Re: Why does removing Bar_engraver also removes clef?

[Marc Hohl]

Am 13.11.2014 um 23:29 schrieb Gez:
> I know this has been written about on the list before but the
> documentation has changed since then (I've checked pretty thoroughly).
>
> I'm looking for a way to write a load of short free-form pieces with
> automatic line breaks (so candenzaOn is not useful since it requires
> manual breaks).  I'd like to inhibit the Bar_engraver in all the pieces
> in one book/ly file, rather than write an override in each melody.  So
> far the workaround I've found uses a variable with override that I do
> have to insert in each score, but at least I can use the variable for
> other purposes as well.
>
> My minimal examples here show various scenarios I tried.   If someone
> can confirm that it's all working as it's supposed to, then that's good
> to know, but 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,

Marc

>