Trevor Bača <trevorb...@gmail.com> writes:
> %%% BEGIN %%%
>
> \version "2.25.6"
> \paper { indent = 0 tagline = ##f }
>
> \markuplist \column-lines {
> "TextSpanner.bound-details.text.left = \"red\" when spanner color is
> red;"
> "TextSpanner.bound-details.text.left = \"other\" when spanner color is
> not red:"
> " "
> }
>
> {
> \override TextSpanner.bound-details =
> #(grob-transformer
> 'bound-details
> (lambda (grob orig)
> (assoc-set! (alist-copy orig)
> 'left
> (assoc-set! (alist-copy (assoc-ref orig 'left))
> 'text
> (if (equal? red (ly:grob-property grob
> 'color))
> "red" "other")))))
> c'1
> - \tweak color #red
> \startTextSpan
> d'1
> e'1
> \stopTextSpan
> f'1
> - \tweak color #blue
> \startTextSpan
> g'1
> a'1
> \stopTextSpan
> }
>
> %%% END %%%
>
> But because successive calls to grob-transformer effectively overwrite
> earlier calls to grob-transformer, we can't use this pattern to (say)
> override bound-details.left.text and bound-details.left-broken.text at the
> same time:
Your analysis is wrong. Successive calls to grob-transformer work just
fine. Your problem is that successive \override incantations revert
previous incantations in the same context _unless_ you use \temporary
\override .
If you do your second grob-transformer invocation (or both) with a
\temporary \override, it will leave the first call in place. Of course
you'll need a double \revert then if you want to get rid of both calls.
--
David Kastrup
