Hi Jean, I'm sorry for my last confused email. I see what you mean about overriding the VoiceFollower property outside of the engraver. In my test file I was trying to override incorrectly.
Thanks again for your help, greg On Sat, Jul 15, 2023 at 2:10 PM Gregory Evans <gregoryrowlandev...@gmail.com> wrote: > Hi Jean, > Yes I’m still pretty much a Scheme beginner even though I have been trying > to learn. My first language is Python. > > Thanks for the advice about not destroying the other details values. > > No, there is no special reason to read from the notehead, except that I > don’t know how to read the value by setting the voice follower. How would I > reference that property in that location? Do you mean I should remove the > commented line entirely? I don’t seem to read the value when I set \once > \override Staff.VoiceFollower.details.used-proportion = 0.5. I’m sorry I > think I haven’t understood your suggestion. > > best, > greg > > On Sat, Jul 15, 2023 at 1:25 PM Jean Abou Samra <j...@abou-samra.fr> > wrote: > >> Hi, >> >> (ly:grob-set-property! follower 'details '((used-proportion >> . 0.5))) ;;; HERE I would like to have user-input instead of 0.5 >> ;; would prefer the above line to read something like: >> ;; (ly:grob-set-property! follower 'details >> '((used-proportion . (assoc-get 'used-proportion (ly:grob-property elt >> 'details '()))))) >> )))) >> >> >> The outcommented line sounds like you are confused about quoting, which >> is pretty common for Scheme beginners. >> >> You probably want to read about it more in detail, for example on >> https://extending-lilypond.gitlab.io/en/scheme/quoting.html >> >> >> With that being said, what is the purpose of copying 'used-proportion >> from a note head to a voice follower, can't you read and set it on the >> voice follower directly? >> >> Also, beware of doing (ly:grob-set-property! follower 'details ...) since >> that will destroy all other entries that might be in the details alist. >> Better do >> >> (ly:grob-set-nested-property! follower '(details used-proportion) ...) >> >> to update only the used-proportion entry while keeping the others intact. >> >> Best, >> Jean >> >> > > -- > gregory rowland evans > http://www.gregoryrowlandevans.com > https://github.com/GregoryREvans > https://soundcloud.com/gregory-rowland-evans > -- gregory rowland evans http://www.gregoryrowlandevans.com https://github.com/GregoryREvans https://soundcloud.com/gregory-rowland-evans
