Re: TextScript.outside-staff-padding and text's baseline

[Aaron Hill]

On 2018-10-20 2:51 pm, David Kastrup wrote:
> Torsten Hämmerle <address@hidden> writes:
>
> > The only thing I do not like about staff-padding is that, strictly 
> > speaking,
> > we'd need different values for up and down direction:
> > Above the stave, just the descenders go between stave and text 
> > baseline,
> > whereas below the stave, the baseline has to be sufficiently far away 
> > from
> > the stave so that there's enough space for the full text height:
> >
> > <http://lilypond.1069038.n5.nabble.com/file/t3887/staff-padding.png>
> >
> > Wouldn't it be nice to have staff-padding accept a pair of values?
>
> Anything wrong with using a callback?

%%%%
\version "2.19.82"
{
  \override TextScript.staff-padding = #(lambda (grob)
    (let ((dir (ly:event-property (event-cause grob) 'direction)))
      (if (> dir 0) 2.5 3.5)))
  g' _"g" ^"q"
  g' _"b" ^"b"
}
%%%%

Semi-related question... Are there cases when you cannot use a callback? 
 Or is it always the case that any property can be a callback?

-- Aaron Hill