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--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "context.hh"
  10 #include "event.hh"
  11 #include "music-wrapper-iterator.hh"
  12 #include "direction.hh"
  13
  14 class Auto_change_iterator : public Music_wrapper_iterator
  15 {
  16 public:
  17   DECLARE_SCHEME_CALLBACK (constructor, ());
  18
  19   Auto_change_iterator ();
  20
  21 protected:
  22   virtual void do_quit ();
  23   virtual void construct_children ();
  24   virtual void process (Moment);
  25   Array<Pitch> pending_pitch (Moment) const;
  26 private:
  27   SCM split_list_;
  28   Direction where_dir_;
  29   void change_to (Music_iterator *, SCM, String);
  30   Moment start_moment_;
  31
  32   Context_handle up_;
  33   Context_handle down_;
  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->get_parent_context ();
  57     }
  58
  59   if (current && current->id_string () == to_id)
  60     {
  61       String msg;
  62       msg += _f ("can't change, already in translator: %s", to_id);
  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 void
  85 Auto_change_iterator::process (Moment m)
  86 {
  87   Music_wrapper_iterator::process (m);
  88
  89   Moment now = get_outlet ()->now_mom ();
  90   Moment *splitm = 0;
  91
  92   for (; scm_is_pair (split_list_); split_list_ = scm_cdr (split_list_))
  93     {
  94       splitm = unsmob_moment (scm_caar (split_list_));
  95       if ((*splitm + start_moment_) > now)
  96         break;
  97
  98       SCM tag = scm_cdar (split_list_);
  99       Direction d = to_dir (tag);
 100
 101       if (d && d != where_dir_)
 102         {
 103           where_dir_ = d;
 104           String to_id = (d >= 0) ? "up" : "down";
 105           change_to (child_iter_,
 106                      ly_symbol2scm ("Staff"),
 107                      to_id);
 108         }
 109     }
 110 }
 111
 112 Auto_change_iterator::Auto_change_iterator ()
 113 {
 114   where_dir_ = CENTER;
 115   split_list_ = SCM_EOL;
 116 }
 117
 118 void
 119 Auto_change_iterator::construct_children ()
 120 {
 121   split_list_ = get_music ()->get_property ("split-list");
 122   start_moment_ = get_outlet ()->now_mom ();
 123
 124   SCM props = get_outlet ()->get_property ("trebleStaffProperties");
 125   Context *up = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
 126                                                     "up", props);
 127
 128   props = get_outlet ()->get_property ("bassStaffProperties");
 129   Context *down = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
 130                                                       "down", props);
 131
 132   up_.set_context (up);
 133   down_.set_context (down);
 134
 135   Context *voice = up->find_create_context (ly_symbol2scm ("Voice"),
 136                                             "", SCM_EOL);
 137   set_context (voice);
 138   Music_wrapper_iterator::construct_children ();
 139 }
 140
 141 void
 142 Auto_change_iterator::do_quit ()
 143 {
 144   up_.set_context (0);
 145   down_.set_context (0);
 146 }
 147
 148 IMPLEMENT_CTOR_CALLBACK (Auto_change_iterator);