EDIT: [SOLVED]
View this post for solution

Ok, i use firefox in fullscreen mode with Desktop Effect activated and everytime i left click so the menu appears the screen "flicks", it gets black for like 0.1ms and then redraws, or so it seems.
Also occurs if i hit bookmarks or move a tab, always when a new menu appears.

Can anyone confirm this?
Firefox + Desktop Effect in Fullscreen mode (doesn't matter if the builtin F11 fullscreenmode or the Alt +F3 kde mode).

If i disable desktop effects and use firefox in fullscreen everything works fine.
If i use Firefox with desktop effects not in fullscreen everything works fine.

EDIT:
Oddly it doesn't "flick" if i have the Amarok OSD displaying my current track. Very odd...

I can explain the reason for this flickering but I don't know a fix, unfortunately.

In order to provide "dekstop effects" (i.e. transparency, fading windows and the like) windows are not drawn directly on the screen. Instead they first draw their contents into a so-called off-screen pixmap. Then kwin copies that pixmap onto the screen. By doing this, kwin "knows" the contents of each window and can provide effects like transparency. That procedure is called redirecting and compositing.

However, since those additional steps slow down your system they are automatically disabled when a window is displayed full-screen. Since there isn't anything that shows on top or below the window, composition is not needed. That way you can view full-screen video without any slowdown.

However, as soon as something shows on top of the full-screen window (like a menu or popup) kwin has to switch to compositing mode again. Every time it switches, it causes a short flicker.

Compiz offers an option to disable "unredirection of full-screen windows" but I can't find such an option for kwin.

Hey, thanks for the answer, although it doesn't help it feels better to know why it flickers

i can confirm that compiz doens't "flick" in the exact same situation. i actually just switched back from compiz to try out 4.4 a bit. Somehow nor kwin nor compiz make me happy for now

Please file a feature request at bugs.kde.org so the KWin developers can assess if a feature to always redirect windows is needed.

Done:

https://bugs.kde.org/show_bug.cgi?id=226852

This feature is already available! Add the following line to your ~/.kde4/share/config/kwinrc in the [Compositing] section:

Code: Select all

UnredirectFullscreen=false

Be sure to restart KWin afterwards:

Code: Select all

kwin --replace

Hey, that's good to know, thanks.

However, I'd like if it was possible to disable this only for specific windows. For example, I want mplayer to be unredirected in full screen for smooth video playback but I want to disable the feature for firefox.

Hey thanks for the solution.
I quoted the solution on the bugtracker so it is available there, too.

OT: Why am i unable to add a [solved] to the topic title? I did "accept the answer" of ademmer but title didn't change...

dye464 wrote:Hey thanks for the solution.
I quoted the solution on the bugtracker so it is available there, too.

OT: Why am i unable to add a [solved] to the topic title? I did "accept the answer" of ademmer but title didn't change...

Clicking on below the post with the answer is all you need to do to mark topics as solved . Either you did it, or a mod did it for your and removed [solved] in the title. (See thee green checkmark next to the title?)

You can revert the solved status by clicking on .