X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fdrum-note-engraver.cc;h=73bec0ed9f83f171ea060e9b74a7295ad4cf1c21;hb=5d84bfad4626892bcffd05adcced53c8a2329047;hp=37cf47a2174e4ad25145110ce4e843e12f912b2e;hpb=59a6d1a06432fc0ca88c3023c646182f389ec1b5;p=lilypond.git

diff --git a/lily/drum-note-engraver.cc b/lily/drum-note-engraver.cc
index 37cf47a217..73bec0ed9f 100644
--- a/lily/drum-note-engraver.cc
+++ b/lily/drum-note-engraver.cc
@@ -18,6 +18,7 @@
 */
 
 #include <cctype>
+using namespace std;
 
 #include "item.hh"
 #include "duration.hh"
@@ -32,8 +33,6 @@
 
 #include "translator.icc"
 
-using std::vector;
-
 class Drum_notes_engraver : public Engraver
 {
   vector<Item *> scripts_;
@@ -44,17 +43,17 @@ public:
 
 protected:
   void process_music ();
-  DECLARE_ACKNOWLEDGER (stem);
-  DECLARE_ACKNOWLEDGER (note_column);
-  DECLARE_TRANSLATOR_LISTENER (note);
+  void acknowledge_stem (Grob_info);
+  void acknowledge_note_column (Grob_info);
+  void listen_note (Stream_event *);
   void stop_translation_timestep ();
 };
 
-Drum_notes_engraver::Drum_notes_engraver ()
+Drum_notes_engraver::Drum_notes_engraver (Context *c)
+  : Engraver (c)
 {
 }
 
-IMPLEMENT_TRANSLATOR_LISTENER (Drum_notes_engraver, note);
 void
 Drum_notes_engraver::listen_note (Stream_event *ev)
 {
@@ -64,12 +63,12 @@ Drum_notes_engraver::listen_note (Stream_event *ev)
 void
 Drum_notes_engraver::process_music ()
 {
-  SCM tab = 0;
+  if (events_.empty ())
+    return;
+
+  SCM tab = get_property ("drumStyleTable");
   for (vsize i = 0; i < events_.size (); i++)
     {
-      if (!tab)
-        tab = get_property ("drumStyleTable");
-
       Stream_event *ev = events_[i];
       Item *note = make_item ("NoteHead", ev->self_scm ());
 
@@ -141,8 +140,14 @@ Drum_notes_engraver::stop_translation_timestep ()
   events_.clear ();
 }
 
-ADD_ACKNOWLEDGER (Drum_notes_engraver, stem);
-ADD_ACKNOWLEDGER (Drum_notes_engraver, note_column);
+
+void
+Drum_notes_engraver::boot ()
+{
+  ADD_LISTENER (Drum_notes_engraver, note);
+  ADD_ACKNOWLEDGER (Drum_notes_engraver, stem);
+  ADD_ACKNOWLEDGER (Drum_notes_engraver, note_column);
+}
 
 ADD_TRANSLATOR (Drum_notes_engraver,
                 /* doc */