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@xs4all.nl>
   7 */
   8
   9 #include "context.hh"
  10 #include "direction.hh"
  11 #include "international.hh"
  12 #include "music.hh"
  13 #include "music-wrapper-iterator.hh"
  14
  15 class Auto_change_iterator : public Music_wrapper_iterator
  16 {
  17 public:
  18   DECLARE_SCHEME_CALLBACK (constructor, ());
  19
  20   Auto_change_iterator ();
  21
  22 protected:
  23   virtual void do_quit ();
  24   virtual void construct_children ();
  25   virtual void process (Moment);
  26   vector<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   Context_handle up_;
  34   Context_handle down_;
  35 };
  36
  37 void
  38 Auto_change_iterator::change_to (Music_iterator *it, SCM to_type_sym,
  39                                  string to_id)
  40 {
  41   Context *current = it->get_outlet ();
  42   Context *last = 0;
  43
  44   /*
  45     Cut & Paste from Change_iterator (ugh).
  46
  47     TODO: abstract this function
  48   */
  49
  50   /* find the type  of translator that we're changing.
  51
  52   If \translator Staff = bass, then look for Staff = *
  53   */
  54   while (current && !current->is_alias (to_type_sym))
  55     {
  56       last = current;
  57       current = current->get_parent_context ();
  58     }
  59
  60   if (current && current->id_string () == to_id)
  61     {
  62       string msg;
  63       msg += _f ("cannot change, already in translator: %s", to_id);
  64     }
  65
  66   if (current)
  67     {
  68       if (last)
  69         {
  70           Context *dest
  71             = it->get_outlet ()->find_create_context (to_type_sym, to_id, SCM_EOL);
  72
  73           send_stream_event (last, "ChangeParent", get_music ()->origin (),
  74                                ly_symbol2scm ("context"), dest->self_scm ());
  75         }
  76       else
  77         {
  78           /*
  79             We could change the current translator's id, but that would make
  80             errors hard to catch
  81
  82           */
  83           ;
  84         }
  85     }
  86 }
  87
  88 void
  89 Auto_change_iterator::process (Moment m)
  90 {
  91   Music_wrapper_iterator::process (m);
  92
  93   Moment now = get_outlet ()->now_mom ();
  94   Moment *splitm = 0;
  95   if (start_moment_.main_part_.is_infinity () && start_moment_ < 0)
  96     start_moment_ = now;
  97
  98   for (; scm_is_pair (split_list_); split_list_ = scm_cdr (split_list_))
  99     {
 100       splitm = unsmob_moment (scm_caar (split_list_));
 101       if ((*splitm + start_moment_) > now)
 102         break;
 103
 104       SCM tag = scm_cdar (split_list_);
 105       Direction d = to_dir (tag);
 106
 107       if (d && d != where_dir_)
 108         {
 109           where_dir_ = d;
 110           string to_id = (d >= 0) ? "up" : "down";
 111           change_to (child_iter_,
 112                      ly_symbol2scm ("Staff"),
 113                      to_id);
 114         }
 115     }
 116 }
 117
 118 Auto_change_iterator::Auto_change_iterator ()
 119 {
 120   where_dir_ = CENTER;
 121   split_list_ = SCM_EOL;
 122 }
 123
 124 void
 125 Auto_change_iterator::construct_children ()
 126 {
 127   split_list_ = get_music ()->get_property ("split-list");
 128   start_moment_ = get_outlet ()->now_mom ();
 129
 130   SCM props = get_outlet ()->get_property ("trebleStaffProperties");
 131   Context *up = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
 132                                                     "up", props);
 133
 134   props = get_outlet ()->get_property ("bassStaffProperties");
 135   Context *down = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
 136                                                       "down", props);
 137
 138   up_.set_context (up);
 139   down_.set_context (down);
 140
 141   Context *voice = up->find_create_context (ly_symbol2scm ("Voice"),
 142                                             "", SCM_EOL);
 143   set_context (voice);
 144   Music_wrapper_iterator::construct_children ();
 145 }
 146
 147 void
 148 Auto_change_iterator::do_quit ()
 149 {
 150   up_.set_context (0);
 151   down_.set_context (0);
 152 }
 153
 154 IMPLEMENT_CTOR_CALLBACK (Auto_change_iterator);