* configure.in: check for C language.

[lilypond.git] / lily / note-head-line-engraver.cc

diff --git a/lily/note-head-line-engraver.cc b/lily/note-head-line-engraver.cc
index 3f7d9d3f53b71c5d1d60487b208e1abf1d19ceca..fee6c1e63c9c6fb4a30217b0945140519fa85e90 100644 (file)
--- a/lily/note-head-line-engraver.cc
+++ b/lily/note-head-line-engraver.cc
@@ -3,94 +3,98 @@
   
   source file of the GNU LilyPond music typesetter
   
-  (c) 2000 Jan Nieuwenhuizen <janneke@gnu.org>
+  (c) 2000--2004 Jan Nieuwenhuizen <janneke@gnu.org>
  */
 
 #include "engraver.hh"
 #include "group-interface.hh"
 #include "item.hh"
-#include "musical-request.hh"
+#include "event.hh"
 #include "spanner.hh"
+#include "stem.hh"
 #include "rhythmic-head.hh"
 #include "side-position-interface.hh"
 #include "staff-symbol-referencer.hh"
-#include "protected-scm.hh"
+#include "context.hh"
+
 
 /**
-   Create line-spanner grobs for glissandi (and possibly other) lines
-   that connect note heads.
- */
+   Create line-spanner grobs for lines that connect note heads.
 
+   TODO: have the line commit suicide if the notes are connected with
+   either slur or beam.
+
+*/
 class Note_head_line_engraver : public Engraver
 {
 public:
-  VIRTUAL_COPY_CONS (Translator);
-  Note_head_line_engraver ();
+  TRANSLATOR_DECLARATIONS (Note_head_line_engraver);
 
 protected:
   virtual void acknowledge_grob (Grob_info);
-  virtual void create_grobs ();
+  virtual void process_acknowledged_grobs ();
   virtual void stop_translation_timestep ();
-  virtual bool try_music (Music *);
 
 private:
   Spanner* line_; 
-  Request* req_;
-  Protected_scm heads_;
+  Context* last_staff_;
+  bool follow_;
+  Grob* head_;
+  Grob* last_head_;
 };
 
 Note_head_line_engraver::Note_head_line_engraver ()
 {
   line_ = 0;
-  req_ = 0;
-  heads_ = SCM_EOL;
-}
-
-bool
-Note_head_line_engraver::try_music (Music* m)
-{
-  if (!req_)
-    {
-      if (Glissando_req *r = dynamic_cast<Glissando_req*> (m))
-       {
-         req_ = r;
-         return true;
-       }
-    }
-  return false;
+  follow_ = false;
+  head_ = 0;
+  last_head_ = 0;
+  last_staff_ = 0;
 }
 
 void
 Note_head_line_engraver::acknowledge_grob (Grob_info info)
 {
-  if (req_)
+  if (Rhythmic_head::has_interface (info.grob_))
     {
-      if (Rhythmic_head::has_interface (info.elem_l_))
+      head_ = info.grob_;
+      if (to_boolean (get_property ("followVoice")))
        {
-         heads_ = gh_cons (info.elem_l_->self_scm (), heads_);
+         Context * tr = daddy_context_;
+         while (tr && !tr->is_alias (ly_symbol2scm ( "Staff")))
+           tr = tr->daddy_context_ ;
+
+         if (tr
+             && tr->is_alias (ly_symbol2scm ("Staff")) && tr != last_staff_)
+           {
+             if (last_head_)
+               follow_ = true;
+             last_staff_ = tr;
+           }
        }
     }
 }
 
+
 void
-Note_head_line_engraver::create_grobs ()
+Note_head_line_engraver::process_acknowledged_grobs ()
 {
-  if (!line_ && scm_ilength (heads_) > 1)
+  if (!line_ && follow_ && last_head_ && head_)
     {
-      /* type Glissando? */
-      line_ = new Spanner (get_property ("NoteHeadLine"));
-      line_->set_bound (LEFT, unsmob_grob (gh_car (heads_)));
-      line_->set_bound (RIGHT, unsmob_grob (ly_last (heads_)));
-
-      line_->set_parent (unsmob_grob (gh_car (heads_)), X_AXIS);
-      line_->set_parent (unsmob_grob (gh_car (heads_)), Y_AXIS);
-
-      line_->set_parent (unsmob_grob (ly_last (heads_)), X_AXIS);
-      line_->set_parent (unsmob_grob (ly_last (heads_)), Y_AXIS);
-
-      announce_grob (line_, req_);
-      req_ = 0;
-      heads_ = SCM_EOL;
+      /* TODO: Don't follow if there's a beam.
+
+        We can't do beam-stuff here, since beam doesn't exist yet.
+        Should probably store follow_ in line_, and suicide at some
+        later point */
+      if (follow_)
+       line_ = make_spanner ("VoiceFollower");
+         
+      line_->set_bound (LEFT, last_head_);
+      line_->set_bound (RIGHT, head_);
+      
+      announce_grob (line_, head_->self_scm ());
+
+      follow_ = false;
     }
 }
 
@@ -102,8 +106,19 @@ Note_head_line_engraver::stop_translation_timestep ()
       typeset_grob (line_);
       line_ = 0;
     }
+  if (head_)
+    last_head_ = head_;
+  head_ = 0;
 }
 
 
-ADD_THIS_TRANSLATOR (Note_head_line_engraver);
 
+
+ENTER_DESCRIPTION (Note_head_line_engraver,
+/* descr */       "Engrave a line between two note heads, for example a glissando.  If "
+" followVoice is set, staff switches also generate a line.",
+/* creats*/       "Glissando VoiceFollower",
+/* accepts */     "glissando-event",
+/* acks  */       "rhythmic-head-interface",
+/* reads */       "followVoice",
+/* write */       "");