release: 1.3.90

[lilypond.git] / lily / auto-change-iterator.cc

diff --git a/lily/auto-change-iterator.cc b/lily/auto-change-iterator.cc
index cd4a350c85267b0d02cccd0afa940ce8417c2d43..cf291348c0695d8c6ea984aa44d0a01dee467c7e 100644 (file)
--- a/lily/auto-change-iterator.cc
+++ b/lily/auto-change-iterator.cc
@@ -66,21 +66,58 @@ Auto_change_iterator::change_to (Music_iterator *it, String to_type,
 
 }
 
-Pitch_interrogate_req* spanish_inquisition; // nobody expects it
+/*
+  Look ahead to find first pitches to determine staff position.
+  WARNING: this means that
 
-void
-Auto_change_iterator::process (Moment m)
+  \autochange Staff \notes { .... \context Staff = otherstaff { .. } .. }
+
+  will confuse the autochanger, since it will not notice that the
+  music for OTHERSTAFF is not his.
+
+  PRECONDITION: this->ok() holds.
+*/
+Array<Musical_pitch>
+Auto_change_iterator::pending_pitch (Moment m) const
 {
-  Music_wrapper_iterator::process (m);
+  Music_iterator * iter = child_iter_p_ ->clone ();
+  Array<Musical_pitch> ps;
+  while (1)
+    {
+      SCM muses = iter->get_music (m);
+      for (SCM s = muses; gh_pair_p (s); s=gh_cdr (s))
+       if (Note_req* nr = dynamic_cast<Note_req*> (unsmob_music (gh_car (s))))
+         {
+           ps.push (nr->pitch_);
+         }
+
+      if (ps.size ())
+       break;
+
+      iter->skip (m);
+      if (!iter->ok())
+       break;
+      
+      m = iter->pending_moment ();
+    }
 
-  if (!spanish_inquisition)
-    spanish_inquisition = new Pitch_interrogate_req;
+  delete iter;
+  return ps;
+}
 
-  Music_iterator *it = try_music (spanish_inquisition);
+void
+Auto_change_iterator::process (Moment m)
+{
+  /*
+    first we get the pitches, then we do the real work.
+    Music_wrapper_iterator::process() might process (and throw away)
+    pitches we need.  */
+  Array<Musical_pitch> ps = pending_pitch (m);
 
-  if (it && spanish_inquisition->pitch_arr_.size ())
+  Music_wrapper_iterator::process (m);
+  if (ps.size ())
     {
-      Musical_pitch p = spanish_inquisition->pitch_arr_[0];
+      Musical_pitch p = ps[0];
       Direction s = Direction (sign(p.steps ()));
       if (s != where_dir_)
        {
@@ -88,11 +125,9 @@ Auto_change_iterator::process (Moment m)
          String to_id =  (s >= 0) ?  "up" : "down";
          Auto_change_music const * auto_mus = dynamic_cast<Auto_change_music const* > (music_l_);
 
-         change_to (it, auto_mus->what_str_, to_id);     
+         change_to (child_iter_p_, auto_mus->what_str_, to_id);          
        }
     }
-
-  spanish_inquisition->pitch_arr_.clear ();
 }
 
 Auto_change_iterator::Auto_change_iterator( )