Re: Manual bar number visibility

[Dan Eble]

On Jul 7, 2014, at 06:10 , Thomas Morley <address@hidden> wrote:

> I've still 2.12.3 installed and could do some testing.
> All I can say right now is, that 'visibleBarNumbers is not a valid
> context-property and it wasn't in 2.12.3 as well.

Valid or not, it solved a problem and worked for years.  Is there a way to make 
2.18 let me set this property, or is there another way that I can store and 
retrieve my own score-level information?  I have other functions that are 
producing similar warnings.  A full example follows.

Thanks,
— 
Dan

barNumber =
#(define-music-function (parser location) ()
   (let ((m (make-music 'ApplyContext)))

     (define (force-bar-number ctx)
       (let* ((barnum-table (ly:context-property ctx 'visibleBarNumbers)))

         (if (not (hash-table? barnum-table)) ; first use in this score?
             (begin
               ; create the set of visible bar numbers
               (set! barnum-table (make-hash-table 16))
               (ly:context-set-property! ctx 'visibleBarNumbers barnum-table)))

         (let* ((barnum (ly:context-property ctx 'currentBarNumber))
                (measurePos (ly:context-property ctx 'measurePosition))
                (measureLen (ly:context-property ctx 'measureLength))
                (mid-measure (and (ly:moment<? ZERO-MOMENT measurePos)
                                  (ly:moment<? measurePos measureLen))))
           (if mid-measure
               (set! barnum (1+ barnum)))

           (hash-set! barnum-table barnum #t)
           )))

     (set! (ly:music-property m 'procedure) force-bar-number)

     (context-spec-music m 'Score)))

manualBarNumbersOn =
#(define-music-function (parser location) ()
   (define (set-properties ctx)
     (let ()

       ; this special formatter is necessary for string->number to
       ; work in the visibility callback below
       (define (bar-number-formatter barnum measure-pos alt-number ctx)
         (number->string barnum))

       (define (bar-number-break-visibility-callback grob)
         (let ((barnum-table (ly:context-property ctx 'visibleBarNumbers))
               (barnum (string->number (ly:grob-property grob 'text))))
           (if (and (hash-table? barnum-table)
                    (hash-ref barnum-table barnum))
               end-of-line-invisible
               begin-of-line-visible
               )))

       (ly:context-set-property! ctx 'barNumberFormatter bar-number-formatter)
       (ly:context-pushpop-property ctx 'BarNumber 'break-visibility
                                    bar-number-break-visibility-callback)
       ))

   (context-spec-music (make-apply-context set-properties) 'Score))

% Encourage a line break in the music.
% This is intended to mark the end of a line of lyrics.
meterBreak =
{
 \overrideProperty "Timing.NonMusicalPaperColumn" #'line-break-penalty #-1 % 
2.16.1
%  \overrideProperty Timing.NonMusicalPaperColumn.line-break-penalty #-1 % 
2.18.2
  \bar ""
  \barNumber
}

% 2.12.3 prints bar numbers 5, 8, and 12 without complaint.
%
% 2.16.1 prints bar numbers 5, 8, and 12 and complains
%     warning: cannot find property type-check for `visibleBarNumbers'
%              (translation-type?).  perhaps a typing error?
%     warning: doing assignment anyway
%
% 2.18.2 does not print any bar numbers and complains
%     warning: cannot find property type-check for `visibleBarNumbers'
%              (translation-type?).  perhaps a typing error?
%     warning: skipping assignment

\new Staff {
  \manualBarNumbersOn
  \relative d' {
    \time 3/4
    \partial 4
    d4 | g2 b4 | b2 a4 | g2 e4 | d2 \meterBreak
    d4 | g2 b4 | b2 a4 | d2 \meterBreak
    d4 | d2 b4 | g2 d4 | e2 g4 | d2 \meterBreak
    d4 | g2 b4 | b2 a4 | g2 \bar "|."
  }
}