Caches the interior skylines of vertical axis groups and systems.

input/regression/scheme-text-spanner.ly

 \version "2.17.6"
 
 \header {
   texidoc = "Use @code{define-event-class}, scheme engraver methods,
 and grob creation methods to create a fully functional text spanner
 in scheme."
 }
 
 #(define my-grob-descriptions '())
 
@@ skipping 62 matching lines @@
     (outside-staff-priority . 350)
     (right-bound-info . ,ly:line-spanner::calc-right-bound-info)
     (staff-padding . 0.8)
     (stencil . ,ly:line-spanner::print)
     (style . dashed-line)
 
     (meta . ((class . Spanner)
              (interfaces . (font-interface
                             line-interface
                             line-spanner-interface
+                            outside-staff-interface
                             side-position-interface))))))
 
 #(define scheme-event-spanner-types
    '(
      (SchemeTextSpanEvent
       . ((description . "Used to signal where scheme text spanner brackets
 start and stop.")
          (types . (general-music scheme-text-span-event span-event event))
          ))
      ))
@@ skipping 28 matching lines @@
 #(define (set-axis! grob axis)
   (if (not (number? (ly:grob-property grob 'side-axis)))
       (begin
         (set! (ly:grob-property grob 'side-axis) axis)
         (ly:grob-chain-callback
          grob
          (if (eq? axis X)
              ly:side-position-interface::x-aligned-side
              side-position-interface::y-aligned-side)
          (axis-offset-symbol axis)))))
+
+#(define (outside-staff-interface::chain-y-offset-callback grob)
+  (ly:grob-chain-callback
+    grob
+    outside-staff-interface::y-aligned-side
+    (axis-offset-symbol Y)))
 
 schemeTextSpannerEngraver =
 #(lambda (context)
    (let ((span '())
          (finished '())
          (current-event '())
          (event-drul '(() . ())))
      (make-engraver
       (listeners ((scheme-text-span-event engraver event)
                   (if (= START (ly:event-property event 'span-direction))
@@ skipping 14 matching lines @@
                (ly:warning "You're trying to end a scheme text spanner but you haven't started one.")
                (begin (set! finished span)
                       (ly:engraver-announce-end-grob trans finished current-event)
                       (set! span '())
                       (set! current-event '())
                       (set-cdr! event-drul '()))))
        (if (ly:stream-event? (car event-drul))
            (begin (set! current-event (car event-drul))
                   (set! span (ly:engraver-make-grob trans 'SchemeTextSpanner current-event))
                   (set-axis! span Y)
+                  (outside-staff-interface::chain-y-offset-callback span)
                   (set-car! event-drul '()))))
       ((stop-translation-timestep trans)
        (if (and (ly:spanner? span)
                 (null? (ly:spanner-bound span LEFT)))
            (set! (ly:spanner-bound span LEFT)
                  (ly:context-property context 'currentMusicalColumn)))
        (if (ly:spanner? finished)
            (begin
              (if (null? (ly:spanner-bound finished RIGHT))
                  (set! (ly:spanner-bound finished RIGHT)
@@ skipping 33 matching lines @@
 
 \relative c' {
   a4 b\schemeTextSpannerStart c d |
   \repeat unfold 20 { a4 b c d | }
   a4 b c\schemeTextSpannerEnd d |
   \override SchemeTextSpanner.to-barline = ##t
   a4\schemeTextSpannerStart b d c |
   \repeat unfold 20 { a4 b c d | }
   a1\schemeTextSpannerEnd |
 }