Hi,

I am using KDE a lot over VNC connections (vnc4server and vnc4client from ubuntu packages mainly). I am enhancing the experience (speed and display quality) by choosing simple styles for window decorations and switching off all effects. But there are things which I don't get fixed. For instance krunner always looks cluttered (independent of resolution and colour), such that you cannot recognize anything except the input field. Also the background of the icons appears black. Same for the buttons in window decorations which also change if the mouse hovers over. Any hints on which themes/styles to use and which options to use for good experience with VNC are highly welcome.

Thanks,
Andreas

Which application style and window decoration are you currently using?
Oxygen uses gradients, etc heavily - which may result in a degraded/slow experience over VNC.

I use the Plastik theme for window decorations and Air as desktop theme, Oxygen icons and the Default color scheme. Still the result if far from optimal, especially when using less display colors. Some problems, such as that with krunner, seem to be independent of the used schemes.

Where does the background of icons appear to be black? In all KDE applications?
Just to confirm - you have compositing disabled correct?

With my present settings the background appears black in the system tray and the window decorations. Krunner is awful.

In the system settings the page about the effects shows the message:
Desktop effects are not available on this system due to the following technical issues:
Required X extensions (XComposite and XDamage) are not available.

The advanced tab says: Compositing type "OpenGL 2.0" and Qt graphics system "Raster". If I try to change compositing type to XRender I get an error message saying: "Failed to activate desktop effects using the given configuration options. Setting will be reverted to their previous values..." and it returns to "OpenGL 2.0". That's maybe a bug. Another buggy behaviour wich seems to come along with VNC use is that klipper does not read the clipboard correctly. In non-KDE applications I observe that I can use the clipboard within these applications, but the content is not copied to klipper.

Can you please provide a screenshot? It sounds like the current graphics server you are using to run KDE has no support for ARGB visuals.

https://www.dropbox.com/s/zv57gaem43i7hvr/snapshot2.png

Very unusual. Definitely looks like you could be missing ARGB visual support. How are you running KDE through VNC? Is it a full blown X server with a VNC server attached to it, or something else?

> Required X extensions (XComposite and XDamage) are not available.
You cannot use compositing in this configuration, neither XRender nor OpenGL will be activated.

I rather guess that the server has issues with ARGB visuals, rather than not supporting them.
Since you cannot use compositing in the first place, try

export XLIB_SKIP_ARGB_VISUALS=1

for the session. You can do so by adding

~/.kde/env/skip_argb.sh # notice that it may be ~/.kde4/...
--------- snip -----------
#!/bin/sh
export XLIB_SKIP_ARGB_VISUALS=1
--------- /snip -----------

and "chmod +x ~/.kde/env/skip_argb.sh"

reg. performance you can try "export QT_GRAPHICSSYSTEM=raster", resp. "export QT_GRAPHICSSYSTEM=native"

Thanks for your replies! I will definitely try these as soon as I can restart the session. As for my vnc, I don't know exactly what they do internally, but I think vnc4server is pretty much ubuntu standard. I run server and viewer usually with

vnc4server -name "$my_name" -geometry $geometry -geometry 1280x720 -geometry 1024x768 -geometry 1600x900 -geometry 1680x1050 -geometry 1920x1080 -depth 16
xvnc4viewer -PasswordFile $HOME/.vnc/passwd -SendPrimary=1 -AcceptClipboard=0 -SendClipboard=0 -LowColourLevel=2 -FullScreen -PreferredEncoding ZRLE

The kde krfb/krdc solution is a lot slower than this unfortunately.
Note however, the screenshot was taken with full color. Despite the clipboard options, the remote clipboard is neither copied to klipper nor to the viewer clipboard.

I just restarted - after upgrading to 4.12. Adding
export XLIB_SKIP_ARGB_VISUALS=1
does not seem to change anything, unfortunately.
Adding also "export QT_GRAPHICSSYSTEM=raster", resp. "export QT_GRAPHICSSYSTEM=native" makes it even worse
https://www.dropbox.com/s/1wccvjkt0fhp81y/snapshot3.png

Since the systemsettings dialog still shows OpenGL which cannot be changed to XRender, I will probably connect a monitor once and change it to XRender then.

After connecting a screen, the settings in the systemsettings dialog are XRender and Raster now, but this didn't solve the icon issue.

Unfortunate. The lack of change after setting XLIB_SKIP_ARGB_VISUALS is unusual though - can you verify in a terminal that it is being set (and isn't being overridden/unset elsewhere)?

The only other solution would be to try a different VNC server i'm afraid.

Yes, it is set. Thanks for trying.