High-resolution scroll events

[Max Schwarz <Max x-quadraht de>]

Hi,

I'm currently developing patches for the X11 ecosystem to provide higher-
resolution scrolling for devices that support it (touchpads, trackpoints, 
etc). My patches are kept in a github repo ([1]).

It looks like my patch will get merged into Xorg eventually (see my thread 
over at xorg-devel [2]) and I wanted to have a first look at GTK/GDK and how to 
implement support there.

It seems to me that the crux of the matter is the GdkEventScroll, which has no 
way of specifying the precise amount to scroll. It's just emitted for each 
old-style scroll tick.

Do you have an idea on how to implement this? I think Qt's model is quite 
nice, they have a 'delta' field in their event [3] which gives more precise 
information. Of course, If you want to retain API compability (which I think 
you do) a new event would have to be introduced that is emitted in parallel.

Thoughts?

Thanks,
  Max

[1]: http://github.com/x-quadraht/pscroll .
[2]: http://www.mail-archive.com/xorg-devel lists x org/msg14536.html
[3]: http://doc.qt.nokia.com/4.7/qwheelevent.html#delta