Re: TabStaff.keepAliveInterfaces

[Thomas Morley]

Am Sa., 2. Nov. 2019 um 09:41 Uhr schrieb Malte Meyn <address@hidden>:
>
> Hi list,
>
> what am I (or what is LilyPond) doing wrong here?
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> \version "2.19.83"
>
> bla = { \repeat unfold 100 e'4 }
> git = {
>    \set TabStaff.keepAliveInterfaces = #'()
>    R1*10
>    \repeat unfold 60 c'4
> }
>
> <<
>    \new Staff \bla
>    \new Staff \with { \RemoveAllEmptyStaves } \git
>    \new TabStaff \with { \RemoveAllEmptyStaves } \git
>  >>
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> A stub for the first TabStaff is printed (clef and short staff lines). If I
> • don’t \set TabStaff.keepAliveInterfaces or
> • \set Staff.keepAliveInterfaces = #'() too
> the TabStaff is hidden as expected. Seems like the \set TabStaff… partly
> revives the TabStaff from being hidden. But why does the \set Staff…
> have an effect at all?
>
> Cheers,
> Malte
>

Hi Malte,

you initiate TabStaff last, thus there is no TabStaff at the time \set
TabStaff is read (in Staff). So LilyPond creates a TabStaff herself.

(1)
You could use that autogenerated TabStaff. Though, because then the
TabStaff is already there a \with comes too late, so you need to go
for score-layout.
Makes for:

bla = { \repeat unfold 100 e'4 f'1}
git = {
   \set TabStaff.keepAliveInterfaces = #'()
   R1*10
   \repeat unfold 60 c'4
   \break
   \unset TabStaff.keepAliveInterfaces
   d'1
}

\score {
  <<
     \new Staff \bla
     \new Staff \with { \RemoveAllEmptyStaves } \git
     \context TabStaff \git
  >>
  \layout {
    \context {
      \TabStaff
      \RemoveAllEmptyStaves
    }
  }
}

Though, fiddling with autogenerated contexts is not really nice...

(2)
You could initiate the TabStaff before Staff and align it properly.
Makes for:

bla = { \repeat unfold 100 e'4 f'1}
git = {
   \set TabStaff.keepAliveInterfaces = #'()
   R1*10
   \repeat unfold 60 c'4
   \break
   \unset TabStaff.keepAliveInterfaces
   d'1
}

<<
   \new Staff \bla
   \new TabStaff = "tab" \with { \RemoveAllEmptyStaves } \git
   \new Staff \with { alignAboveContext = "tab" \RemoveAllEmptyStaves } \git
>>

Though, speaking only for me, I don't like this ordering and it feels
very much like a workaround. Well, it _is_ a workaround ;)

I'd go for:
(3)
_Limit_ the \set TabStaff to this context.
Makes for:

%% A simple \set TabStaff applied right at the start of some music will
%% probably causesome spurious TabStaff, because the meant TabStaff is
%% probably not (fully) initiated at that timestep.
%% Thus better make sure the \set is limited to TabStaff
%% Lateron it would not be a problem.
removeTabStaff =
  \applyContext
    #(lambda (ctx)
       (if (eq? (ly:context-name ctx) 'TabStaff)
           (ly:context-set-property! ctx 'keepAliveInterfaces '())))

%% Unset keepAliveInterfaces in TabStaff (now the settings from Score apply)
unsetRemoveTabStaff = \unset TabStaff.keepAliveInterfaces

bla = { \repeat unfold 100 e'4 f'1}
git = {
   \removeTabStaff
   R1*10
   \repeat unfold 60 c'4
   \break
   \unsetRemoveTabStaff
   d'1
}

<<
  \new Staff \bla
  \new Staff \with { \RemoveAllEmptyStaves } \git
  \new TabStaff \with { \RemoveAllEmptyStaves }\git
>>


HTH,
  Harm