Bug 463766

Summary:	Slide animation for virtual desktops with multiple monitors is disorienting
Product:	[Plasma] kwin	Reporter:	Michael <burnsmellfactory>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	burnsmellfactory
Priority:	NOR
Version First Reported In:	5.25.5
Target Milestone:	---
Platform:	Gentoo Packages
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Michael 2023-01-03 03:01:21 UTC

SUMMARY
Recently, in response to bug #448419, the slide animation for virtual desktops was changed so that each monitor in a multi-monitor setup would independently have its own slide animation, as opposed to animating the entire canvas as one piece. The reason given in that bug was that the old behavior was disorienting. I won't dispute that some people found it disorienting, but I would like to point out that KDE had behaved that way for many years and in fact I find the new behavior quite disorienting on my main PC. I have another PC with an ultrawide display that is connected using 2 cables, so the computer behaves as if there are 2 monitors (which in 99% of cases was the intended result), and in such a setup the new behavior is even more jarring.

STEPS TO REPRODUCE
1. Have multiple monitors (I have 2 like-sided monitors in a left-right configuration)
2. Setup multiple virtual desktops (I have 2 rows of 3 each, for a total of 6 virtual desktops)
3. Enable "Slide" animation under "Virtual Desktop Switching Animation"
4. Open some windows in various virtual desktops
5. Cycle through the virtual desktops

OBSERVED RESULT
With multiple monitors, windows sliding off one monitor in the direction of another other monitor will disappear as they pass the boundary point between the monitors.

EXPECTED RESULT
Windows sliding off one monitor in the direction of another monitor should slide across that other monitor, the way it used to be. But since some people don't like that, there should be a configuration option for the "Slide" effect -- maybe a checkbox named "Slide each monitor independently" (or "Slide all monitors as one"), with the default being checked (or unchecked) if you want to preserve the behavior after bug #448419 was fixed. Maybe a tooltip or some other text could inform the user that this option's effect is not observable unless you have multiple monitors.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.96.0
Qt Version: 5.15.5

Comment 1 Michael 2023-01-03 03:03:10 UTC

For reference, it appears that the merge request wherein this behavior was introduced is https://invent.kde.org/plasma/kwin/-/merge_requests/1980.

Comment 2 Vlad Zahorodnii 2023-01-06 09:02:59 UTC

> but I would like to point out that KDE had behaved that way for many years
It's not a good reason not to try new things.

> and in fact I find the new behavior quite disorienting on my main PC
If you have tiled outputs, it's expected behavior because the monitors are not united to act like one big output.

---

Reopen the bug report if the number of duplicates gets above the number that we can't ignore, or if there are UX advantages of the old design that have been overlooked.

Comment 3 Michael 2023-02-01 04:48:41 UTC

I feel like I made the case about UX advantages of the old behavior that were overlooked.  For the record I never stated that the long-standing behavior was a reason "not to try new things", in fact I went out of my way to explain that I understood why some might like this new behavior and suggested making it a setting.

If you're unconvinced, I could try putting together a screen capture or video demonstrating how terrible and disorienting this new behavior looks.

Comment 4 Vlad Zahorodnii 2023-02-02 18:26:13 UTC

The only relevant point was that it looks weird with tiled outputs, but I explained that it's unrelated issue. I would like to re-iterate that it's the only bug report about this new behavior of the slide effect, so we probably won't act on it.