X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Ftime-signature-engraver.cc;h=5dc4913a80de7d10b1b1e176369d3a96aa5f8490;hb=34e6d3d79f3b5fc6188a20f9a2a5c0d34b2c81c8;hp=f485c22afd329a87d2d2a6293ddb1be8565ea322;hpb=fbb6d20e9f58d691ffe845284cbb4d8bacf9ca60;p=lilypond.git

diff --git a/lily/time-signature-engraver.cc b/lily/time-signature-engraver.cc
index f485c22afd..5dc4913a80 100644
--- a/lily/time-signature-engraver.cc
+++ b/lily/time-signature-engraver.cc
@@ -1,63 +1,77 @@
 /*
-  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--2005 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-group-engraver.hh"
+#include "misc.hh"
 
-Time_signature_engraver::Time_signature_engraver()
-{ 
-  time_signature_p_ =0;
-}
-
-void
-Time_signature_engraver::do_process_music()
+/**
+   generate time_signatures.
+*/
+class Time_signature_engraver : public Engraver
 {
-  Translator * result =
-    daddy_grav_l()->get_simple_translator ("Timing_engraver");	// ugh
+  Item *time_signature_;
+  SCM last_time_fraction_;
 
-  if (!result)
-    {
-      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);
-    }
+protected:
+  virtual void stop_translation_timestep ();
+  virtual void process_music ();
+public:
+  TRANSLATOR_DECLARATIONS (Time_signature_engraver);
+};
 
-  
-  if (time_signature_p_)
-    announce_element (Score_element_info (time_signature_p_, req));
+Time_signature_engraver::Time_signature_engraver ()
+{
+  time_signature_ = 0;
+  last_time_fraction_ = SCM_BOOL_F;
 }
 
 void
-Time_signature_engraver::do_pre_move_processing()
+Time_signature_engraver::process_music ()
 {
-  if (time_signature_p_) 
+  /*
+    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
+      && scm_is_pair (fr))
     {
-      typeset_element (time_signature_p_);
-      time_signature_p_ =0;
+      int den = scm_to_int (scm_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,
+		       scm_to_int (scm_car (fr))));
+	}
+
+      last_time_fraction_ = fr;
+      time_signature_ = make_item ("TimeSignature", SCM_EOL);
+      time_signature_->set_property ("fraction", fr);
     }
 }
 
+void
+Time_signature_engraver::stop_translation_timestep ()
+{
+  time_signature_ = 0;
+}
 
-ADD_THIS_TRANSLATOR(Time_signature_engraver);
- 
-
+ADD_TRANSLATOR (Time_signature_engraver,
+		/* descr */ "Create a TimeSignature whenever @code{timeSignatureFraction} changes",
+		/* creats*/ "TimeSignature",
+		/* accepts */ "",
+		/* acks  */ "",
+		/* reads */ "",
+		/* write */ "");