On Sat, Mar 30, 2013 at 8:44 PM, Daniel Stone <dan...@fooishbar.org> wrote: > Hi, > > On 30 March 2013 16:55, Thiago Macieira <thiago.macie...@intel.com> wrote: >> >> On sábado, 30 de março de 2013 09.34.24, Matthias Clasen wrote: >> > > Monotonic (ideally) time in an undefined domain, i.e. they're only >> > > meaningful on relation to each other. >> > >> > What can you do with them ? For the use case that Giulio mentioned >> > (double-click detection), I'd need to know at least if the difference >> > between two times is seconds or milliseconds or microseconds... >> >> The protocol needs to specify the unit. It can't be dependent on the >> device >> driver, that makes no sense. If it's in milliseconds, it will overflow >> every >> 49.7 days. If it's microseconds, it will overflow every 71.6 minutes. > > > Yes, they are in milliseconds, I just explained it poorly. > >> >> It also needs to specify which timestamps are in the same time domain. Can >> two >> timestamps be compared to each other only if: >> >> - they are in the same input device (same mouse, same keyboard), but not >> across devices >> - they are in the same seat, but not across seats >> - they are in input event messages, but not other types of messages that >> carry timestamps >> - no restriction > > > Personally, I think either #1 or #2. Definitely not #3 or #4. We want to > be able to use the evdev timestamps rather than gettimeofday() when we > receive it, so we can ensure that if someone clicks twice slowly, and the > compositor takes a while to process the same event, it's not interpreted as > a double-click. > >> >> For example, imagine the case of trying to ensure that a Ctrl key was >> pressed >> before a mouse click happened, after the events were plucked out of the >> event >> stream. >> >> Or is there another, recommended way of doing that, such as by using the >> serials? > > > Hmmm. I was going to say using the event order, but it all depends on which > order the devices were read in. So I guess for this case we'd need to go > with #2.
As a side note, #2 also makes more sense for the wl_pointer which is an agrigate from more than one source. --Jason Ekstrand > > Cheers, > Daniel > > _______________________________________________ > wayland-devel mailing list > wayland-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/wayland-devel > _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
