On Fri, Jan 23, 2015 at 12:20:55PM +0100, Hans de Goede wrote: > Hi, > > On 23-01-15 09:51, Jonas Ådahl wrote: > >On Fri, Jan 23, 2015 at 09:38:06AM +0100, Hans de Goede wrote: > >>Hi, > >> > >>On 23-01-15 07:18, Jonas Ådahl wrote: > > <snip> > > >>>>As for 2 finger swipe at least: isn't that covered by scrolling? with the > >>>>caller deciding when a scroll event event is a swipe and when it is a > >>>>scroll > >>>>event. It's the odd one out of course, but scrolling is a special case and > >>>>will be the odd one out anyway. > >>> > >>>Scrolling doesn't completely cover it because a user can disable > >>>2-finger scroll for the whole session, and the application won't even > >>>see the scroll events. If an application wants to handle the 2-finger > >>>swipe no matter what configuration the user has chosen, then it'd > >>>probably have to come via something like a gesture API. > >> > >>AFAIK there is no such thing as a 2fg swipe on other platforms, why would > >>we make things difficult to try and support it in the first place ? > > > >Well, don't we already have it fully implemented except we call it > >scroll and only enable it if it (although by default) configured so? I > >agree though that its not very nice to send out duplicate events for the > >same gesture, but still, it feels some how wrong to not let applications > >depend on the most simple swipe (deliberately ignoring 1 finger swipe > >here) gesture. > > Yes it is the most simple swipe gesture, but it is already taken for > scrolling and sending 2 events for the user doing a single thing just seems > very very wrong to me, and I really believe that that is something which > libinput should never ever do. > > > Also in click-to-scroll configurations, don't we disable 2 finger scroll? > > We don't have click-to-scroll for touchpads, we've edge scrolling or > 2 finger scrolling.
my first thought here was: should we drop 2-finger scrolling and move it to swipe events, then let the caller decide when to interpret swipe as scroll. doable, with a couple of benefits and a couple of drawbacks. I think what it comes down to though is that scrolling and swiping have two different usages: scrolling is almost exclusively vertical, with the odd horizontal component. it's also high-precision with slow finger movement. swiping is almost exclusively horizontal and usually not very precise, it's more of a flick than anything. so I think we could enable 2fg swipe on touchpads and then let libinput internally decide when to trigger a scroll and when to trigger a swipe. Plus the subtle hint in the documentation that vertical 2fg swiping is not a good gesture to rely on in a UI :) Cheers, Peter _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel