lily/change-iterator.cc

   1 /*
   2   change-iterator.cc -- implement Change_iterator
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "change-iterator.hh"
  10 #include "context.hh"
  11 #include "music.hh"
  12 #include "warn.hh"
  13 #include "input.hh"
  14
  15
  16 void
  17 Change_iterator::error (String reason)
  18 {
  19   String to_type = ly_symbol2string (get_music ()->get_property ("change-to-type"));
  20   String to_id = ly_scm2string (get_music ()->get_property ("change-to-id"));
  21
  22   String warn1 = _f ("can't change `%s' to `%s'", to_type, to_id)
  23     + ": " + reason;
  24
  25   /*
  26     GUHG!
  27    */
  28   String warn2= "Change_iterator::process (): "
  29     + get_outlet ()->context_name () + " = `"
  30     + get_outlet ()->id_string_ + "': ";
  31   warning (warn2);
  32   get_music ()->origin ()->warning (warn1);
  33 }
  34
  35 /*
  36   move to construct_children ?
  37  */
  38 void
  39 Change_iterator::process (Moment m)
  40 {
  41   Context * current = get_outlet ();
  42   Context * last = 0;
  43
  44   SCM to_type = get_music ()->get_property ("change-to-type");
  45   String to_id =  ly_scm2string (get_music ()->get_property ("change-to-id"));
  46
  47
  48   /* find the type  of translator that we're changing.
  49
  50      If \translator Staff = bass, then look for Staff = *
  51    */
  52   while (current && !current->is_alias (to_type))
  53     {
  54       last = current;
  55       current = current->daddy_context_;
  56     }
  57
  58   if (current && current->id_string_ == to_id)
  59     {
  60       String msg;
  61       msg += _ ("Can't switch translators, I'm there already");
  62     }
  63
  64   if (current)
  65     if (last)
  66       {
  67         Context * dest =
  68           get_outlet ()->find_create_context (to_type, to_id, SCM_EOL);
  69         current->remove_context (last);
  70         dest->add_context (last);
  71       }
  72     else
  73       {
  74         /*
  75           We could change the current translator's id, but that would make
  76           errors hard to catch
  77
  78            last->translator_id_string_  = get_change ()->change_to_id_string_;
  79         */
  80         error (_ ("I'm one myself"));
  81       }
  82   else
  83     error (_ ("none of these in my family"));
  84
  85   Simple_music_iterator::process (m);
  86 }
  87
  88
  89
  90 IMPLEMENT_CTOR_CALLBACK (Change_iterator);