Re: trying to solve "cyclic chain in pure-Y-offset callbacks" error in custom (ScoreMarks) context

[Kieren MacMillan]

Hi Harm,

> if I understand correctly, consisting "Staff_collecting_engraver" is part of 
> the Problem.

Thanks! This solves the problem, with no obvious negative side-effects.

> This makes sense only if ScoreMarks would be of type staff, which it isn't 
> currently.
> More, your setting of \override VerticalAxisGroup.staff-affinity =
> #DOWN let me think you don't _want_ it to be of type staff.

Correct.

I *vaguely* remember that I added the "Staff_collecting_engraver" a few years 
ago, when I was trying to find a way to "couple" each ScoreMark context with 
its associated StaffGroup, so that the marks disappeared along with the *last 
visible context* of that StaffGroup when french-ed. No doubt recent 
improvements in that area (keep-alive-together engravers etc.) make that moot — 
but I will have to look into it further when that use case comes up again (as 
it surely will).

In any case, your first fix is the answer I was looking for right now:

> \layout {
>  \context {
>    \type "Engraver_group"
>    \name ScoreMarks
>    \consists "Axis_group_engraver"
>    \override VerticalAxisGroup.staff-affinity = #DOWN
>    \override VerticalAxisGroup.nonstaff-relatedstaff-spacing.padding = 10
>    \consists "Time_signature_engraver"
>    \omit TimeSignature
>    \consists "Metronome_mark_engraver"
>    \override MetronomeMark.break-align-symbols =
>      #'(left-edge staff-bar clef time-signature key-signature)
>    \override MetronomeMark.non-break-align-symbols =
>      #'(paper-column-interface)
>  }

Many thanks!
Kieren.
________________________________

Kieren MacMillan, composer
‣ website: www.kierenmacmillan.info
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