Re: Does \balloonText only work inside chords?

[Urs Liska]

Am 18.06.2018 um 11:56 schrieb Urs Liska:
> <... snip discussion of documentation...>
>
> 2) Additionally, it seems that \balloonText only works within chords, 
> which seems sort-of strange to me
>
> Modified from an example in NR 1.7.2:
>
> \version "2.19.80"
>
> \new Voice \with {
>    \consists "Balloon_engraver"
> }
> \relative {
>   \displayMusic { <c' -\balloonText #'(-2 . -2) \markup { "I'm a note head" } >}
>   \displayMusic { c' -\balloonText #'(-2 . -2) \markup { "I'm a note head" }}
> }

After David's comment I wrote a music-function modeled after \footnote:

myBalloon =
#(define-music-function (offset text mus)
   (number-pair? markup? ly:music?)
   (let ((ann (make-music
               'AnnotateOutputEvent
               'X-offset (car offset)
               'Y-offset (cdr offset)
               'text (markup #:line (#:simple text)))))
     (ly:music-set-property! mus 'articulations (list ann))
     mus))

This allows the following expressions:

    <c' \myBalloon #'(2 . -2) "Hey" c''> % annotate the c'' *after* \myBalloon
    c' -\myBalloon #'(2 . -2) "Hey" -!   % this properly annotates the 
articulation

but (as said in my initial post) it is not possible to annotate single 
notes outside of chords:

    \myBalloon #'(2 . -2) "Hey" c'
    % like the "official" c' -\balloonText #'(-2 . -2) \markup { "Hey" }

errors out with:

/home/uliska/software/lilypond/releases/2.19.80/usr/share/lilypond/current/scm/lily.scmBacktrace:
In unknown file:
   ?:  0* [lilypond-main ("/home/uliska/Schreibtisch/unknown.ly")]
In 
/home/uliska/software/lilypond/releases/2.19.80/usr/share/lilypond/current/scm/lily.scm:
1025:  1* (let* ((failed #)) (if (ly:get-option #) (begin #)) ...)
1025:  2* [lilypond-all ("/home/uliska/Schreibtisch/unknown.ly")]
1038:  3  (let* ((failed #) (separate-logs #) (ping-log #) ...) (gc) ...)
1050:  4* [for-each #<procedure #f (x)> 
("/home/uliska/Schreibtisch/unknown.ly")]
In unknown file:
   ?:  5* [#<procedure #f (x)> "/home/uliska/Schreibtisch/unknown.ly"]
In 
/home/uliska/software/lilypond/releases/2.19.80/usr/share/lilypond/current/scm/lily.scm:
1052:  6* (let* (# # #) (if separate-logs #) (if ping-log #) ...)
1063:  7* [lilypond-file #<procedure #f #> 
"/home/uliska/Schreibtisch/unknown.ly"]
1098:  8  [catch ly-file-failed #<procedure #f {()}> #<procedure #f (x . args)>]
In unknown file:
   ?:  9* [#<procedure #f {()}>]
In 
/home/uliska/software/lilypond/releases/2.19.80/usr/share/lilypond/current/scm/lily.scm:
1099: 10* [ly:parse-file "/home/uliska/Schreibtisch/unknown.ly"]
In 
/home/uliska/software/lilypond/releases/2.19.80/usr/share/lilypond/current/ly/init.ly:
  56: 11* (let* ((book-handler #)) (cond (# #) (# #)))
  59: 12  (cond (# #) (# #))
In 
/home/uliska/software/lilypond/releases/2.19.80/usr/share/lilypond/current/scm/lily-library.scm:
    ...
 243: 13  [ly:book-process #<Book> #< Output_def> #< Output_def> "unknown"]
In unknown file:
   ?: 14* [# #]
   ?: 15* [# # #]
   ?: 16* [# # # #]

ERROR: In procedure symbol->string:
ERROR: Wrong type argument in position 1 (expecting symbol): ()
Exited with return code 1.

Any idea what is wrong here?
And would it be useful to turn my function in a proposal? It does seem 
to work like footnotes, and while the chord issue isn't sorted out I 
think this is at a completely different location and independent of such 
a change.

Urs