Re: changing grob properties?

[Marc Hohl]

Neil Puttock schrieb:
> 2009/5/13 Marc Hohl <address@hidden>:
>
>   
> > How can I achieve this?
> >     
>
> Remember how you got the bounds of a glissando?
>
> In the case of the broken tie, the right bound will be the notehead
> you want to make transparent, so you can retrieve the TabNoteHead grob
> using ly:spanner-bound.
>
>   
Upto now, I have achieved to make tablature fret numbers invisible which 
are tied to another note.
But I don't know how to add parentheses to the numbers that are tied but 
show up after a line break
(for example the first note in measure 5, see attachment).

I tried something like

(set! (ly:music-property note 'elements)
                (cons (make-music 'NoteEvent 'parenthesize #t)
                      (ly:music-property note 'elements)))

but I realized that a grob is not a music expression as the variable called 
"note" in the code fragment above.


Then I came up with the vague idea to combine the TabNoteHead-Stencil 
with the
stencil for the parentheses, but this was beyond my knowledge, it didn't 
work.

Any hints are gladly appreciated!

Marc


> > Is this even the right way to solve this task?
> >     
>
> It's certainly the most elegant method if you're making the notehead
> transparent.
>
> Regards,
> Neil
>
>   

\version "2.12.2"

#(define (tie::handle-tab-tie grob)
  (let* ((original (ly:grob-original grob))
         (tied-tabnotehead (ly:spanner-bound original RIGHT))
         (siblings (if (ly:grob? original)
                     (ly:spanner-broken-into original) '() )))

    (if (and (>= (length siblings) 2)
            (eq? (car (last-pair siblings)) grob))
       ;; tie is split
       ;; just a dummy function here, parentheses should be inserted
       (begin (ly:grob-set-property! tied-tabnotehead 'transparent #f)
              (newline)
              (display "Tie is split.")
              (newline))
       ;; tie is not split -> make fret number invisible
       (ly:grob-set-property! tied-tabnotehead 'transparent #t)
       );; end if
       ))

test = \relative c {
       f2 ~ f4 \parenthesize e
       g8 g ~ g g ~ g g~ g g ~
       g1
       c1 ~ \break c2 ~ c
       < c\3 e\2 g\1 >4 < c\3 e\2 g\1 > ~ < c\3 e\2 g\1 > < c\3 e\2 g\1 >
       \bar "|."
       }

\score {
   << \new Staff { \clef "G_8" \test }
      \new TabStaff { \clef "tab"
                      \override Tie  #'stencil = #tie::handle-tab-tie
                      \override Stem #'stencil = ##f
                      \override Beam #'stencil = ##f
                      \override Dots #'stencil = ##f
                      \test }
   >>
}

tietest.pdf
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