On Fri, Sep 28, 2012 at 2:47 PM, Pekka Paalanen <ppaala...@gmail.com> wrote: > On Fri, 28 Sep 2012 14:30:18 +0200 > Jonas Ådahl <jad...@gmail.com> wrote: > >> On Fri, Sep 28, 2012 at 2:13 PM, Pekka Paalanen <ppaala...@gmail.com> wrote: >> > I have an old discrete-stepped mouse wheel, it reports: >> > >> > Event: time 1348834027.330811, type 2 (EV_REL), code 8 (REL_WHEEL), value 1 >> > Event: time 1348834027.330812, -------------- SYN_REPORT ------------ >> > >> > and the other direction: >> >> Which one did you scroll downward? > > Negative is down, positive is up. > >> > Event: time 1348834027.906825, type 2 (EV_REL), code 8 (REL_WHEEL), value >> > -1 >> > Event: time 1348834027.906827, -------------- SYN_REPORT ------------ >> > >> > So it reports literally the number of "steps" it rotates. In urxvt on X, >> > each step seems to scroll 5 lines. >> >> Ok, so to emulate the axis movement for the event it needs to move a >> number of pixels per event. For the X11 compositor I made it move 10 >> pixels units per step, maybe can do the same with evdev. Is it worth >> having discrete scroll events handled separately in another way (or >> even both ways) as it could be good to be able to detect discrete >> scroll movements correctly as well? > > Do you mean adding more protocol for discrete axis motion? I don't > know. At first thought it seems just emitting motion in steps of 10 or > whatever is good enough. > > Btw. the clarify pointer axis event -commit didn't make too much sense > until I thought of touchpads. On mice, the motion and wheel are > inherently in different, arbitrary units. One might even argue, that > for wheels, the motion is an angle instead of a length. I don't have > any strong opinions here, and I don't know how existing smooth > scrolling works. >
It makes most sense on touchpads indeed, but it is more or less the only coordinate space we can relate to, as I see it. The other way to make it more like the traditional protocols is to have 1 "step" be 1 unit, and have "smooth" scroll wheels or touchpads use fractions of 1 to step smaller steps. This would however make the coordinate space of the axis event harder to relate to a surface, and I don't think it's better. Jonas _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel