[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

--- Comment #9 from Hans de Goede <jwrdegoede at fedoraproject.org> ---
(In reply to Peter Hutterer from comment #6)
> (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.

On clickpads yes, ack. That should solve your use-case.

I still think the patch I attached is a good idea regardless though, shall I
post it to the list for review ?

> 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.

Ok.

> 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.

How about simply counting (combined) movement from all "active" (so not pinned
not in button area) fingers when a clickpad is clicked down. Or maybe go one
step further and simply always report movement from all active fingers ?

-- 
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/20141202/20faf0cb/attachment.html>