[Wayland-bugs] [Bug 89999] Add support for 3-finger dragging

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=89999

--- Comment #6 from Sui Chen <baiypwup at hotmail.com> ---
(In reply to Hans de Goede from comment #5)
> (In reply to Peter Hutterer from comment #4)
> > (In reply to Hans de Goede from comment #3)
> > > Finger 1 down
> > > Finger 1 moves over tap threshold
> > > Fingers 2 + 3 down
> > > Timeout
> > >  (omitted)
> > 
> > I'd say that's definitely desirable behaviour,  ... (omitted)
> 
> Ok, I was actually thinking the same (that this is actually desirable) but I
> wanted to double check with you, ok in that case it should be easy to add
> support for this using an initial timeout to choice between this and a 3fg
> swipe. I do believe that this should be only enabled when tapping is enabled.

Hi,
I am playing with emulating 3-finger drag in the Synaptics driver these days
(now I think I should look into libinput), and I agree it's convenient to allow
the user to put the extra fingers down to drag.

I think there is another thing that may need to be taken care of: the 3-finger
drag should also support "locked dragging". 
Reason is it's easy to run out of space on a trackpad with 3 fingers. If the
user wants to do a long distance drag (like drawing a window to another
monitor), s/he has to either do a drag with a high initial speed, or keep
swinging back and forth to take advantage of the acceleration mechanism. That
is easy to do with 1 finger dragging, but with 3 fingers there is greater
friction so it's harder. Because of this, a locked dragging is more convenient
for long-distance 3-finger drags.

IMHO it may look like the following in the program:
1. The user is already in a 3-finger drag.
2. The user lifts 3 fingers from the trackpad because s/he is running out of
space. The countdown starts.
3. Any time before the countdown reaches zero, the user may move the cursor
with 1 or 2 or 3 fingers (that means 2-finger scroll is ignored).
4. If the user puts 3 fingers back onto the trackpad to continue the 3-finger
drag any time before the countdown reaches zero, the countdown resets.
5. If the countdown reaches zero the drag is stopped. (It may also be stopped
by other events like pressing the physical button on the trackpad)

Thanks,
Sui

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/wayland-bugs/attachments/20150414/735cf8d3/attachment-0001.html>