Updated the measure counter engraver to the new internal workings of lilypond

measureCounterEngraver.ily

+\version "2.15.40"
+
+% All this code was copied and adapted from lilypond's input/regression/scheme-text-spanner.ly
+% The real measure counter engraver was done by David Nalesnik in April 2012
+% 
+#(define my-grob-descriptions '())
+
+#(define my-event-classes (ly:make-context-mod))
+
+defineEventClass =
+#(define-void-function (parser location class parent)
+   (symbol? symbol?)
+   (ly:add-context-mod
+    my-event-classes
+    `(apply
+      ,(lambda (context class parent)
+	 (ly:context-set-property!
+	  context
+	  'EventClasses
+	  (event-class-cons
+	   class
+	   parent
+	   (ly:context-property context 'EventClasses '()))))
+      ,class ,parent)))
+
+\defineEventClass #'measure-counter-event #'span-event
 
 #(define (define-grob-property symbol type? description)
   (if (not (equal? (object-property symbol 'backend-doc) #f))
@@ -15,39 +41,6 @@
     (counter ,integer? "initial number of a measure count")
   ))
 
-#(define-event-class 'measure-counter-event
-   '(measure-counter-event
-     span-event
-     music-event
-     StreamEvent))
-
-#(define measure-counter-types
-   '(
-     (MeasureCounterEvent
-      . ((description . "Used to signal the start and end of a measure counter.")
-         (types . (general-music measure-counter-event span-event event))
-         ))
-     ))
-
-#(set!
-  measure-counter-types
-  (map (lambda (x)
-         (set-object-property! (car x)
-                               'music-description
-                               (cdr (assq 'description (cdr x))))
-         (let ((lst (cdr x)))
-           (set! lst (assoc-set! lst 'name (car x)))
-           (set! lst (assq-remove! lst 'description))
-           (hashq-set! music-name-to-property-table (car x) lst)
-           (cons (car x) lst)))
-       measure-counter-types))
-
-#(set! music-descriptions
-       (append measure-counter-types music-descriptions))
-
-#(set! music-descriptions
-       (sort music-descriptions alist<?))
-
 #(define (add-grob-definition grob-name grob-entry)
    (let* ((meta-entry   (assoc-get 'meta grob-entry))
           (class        (assoc-get 'class meta-entry))
@@ -69,11 +62,11 @@
      (set! meta-entry (assoc-set! meta-entry 'interfaces
                                   ifaces-entry))
      (set! grob-entry (assoc-set! grob-entry 'meta meta-entry))
-     (set! all-grob-descriptions
+     (set! my-grob-descriptions
            (cons (cons grob-name grob-entry)
-                 all-grob-descriptions))))
+                 my-grob-descriptions))))
 
-#(define (measure-counter-stencil grob)
+#(define-public (measure-counter-stencil grob)
   (let* ((elts (ly:grob-object grob 'elements))
          (refp (ly:grob-common-refpoint-of-array grob elts X))
          (col-L (ly:spanner-bound grob LEFT))
@@ -103,6 +96,33 @@
                             text-script-interface
                             font-interface))))))
 
+#(define measure-counter-types
+   '(
+     (MeasureCounterEvent
+      . ((description . "Used to signal the start and end of a measure counter.")
+         (types . (general-music measure-counter-event span-event event))
+         ))
+     ))
+
+#(set!
+  measure-counter-types
+  (map (lambda (x)
+         (set-object-property! (car x)
+                               'music-description
+                               (cdr (assq 'description (cdr x))))
+         (let ((lst (cdr x)))
+           (set! lst (assoc-set! lst 'name (car x)))
+           (set! lst (assq-remove! lst 'description))
+           (hashq-set! music-name-to-property-table (car x) lst)
+           (cons (car x) lst)))
+       measure-counter-types))
+
+#(set! music-descriptions
+       (append measure-counter-types music-descriptions))
+
+#(set! music-descriptions
+       (sort music-descriptions alist<?))
+
 measureCounterEngraver =
 #(lambda (context)
   (let ((span '())
@@ -172,7 +192,8 @@ measureCounterEnd =
 \layout {
   \context {
     \Global
-    \grobdescriptions #all-grob-descriptions
+    \grobdescriptions #my-grob-descriptions
+    #my-event-classes
   }
   \context{
     \Staff