HOWTO: (GDM) Show the user wallpaper/background color, while logging in

[dwitkin]

Originally Posted by dwitkin Hello. Just wanted to say that I also experience the screen turning black at a certain point, but it doesn't appear to be a Compiz issue. I read earlier in this thread that the thinking was the screen turns black due to Compiz, so I uninstalled Compiz. I still get the same black screen issue in this order: (1) I get the wallpaper, as expected, almost immediately after entering my pasword; (2) about 10 seconds later, I get a completely black background but I can see the panels and a few programs that show windows as they start up (note: my login / background color is set to Brown, I believe, not black); (3) About 10 seconds later, I get the wallpaper again. Any other ideas on how to address the issue? Thanks.

Ignore my post above about Compiz not being the issue. I must have not fully re-booted before or something. In any case, Compiz is uninstalled and I am no longer experiencing the black screen issue... So, I guess Compiz is the culprit.

Aside from the black screen interaction with Compiz, this hack works great. Thanks.

[peakpc]

This trick works very well for me in Hardy with compiz-fusion it even works with webiulder (background picture changer so I have a differnt desktop every hour) I just had to make sure that all my desktop photos were sized to 1280X800 (laptop screen size) now I have to pick out a new splash screen...as the old one was geared to blend in with the black screen I had before (got rid of the ugly brown color a while back)

[hollerith]

I'm having a problem with gnome is obscuring the rootwindow with the desktop background. I turned off nautilus show_desktop and I still see the wallpaper specified in Appearance Preferences/Backgrounds. This hack for setting the rootwindow with xsetroot or xloadimage or xscreensaver-getimage doesn't work for me as they all behind the wallpaper. Is there a gdm setting 'use real root window not a virtual one'. How you guys don't have this problem?

[peakpc]

Hey Kirsis this how to works great, Is there a way to get the current background (mine changes) to be directed to the gdm login screen? maybe some modification of your code in the background area of the greeter's .xml file? any help would be appreciated.

[peakpc]

I have given this some further thought and have some new questions?

Can this script be modified to run before the GDM login?

Can the background image in the Login be made transparent (png instead of jpg)?

I don't understand everything your script is doing exactly, yet. but I do like it!

[kirsis]

peakpc:

It's possible to make the script run before GDM, most things are on GNU/Linux systems Don't think GDM'd honor transparency in a background PNG, though.

If you want it to set the background of your GDM login screen, your best bet would be to run it before GDM (as an init script, thus - as root), extract the path to the background image as in this script (though you'd have to manually specify the user, whose background should be chosen) and make a link between that image and the background image of your GDM theme.

This would break, though, if you'd change your GDM theme (as it'd likely look for the background elsewhere and you'd have to adjust the script)

Probably not worth the hassle

[mike-uk]

kirsis - first of all I would like to thank you for your solution; It worked perfectly
Excuse my ignorance but is it possible to have the compiz-fusion splash appear during this period
Just looking for something animated.
mike-uk

[vexorian]

This doesn't seem to be working for me, out of the box that is, I noticed that script is run by root, not by my user, so it wasn't getting any background file and it was placing a primary_color that was totally different from mine, I had to use "sudo -u myUserName" It works, but it won't work for multi user...

Edit: GDM documentation to the rescue!

This version of the script should work on more situations (aka when there are many users and each has a different wallpaper), for example if root's wallpaper is different to what you really want... Hey, at least you don't have to manually add and remove -tile when you change that option of your wallpaper...

#!/bin/sh
#
# Note that output goes into the .xsession-errors file for easy debugging
#

# gdm always runs PostLogin as root, the USER variable is set to point out the user name.
# that, and sudo are enough to get the correct configuration.

# Extract the wallpaper filename
WALLPAPER=$(sudo -u $USER gconftool-2 --get /desktop/gnome/background/picture_filename)
# Extract the picture option (important so we know if -tile should be used)
MODE=$(sudo -u $USER gconftool-2 --get /desktop/gnome/background/picture_options)
# Extract the primary_color (in case the wallpaper image cannot be used)
PRIMARY_COLOR=$(sudo -u $USER gconftool-2 --get /desktop/gnome/background/primary_color)

# Check if the wallpaper file exists. If yes - draw it, if no - use primary background color
if [ -e "$WALLPAPER" ] && [ -f "$WALLPAPER" ] ; then

    # if mode is "wallpaper", use the -tile option
    if [ "$MODE" = "wallpaper" ]; then
        xsetbg -tile -onroot "$WALLPAPER"
    else
        xsetbg -fullscreen -onroot "$WALLPAPER"
    fi
else
    xsetroot -cursor_name left_ptr -solid "$PRIMARY_COLOR"
fi

exit 0

A lot of thanks since I only needed to do small tweaks to the script to make it work, the rest are things that I wouldn't be able to know that existed, like the whole utility to draw on the background and the GDM scripting. My desktop quality of life has improved a lot now that the background is loaded just after you make a succesful login.

[kirsis]

That's pretty cool, vexorian. Updated the first post to point to here.

edit: odd, though, that it was ran by root. '~' should've worked in PostLogin

[vexorian]

Well, I don't know, but GDM's documentation actually says postlogin is run for root. This doesn't explain how ~ has worked for so many people...

It seems [xsetbg -onroot "$WALLPAPER"] needs to change to [xsetbj -fullscreen -onroot "$WALLPAPER"]