Point-and-click data and backend futures

[Ed Baskerville]

Hi all,

As some of you might have seen on the lilypond-user list, I'm working 
on a Mac OS X integrated text editor/previewer for LilyPond. Several 
users have asked for point-and-click support, and I'd like it too.

So, a couple clusters of questions on this topic:

(1) As I understand it, the data mapping between layout coordinates and 
line/column numbers in the source code is already embedded in the DVI 
output. I know nothing about DVI--can anyone point me to a reference 
for getting at this data? Is this the best way to get the data? And 
since I'm actually displaying PDF in the app, not DVI, will these 
coordinates match the coordinates in the PDF output exactly?

(2) I've seen things here and there in the archives about the various 
backends--PS, TeX, GNOME, etc.--and wanted to know how the future of 
these backends might affect point-and-click in my previewer, or, to be 
more open-ended, how it might affect the design of the previewer in any 
way. Will the DVI point-and-click data continue to be available? Should 
I be designing my previewer to display something other than PDF? Etc.

Lastly: any objections around here to me calling the app LilyPad?

Thanks much,
Ed