Re: point-and-click in SVG

[Graham Percival]

On Thu, Apr 04, 2013 at 07:05:03AM +0200, Jan Nieuwenhuizen wrote:
> Graham Percival writes:
> 
> > This is because output-svg.scm's
> >   (grob-cause ...)
> > is called *before* drawing the path of the notehead, and SVG has
> > no z-index.
> 
> What if you have grob-cause set a grob-cause for the subsequent
> notehead/grob to pick up and draw?  Something like
> 
>    (define cause #f)

Thanks for the hints, everybody!  Doesn't this global variable
break the whole scheme philosophy, though?

> would that work?

Indeed it does.  I've uploaded a patch with this change.

> Can some of this code be shared with output-ps and moved to
> output-lib.scm?

Potentially.  I began by copying (grob-cause...) from
output-ps.scm, but then altered the (ly:format...) bit to be
suitable for svg rather than ps.  I suppose that I could abstract
that into a function which is defined in output-ps and output-svg,
then move the rest of the existing (grob-cause ...) into
output-lib.scm.  My concern is that this would add complexity;
it's easier to understand a single function rather than spreading
the functionality between a single-order and second-order
functions in two separate source files.

I have no firm opinion on whether that change is worth it; I'm
just raising that possible concern.

- Graham