[Wayland-bugs] [Bug 86807] Continue moving the pointer when 2fg scrolling ends

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=86807

Peter Hutterer <peter.hutterer at who-t.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |peter.hutterer at who-t.net

--- Comment #6 from Peter Hutterer <peter.hutterer at who-t.net> ---
(In reply to Hans de Goede from comment #1)
> The problem here is not 2fg scrolling triggering, the problem is the finger
> getting unpinned, once unpinned it counts for 2fg scrolling, and as such as
> long as 2 fg are down you will be in a 2fg scrolling situation. Note that
> this is only a problem when doing click + drag outside the button areas.

correct, but "outside" also means "moves outside". And that was what happened
to me when I was using my thumb to click. As the touchpoint changes shape
during hand movement, the actual touch point may move outside the buttons and
trigger scrolling. User-visible change is that movement stops suddenly.


 +------------------------+
 |          __            |
 |         /Y \           |
 |         \   \          |
 |          \   \  ______ |
 |     __    \   \/   \   \
 +----/  \---+\   \    \   \
 |    \ X \  | | 
 +-----\   \-+-|
        \   \__|

As Y moves around, the angle of the thumb changes (rolls sideways or forward)
and X moves up and down. That can move it outside the button area. I'll attach
evemu recordings to illustrate the point.

fwiw, with the patch I get occasional cursor jumps and errors of "invalid
event, no fingers are down" (the errors seem to be unrelated to the patch, see
#86917).

I think not scrolling while dragging is a good solution for now. We originally
allowed it because it's not that uncommon to have to scroll while dragging but
if it breaks a more common use-case then we should go for the more common one.

I'd like us to bounce around some more ideas on how we can fix Jasper's
use-case though, I don't think it's that uncommon. Jasper, can you attach a few
evemu recordings with common uses, preferable in all directions? maybe there's
some common data that we can easily detect.

-- 
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/20141201/f77bea91/attachment.html>