libinput: Disable tap-and-drag

[Peter Hutterer]

On Tue, Jan 05, 2016 at 12:05:17AM +0000, Caibin Chen wrote:
> The reason why it's annoying to me is that often time I tap something and
> move the cursor immediately. For example closing a browser tab then move
> back to the content. This triggers tap-and-drag unexpectedly.

the timeout is currently 300ms. Maybe we can reduce the timeout to provide a
middle ground?

> As of dragging without clicking the touchpad, I have a WIP branch adding
> three-finger-to-drag feature[1]. You just drag with three fingers, no
> tapping needed. I've been testing it for a while.
> 
> [1].
> https://github.com/tigersoldier/libinput/tree/wip/three-fingers-dragging

Please see this bug here
https://bugs.freedesktop.org/show_bug.cgi?id=89999

Cheers,
   Peter


> Peter Hutterer <peter.hutterer at who-t.net>于2016年1月3日周日 下午10:40写道：
> 
> > On Sat, Jan 02, 2016 at 04:02:29AM +0000, Caibin Chen wrote:
> > > Hi,
> > >
> > > I've been working on disabling tap-and-drag feature in libinput because
> > I'm
> > > not used to it. The code is on my Github branch:
> > > https://github.com/tigersoldier/libinput/tree/wip/disable-tap-to-drag
> > >
> > > The basic idea is adding a branch at STATE_TOUCHED + EVENT_RELEASE
> > > transition:
> > >
> > >    STATE_TOUCHED
> > >          |
> > >          |
> > >    EVENT_RELEASE
> > >          |
> > >          |
> > >          v
> > > tap-and-drag enabled?  --- yes ---> (unchanged)
> > >          |
> > >          no
> > >          |
> > >          v
> > >     button press
> > >     button release
> > >          |
> > >          v
> > >     STATE_IDLE
> > >
> > > Aside from disabling the feature, this reduces the tapping latency as
> > well,
> > > because we don't have to wait for the timeout for STATE_IDLE to
> > > STATE_DRAGGING_OR_DOUBLE_TAP/STATE_IDLE transition.
> > >
> > > What do you guys think? If this makes sense, I can work on the
> > > documentation and tests and send patches to the list.
> >
> > thanks for doing this work. tbh, I'm not a big fan of having this as a
> > configuration option. IMO if you are using tapping as an interaction method
> > on the touchpad, having tap-and-drag available is the natural extension and
> > I don't see why we should disable it. Without it, a user would have to
> > physically click the touchpad and move with a second finger, despite
> > otherwise using tapping as the clicking interaction. That seems disjointed.
> > And while I can see that this is what some people do (I use tapping and
> > clicking interchangeable), I don't really want to provide/maintain/test
> > configuration options for this. sorry.
> >
> > Cheers,
> >    Peter
> >
> >
> >