Bug 465878

Summary:	Windows snapping is difficult when using touch input
Product:	[Plasma] kwin	Reporter:	kelnio <kelnio>
Component:	Quick Tiling	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate
Priority:	NOR	Keywords:	wayland-only
Version First Reported In:	5.27.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description kelnio@yahoo.com 2023-02-16 22:29:55 UTC

SUMMARY
***
Windows snapping has become very difficult to do on a touchscreen when dragging the windows to the edge of the screen in the snap zones. This actually started happening around 5.26.5 and has not been fixed or improved with 5.27.
***

STEPS TO REPRODUCE
1. On a touchscreen device, open an application window
2. Grab the application window title bar with your finger (touch input)
3. Move the application window towards one of the snapping zones

OBSERVED RESULT
The window has to stay in the zone for a long(er) period of time before the snap zone is activated and you can release the window. The period seems to be 3 to 4 times longer than if you use mouse/trackpad input. The zone area to activate the snap also seems to be smaller than the area for mouse/trackpad input. If you move the window too fast, it will go off the screen. The top zone (the one that maximizes the window) has completely stopped working when using touch input.

EXPECTED RESULT
Window snapping with touch input should behave similar to snapping with mouse/trackpad input. The activation zone size and activation time should be the same. Windows should not be allowed to bypass the zones and go off the screen (a long time problem with Wayland!!).

SOFTWARE/OS VERSIONS
Linux: EndeavourOS
(available in About System)
KDE Plasma Version: 5.27.0
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
Graphics Platform: Wayland
Kernel Version: 6.1.11-arch1-1-surface(64-bit)
Device: Microsoft Surface Pro 8

Comment 1 Nate Graham 2023-02-17 21:02:58 UTC

Cannot reproduce the issue on Wayland. When I drag a window from its titlebar into a quick tiling zone or to the top of the screen, I can release immediately to have it tile to that zone or maximize.

Comment 2 kelnio@yahoo.com 2023-02-18 15:54:17 UTC

(In reply to Nate Graham from comment #1)
> Cannot reproduce the issue on Wayland. When I drag a window from its
> titlebar into a quick tiling zone or to the top of the screen, I can release
> immediately to have it tile to that zone or maximize.

That's weird. Are you dragging the window with your finger? Dragging it with the mouse works fine. 

After reading your post, I created a new user, then tried it again. I got the same results. Could you please test by dragging a window slowly towards a screen edge and slightly off center?

Comment 3 kelnio@yahoo.com 2023-02-18 15:56:10 UTC

..I can only get it to work if the window approaches the zone at an angle, not straight on.