Re: repeating bar numbers and rehearsal marks in frenched score

[Mark Knoop]

At 17:43 on 28 Jul 2016, David Kastrup wrote:
>Mark Knoop <address@hidden> writes:
>> OK, here's a patch using only the remove-layer property with these
>> values:
>>
>> - #f: ignored by Keep_alive_together_engraver
>> - -1: kept alive by any other layer
>
>Isn't that the same as '() ?

Well no, because of the next paragraph...

>> The prior comment at lily/keep-alive-together-engraver.cc, line 72:
>> "Unspecified layers are kept alive by anything else" was not quite
>> true - unspecified layers are not kept alive by ignored layers, i.e.
>> those with remove-layer = ##f.
>
>Ugh, this is a bit too random. 

Seems pretty random to me at the moment, having to set a property
called "remove-layer" to false in order to remove the layer...

>It would probably make more sense to use number-or-symbol? here and
>then assign various symbols to various behaviors.

I thought of that option, but just wanted to get the behavior working
first before continuing down this path.

>At any rate, I think the principal problem is that the
>Keep_alive_together_engraver is desired to keep the marks context alive
>with _either_ of the two voices under it.  That would sound like we
>should have some way of grouping the marks context with the
>_StaffGroup_ rather than the individual contexts.
>
>So should the Keep_alive_together_engraver stop at a VerticalAlignment?
>If you want to keep together the contexts in a vertical alignment (like
>a StaffGroup), you could still add another Keep_alive_together_engraver
>in the context carrying the Vertical_alignment_engraver.

If I understand this correctly it would seem to be a more intrusive and
less backward compatible change. And I have no idea how to implement
this.

>Basically, we would add the hara-kiri-interface to VerticalAlignment as
>well?  Something like that?

How would this be done? Just by adding the interface and Y-extent calls
in define-grobs.scm?

--
Mark Knoop