Re: TimeSignature Event

[Jan-Peter Voigt]

Thank you Neil,

now I created the following time-signature engraver:
--snip--
\version "2.14.2"

#(define-public orff (lambda (context)
          (let ((time-signature '())
                (last-fraction #f))

               `((process-music
                  . ,(lambda (trans)
                          (let ((frac (ly:context-property context 
'timeSignatureFraction)))
                               (if (and (null? time-signature)
                                        (not (equal? last-fraction frac))
                                        (pair? frac))
                                   (begin
                                     (set! time-signature 
(ly:engraver-make-grob trans 'TimeSignature '()))
                                     (set! (ly:grob-property 
time-signature 'fraction) frac)
                                     (set! (ly:grob-property 
time-signature 'stencil) ly:text-interface::print)
                                     (set! (ly:grob-property 
time-signature 'text)
                                           (markup #:translate '(0 . 2) 
#:concat (
                                               #:bold (format "~a " 
(car frac))
                                               #:translate '(-2 . -2) 
#:draw-line '(3 . 3)
                                               #:translate '(-2 . -3.5) 
#:smaller #:smaller #:note (format "~a" (cdr frac)) UP)
                                     ))

                                     (and (not last-fraction)
                                          (set! (ly:grob-property 
time-signature 'break-visibility)
                                                (ly:context-property 
context 'implicitTimeSignatureVisibility)))

                                     (set! last-fraction frac))))))

                (stop-translation-timestep
                  . ,(lambda (trans)
                          (set! time-signature '()))))
)))

meta = {
  \key bes \major \time 3/4 s2.*2
  \key a \minor \time 5/8 s8*5
  \key bes \major \time 3/4 s2.*2
}

mel = \relative c'' {
  a8 bes c d c d | a bes c d c d | a c d c d | ees d c bes a bes | ees 
d c bes a bes |
}

\score {
  \new StaffGroup <<
    \new Dynamics \with {
      \consists \orff
      \override TimeSignature #'extra-offset = #'(-1 . 0)
    } { \meta }
    \new Staff \with {
      \remove "Time_signature_engraver"
    } <<
      \meta
      \new Voice = "mel" { \mel } >> >> % e-mail-compatible line breaks ;-)
}
--snip--

I will optimize and use overrides for this engraver - the markup is a 
first shot. If I have time and/or a need, I will look for another 
context than Dynamics.

Cheers,
Jan-Peter

Am 13.08.2011 16:31, schrieb Neil Puttock:
> On 13 August 2011 10:27, Jan-Peter Voigt<address@hidden>  wrote:
>
> > So my question is: How do I catch the right event and get the time sig probs to 
> > display?
> There's no event* for time signatures; they're generated when certain
> context properties change.
>
> See the scheme engraver I posted here for an idea:
>
> http://lists.gnu.org/archive/html/lilypond-user/2011-05/msg00468.html
>
> * there is a music object (TimeSignatureMusic), but that's only used
> for iteration so the relevant settings are accessible by
> \displayLilyMusic
>
> Cheers,
> Neil