Lock/Disable "Change Desktop Background"

[stiV]

Hello!

Is there any way to make it impossible for a user to change its desktop background image? Or even better - change the Theme at all?

We have a few surf stations, which are relatively "open", but users keep changing the background image... And no they are not pretty ;)

Can I stop that somehow?

Ubuntu 12.04 and 11.10

[MG&TL]

I think you're after dconf keys. http://askubuntu.com/questions/132175/how-to-store-a-dconf-key-as-read-only

...the one you're after is org.gnome.desktop.background.picture-uri , I think.

[stiV]

Can you help me a little more?

There is no "/etc/dconf", and what I have tried in a virtual machine ended up destroying the machine ... (at least Gnome did not start anymore)

I don't really know what files/folders I need to create to make that work ... one user (which can't use "sudo") should not be able to change the background image...?

[MG&TL]

Okay, my bad, I don't have that on my system either.

One thing you could do (instead of stopping users changing the background) is to reset it every login-is that a problem or not? The command you'd put in startup applications would be:


gsettings set org.gnome.desktop.background picture-uri "file:///usr/share/backgrounds/warty-final-ubuntu.png"

...and I've tested this myself this time. :)

I'm not really sure how to accomplish this as you wish, as it's not something ubuntu's been designed to do.

[stiV]

Thank you! ... I guess I'll create a cronjob that runs every few minutes that exectues that command, should be enough.

I love ubuntu and have loved ubuntu for years, but it really does lack features and seems seriously unfinished at times. A task like this is not easy in windows, but it is possible ... without such a bad workaround.

[MG&TL]

Thank you! ... I guess I'll create a cronjob that runs every few minutes that exectues that command, should be enough.

I love ubuntu and have loved ubuntu for years, but it really does lack features and seems seriously unfinished at times. A task like this is not easy in windows, but it is possible ... without such a bad workaround.

gsettings is per-user...I'm guessing a cronjob will only affect cron's background. :lolflag:
Maybe a "while true" in the startup thing? I agree with you about the workaround bit...but you'd really have to rewrite a lot of stuff to get that done.

[stiV]

It works if I execute it as root using "su USERNAME -c 'COMMAND' ", the background gets set ;)

[MG&TL]

It works if I execute it as root using "su USERNAME -c 'COMMAND' ", the background gets set ;)

Fair enough. Whatever works. :)

[wittyman37]

Thank you this works for me as a workaround for now. I really want to be able to completely block the user (student in my case) from being able to change the desktop background at all. We already had one student put a dirty picture as the background.

I used this for Edubuntu 12.04 with gnome fall back desktop with no effects:



gsettings set org.gnome.desktop.background picture-uri "file:///usr/share/backgrounds/edubuntu_default.png"

This will change the desktop background back each time the user logs in (or boots up). This is not perfect, but it will work until I find a real way to completely block the user from changing the background image like I can in Windows 7.