Re: NoteColumn without parents?

[Thomas Morley]

Am Di., 19. Okt. 2021 um 19:42 Uhr schrieb Jean Abou Samra <jean@abou-samra.fr>:
>
> Le 19/10/2021 à 17:47, Thomas Morley a écrit :
> > Hi,
> >
> > please consider:
> >
> > {
> >    b4\glissando
> >    \once \override NoteColumn.glissando-skip =
> >      #(lambda (grob)
> >        (pretty-print
> >          (list
> >            (cons 'X-parent (ly:grob-parent grob X))
> >            (cons 'Y-parent (ly:grob-parent grob Y))))
> >         #t)
> >    c'
> >    d'
> > }
> >
> > I.e. NoteColumn seems to have no parents, at least I can't read any
> > parent from 'glissando-skip.
> > Is this on purpose?
>
>
> If you use ly:message to avoid intermingling of
> stdout with stderr, you will see that glissando-skip
> is being read in the translation stage. What triggers
> it is an acknowledger in the Glissando_engraver, in
> Voice context. The default parent of PaperColumn for
> NoteColumn is set by the Paper_column_engraver in
> stop-translation-timestep; if there are several
> voices, the Collision_engraver -- in Staff context,
> so its acknowledgers run after the Glissando_engraver's --
> will gather the NoteColumn grobs in a NoteCollision.
> Consequently, glissando-skip is in all cases read
> at a point of time by which the NoteColumn has no parent.
>
> What is your objective?
>
> Best,
> Jean

Hi Jean,

thanks for your insights.

Currently I try a complex coding, messing with Glissando, Beam,
NoteHead just looking for Grob.property combinations to find something
which gives me acces to all needed data but early enough to not loose
the ability to manipulate this data.

Basically I aim to continue at
https://lists.gnu.org/archive/html/lilypond-user/2021-04/msg00036.html

NoteColumn.glissando-skip was one thing I tried out, obviously the best one.
In the light of your explanations it works too early.

Thanks,
  Harm