4

As far as I remember, on previous Kubuntu version (18.10) when I hit Ctrl-F9 - KWin shows all open windows. But after upgrade to 19.04 it does not work anymore. In hotkeys settings Ctrl-F9 is still shortcut for this feature, but when I press it - nothing happens and I don't know neither how to launch it from command line to see errors nor where to see logs.

  • 2
    Are you sure compositing is enabled? Shift+Alt+F12 toggles compositing which is needed for certain desktop effects including Ctrl+F9. – DK Bose May 4 at 1:36
3

Present Windows is a desktop effect. For it, and certain other desktop effects, to work, compositing needs to be enabled. You can check the status by opening a terminal and running:

qdbus org.kde.KWin /KWin supportInformation | grep -i composit

You may see something like this as the output:

Composite: yes; Version: 0x4
compositingMode: 1
useCompositing: true
compositingInitialized: true
windowsBlockCompositing: true
Compositing
Compositing is active
Compositing Type: OpenGL

You can toggle compositing on and off using Shift+Alt+F12.

Alternatively, use the GUI to ensure that compositing is turned on when the system starts:

Set compositing enabled on startup

  • Thanks for answer. Checked "supportInformation" - "useCompositing: true". In system settings corresponding checkbox is already checked. Ctrl-F9 still does not work. – Dmitriy Vinokurov May 4 at 8:37
  • 1
    After reboot it started to work. – Dmitriy Vinokurov May 19 at 10:42
  • 1
    Question was about my personal laptop, now I faced same trouble on work PC. Compositing was enabled but command from this post shows "Compositing is not active". I solved it switching to XRender instead of OpenGL. – Dmitriy Vinokurov Jun 10 at 11:56
  • Thanks for updating! Does your work PC not have a nice GPU? – DK Bose Jun 10 at 11:59
  • lspci shows "NVIDIA Corporation GF119 [GeForce GT 610] (rev a1)" – Dmitriy Vinokurov Jun 10 at 12:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.