]> git.donarmstrong.com Git - lilypond.git/blobdiff - lily/time-signature-engraver.cc
*** empty log message ***
[lilypond.git] / lily / time-signature-engraver.cc
index 0e6f874f1f6d5393deff9355a4619ff5c8308446..ff335a0f974827ffc329fcba4eede009a45a81d3 100644 (file)
@@ -1,63 +1,90 @@
 /*
-  time_signature-reg.cc -- implement Time_signature_engraver
+  time-signature-engraver.cc -- implement Time_signature_engraver
 
   source file of the GNU LilyPond music typesetter
 
-  (c)  1997--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c)  1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
 */
 
-#include "time-signature-engraver.hh"
 #include "time-signature.hh"
-#include "command-request.hh"
-#include "timing-engraver.hh"
+#include "warn.hh"
+
+#include "engraver.hh"
 #include "engraver-group-engraver.hh"
+#include "misc.hh"
+
+/**
+  generate time_signatures. 
+  */
+class Time_signature_engraver : public Engraver
+{
+  Item * time_signature_;
+  SCM last_time_fraction_;
+
+protected:
+  virtual void stop_translation_timestep ();
+  virtual void process_music ();
+public:
+  TRANSLATOR_DECLARATIONS(Time_signature_engraver);
+};
 
-Time_signature_engraver::Time_signature_engraver()
+
+Time_signature_engraver::Time_signature_engraver ()
 { 
-  time_signature_p_ =0;
+  time_signature_ =0;
+  last_time_fraction_ = SCM_BOOL_F;
 }
 
 void
-Time_signature_engraver::do_process_requests()
+Time_signature_engraver::process_music ()
 {
-  Translator * result =
-    daddy_grav_l()->get_simple_translator ("Timing_engraver"); // ugh
-
-  if (!result)
+  /*
+    not rigorously safe, since the value might get GC'd and
+    reallocated in the same spot */
+  SCM fr= get_property ("timeSignatureFraction");
+  if (!time_signature_
+      && last_time_fraction_ != fr
+      && gh_pair_p (fr))
     {
-      warning (_ ("lost in time:"));
-      warning (_f ("Can't find: `%s'", " Timing_translator"));
-      return ;
-    }
-  
-  Timing_engraver * timing_grav_l= dynamic_cast<Timing_engraver *> (result);
-  
-  Time_signature_change_req *req = timing_grav_l->time_signature_req_l();
-  if (req)
-    {
-      time_signature_p_ = new Time_signature;
-      time_signature_p_->set_elt_property ("fraction",
-                                          gh_cons (gh_int2scm (req->beats_i_),
-                                                   gh_int2scm (req->one_beat_i_))); 
-      time_signature_p_->set_elt_property ("break-aligned", SCM_BOOL_T);
-    }
+      int den = gh_scm2int (gh_cdr (fr));
+      if (den != (1 << intlog2 (den)))
+       {
+         /*
+           Todo: should make typecheck?
 
+           OTOH, Tristan Keuris writes 8/20 in his Intermezzi.
+          */
+         warning (_f("Found strange time signature %d/%d.",
+                     den,
+                     gh_scm2int (gh_car (fr))
+                     ));
+       }
   
-  if (time_signature_p_)
-    announce_element (Score_element_info (time_signature_p_, req));
+      
+      last_time_fraction_ = fr; 
+      time_signature_ = new Item (get_property ("TimeSignature"));
+      time_signature_->set_grob_property ("fraction",fr);
+
+      if (time_signature_)
+       announce_grob(time_signature_, SCM_EOL);
+    }
 }
 
 void
-Time_signature_engraver::do_pre_move_processing()
+Time_signature_engraver::stop_translation_timestep ()
 {
-  if (time_signature_p_
+  if (time_signature_) 
     {
-      typeset_element (time_signature_p_);
-      time_signature_p_ =0;
+      typeset_grob (time_signature_);
+      time_signature_ =0;
     }
 }
-
-
-ADD_THIS_TRANSLATOR(Time_signature_engraver);
  
 
+ENTER_DESCRIPTION(Time_signature_engraver,
+/* descr */       "Create a TimeSignature whenever @code{timeSignatureFraction} changes",
+/* creats*/       "TimeSignature",
+/* accepts */     "",
+/* acks  */      "",
+/* reads */       "",
+/* write */       "");