Question [Q] Tablets for Schools: Prevent user changing wallpaper - any ideas?

Hi all,

I'm in the process of preparing a number of Acer Iconia 210a tablets (JB) for use in the school where I work.

They're going to be 'shared' devices used by up to 5 different users each day, from a user base of about 800. This presents some issues, some of which I have addressed already.

I started trialling the tablets this week and have realised that just using an AppLock-style app to keep the users away from the settings isn't enough: they can set the wallpaper from within the Gallery app (I had a wonderful array of inappropriate images to remove yesterday afternoon!)

I was hoping there might be some bright ideas from this forum as to what might be the best way to prevent the wallpaper being changed. I have root on the devices and already have a shell script that runs on boot that could be added to, if that helps. I am also using ADW launcher, in case that makes a difference.

I have contemplated a couple of approaches:
  1. If I knew where the 'current wallpaper' file or setting was stored, I could just copy this to a read-only filesystem and copy it back into the correct location on a scheduled basis or on the device booting. I did wonder if it was stored within ADW and copied /data/data/org.adw.launcher to another location and overwrote it back after changing the wallpaper. This just reset ADW to default settings, except for the unwanted wallpaper!

    There are a couple of threads on the forum that state the location of the wallpaper and suggest that changing the permissions of the file would solve this but they must be for older versions of the OS because the file in question does not exist.

  2. I think Tasker can change the wallpaper, so I could go down that route and get Tasker to 'reset' the wallpaper every 5 mins but it might be expensive with the number of tablets we have. (If Tasker can set the wallpaper, surely I can find a command/simple app to do so??)

  3. I was using a live wallpaper and my first thought was that I might be able to just start that process using the 'am start' command but I couldn't find the correct syntax/activity name to test that idea..

  4. There are apps out there that will cycle through random wallpapers on a timer. I could use one of these and just have a 'pool' of one wallpaper for it to select from. I could then just hide the config for that app behind AppLock or similar. However, most of the similar apps I've looked at have a feature whereby you can 'easily add to your random wallpapers direct from the gallery app' - the exact thing I want to prevent. Maybe there is a similar app without this feature that would suit my needs better..?

Which route do you think might be best for me to investigate? Is there another direction that would be better?

Thanks for your toughts,
Tim