Hi Harm,
On Wed, Mar 3, 2021 at 6:56 AM Thomas Morley <thomasmorle...@gmail.com> wrote:
>
> Hi,
>
> please have a look at the following minimal, producing three staves,
> the middle one with consecutive TextSpanners:
>
> mus = { bes \startTextSpan b\stopTextSpan \startTextSpan bis\stopTextSpan }
> << { a4 a a } \mus { c' c' c' } >>
>
> Now I want to know the starting and ending NoteColumns of the _first_
> TextSpanner.
> Though, the first TextSpanner is left-bounded by NoteColumn and
> right-bounded by PaperColumn.
>
> How to get the NoteColumn at first TextSpanner's end?
>
> Below some test-code.
> Obviously I can filter PaperColumn's elements for NoteColumns, but
> PaperColumn is a Score-grob, thus I get all three.
> How to select?
> (I may not know the position of the Staff with the TextSpanners)
>
> #(define tst
> (lambda (grob)
> (let* ((left-bound (ly:spanner-bound grob LEFT))
> (right-bound (ly:spanner-bound grob RIGHT))
> (ncs-from-grob
> (ly:grob-array->list (ly:grob-object grob 'note-columns)))
> (right-bound-elts
> (ly:grob-array->list
> (ly:grob-object right-bound 'elements)))
> (ncs-from-right-bound
> (filter
> (lambda (elt) (grob::has-interface elt 'note-column-interface))
> right-bound-elts))
> )
> (pretty-print
> (list
> left-bound
> right-bound
> ncs-from-grob
> (equal? left-bound (car ncs-from-grob))
> ncs-from-right-bound
> )))))
>
> mus = {
> bes4-\tweak #'after-line-breaking #tst
> \startTextSpan
> b\stopTextSpan
> \startTextSpan
> bis\stopTextSpan
> }
>
> <<
> { a4 a a }
> \mus
> { c' c' c' }
> >>
>
> Thanks,
> Harm
>
The only thing I can think of at the moment is to compare the
StaffSymbol of the left bound with that of each of the NoteColumns on
the right. Of course, I realize right away that that will break down
if the spanner crosses a line break. (Use an override of
'before-line-breaking?)
Here's the code I hacked up. I'll keep thinking about this.
Best,
David
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
#(define tst
(lambda (grob)
(let* ((left-bound (ly:spanner-bound grob LEFT))
(right-bound (ly:spanner-bound grob RIGHT))
(ncs-from-grob
(ly:grob-array->list (ly:grob-object grob 'note-columns)))
(right-bound-elts
(ly:grob-array->list
(ly:grob-object right-bound 'elements)))
(ncs-from-right-bound
(filter
(lambda (elt) (grob::has-interface elt 'note-column-interface))
right-bound-elts))
(left-bound-staff-symbol (ly:grob-object left-bound 'staff-symbol))
(same-staff-right-bound-nc
(filter
(lambda (nc)
(eq? (ly:grob-object nc 'staff-symbol)
left-bound-staff-symbol))
ncs-from-right-bound))
)
(ly:grob-set-property!
(ly:grob-array-ref
(ly:grob-object (car same-staff-right-bound-nc) 'note-heads)
0)
'color red)
(pretty-print
(list
left-bound
right-bound
ncs-from-grob
(equal? left-bound (car ncs-from-grob))
ncs-from-right-bound
same-staff-right-bound-nc
)))))
mus = {
bes4-\tweak #'after-line-breaking #tst
\startTextSpan
b\stopTextSpan
\startTextSpan
bis\stopTextSpan
}
<<
{ a4 a a }
\mus
{ c' c' c' }
>>
