On 05/01/15 06:52, Peter Hutterer wrote: > On Mon, Dec 29, 2014 at 08:07:31PM +0100, dustin wrote: >> Hi, >> >> i recently started to play around with the input facilitys of X. My goal is >> to develop a remote control for my PC and for that purpose i want to control >> the mouse with an android tablet. (Maybe other embeded devices) >> >> I found a few ways to do this namely xtest and uinput/evdev (and untested >> xlib/xcb). Both working out of the box but i think i'll stick with >> uinput/evdev cuz i think this approach should work with libinput(wayland) as >> well? One problem arises that i can't circumvent and this is the scrolling. >> my first implementation works by simply emitting button 4/5 events like what >> ordinary mouse wheels do (looking at xev xinput tools) but what i am rally >> looking for is emitting "smooth scroll events"/"pixel perfect scrolling" >> (whatever this means). I came across some articles from Peter Hutterer >> talking about this and that Gnome implemented this. One can see this in live >> action via touchpad and the epiphany webbrowser. What i discovered was, that >> a client program has to catch XI2 events (XIDeviceEvent)and watch for >> XI_Motion and its valuators. But i really don't know how to emit these? with >> uinput/evdev even if i am emiting EV_REL, REL_WHEEL events and not button >> 4/5 events i got ordinary scrolling. what is the "right way" to emit these >> XIDeviceEvent/XI_Motion events (if these are really the ones i am looking >> for) >> >> what i was seeing from xinput --test-xi2 for ordinary mouse wheels was >> >> EVENT type 17 (RawMotion) >> device: 2 (10) >> detail: 0 >> valuators: >> flags: >> 2: -1.00 (-1.00) >> >> EVENT type 15 (RawButtonPress) >> device: 2 (10) >> detail: 5 >> valuators: >> flags: emulated >> >> EVENT type 16 (RawButtonRelease) >> device: 2 (10) >> detail: 5 >> valuators: >> flags: emulated >> >> As i understand this right the first XI_RawMotion is the "now" the regular >> new event and the button presses are for compatibility and can be ignored >> cuz of the "emulated" flag >> >> the valuator 2 means >> >> Class originated from: 10. Type: XIValuatorClass >> Detail for Valuator 2: >> Label: Rel Vert Wheel >> Range: -1.000000 - -1.000000 >> Resolution: 1 units/m >> Mode: relative >> >> if i scroll with my touchpad i get >> >> EVENT type 17 (RawMotion) >> device: 2 (13) >> detail: 0 >> valuators: >> flags: >> 3: 4.00 (4.00) >> >> there i have a valuator 3 which i guess means Rel Vert Scroll regarding to >> this >> >> Class originated from: 13. Type: XIValuatorClass >> Detail for Valuator 3: >> Label: Rel Vert Scroll >> Range: 0.000000 - -1.000000 >> Resolution: 0 units/m >> Mode: relative >> >> So the difference must somehow be with the different valuators. If so i just >> don't know how i can influence this with uinput/evdev. Maybe its only doable >> with xlib/xcb/xtest etc. i don't know. >> >> all i want is to simulate the "pixel perfect smooth scrolling" i get from >> regular laptop touchpads so that apps who respond to this will do from my >> application. > > the output of xinput should also include a XIScrollClass. That contains > information whether it's vertical/horizontal and refers to the valuator > number. If such a class is present, the valuator listed is a scrolling > valuator and should be interpreted as such. > > You don't have to do anything special in uinput, just send REL_WHEEL and the > rest of the xorg stack will do the right thing. Though since REL_WHEEL is > discreet, you won't get as much use out of smooth scrolling as you would > from a touchpad. When I send REL_WHEEL via uinput, applications that normally do smooth scrolling (ie: a browser) will scroll a few lines of text at a time, as if I had used the wheel using my mouse. That's expected.
What I would like to be able to do is emulate the behaviour I get from my trackpad with two-finger scrolling. I was hoping that simply setting uinput's absmax would have an effect on the valuator that gets assigned but this makes no difference. I assume that I need to get uinput to emulate a more "complete" device, but all my attempts have failed so far. Any ideas? Thanks Antoine > > Cheers, > Peter > _______________________________________________ > xorg@lists.x.org: X.Org support > Archives: http://lists.freedesktop.org/archives/xorg > Info: http://lists.x.org/mailman/listinfo/xorg > Your subscription address: %(user_address)s > _______________________________________________ xorg@lists.x.org: X.Org support Archives: http://lists.freedesktop.org/archives/xorg Info: https://lists.x.org/mailman/listinfo/xorg Your subscription address: %(user_address)s
