Fedora 29, x64 Xfce 4.13 Libre Office 6.1.3.2 pulses at me every two seconds or so. Calc will stop if I activate a cell. Writer keeps pulsing
Other folks reproductions from the Fedora mailing list (Community support for Fedora users <users@lists.fedoraproject.org>): I'm also experiencing this flickering issue under XFCE. If I open LibreOffice and leave the mouse pointer over a recent document preview image, this image starts blinking. A similar issue happens if I leave the mouse pointer over a menu icon (e.g., open a document and move the mouse pointer over the "Save" button; the image will start flickering). This issue is not present under GNOME (I tried both in the Wayland and the X.org version of GNOME). Yeah, I see this. If I move the pointer inside the icon, but still within the icon's area, the flickering stops. After I stop, half a second later the flickering comes back. The flicking seems to be caused by repeated rendering of the pointer focus border around the icon, and the icon's gradient background, when the pointer is on top of it. Also, with no mouse movement, the mouse pointer itself seems to occasionally jump about a dozen pixels diagonally, before snapping back to its actual position. Something is losing track of the mouse pointer and thinks it moved away, draws the icon as if it's no longer under the pointer, then realizes that no, the pointer is where it should be, so the icon should still be highlighted. top shows libreoffice's process eating 12% CPU, and X itself adds another 15% on top of it.
This seems to be a problem with tooltips. Before upgrading my last laptop, I did some testing. In f28, moving the pointer on top of any icon in the toolbar, such as the "Save" icon, results in a semi-transparent tooltip popping up, for that icon, after a brief delay. In f29, after a brief delay the same results in flickering and libreoffice pinning the CPU. I am also not seeing any visual indication of the tooltip coming up, even briefly, but the app appears to interpret the process of the tooltip getting created as losing the pointer focus on the tooltip's icon; so it gets redrawn without the active pointer focus background, and let's lose the tooltip we just created. But, wait a second, the pointer is now on top of the icon, so it must have pointer focus, so let's draw it with active pointer focus background. And since it's been idle for a while, let's try to draw the tooltip again.
This may be caused by a known bug in GTK3. https://forum.xfce.org/viewtopic.php?pid=50258#p50258
-> Applications --> Settings Editor --> Others --> Settings Editor --> xsettings --> xsetting (bottom left) --> Gtk (drop down pointer on right) --> CursorThemeSize (default is 21, change to 16) Did not help. Sniffle.
I've seen a similar issue related to Thunar's side panel, can't find the bug right now, but here's a thread of people commenting about it: https://forum.manjaro.org/t/gtk-3-3-24-tooltip-flickering/58767/11 I would close this bug as INVALID, but please let us know if you guys are still experiencing this.
Closing, please update gtk to the most recent release. Reopen if this is indeed an Xfce bug.