X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fchord-tremolo-engraver.cc;h=9e48a1a4908d5a21bf0c0e59a9242483979f4dd3;hb=5d84bfad4626892bcffd05adcced53c8a2329047;hp=141f7313e45d266c8489137d16c97cff1a411d98;hpb=a6bd229f7fe1dc4a03478e14ccc0c0c66b225061;p=lilypond.git

diff --git a/lily/chord-tremolo-engraver.cc b/lily/chord-tremolo-engraver.cc
index 141f7313e4..9e48a1a490 100644
--- a/lily/chord-tremolo-engraver.cc
+++ b/lily/chord-tremolo-engraver.cc
@@ -1,8 +1,8 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 2000--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
-  		 Erik Sandberg <mandolaerik@gmail.com>
+  Copyright (C) 2000--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
+                 Erik Sandberg <mandolaerik@gmail.com>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -54,44 +54,41 @@ class Chord_tremolo_engraver : public Engraver
 protected:
   Stream_event *repeat_;
 
-  // current direction of beam (first RIGHT, then LEFT)
-  Direction beam_dir_;
-
   Spanner *beam_;
+  // Store the pointer to the previous stem, so we can create a beam if
+  // necessary and end the spanner
+  Grob *previous_stem_;
 
 protected:
   virtual void finalize ();
   void process_music ();
-  DECLARE_TRANSLATOR_LISTENER (tremolo_span);
-  DECLARE_ACKNOWLEDGER (stem);
+  void listen_tremolo_span (Stream_event *);
+  void acknowledge_stem (Grob_info);
 };
 
-Chord_tremolo_engraver::Chord_tremolo_engraver ()
+Chord_tremolo_engraver::Chord_tremolo_engraver (Context *c)
+  : Engraver (c)
 {
   beam_ = 0;
   repeat_ = 0;
-  beam_dir_ = CENTER;
+  previous_stem_ = 0;
 }
 
-IMPLEMENT_TRANSLATOR_LISTENER (Chord_tremolo_engraver, tremolo_span);
 void
 Chord_tremolo_engraver::listen_tremolo_span (Stream_event *ev)
 {
   Direction span_dir = to_dir (ev->get_property ("span-direction"));
   if (span_dir == START)
     {
-      if (ASSIGN_EVENT_ONCE (repeat_, ev))
-	{
-	  beam_dir_ = RIGHT;
-	}
+      ASSIGN_EVENT_ONCE (repeat_, ev);
     }
   else if (span_dir == STOP)
     {
       if (!repeat_)
-	ev->origin ()->warning (_ ("No tremolo to end"));
+        ev->origin ()->warning (_ ("No tremolo to end"));
       repeat_ = 0;
       beam_ = 0;
-      beam_dir_ = CENTER;
+      previous_stem_ = 0;
     }
 }
 
@@ -126,41 +123,58 @@ Chord_tremolo_engraver::acknowledge_stem (Grob_info info)
       int gap_count = min (flags, intlog2 (repeat_count) + 1);
 
       Grob *s = info.grob ();
-      Stem::set_beaming (s, flags, beam_dir_);
+      if (previous_stem_)
+        {
+          // FIXME: We know that the beam has ended only in listen_tremolo_span
+          //        but then it is too late for Spanner_break_forbid_engraver
+          //        to allow a line break... So, as a nasty hack, announce the
+          //        spanner's end after each note except the first. The only
+          //        "drawback" is that for multi-note tremolos a break would
+          //        theoretically be allowed after the second note (but since
+          //        that note is typically not at a barline, I don't think
+          //        anyone will ever notice!)
+          announce_end_grob (beam_, previous_stem_->self_scm ());
+          // Create the whole beam between previous and current note
+          Stem::set_beaming (previous_stem_, flags, RIGHT);
+          Stem::set_beaming (s, flags, LEFT);
+        }
 
       if (Stem::duration_log (s) != 1)
-	beam_->set_property ("gap-count", scm_from_int (gap_count));
-
-      if (beam_dir_ == RIGHT)
-	{
-	  beam_dir_ = LEFT;
-	  announce_end_grob (beam_, s->self_scm ());
-	}
-      
+        beam_->set_property ("gap-count", scm_from_int (gap_count));
+
       if (info.ultimate_event_cause ()->in_event_class ("rhythmic-event"))
-	Beam::add_stem (beam_, s);
+        Beam::add_stem (beam_, s);
       else
-	{
-	  string s = _ ("stem must have Rhythmic structure");
-	  if (info.event_cause ())
-	    info.event_cause ()->origin ()->warning (s);
-	  else
-	    ::warning (s);
-	}
+        {
+          string s = _ ("stem must have Rhythmic structure");
+          if (info.event_cause ())
+            info.event_cause ()->origin ()->warning (s);
+          else
+            ::warning (s);
+        }
+      // Store current grob, so we can possibly end the spanner here (and
+      // reset the beam direction to RIGHT)
+      previous_stem_ = s;
     }
 }
 
-ADD_ACKNOWLEDGER (Chord_tremolo_engraver, stem);
+void
+Chord_tremolo_engraver::boot ()
+{
+  ADD_LISTENER (Chord_tremolo_engraver, tremolo_span);
+  ADD_ACKNOWLEDGER (Chord_tremolo_engraver, stem);
+}
+
 ADD_TRANSLATOR (Chord_tremolo_engraver,
-		/* doc */
-		"Generate beams for tremolo repeats.",
+                /* doc */
+                "Generate beams for tremolo repeats.",
 
-		/* create */
-		"Beam ",
+                /* create */
+                "Beam ",
 
-		/* read */
-		"",
+                /* read */
+                "",
 
-		/* write */
-		""
-		);
+                /* write */
+                ""
+               );