From 6c3355d38e032dd17486fe99f91366ba948152b3 Mon Sep 17 00:00:00 2001
From: Han-Wen Nienhuys <hanwen@xs4all.nl>
Date: Fri, 8 Feb 2008 01:42:33 -0200
Subject: [PATCH] Fix #83 / #297.

Revamp ligature-bracket-engraver: do not inherit from
Ligature_engraver, but create plain brackets.
---
 lily/ligature-bracket-engraver.cc | 86 ++++++++++++++++++++-----------
 1 file changed, 57 insertions(+), 29 deletions(-)

diff --git a/lily/ligature-bracket-engraver.cc b/lily/ligature-bracket-engraver.cc
index 85cd473ecd..9a4374f2ca 100644
--- a/lily/ligature-bracket-engraver.cc
+++ b/lily/ligature-bracket-engraver.cc
@@ -6,6 +6,8 @@
   (c) 2002--2007 Juergen Reuter <reuter@ipd.uka.de>
 */
 
+#include "international.hh"
+
 #include "ligature-engraver.hh"
 #include "note-column.hh"
 #include "tuplet-bracket.hh"
@@ -16,67 +18,93 @@
 
 #include "translator.icc"
 
-/*
- * This engraver marks ligatures of any kind by just printing a
- * horizontal square bracket on top of each ligature.  See class
- * Ligature_engraver for more information on the interaction between
- * this class and its superclass.
- */
-class Ligature_bracket_engraver : public Ligature_engraver
+class Ligature_bracket_engraver : public Engraver
 {
 protected:
-  virtual Spanner *create_ligature_spanner ();
-  virtual void typeset_ligature (Spanner *ligature,
-				 vector<Grob_info> primitives);
+  virtual void process_music ();
+  virtual void stop_translation_timestep ();
   DECLARE_ACKNOWLEDGER (rest);
   DECLARE_ACKNOWLEDGER (note_column);
   DECLARE_TRANSLATOR_LISTENER (ligature);
 public:
   TRANSLATOR_DECLARATIONS (Ligature_bracket_engraver);
+
+private:
+  Drul_array<Stream_event *> events_drul_;
+  Spanner *finished_ligature_;
+  Spanner *ligature_;
+  Stream_event *previous_start_event_;
 };
 
 IMPLEMENT_TRANSLATOR_LISTENER (Ligature_bracket_engraver, ligature);
 void
 Ligature_bracket_engraver::listen_ligature (Stream_event *ev)
 {
-  Ligature_engraver::listen_ligature (ev);
+  Direction d = to_dir (ev->get_property ("span-direction"));
+  ASSIGN_EVENT_ONCE (events_drul_[d], ev);
 }
 
 Ligature_bracket_engraver::Ligature_bracket_engraver ()
 {
-}
-
-Spanner *
-Ligature_bracket_engraver::create_ligature_spanner ()
-{
-  return make_spanner ("LigatureBracket", SCM_EOL);
+  ligature_ = 0;
+  finished_ligature_ = 0;
+  events_drul_[LEFT] = events_drul_[RIGHT] = 0;
+  previous_start_event_ = 0;
 }
 
 void
-Ligature_bracket_engraver::typeset_ligature (Spanner *, vector<Grob_info>)
+Ligature_bracket_engraver::process_music()
 {
-  // no real ligature to typeset; the LigatureBracket just does it
+  if (events_drul_[STOP])
+    {
+      if (!ligature_)
+	{
+	  events_drul_[STOP]->origin ()->warning (_ ("cannot find start of ligature"));
+	  return;
+	}
+
+      finished_ligature_ = ligature_;
+      ligature_ = 0;
+      previous_start_event_ = 0;
+    }
+
+  if (events_drul_[START])
+    {
+      if (ligature_)
+	{
+	  events_drul_[START]->origin ()->warning (_ ("already have a ligature"));
+	  return;
+	}
+
+      previous_start_event_ = events_drul_[START];
+      ligature_ = make_spanner ("LigatureBracket", events_drul_[START]->self_scm ());
+    }
 }
 
 void
 Ligature_bracket_engraver::acknowledge_note_column (Grob_info info)
 {
-  if (current_ligature ())
+  if (ligature_)
     {
-      Tuplet_bracket::add_column (current_ligature (),
-				  dynamic_cast<Item *> (info.grob ()));
-
-      // avoid "junking empty ligature" message by acknowledging dummy
-      // note head
-      Ligature_engraver::acknowledge_note_head (Grob_info ());
+      Tuplet_bracket::add_column (ligature_,
+				  info.item ());
+      add_bound_item (ligature_, info.item());
     }
 }
 
 void
 Ligature_bracket_engraver::acknowledge_rest (Grob_info info)
 {
-  if (current_ligature ())
-    Ligature_engraver::acknowledge_rest (info);
+  acknowledge_note_column(info);
+}
+
+
+void
+Ligature_bracket_engraver::stop_translation_timestep ()
+{
+  events_drul_[LEFT] =  
+    events_drul_[RIGHT] = 0;
+  finished_ligature_ = 0;
 }
 
 ADD_ACKNOWLEDGER (Ligature_bracket_engraver, rest);
@@ -84,6 +112,6 @@ ADD_ACKNOWLEDGER (Ligature_bracket_engraver, note_column);
 
 ADD_TRANSLATOR (Ligature_bracket_engraver,
 		/* doc */ "Handles Ligature_events by engraving Ligature brackets.",
-		/* create */ "TupletBracket",
+		/* create */ "LigatureBracket",
 		/* read */ "",
 		/* write */ "");
-- 
2.39.2