Re: HaraKiri in PianoStaff

[Mats Bengtsson]

> Is there a way to make the bass staff of a PianoStaff disappear when
> there is nothing in it?  This seems like what I want, but it doesn't work:
> 
> \context PianoStaff \notes <
>    \context Staff = "up" <
>      \property Score.skipBars = ##t
>      \clef treble
>      \global
>      \organ
>      >
>    \context HaraKiriStaff = "down" <
>      \property Score.skipBars = ##t
>      \clef bass
>      \global
>      \organbass
>      >
> >
> 
> I get a message 
> "warning: can't find or create `HaraKiriStaff' called `down'"
> in the interpretation phase.  Then I get three staves in the output, and 
> the order is all out of whack.

The HaraKiriStaff doesn't exist as a separate \context type.
When you say \translator { \HaraKiriStaffContext } you simply
redefine the ordinary Staff contexts. If you want to get a 
clearer idea of how the different contexts are defined, you
could take a look at ly/engraver.ly.


> I also tried adding
> \translator { \HaraKiriStaffContext }
> to my paper definition, but this wipes out both staves when both staves
> are empty, which doesn't look good for orchestral parts. 

Unfortunately, the only way to get what you want is to add
a new separate \context type for hara kiri staffs. This is
a bit hairy since you have to add the new context to the
context hierarchy using \accept ...
There are some examples available in input/test/improv.ly and
input/test/part-combine-moments.ly.

    /Mats