Re: [Pseudo-patch] Add support for HairpinText indications. (issue3509041)

[v . villenave]

[I should probably subscribe the codereview mail address to Frogs- and
move the discussion there.]

Thanks Neil! I've now tried to make a proper Spanner, which raises more
questions of course (namely, how to properly start and finish it): right
now there's no segfault anymore, but a "must have Item for spanner
bound" error.

I'll keep looking :-)

Thanks!


http://codereview.appspot.com/3509041/diff/3001/lily/new-dynamic-engraver.cc
File lily/new-dynamic-engraver.cc (right):

http://codereview.appspot.com/3509041/diff/3001/lily/new-dynamic-engraver.cc#newcode147
lily/new-dynamic-engraver.cc:147: hairpin_text_ = make_item
("HairpinText", hairpin_text_->self_scm ());
On 2010/12/08 01:09:38, Neil Puttock wrote:
> I suspect this is part of where your segfault comes from: you can't
make the
> cause of a grob the grob itself :)

Interesting.  I hadn't understood that the second argument was the grob
cause, but that makes sense. (I guess that's why many grobs are created
with make_item ("FooBar", SCM_EOL)?

> make_item ("HairpinText", current_span_event_->self_scm ());

> You need to decide what kind of grob you're creating; though you've
defined
> HairpinText as an Item, some of the default settings in
define-grobs.scm are for
> a Spanner (which will probably cause you more segfaulting issues).

Yes.  As you've noticed, it was an ugly mashup of various properties
found here and there :-)

> Since you want to centre the text between the bounds of the Hairpin,
it probably
> makes more sense to define HairpinText as a spanner.

Done. I also considered the possibility of using a Scheme procedure as a
translator, but it seemed somehow uncanonical.

http://codereview.appspot.com/3509041/