On Sat, Apr 11, 2015 at 11:41:32PM +0800, Chen Sui wrote: > Hello Xorg, > I recently got a Magic Trackpad for use with my Xubuntu laptop. I found > the "three-finger dragging" feature is not supported, so I decided to look > into the Synaptics Xorg driver to see if it is possible to add this > feature :D > (Note: "Three-finger dragging" is different from a "three-finger gesture". > In 3-finger dragging, the pointer follows the motion of your fingers > throughout the dragging action. In a three-finger gesture, the pointer > stays in the same place until the gesture is completed. The "three-finger > dragging" feature is commonly found on Macbooks which is by default turned > off but I think it's very convenient feature. Should three-finger dragging > be supported by the Synaptics driver on Linux, I can set SingleTapTimeout > to 0 to get a more responsive single click tap because I don't need > tap-and-drag anymore.)My distro is Xubuntu 14.04 and the default version > of the driver that came with it is xf86-input-synaptics-1.7.4 .I did a > quick skim through the source of the latest version 1.8.2, the latest as > of today. As far as I can tell, there doesn't seem to be a great > difference in their support for 3-finger dragging (neither explicitly says > it supports 3-finger dragging). > In the 1.7.4 source (synaptics.c), adding 3-finger dragging required > adding several state transitions in the HandleTapProcessing function. That > means the Synaptics driver has everything ready for implementing this > feature, and it is not very difficult. > I have posted my modified xf86-input-synaptics-1.7.4 here if anyone is > interested in trying > out:https://github.com/quadpixels/three-finger-dragging > If you just want to know what the outcome is like, you may also check out > this video:https://www.youtube.com/watch?v=4eLSEtibfyw > The code is still a proof-of-concept now: some configurations are > hard-coded, there may be some little bugs, and it also needs some > polishing for easier configuration and use. > I think this feature should work with any trackpad, not just Apple's Magic > Trackpad, as long as they support 3 or more fingers simultaneously touching > the trackpad.
I like it, but I don't think we should add it to synaptics. It is mostly in maintenance mode with almost all of the effort going into libinput now. I've filed a bug for libinput to support this, please CC yourself on that to follow the discussion. https://bugs.freedesktop.org/show_bug.cgi?id=89999 Cheers, Peter > I hope this may be useful for you. > Thanks!Sui (Tommy) Chen2015-04-11 > P.S. What is the good way to make X > load/usr/local/lib/xorg/modules/input/synaptics_drv.soinstead > of/usr/lib/xorg/modules/input/synaptics_drv.so ? > Currently I keep a symbolic link in /usr/lib/xorg/modules/input/, but I'm > wondering if there's a more elegant way. _______________________________________________ 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
