Re: String number spanner

[Phil Burfitt]

From: "Nick Payne"

> I'm stuck on the last part of getting this working - the part that is 
> eluding me is getting a short vertical line drawn at the RH end of the 
> spanner. According the the Internals reference, UP = 1 and DOWN = -1, and 
> that works fine when I use the return value from the updown function to 
> set TextSpanner.direction in beginStringNum. But when I try to use the 
> value returned from updown in the section of code that is commented out in 
> beginStringNum, I get an error. If I hardcode 1 or -1 instead of updown 
> then the line is drawn as expected.
>
> I also tried the righttext function below to draw the line: no error is 
> indicated but neither is the vertical line drawn.
>
> \version "2.17.6"
>
> #(define (updown grob)
>   (let ((dirn (ly:event-property (event-cause grob) 'direction)))
>     (if (eq? -1 dirn)
>       DOWN
>       UP)))
>
> #(define (righttext grob)
>   (let ((dirn (ly:event-property (event-cause grob) 'direction)))
>     (if (eq? -1 dirn)
>       (markup #:draw-line (cons 0 0.5))
>       (markup #:draw-line (cons 0 -0.5)))))
>
> beginStringNum = #(define-event-function (parser location strng)
>   (number?)
>   #{
>     \tweak bound-details.left.text \markup\bold\teeny\concat
>       { \circle { \finger #(number->string strng) } \char ##x2006 }
>     \tweak font-shape #'upright
>     \tweak direction #updown
>     \tweak bound-details.left.stencil-align-dir-y #CENTER
>     \tweak dash-period #0.8
>     \tweak dash-fraction #0.6
>     \tweak thickness #0.8
>     \tweak bound-details.right.text #righttext
> %    \tweak bound-details.right.text \markup {
> %      \draw-line #(cons 0 (/ updown -2)) }
>     \tweak bound-details.left.padding #0.25
>     \tweak bound-details.right.padding #-1
>     \tweak bound-details.right-broken.padding #0.5
>     \tweak bound-details.left-broken.padding #2
>     \tweak bound-details.left-broken.text ##f
>     \tweak bound-details.right-broken.text ##f
>     \startTextSpan
>   #}
> )
> endStringNum = \stopTextSpan
>
> \relative c {
>   \clef "treble_8"
>   c4_\beginStringNum 5 c c \times 2/3 { c8 c c\endStringNum }
> }


Hi Nick,

Can't help you much with scheme, but this is the function I created for a 
string number spanner...


% use: stringNumberSpanner  #direction (UP/DOWN) #stringnumber #padding

stringNumberSpanner = #(define-music-function (parser location direction 
string padding) (number? number? number?)
 #{
  \once \override Voice.TextSpanner.padding = #padding
  \once \override Voice.TextSpanner.style = #'dashed-line
  \once \override Voice.TextSpanner.dash-period = #0.6
  \once \override Voice.TextSpanner.dash-fraction = #0.2
  \once \override Voice.TextSpanner.bound-details.left.padding = #-0.1
  \once \override Voice.TextSpanner.bound-details.right.padding = #-0.8
  \once \override Voice.TextSpanner.bound-details.left.stencil-align-dir-y 
= #CENTER
  \once \override Voice.TextSpanner.font-encoding = #'latin1
  \once \override Voice.TextSpanner.font-series = #'normal
  \once \override Voice.TextSpanner.font-size = #-2.5
  \once \override Voice.TextSpanner.bound-details.left.text = \markup { 
\override #'(circle-padding . 0.55) \circle \upright $(number->string 
string) }
  \once \override Voice.TextSpanner.bound-details.left-broken.text = 
\markup { \null }
  \once \override Voice.TextSpanner.bound-details.left-broken.padding = #-3
  \once \override Voice.TextSpanner.bound-details.right-broken.text = 
\markup { \null }
  \once \override Voice.TextSpanner.bound-details.right-broken.padding = 
#0.5

  \once \override Voice.TextSpanner.direction = #direction
  \once \override Voice.TextSpanner.bound-details.right.text = \markup { 
\draw-line $(cons 0 ( * -0.45 direction )) }
 #})


As you say...according the the Internals reference, UP = 1 and DOWN = -1, so 
I use that as a multiplier for the right hand end of the spanner to get an 
upward or downward pointing end line. (last line of above code).

HTH.

Phil.