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--2005 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "change-iterator.hh"
  10
  11 #include "context.hh"
  12 #include "input.hh"
  13 #include "international.hh"
  14 #include "music.hh"
  15 #include "warn.hh"
  16
  17 void
  18 Change_iterator::error (string reason)
  19 {
  20   string to_type = ly_symbol2string (get_music ()->get_property ("change-to-type"));
  21   string to_id = ly_scm2string (get_music ()->get_property ("change-to-id"));
  22
  23   string warn1 = _f ("cannot change `%s' to `%s'", to_type, to_id)
  24     + ": " + reason;
  25
  26   /*
  27     GUHG!
  28   */
  29   string warn2= "Change_iterator::process (): "
  30     + get_outlet ()->context_name () + " = `"
  31     + get_outlet ()->id_string () + "': ";
  32   warning (warn2);
  33   get_music ()->origin ()->warning (warn1);
  34 }
  35
  36 /*
  37   move to construct_children ?
  38 */
  39 void
  40 Change_iterator::process (Moment m)
  41 {
  42   Context *current = get_outlet ();
  43   Context *last = 0;
  44
  45   SCM to_type = get_music ()->get_property ("change-to-type");
  46   string to_id = ly_scm2string (get_music ()->get_property ("change-to-id"));
  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 += _f ("cannot change, already in translator: %s", to_id);
  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             send_stream_event (last, "ChangeParent", get_music ()->origin (),
  78                                ly_symbol2scm ("context"), dest->self_scm ());
  79           }
  80         else
  81           /* FIXME: constant error message.  */
  82           get_music ()->origin ()->warning (_ ("cannot find context to switch to"));
  83       }
  84     else
  85       {
  86         /* We could change the current translator's id, but that would make
  87            errors hard to catch.
  88
  89            last->translator_id_string () = get_change
  90            ()->change_to_id_string (); */
  91         error (_f ("not changing to same context type: %s", ly_symbol2string (to_type).c_str ()));
  92       }
  93   else
  94     /* FIXME: uncomprehensable message */
  95     error (_ ("none of these in my family"));
  96
  97   Simple_music_iterator::process (m);
  98 }
  99
 100 IMPLEMENT_CTOR_CALLBACK (Change_iterator);