lily/auto-change-iterator.cc

   1 /*
   2   auto-change-iterator.cc -- implement  Auto_change_iterator
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "music.hh"
  11 #include "auto-change-iterator.hh"
  12 #include "translator-group.hh"
  13 #include "musical-request.hh"
  14
  15
  16
  17 void
  18 Auto_change_iterator::change_to (Music_iterator *it, String to_type,
  19                                  String to_id)
  20 {
  21   Translator_group * current = it->report_to_l ();
  22   Translator_group * last = 0;
  23
  24   /*
  25     Cut & Paste from Change_iterator (ugh).
  26
  27     TODO: abstract this function
  28    */
  29
  30   /* find the type  of translator that we're changing.
  31
  32      If \translator Staff = bass, then look for Staff = *
  33    */
  34   while (current && current->type_str_ != to_type)
  35     {
  36       last = current;
  37       current = current->daddy_trans_l_;
  38     }
  39
  40   if (current && current->id_str_ == to_id)
  41     {
  42       String msg;
  43       msg += _ ("Can't switch translators, I'm there already");
  44     }
  45
  46   if (current)
  47     if (last)
  48       {
  49         Translator_group * dest =
  50           it->report_to_l ()->find_create_translator_l (to_type, to_id);
  51         current->remove_translator_p (last);
  52         dest->add_group_translator (last);
  53       }
  54     else
  55       {
  56         /*
  57           We could change the current translator's id, but that would make
  58           errors hard to catch
  59
  60            last->translator_id_str_  = change_l ()->change_to_id_str_;
  61         */
  62         //      error (_ ("I'm one myself"));
  63       }
  64   else
  65     ; //    error (_ ("none of these in my family"));
  66
  67 }
  68
  69 /*
  70   Look ahead to find first pitches to determine staff position.
  71   WARNING: this means that
  72
  73   \autochange Staff \notes { .... \context Staff = otherstaff { .. } .. }
  74
  75   will confuse the autochanger, since it will not notice that the
  76   music for OTHERSTAFF is not his.
  77
  78   PRECONDITION: this->ok () holds.
  79 */
  80 Array<Pitch>
  81 Auto_change_iterator::pending_pitch (Moment m) const
  82 {
  83   Music_iterator * iter = child_iter_p_ ->clone ();
  84   Array<Pitch> ps;
  85   while (1)
  86     {
  87       SCM muses = iter->get_music (m);
  88       for (SCM s = muses; gh_pair_p (s); s=gh_cdr (s))
  89         if (Note_req* nr = dynamic_cast<Note_req*> (unsmob_music (gh_car (s))))
  90           {
  91             ps.push (*unsmob_pitch (nr->get_mus_property ("pitch")));
  92           }
  93
  94       if (ps.size ())
  95         break;
  96
  97       iter->skip (m);
  98       if (!iter->ok ())
  99         break;
 100
 101       m = iter->pending_moment ();
 102     }
 103
 104   delete iter;
 105   return ps;
 106 }
 107
 108 void
 109 Auto_change_iterator::process (Moment m)
 110 {
 111   /*
 112     first we get the pitches, then we do the real work.
 113     Music_wrapper_iterator::process () might process (and throw away)
 114     pitches we need.  */
 115   Array<Pitch> ps = pending_pitch (m);
 116
 117   Music_wrapper_iterator::process (m);
 118   if (ps.size ())
 119     {
 120       Pitch p = ps[0];
 121       Direction s = Direction (sign (p.steps ()));
 122       if (s != where_dir_)
 123         {
 124           where_dir_ = s;
 125           String to_id = (s >= 0) ?  "up" : "down";
 126           String wh = ly_scm2string (music_l ()->get_mus_property ("what"));
 127           change_to (child_iter_p_, wh, to_id);
 128         }
 129     }
 130 }
 131
 132 Auto_change_iterator::Auto_change_iterator ()
 133 {
 134   where_dir_ = CENTER;
 135 }
 136
 137 IMPLEMENT_CTOR_CALLBACK (Auto_change_iterator);