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->get_parent_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 = 0;
  68         Context * where = get_outlet ();
  69         while (!dest && where)
  70           {
  71             dest = find_context_below (where, to_type, to_id);
  72             where = where->get_parent_context ();
  73           }
  74
  75         if (dest)
  76           {
  77             current->remove_context (last);
  78             dest->add_context (last);
  79           }
  80         else
  81           {
  82             get_music ()->origin ()->warning  ("could not find context to switch to.");
  83           }
  84       }
  85     else
  86       {
  87         /*
  88           We could change the current translator's id, but that would make
  89           errors hard to catch
  90
  91            last->translator_id_string ()  = get_change ()->change_to_id_string ();
  92         */
  93         error (_ ("I'm one myself"));
  94       }
  95   else
  96     error (_ ("none of these in my family"));
  97
  98   Simple_music_iterator::process (m);
  99 }
 100
 101
 102
 103 IMPLEMENT_CTOR_CALLBACK (Change_iterator);