Create a Custom Transitioning Background for Your Gnome 2.28 Desktop

Both. Does the XML have to be in the "background" folder or can it be in another folder and still work? I've been doing the latter, but if it is the former, then I'll put it in there. Would 9.04's already present transistioning effect when changing wallpapers under normal circumstances be the cause of the XML not working, too?

I have created a Unix/Linux Shell Script to automate the process of creating an XML file in the format described above. It should prove to be more flexible than the PERL script provided earlier because with my script you can specify image files from multiple directories on your computer rather than just a single directory, and you can control the order in which the images will display. Furthermore, my script is not interactive; so you can type all the input at once, check it for correctness, and simply press enter to create the XML file. The script also has error-checking built into it; so if you give it faulty input, it will tell you instead of creating an XML file that you cannot use.

If you want to use this script, here is how to do it:
1) Copy the code for the script below into a file called mkwlppr.sh (short for "make wallpaper").
2) Make the script executable by typing:
sudo chmod 711 mkwlppr.sh
3) Place this file in the directory /usr/local/bin so that you can run it from any directory by just using its name. Here is the command: sudo mv mkwlppr.sh /usr/local/bin
4) Execute the script by simply typing its name to see how it is used; it will tell you what input it requires from you.
5) Use the script with input to create as many wallpaper XML files as you want.
6) Use the instructions originally posted here to set your new XML files as dynamic backgrounds.

Important Notes:
A) Since this script is not interactive, you can use Unix's wildcards with it if you want to use all files in a directory and/or if you do not care about the order of the images.
B) You can specify paths relative to your current directory, and the script will put the files' absolute paths into the XML file for you; so you can create the XML file anywhere you want and move it afterward without rendering it useless.
C) If you want to run the script inside the /usr/share/backgrounds/ directory (which is where you will probably want to place the XML file after you create it), you might have problems with permissions unless you run the command with sudo like this:
sudo mkwlppr.sh parameters
D) If you do not know what duration to specify for the images, simply do not provide a number in the input, and the progam will use a default value. The default duration value is the same as the cosmos wallpaper that ships with Ubuntu.

Here is the code for the script:

#!/bin/sh
#This script creates xml files that can act as dynamic wallpapers for Gnome by referring to multiple wallpapers
#Coded by David J Krajnik

if [ "$*" = "" ]; then
  echo "This script creates xml files that can act as dynamic backgrounds for Gnome by referring to multiple wallpapers";
  echo "Usage: mkwlppr.sh target-file.xml [duration] pic1 pic2 [pic3 .. picN]";
else
  files=$*;
  #Grab the name of the target xml file
  xmlfile=`echo $files | cut -d " " -f 1`;
  #remove the first item from $files
  files=`echo $files | sed 's/^\<[^ ]*\>//'`;
  if [ "`echo $xmlfile | grep '\.xml$'`" = "" ]; then
    echo "Your target file must be an XML file";
  else
    inputIsValid="true";
    firstItem=`echo $files | cut -d " " -f 1`;
    duration="1795.0";#set the default duration
    if [ "`echo $firstItem | grep '^[0-9]\+\.[0-9]\+$'`" != "" ]; then
      echo "The duration must be an integer";
      files=`echo $files | sed 's/^\<[^ ]*\>//'`;
      inputIsValid="";
    elif [ "`echo $firstItem | grep '^[0-9]\+$'`" != "" ]; then
      #If the item is a number, then use it as the duration for each wallpaper image
      duration="`expr $firstItem - 5`.0";
      #remove the duration from the list of files
      files=`echo $files | sed 's/^\<[^ ]*\>//'`;
    fi
    if [ "$files" = "" ]; then
      echo "You must enter image files to associate with the XML file";
    else
      for file in $files
      do
        if [ ! -f $file ]; then
	  echo "\"$file\" does not exist";
	  inputIsValid="";
        elif [ "`echo $file | sed 's/^.*\.\(jpg\|jpeg\|bmp\|png\|gif\|tif\|tiff\|jif\|jfif\|jp2\|jpx\|j2k\|j2c\)$//'`" != "" ]; then
	  echo "\"$file\" is not an image file";
	  inputIsValid="";
	fi
      done
      if [ $inputIsValid ]; then
        currDir=`pwd`;
        echo "<background>" >> $xmlfile
        echo "  <starttime>\n    <year>2009</year>\n    <month>08</month>\n    <day>04</day>" >> $xmlfile;
        echo "    <hour>00</hour>\n    <minute>00</minute>\n    <second>00</second>\n  </starttime>" >> $xmlfile;
        echo "  <!-- This animation will start at midnight. -->" >> $xmlfile;
        firstFile=`echo $files | cut -d " " -f 1`;#grab the first item
        if [ "`echo $firstFile | sed 's/\(.\).*/\1/'`" != "/" ]; then
          #If the first character in the filename is not '/', then it is a relative path and must have the current directory's path appended
          firstFile="$currDir/$firstFile";
        fi
        firstFile=`echo $firstFile | sed 's/[^/]\+\/\.\.\/\?//g'`;#Remove occurrences of ".." from the filepath
        files=`echo $files | sed 's/^\<[^ ]*\>//'`;#remove the first item
        prevFile=$firstFile;
        currFile="";
        #TODO add absolute path to the filenames
        #if $currFile =~ "^/.*" then the file needs to path appended
        echo "  <static>\n    <duration>$duration</duration>\n    <file>$firstFile</file>\n  </static>" >> $xmlfile;
        for currFile in $files
        do
          if [ "`echo $currFile | sed 's/\(.\).*/\1/'`" != "/" ]; then
            #If the first character in the filename is not '/', then it is a relative path and must have the current directory's path appended
            currFile="$currDir/$currFile";
          fi
          currFile=`echo $currFile | sed 's/[^/]\+\/\.\.\/\?//g'`;#Remove occurrences of ".." from the filepath
          echo "  <transition>\n    <duration>5.0</duration>\n    <from>$prevFile</from>\n    <to>$currFile</to>\n  </transition>" >> $xmlfile;
          echo "  <static>\n    <duration>$duration</duration>\n    <file>$currFile</file>\n  </static>" >> $xmlfile;
          prevFile=$currFile;
        done
        echo "  <transition>\n    <duration>5.0</duration>\n    <from>$currFile</from>\n    <to>$firstFile</to>\n  </transition>" >> $xmlfile;
        echo "</background>" >> $xmlfile;
      fi
    fi
  fi
fi

Does anybody know what's the earliest version of Gnome that would work too? Somebody mentioned 2.26. Anything earlier? I have an old computer running an old version of Gnome in the basement that is not used often and would be great for running a slide show. I'm afraid it's running Gnome 2.10.

TIA

Just followed your tutorial and worked perfectly!

Wonder if you can do the same in windows?

Can this use an image bucket?

I made the xml files but my pictures do not make the transition correctly, they only change if i save the .xml file or reselect it from the "change background menu". :(

I don't know anything about XML but your tutorial made it simple for me to modify and make my own transitions. Thanks

Sits on your task bar, and you can change pics by simply clicking on it. Made for Gnome.

Xfce had this feature ages ago ;)

Any reason we're ignoring Desktop Drapes here??? Works great. Just not in the default load.

Ive made a perl script to automate the procedure,

http://www.sendspace.com/file/4zypt9

run it using "perl groupphoto.pl"

Enter a Picture folder,

Enter a Duration, i.e 900 will mean 895 plus a 5 sec transition delay

It will generate a xml file in your home directory called photos.xml

Then follow instructions on this page to set as wallpaper