Disable KWin's default left touch screen edge
Closed, ResolvedPublic


KWin sets a left touch screen edge by default. This feature is problematic for several reasons:

First of all, it doesn't work that well. My wife and I both use Kubuntu 17.10 with Plasma 5.12.x on modern touchscreen laptops the the feature is buggy and unreliable.

Second, its implementation breaks a lot of other workflows and use cases because it's implemented using an invisible single-pixel window tthat runs the height of the left screen edge hat eats clicks and scroll events. This breaks Fitt's Law for any content on the left screen edges and causes a lot of headaches for users, which is the source of a significant amount of bug reports, e.g.:

(Ignore the fact that one is closed; it's still a problem, but the maintainer doesn't think it is)

It also comes up a lot on online support forums and Reddit.

KWin's maintainer has made it clear that this will not be changed or fixed anytime soon:

The setting will stay enabled by default. This is a maintainer decision! This is a useful feature and we seem to have conflicts here between users expecting it to work exactly like that and users not having a touch screen and having issues with that. In today's world we need to support touch screens by default in a sensible way (e.g. for notebooks) without looking like yesterdays thing. Thus this will stay on.

I recommend that Kubuntu disables this feature. This will require patching KWin, unfortunately. The code responsible is here: https://cgit.kde.org/kwin.git/tree/tabbox/tabbox.cpp#n847

ngraham created this task.Feb 19 2018, 2:49 PM

I agree, I have never been able to get that working, and disable it as well. I just use touchpad gestures instead. Seems like a cool idea, if it actually worked.

As an alternative to patching, if we ship with a ~/.config/kwinrc file by default, we can add the following to it to turn this off:


A non-coder's perspective: please provide a config file rather than patching. Users can merely remove the config file if they don't like the change.

I agree, but regardless of the approach, users would still be able to change this. The proposed patch was to remove the code that made it get set up default; users would still be able to manually turn it on or do whatever they want.

That said, I agree, a config file is better than a patch.

Additionally to the config file we will need a kconfig update script for people upgrading existing systems.

I'm not sure we'd want to disable this for existing users. Some might be using it, somehow (maybe it actually works for someone, I dunno). I would recommend only disabling it for new installs. That's generally what we do for changes to default settings.

tsimonq2 moved this task from Inbox to Packaging / Devel on the Kubuntu board.Mar 20 2018, 9:37 PM
rikmills closed this task as Resolved.Mar 20 2018, 11:28 PM

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