 125         }
 126     }
 127 }
 128
 129 Auto_change_iterator::Auto_change_iterator ()
 130 {
 131   where_dir_ = CENTER;
 132   split_list_ = SCM_EOL;
 133 }
 134
 135 void
 136 Auto_change_iterator::construct_children ()
 137 {
 138   split_list_ = get_music ()->get_property ("split-list");
 139   start_moment_ = get_outlet ()->now_mom ();
 140
 141   SCM props = get_outlet ()->get_property ("trebleStaffProperties");
 142   Context *up = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
 143                                                     "up", props);
 144
 145   props = get_outlet ()->get_property ("bassStaffProperties");
 146   Context *down = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
 147                                                       "down", props);
 148
 149   up_.set_context (up);
 150   down_.set_context (down);
 151
 152   Context *voice = up->find_create_context (ly_symbol2scm ("Voice"),
 153                                             "", SCM_EOL);
 154   set_context (voice);
 155   Music_wrapper_iterator::construct_children ();
 156 }
 157
 158 void
 159 Auto_change_iterator::do_quit ()
 160 {
 161   up_.set_context (0);
 162   down_.set_context (0);
 163 }
 164
 165 IMPLEMENT_CTOR_CALLBACK (Auto_change_iterator);