Re: Determining location of the staff lines

[Eric Knapp]

On Mon, Feb 15, 2010 at 11:54 AM, Carl Sorensen <address@hidden> wrote:
>
>
> I think it's not yet possible to do this in a Scheme engraver.
>
> Han-Wen indicated that it could be done here:
>
> http://lists.gnu.org/archive/html/lilypond-devel/2010-01/msg00594.html
>
> But I don't think it's been implemented yet.  Perhaps Han-Wen will do so,
> now that we've identified a need.
>

This is good to know. I thought I was losing my chops for learning new
languages! Now I'm relieved to know that it's not just me and that
might be a new feature. When Han-Wen says "I had thought the Scheme
engravers to use context properties to store internal state" what was
envisioned? Can arbitrary properties be added to the context or are
there properties that can be used for new data?


> Exactly.  You'll have a listener for note-events and for string-number
> events.

I had figured this out but was stuck on collecting the data to do what I need.

>
>>
>> How do I create the vectors in Scheme so that they are persistent?
>> Everything I've tried has resulted in only having the last item in the
>> vector there once I'm done.
>
> We need to have the capability to store private data in Scheme engravers.
> Hopefully we can get that implemented.
>

I'm assuming that context properties can't be used for this?

>
> The grob will be created in the process-music function, which occurs after
> all of the notes at the current moment.
>
> You should create StaffTabStringIndicator grobs  (you'll need to create a
> new grob type for that -- see scm/define-grobs.scm).

Thanks, I'll look into this for the time being.

>
> HTH,
>
> Carl
>

This is helping greatly and I sincerely appreciate your detailed and
clear answers.

-Eric