Re: "Text spanner"-ish thing with text in the middle

[Ben]

On 10/28/2017 1:43 AM, Andrew Bernard wrote:

Hi James,

This comes up so frequently it puzzles me why it is not considered for
addition to the lilypond baseline.

Here's my function.

Andrew


=== snip
\version "2.19.39"

% Annotation bracket with centred text.
% Andrew Bernard and Thomas Morley

TextSpannerCentredText =
#(define-music-function (text extra-length) (string? pair?)
   "Use TextSpanner semantics to create spanner brackets with centred text"
   #{
     \once \override TextSpanner.after-line-breaking =
     #(lambda (grob)
        (let* (
                ;; get stencil of grob
                (stil (ly:grob-property grob 'stencil))
                ;; get spanner length
                (spanner-len (interval-length (ly:stencil-extent stil X)))
                ;; make stencil from text arg
                (text-stil (grob-interpret-markup grob
                             (markup #:sans #:upright text)))
                ;; get text length
                (text-len (interval-length (ly:stencil-extent text-stil
X))))
     ...................................etc........................

Andrew,

Thank you so much for sharing this function. It will come in handy for a project I'll be working on shortly.
However, I had one question for you.
I just went to try to use the function 'as is' and I'm seeing an error. I cannot use the function at the moment.
Do you know what this means, and how I can fix it?
(I just simply copied and pasted it into Frescobaldi and attempted to use it - no tweaks)

Thanks!

    Drawing systems...
    line:31 32:15: In procedure memoization in _expression_ (let* (# # # ...) (ly:grob-set-property! grob # ...))
    Bad binding parts in _expression_ (let* ((dir (ly:grob-property grob (quote direction))) (padding 1) (thickness 0.25) (left-ext (car extra-length)) (right-ext (cdr extra-length)) (path-part-len (/ (- spanner-len text-len) 2)) (path-left-part-stil (make-path-stencil (quasiquote         (moveto (unquote #) (unquote #) lineto (unquote #) 0 lineto (unquote path-part-len) 0)) thickness 1 1 #f)) (path-right-part-stil (make-path-stencil (quasiquote (moveto (unquote #) (unquote #) lineto (unquote #) 0 lineto 0 0)) thickness 1 1 #f)) parts (full-stil (stack-            stencils X RIGHT padding (list path-left-part-stil (centered-stencil text-stil) path-right-part-stil)))) (ly:grob-set-property! grob (quote stencil) full-stil)).......etc.............