"present windows" is slow/stuttering after upgrade to 16.10

[chconnor]

Howdy -- upgraded from 16.04. I have a hotkey for the Present Windows desktop effect. It has worked fine for the past several Kubuntu versions, but with this update a strange stutter has begun: I hit the hotkey and the windows hightlight as if they are beginning the animated transition to their presented state, but the effect hangs for maybe 0.5 - 1.5 seconds before then snapping to where it should have been. With subsequent presses of the hotkey, the transition works fine, it's just the first one that hangs up. After a few seconds, or opening a new window, etc, the delay comes back and happens again.

Anything I can try to fix this? I can't seem to google anything up about it. Normally I don't want the animation stuff anyway, but with Present Windows it's actually very useful to visually track which windows go where...

I hear that plasma 5.8 is soon to be released -- will it be making it into 16.10? [edit: answered here]

Thanks for any ideas!

[Snowhog]

My suggestion would be to delete the existing hotkey you have for this item, logout and reboot (to clear the cache information 'in memory'), and recreate the desired hotkey and test.

[chconnor]

Thanks for the idea! -- I tried it and there was no change.

There isn't really a way to delete a shortcut, though: I could set it to "default" or keep it as "custom" with no shortcut. I tried both methods with a reboot each time, and it didn't seem to have an effect.

Any other things to try are welcome. It seems to bog down when there are a number of windows (3-5 or more), and seems to relate to calculating the animation. E.g. when i present all windows and then close them (while presented) with the "X" buttons it provides on each window, the resulting reshuffling of windows drags and skips a lot. But once it has been through the animation once with a given set of windows, it can repeat it smoothly.

[chconnor]

Figured something out: if I adjust the system settings for the present windows effect to disable "Provide buttons to close the windows", then the effect works just fine. Never lags. I think I'm gonna need to file a bug on this one...

edit: filed: https://bugs.kde.org/show_bug.cgi?id=371731

[Snowhog]

Given your discovery, I am prone to think that it actually has to do with the Workspace Theme you are using. It is not the default, but one you downloaded? Have you tried changing all themes to the defaults?

[chconnor]

Thanks -- My Theme is Breeze, which I think is the default, or one of them, right? I didn't download any that I recall.