SUMMARY If you hover the mouse on a small window preview created by the icons-only task manager, it shows a full-size preview of said window. The problem is that this preview is shown as soon as the mouse hovers over it; if you have multiple small previews and move your mouse over them, this makes the screen flash as the previews are very quickly changed. Not only is this unpleasant to a normal person (and I mean "normal" in a statistical way), but it can cause issues to people with specific disabilities and/or conditions (e.g. epilepsy). It would be much better if the full-size preview was shown once the mouse cursor is actually still, or at the very least after a given interval (e.g. 250 ms) has passed so as to avoid this flashing. STEPS TO REPRODUCE 1. Have multiple windows of a given application 2. Bring up the small window preview on the icons-only task manager 3. Move your mouse quickly over those window previews OBSERVED RESULT The screen flashes as it very quickly goes from one full-size preview to the next. EXPECTED RESULT The screen doesn't flash; the full-size preview is only shown once the mouse is actually still. SOFTWARE/OS VERSIONS Linux: KDE neon KDE Plasma Version: 5.27.5 KDE Frameworks Version: 5.105.0 Qt Version: 5.15.9 ADDITIONAL INFORMATION
While adding a delay would be best, a way to reduce flickering/flashing would be to extend the area where the preview window is displayed until it touches the next one. Currently, the middle area between two icons shows no window at all, so moving from one window to the next would cause flashing twice rather than once, moving to a window with one intermediate window causes four flashes rather than two, etc.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/2816
*** Bug 500186 has been marked as a duplicate of this bug. ***
*** Bug 501735 has been marked as a duplicate of this bug. ***
Hi -- came here to comment from https://bugs.kde.org/show_bug.cgi?id=501735 (I tried creating an account to comment on https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/2816, did so, and then every attempt to login with the new account failed). If someone could copy this feedback there I would be obliged. 1. I think cwo's comment https://bugs.kde.org/show_bug.cgi?id=469983#c1 is correct about the border -- that border between thumbnail items is responsible for the very brief flash of the full desktop and is very distracting. If the border wasn't present there would be no flash. 2. If you must add a delay before showing the windows, please ensure the delay respects the existing animation delay settings (i.e., the delay can be turned off completely). I use this feature to rapidly switch between windows hundreds of times a day, and adding an artificial delay to that would be very frustrating. Thanks.
(In reply to Nik Clayton from comment #5) > 1. I think cwo's comment https://bugs.kde.org/show_bug.cgi?id=469983#c1 is > correct about the border -- that border between thumbnail items is > responsible for the very brief flash of the full desktop and is very > distracting. If the border wasn't present there would be no flash. This would not solve moving over the thumbnail from the task manager, as in the first set of videos on the MR. (There's also some other issues with this that I realized while considering how to implement it, largely relating to feedback and consistency, these might be solvable of course but will need more thinking and testing if I get around to attemt an implementation). > 2. If you must add a delay before showing the windows, please ensure the > delay respects the existing animation delay settings (i.e., the delay can be > turned off completely). I use this feature to rapidly switch between windows > hundreds of times a day, and adding an artificial delay to that would be > very frustrating. It's not an animation but a hover delay, like the delay for showing the tooltips in the first place. Animation speed does not affect that either (I just tested it). In fact, it works the same way - once the tooltip is active, moving to another thing showing the tooltip is instant, as is the highlight effect, only the initial showing of the tooltip is delayed to prevent accidentally showing it. But it's a fair bit faster at half the time it takes for the initial tooltip to show up. (Another reason to not use animation speed is that often people lower or eliminate animation speed to reduce movement on the screen, e.g. for accessibility reasons. Making this instant increases movement on the screen, so would clash with that). I wouldn't be opposed to making it conditional on something, but I don't think we have a good setting for that already, and I'd prefer not adding one. But there might be something we could use that I can't think of at the moment. I'll also cross-post this to invent.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/3077
Git commit 5d0f0926846090e2f60d45f97f944f4d791f9198 by Nate Graham. Committed on 23/06/2025 at 15:17. Pushed by ngraham into branch 'master'. applets/taskmanager: disable window highlighting by default Part of https://invent.kde.org/plasma/plasma-desktop/-/issues/149 This effect can trigger full-screen-flickering when invoked on maximized windows, which is distracting and disorienting. When there are multiple such windows and you make it happen by moving the pointer over their tasks, it can actually trigger a seizure in people sensitive to that kind of thing, since the flickering happens at faster than 3 Hz. The effect is therefore too dangerous to have on by default; disable it. @teams/accessibility M +1 -1 applets/taskmanager/package/contents/config/main.xml https://invent.kde.org/plasma/plasma-desktop/-/commit/5d0f0926846090e2f60d45f97f944f4d791f9198
Git commit 2146e26d68cab46c7df0dd9631bde32225ebfbf7 by Nate Graham. Committed on 23/06/2025 at 15:18. Pushed by ngraham into branch 'Plasma/6.4'. applets/taskmanager: disable window highlighting by default Part of https://invent.kde.org/plasma/plasma-desktop/-/issues/149 This effect can trigger full-screen-flickering when invoked on maximized windows, which is distracting and disorienting. When there are multiple such windows and you make it happen by moving the pointer over their tasks, it can actually trigger a seizure in people sensitive to that kind of thing, since the flickering happens at faster than 3 Hz. The effect is therefore too dangerous to have on by default; disable it. @teams/accessibility (cherry picked from commit 5d0f0926846090e2f60d45f97f944f4d791f9198) 26fb2592 applets/taskmanager: disable window highlighting by default Co-authored-by: Nate Graham <nate@kde.org> M +1 -1 applets/taskmanager/package/contents/config/main.xml https://invent.kde.org/plasma/plasma-desktop/-/commit/2146e26d68cab46c7df0dd9631bde32225ebfbf7
Raising this as a "see also" thing for those drawn to this bug - there's a bug I found (and reproduced by @cwo) where you can actually get the window preview to rapidly flicker at 60 hz or higher between the window and the desktop, in certain situations. This and several related issues are currently being discussed here: https://bugs.kde.org/show_bug.cgi?id=504900 I have a video attached to that issue.
Hi Nik, So, I was really excited when I recently discovered this: https://discuss.kde.org/t/all-this-time-i-just-thought-it-was-slow/30523 TLDR > kwriteconfig6 --file ~/.config/plasmarc --group PlasmaToolTips --key Delay 100 (alter the delay to your taste. 0 disables all tooltips so you probably don't want that, use 1 for 'no delay') Since, I have been enjoying the ability to flip through the previews quickly like you mentioned in #5. It needed to be reapplied in 6.4, but generally sticks through updates. Hope this helps.