On Wed, Jan 14, 2015 at 01:07:40PM +0100, Zbigniew Jędrzejewski-Szmek wrote: > On Wed, Jan 14, 2015 at 03:57:03PM +1000, Peter Hutterer wrote: > > On Mon, Jan 12, 2015 at 09:48:55AM +1000, Peter Hutterer wrote: > > > Most mice have a wheel click angle of 15 degrees, i.e. 24 clicks per full > > > wheel rotation. Some mice, like the Logitech M325 have a larger angle. To > > > allow userspace to make use of that knowledge, add a property to the hwdb. > > > --- > > > libinput patches to read this are here: > > > http://lists.freedesktop.org/archives/wayland-devel/2015-January/019340.html > > > > > > This is an RFC, unless we ack this for libinput there's no user for it so > > > I'd like to get both out first for review. Please don't merge yet. > > > > alrighty, we'll go ahead with that for libinput. If anyone has any > > suggestions let me know, otherwise I'll push this over the next couple of > > days. > > Yeah, it looks fine. For the record, what it the mouse angle useful > for? (Uniform scrolling?)
better predictive scrolling, yes. e.g. a mouse that has a smaller click angle will scroll faster, with this value you can accommodate this where needed. Likewise, using "half turn of the wheel" or "full turn of the wheel" as a UI element becomes possible. Not 100% sure on use-cases though. tbh the main driving factor was that we have a ...get_value() function that returns subpixel-precision scrolling for touchpads and other continuous scroll events but unpredictable magic numbers for mice. We used to return a hardcoded multiplier (10 * click-count) but that is at odds with the precision coming from the same call on other devices. Having the degrees gives us a cleaner API. we now have a ..get_value() return a continuous value range (pixels or degrees) and get_value_discrete() return "steps", i.e. mouse clicks. Callers can choose what they prefer based on the device. And someone may come up with a use-case for degrees on the mouse wheel soon :) Cheers, Peter _______________________________________________ systemd-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/systemd-devel
