Re: [GSoC] Implement cross-voice dynamic spanners (issue 304160043 by address@hidden)

[starrynte]

Hello,

Although I haven't thoroughly checked this patch, and I'll likely have
more questions and changes to make, I thought I'd upload this for some
initial general comments since the GSoC deadline is approaching.

My previously-described approach was to have one Spanner_engraver
instance receive all the events/acknowledgments and then forward them to
other instances (of the same engraver). However, I decided to try a bit
different approach: all Spanner_engraver instances receive all
events/acknowledgments, and (for the specified listeners/acknowledgers)
individually filter out all but the ones with matching
spanner-id/spanner-share-context. I'm not sure which way is better, so
the final approach could be subject to change.

I changed spanner-id and spanner-share-context to be properties of
grob-interface so Spanner_engraver can filter acknowledgments based on
those properties of the acknowledged grob. I believe for
Dynamic_align_engraver, one could lookup those properties on the
event_cause () of the Grob_info, but I'm not sure if this is true for
acknowledgments in general. Can acknowledgments to engraver instances be
filtered by the spanner-id and spanner-share-context properties of the
acknowledgments' event_cause ()?

Thanks again for all the help!

Nathan

https://codereview.appspot.com/304160043/