Re: Display Question Mark at center of a measure

[Lukas-Fabian Moser]

Hi Rajesh,

Am 14.01.22 um 01:44 schrieb Rajesh Baskar:
> I'm tying to display a question mark at the center of the 1st measure 
> in a 2 measure score.
>
> I have got this working with hard-coding the offset (3 . 4.5) but this 
> will not work when the number of notes in a measure is larger than 3. 
> Is there a way to get this to work dynamically where the question mark 
> moves to the center of the measure irrespective of the length of a 
> measure.

Please try to remove everything in your examples not actually related to 
the problem at hand (here, for example, everything having to do with 
MIDI, proportional notation, boxed measure counters etc.).

What comes to mind is that your question mark is exactly in the position 
where you would normally expect a whole bar rest. So how about:

\version "2.22.0"

#(define (center-stencil stil)
   (ly:stencil-aligned-to
    (ly:stencil-aligned-to stil X CENTER)
    Y CENTER))

questionMarkMultiMeasureRest = {
  \override MultiMeasureRest.stencil =
  #(grob-transformer
    'stencil
    (lambda (grob default)
      (ly:stencil-translate-axis
       (center-stencil (ly:text-interface::print grob))
       (interval-center (ly:stencil-extent default X))
       X)))
  \override MultiMeasureRest.text = "?"
  \override MultiMeasureRest.font-size = 7
  \override MultiMeasureRest.color = "#6A00F4"
}

\new Staff {
  \clef bass
  <<
    { \hideNotes b2 c }
    \new Voice {
      \questionMarkMultiMeasureRest
      R1
    }
  >>
  \unHideNotes a2 c'4 g
}

One could of course wrap the simultaenous addition of the tweaked full 
bar rest in a music function.

The reason I'm using such a comparatively complex stencil override is 
that the default positioning of the MultiMeasureRest (which is what we 
want here) is handled in the default stencil; if we overwrite that 
function completely, we don't get the nice centered alignment we want.

Lukas