HowTo: Wallpaper Changer for Xubuntu (Xfce)

[hyper_ch]

Hiya

I have switched to Xubuntu a few months ago coming from Kubuntu. I liked there the (already available) option of setting up a list of image files and have them randomly displayed. This was one of the things I have missed so far in Xfce.

As former Windows user I have aquired quite a large number of wallpapers (thx goes to HTTrack for downloading over 18k wallpapers...) and I like to have them displayed on the background. That's more or the less the only major change I do on a theme (if you can call that a change...)

Anyway, thx to TheSheep from the #xubuntu channel on irc.freenode.org (he's a really helpful guy and has helped me countless time) I can provide you with this small howto.

(1) Build your list of images
- Right-click on your desktop
- Select "Desktop settings"
- Make sure that "Allow Xfce to manage the desktop" and "Show Image" boxes are checked (they are by default)
- Click then on "New list"
- Add the image files by clicking on the "+"
- Once you are done, save the list
- You are back in the previous screen and your newly created list should be selected in the "File" input box
- Then close that interface

(2) Creating Cronjob for Wallpaper Changer functionality
- Open a terminal
- If you already have a "cron-command" file for your user, open that one in a text editor if not execute this command: nano cron.txt
- Enter the following two lines to the cron file:


# Reload Background Image
0,5,10,15,20,25,30,35,40,45,50,55 * * * * killall -USR1 xfdesktop

This will change the image every 5 minutes. You can also change the behaviour. Please refer here: Cron HowTo (https://help.ubuntu.com/community/CronHowto)
- Exit nano by pressing ctrl-x
- Press [y] to save the file

(3) Adding the Cronjob for Wallpapcher Changer
- Before you overwrite any existing user cronjobs please execute this command:


crontab -l

If nothing is returned then it's fine to add you wallpaper changer script!
- Add the cron.txt file that we created under section (2) by issuing the following command in the shell:


crontab cron.txt

- Enter now again crontab -l and you should have this output:


hyper@xubi:~$ crontab -l
# Reload Background Image
0,5,10,15,20,25,30,35,40,45,50,55 * * * * killall -USR1 xfdesktop


(4) That's it
- Get some coffee or whatever and enjoy your desktop bakground wallpaper changer :)

[Tails]

ah, nice one, I will try it later night.. this is 1 hell of the hack I want to have in xfce.. :D

[eteran]

Thanks for the hint, works out great.

Just as a little addition, the crontab line could be also written as:

*/5 * * * * killall -USR1 xfdesktop
to change the background every 5 minutes

[eteran]

somebody might find this script useful.
you will need to have at least php4-cli installed to run it.



#!/usr/bin/env php
<?php

/**
* xfce4-background-changer
*
* a bit of automating for the xfce4 desktop
*
* it recreates the background list automaticly as I found the gui
* not comfortable enough and "reloads" afterwards the desktop causing a
* new background picture being randomly displayed
* you can put it in your crontab to change the background every
* now and then (man crontab)
* f.e. "* * * * * ~/scripts/xfce4-background-changer.php"
* or you might place a desktop starter to change the background
* everytime you activate the starter
*
* PHP version 4 and 5
*
* LICENSE:
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* @author David Uhlig <david.uhlig@googlemail.com>
* @copyright 2007 David Uhlig <david.uhlig@googlemail.com>
* @license http://www.gnu.org/licenses/gpl.txt GNU GPL
* @version 1.0
*/

// {{{ settings

/**
* home
*/
define('HOME', $_ENV['HOME']);

/**
* directories with wallpapers, or wallpaper files
* use absolute path, seperate by comma
* !!! no closing slash for directorys
* !!! directories will _not_ be walked through recursive
*/
define('BACKGROUND_DIR', HOME . '/.wallpaper');

/**
* absolute path to your background list as choosen via
* Applications / Settings / Background -> Picture -> File
*/
define('BACKGROUND_LIST', HOME . '/.config/xfce4/desktop/hintergrundbilder.list');

// }}}

// {{{ functions

/**
* rewriteBackgroundList
*/
function rewriteBackgroundList()
{
$res = fopen(BACKGROUND_LIST, "w");
fwrite($res, "# xfce backdrop list\n");

if ($res === false)
{
return;
}

$aryBackgroundDir = split(",", BACKGROUND_DIR);

foreach ($aryBackgroundDir as $strBackgroundDir)
{
if (is_dir($strBackgroundDir))
{
$aryDir = scandir($strBackgroundDir);

foreach ($aryDir as $strFile)
{
if (is_dir($strFile))
{
continue;
}
if ($strFile == "." || $strFile == "..")
{
continue;
}
if (!file_exists($strBackgroundDir . "/" . $strFile))
{
continue;
}

fwrite($res, $strBackgroundDir . "/" . $strFile . "\n");
}
}
elseif (file_exists($strBackgroundDir))
{
fwrite($res, $strBackgroundDir);
}
}

fclose($res);
}

/**
* php4 compat for scandir
* taken from php.net/scandir user comments
*/
if(!function_exists('scandir')) {
function scandir($strDir, $intSortorder = 0) {
if (is_dir($strDir)) {
$strDirlist = opendir($strDir);
while (($strFile = readdir($strDirlist)) !== false) {
if(!is_dir($strFile)) {
$aryFiles[] = $strFile;
}
}
($intSortorder == 0) ? asort($aryFiles) : rsort($aryFiles);
return $aryFiles;
} else {
return false;
}
}
}

// }}}

// {{{ main

rewriteBackgroundList();
exec("killall -USR1 xfdesktop");

// }}}
?>

[ruiferreira]

Try gaze.sourceforge.net it's a nice wallpaper switcher that fetches images from flickr. Just works with gnome, though :|

[BlackTopBum]

Thank you, this is somewhat sweet. I say "somewhat" because if I'm not logged in cron sends the following message (25 of them last night alone <g>):

Cron <cmo@codybeau> killall -USR1 xfdesktop
xfdesktop: no process killed

Know of a way around this and yet allow switching images? i *REALLY* like the changing wallpaper.

[hyper_ch]

could the output maybe piped to /dev/null?

e.g.



0,5,10,15,20,25,30,35,40,45,50,55 * * * * killall -USR1 xfdesktop | /dev/null


I've never tried that above so I have no clue whether this works... just a suggestion that you may want to try.

[BlackTopBum]

could the output maybe piped to /dev/null?

e.g.



0,5,10,15,20,25,30,35,40,45,50,55 * * * * killall -USR1 xfdesktop | /dev/null


I've never tried that above so I have no clue whether this works... just a suggestion that you may want to try.

Thanks for writing ! Yes, you're right that you might be wrong <g>. I've thought it over and this works:

# Reload Background Image
*/30 * * * * killall -USR1 xfdesktop > /dev/null 2>&1

[ramasdf123]

how can i get this to work on gnome?

[BlackTopBum]

You can't. Use this instead: http://ubuntuforums.org/showthread.php?t=18163

[gringogrande]

Nice. Problem is that my computer has a tendency of freezing up during the changes, and when I'm playing games or watching movies, I'd prefer it to not switch, so I whipped up a little script that temporarily lowers it scheduling priority.


#!/bin/bash
#change-background

#get the pid for xfdesktop
pid=`ps -e | grep xfdesktop | gawk '{print $1}'`

#a regular expression containing the names of the processes
#that will defer the switching
deferred='(mplayer|xgame)'

if [[ -z $pid ]] && [[ -n `ps -e | egrep $deferred` ]]; then

else
renice 19 -p $pid
kill -USR1 $pid
renice 0 -p $pid
fi

[daynah]

Nice. Problem is that my computer has a tendency of freezing up during the changes, and when I'm playing games or watching movies, I'd prefer it to not switch, so I whipped up a little script that temporarily lowers it scheduling priority.


#!/bin/bash
#change-background

#get the pid for xfdesktop
pid=`ps -e | grep xfdesktop | gawk '{print $1}'`

#a regular expression containing the names of the processes
#that will defer the switching
deferred='(mplayer|xgame)'

if [[ -z $pid ]] && [[ -n `ps -e | egrep $deferred` ]]; then

else
renice 19 -p $pid
kill -USR1 $pid
renice 0 -p $pid
fi

I'm not smart like you. Is it on line 9 that I could change it to something like...



deferred='(mplayer|xgame|vlc)'

?

[gringogrande]

I'm not smart like you. Is it on line 9 that I could change it to something like...



deferred='(mplayer|xgame|vlc)'

?
Yes, exactly. Any process that contains the three letter combination 'vlc' (like wxvlc, for instance) will then disable the script from changing the background.

[Cheese Sandwich]

how can i get this to work on gnome?

http://ubuntuforums.org/showthread.php?t=415255

[kspn]

Nice. Problem is that my computer has a tendency of freezing up during the changes, and when I'm playing games or watching movies, I'd prefer it to not switch, so I whipped up a little script that temporarily lowers it scheduling priority.


#!/bin/bash
#change-background

#get the pid for xfdesktop
pid=`ps -e | grep xfdesktop | gawk '{print $1}'`

#a regular expression containing the names of the processes
#that will defer the switching
deferred='(mplayer|xgame)'

if [[ -z $pid ]] && [[ -n `ps -e | egrep $deferred` ]]; then

else
renice 19 -p $pid
kill -USR1 $pid
renice 0 -p $pid
fi

I used this script and it is working perfectly, thanks.

It makes life so much easier when things just work! I added an icon so that if I don't feel like using that image then I can switch to a new one.

Thanks for the tip.

[gtr225]

Thanks, this helped.

[dakal]

I ended up using this crontab line to avoid trying to send signals to other users' xfdesktop processes:


*/10 * * * * kill -USR1 $(ps awxu | grep -E '^loginname[ \t]+.+[0-9:]+ /usr/bin/xfdesktop' | awk '{print $2}') >/dev/null 2>&1

Replace the underlined "loginname" with your login name.

[blithen]

I know I'm resurrecting the dead here, but this is AMAZING. Thanks a lot, works perfectly.

[wildemad]

Interesante.

Gracias por el how-to

Un saludo.

[Kangarooo]

I would suggest easyr is this.
After putting wallpaper list and installing cron
just open crontab -e
paste there just */5 * * * * export DISPLAY=:0; /usr/bin/xfdesktop -reload
save and exit with ctrl+shift+X and then Y and Enter
and thats it.
it will make every minute that can be divided by 5 to reload xfdesktop so basicly every 5 minuts

[LoloftheRings]

I would suggest easyr is this.
After putting wallpaper list and installing cron
just open crontab -e
paste there just */5 * * * * export DISPLAY=:0; /usr/bin/xfdesktop -reload
save and exit with ctrl+shift+X and then Y and Enter
and thats it.
it will make every minute that can be divided by 5 to reload xfdesktop so basicly every 5 minuts

Old thread, but people might still be using this
I agree, reloading prevents any flickering from occurring. Also, killing the process about 5/6 times doesnt make it startup again for me. This does work however.

[DaveAtFraud]

Thank you, this is somewhat sweet. I say "somewhat" because if I'm not logged in cron sends the following message (25 of them last night alone <g>):

Cron <cmo@codybeau> killall -USR1 xfdesktop
xfdesktop: no process killed

Know of a way around this and yet allow switching images? i *REALLY* like the changing wallpaper.

[dave@petard ~]$ crontab -l
*/5 * * * * /usr/bin/who | /bin/grep -E "dave *tty1" 2>&1 > /dev/null && /usr/bin/xfdesktop --display=:0 --reload 2>&1 > /dev/null

If I'm logged in, I get a tty. The grep -E matches what comes back from the who command. If the grep fails, I'm not logged in and the result is "false" so the && short circuits and fails without executing the right side of the &&. If I'm logged in, the grep succeeds and the right side of the && has to be evaluated.

Cheers,
Dave