Add basic scheme programmable engravers.

[lilypond.git] / lily / engraver.cc

diff --git a/lily/engraver.cc b/lily/engraver.cc
index e9195564d79849deee822a51933b932948a720af..9e6b23118cecef61641807e6b18c6b2312f1b894 100644 (file)
--- a/lily/engraver.cc
+++ b/lily/engraver.cc
@@ -1,9 +1,20 @@
 /*
-  engraver.cc -- implement Engraver
+  This file is part of LilyPond, the GNU music typesetter.
 
-  Sourcefile of GNU LilyPond music type setter
+  Copyright (C) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
-  (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  LilyPond is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  LilyPond is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "engraver.hh"
@@ -59,9 +70,8 @@ Engraver::announce_grob (Grob *e, SCM cause)
 
 
 /*
-  CAUSE is the object (typically a Music object)  that
-  was the reason for making E.
-*/
+  CAUSE is the object (typically a grob or stream-event object) that
+  was the reason for ending E.  */
 void
 Engraver::announce_end_grob (Grob *e, SCM cause)
 {
@@ -106,13 +116,19 @@ LY_DEFINE (ly_set_grob_creation_callback, "ly:set-grob-creation-callback",
 #endif
 
 Grob *
-Engraver::internal_make_grob (SCM symbol, SCM cause, char const *name, char const *file, int line, char const *fun)
+Engraver::internal_make_grob (SCM symbol,
+                             SCM cause,
+                             char const * /* name */,
+                             char const *file,
+                             int line,
+                             char const *fun)
 {
-  (void) file;
-  (void) fun;
-  (void) line;
-  (void) name;
-  
+#ifdef NDEBUG
+  (void)file;
+  (void)line;
+  (void)fun;
+#endif
+
   SCM props = updated_grob_properties (context (), symbol);
 
   Grob *grob = 0;
@@ -158,13 +174,26 @@ Engraver::internal_make_column (SCM x, char const *name,
 }
 
 Spanner *
-Engraver::internal_make_spanner (SCM x, SCM cause, char const *name, char const *file, int line, char const *fun)
+Engraver::internal_make_spanner (SCM x, SCM cause, char const *name,
+                                char const *file, int line, char const *fun)
 {
   Spanner *sp = dynamic_cast<Spanner *> (internal_make_grob (x, cause, name, file, line, fun));
   assert (sp);
   return sp;
 }
 
+Engraver*
+unsmob_engraver (SCM eng)
+{
+  return dynamic_cast<Engraver*> (unsmob_translator (eng));
+}
+
+bool
+ly_is_grob_cause (SCM obj)
+{
+  return unsmob_grob (obj) || unsmob_stream_event (obj);
+}
+
 #include "translator.icc"
 
 ADD_TRANSLATOR (Engraver,
@@ -181,3 +210,4 @@ ADD_TRANSLATOR (Engraver,
                ""
                );
 
+