Re: Why does removing Bar_engraver also removes clef?

[Gez]

On 14/11/2014 17:14, Marc Hohl wrote:
> Am 13.11.2014 um 23:29 schrieb Gez:
> >  I'd be really grateful if someone can also point me to
> > where the documentation explains why removing the the Bar_engraver also
> > removes the Clefs.
>
> I don't think that this is documented in the docs, but in the sources:
>
> In lily/clef-engraver.cc:
>
>     85    /**
>     86       Generate a clef at the start of a measure. (when you see 
> a Bar,
>     87       ie. a breakpoint)
>     88    */
>     89    void
>     90    Clef_engraver::acknowledge_bar_line (Grob_info info)
>     91    {
>     92      Item *item = info.item ();
>     93      if (item && scm_is_string (get_property ("clefGlyph")))
>     94        create_clef ();
>     95    }
>
> If there is not bar line to be acknowledged, the clef will not be 
> printed.
>
> I don't know whether this is the desired behaviour as there are cases
> where you need the clef and line breaks, but no bar lines.
>
> HTH a bit,
Thanks, Marc - that does help.  Even if I'd thought to look in the 
sources I wouldn't have really grasped what that meant. For me, for this 
purpose, it isn't the desired behaviour.  I wonder if there's a good 
reason for it?  Anyway, at least now on the email list there's a note of 
the behaviour if anyone searches for it in future,

So, to summarise - to remove bar lines and have automatic line breaking 
but retain the clef at the new line you can't use
\context {Staff \remove Bar_engraver}
(.e.g in layout, for a group of scores) - instead, you need to use
\override Staff.BarLine.stencil = ##f
which has to go in each score, but for batch overriding you can add the 
override to the score using a variable, which can of course be used for 
other purposes as well.
-------------------

\version "2.18.0"
thistest = {

\override Staff.BarLine.stencil = ##f

}

\score {

\relative c'{

\thistest

\repeat unfold 40 { c1 }

}

\header {

piece = "Using variable override stencil keeps clef engraved with 
automatic line breaks"

}

}

----------------------------------------------------------

HTH someone!
Gez