(I am not sure if Plasma is the correct choice to report this bug against.) Drag&drop is not usable due to its slowness. When dragging something with the mouse, the object being dragged stays behind the current mouse position by several seconds. I've made a video that demonstrates this bug: https://www.youtube.com/watch?v=2_etvLIzlKQ (I will also attach the video to this bug report.) Note that in the video, I used Dolphin for the demonstration, but the bug is there with everything else too (like for desktop icons or dragging a process line in ksysguard.) Suspending desktop compositing does not have any effect. Drag operations are extremely slow even without compositing. My system: Gentoo Linux AMD64 KDE Plasma 5.5.3 KDE Frameworks 5.18.0 KDE Applications 15.08.3 Qt 5.5.1 X.Org server 1.17.4 NVidia driver 352.63 Kernel 4.1.15 Reproducible: Always
Created attachment 96669 [details] Video demonstrating the bug
I have this problem as well when I have an application rendering something every frame in the background.
(In reply to CapsAdmin from comment #2) > I have this problem as well when I have an application rendering something > every frame in the background. For this happens without even a single application running. Just logging in to KDE without starting anything, the problem is there.
(In reply to Nikos Chantziaras from comment #3) > (In reply to CapsAdmin from comment #2) > > I have this problem as well when I have an application rendering something > > every frame in the background. > > For this happens without even a single application running. Just logging in > to KDE without starting anything, the problem is there. I understand and I think it's somewhat constantly slow here too but for it to get as slow as in your video I'd have to be watching a video or something that refreshes a lot in the background.
Forgot to close this. It was a Qt issue. Recent versions of Qt have fixed it.