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--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "music.hh"
  11 #include "context.hh"
  12 #include "event.hh"
  13 #include "music-wrapper-iterator.hh"
  14 #include "direction.hh"
  15
  16 class Auto_change_iterator : public Music_wrapper_iterator
  17 {
  18 public:
  19   DECLARE_SCHEME_CALLBACK (constructor, ());
  20
  21   Auto_change_iterator ();
  22
  23 protected:
  24   virtual void construct_children ();
  25   virtual void process (Moment);
  26   Array<Pitch> pending_pitch (Moment)const;
  27 private:
  28   SCM split_list_;
  29   Direction where_dir_;
  30   void change_to (Music_iterator* , SCM, String);
  31   Moment start_moment_;
  32 };
  33
  34
  35
  36 void
  37 Auto_change_iterator::change_to (Music_iterator *it, SCM to_type_sym,
  38                                  String to_id)
  39 {
  40   Context * current = it->get_outlet ();
  41   Context * last = 0;
  42
  43   /*
  44     Cut & Paste from Change_iterator (ugh).
  45
  46     TODO: abstract this function
  47    */
  48
  49   /* find the type  of translator that we're changing.
  50
  51      If \translator Staff = bass, then look for Staff = *
  52    */
  53   while (current && !current->is_alias (to_type_sym))
  54     {
  55       last = current;
  56       current = current->daddy_context_;
  57     }
  58
  59   if (current && current->id_string_ == to_id)
  60     {
  61       String msg;
  62       msg += _ ("Can't switch translators, I'm there already");
  63     }
  64
  65   if (current)
  66     if (last)
  67       {
  68         Context * dest =
  69           it->get_outlet ()->find_create_context (to_type_sym, to_id, SCM_EOL);
  70         current->remove_context (last);
  71         dest->add_context (last);
  72       }
  73     else
  74       {
  75         /*
  76           We could change the current translator's id, but that would make
  77           errors hard to catch
  78
  79         */
  80       }
  81   else
  82     ;
  83
  84 }
  85
  86 void
  87 Auto_change_iterator::process (Moment m)
  88 {
  89   Music_wrapper_iterator::process (m);
  90
  91   Moment now = get_outlet ()->now_mom ();
  92   Moment *splitm = 0;
  93
  94   for (; ly_pair_p (split_list_); split_list_ = ly_cdr (split_list_))
  95     {
  96       splitm = unsmob_moment (ly_caar (split_list_));
  97       if ((*splitm + start_moment_) > now)
  98         break ;
  99
 100       SCM tag = ly_cdar (split_list_);
 101       Direction d = to_dir  (tag);
 102
 103       if (d && d != where_dir_)
 104         {
 105           where_dir_ = d;
 106           String to_id = (d >= 0) ?  "up" : "down";
 107           change_to (child_iter_,
 108                      ly_symbol2scm ("Staff"),
 109                      to_id);
 110         }
 111     }
 112 }
 113
 114 Auto_change_iterator::Auto_change_iterator ()
 115 {
 116   where_dir_ = CENTER;
 117   split_list_ = SCM_EOL;
 118 }
 119
 120 void
 121 Auto_change_iterator::construct_children ()
 122 {
 123   Music_wrapper_iterator::construct_children ();
 124   split_list_ =  get_music ()->get_property ("split-list");
 125   start_moment_ = get_outlet ()->now_mom ();
 126 }
 127
 128 IMPLEMENT_CTOR_CALLBACK (Auto_change_iterator);