#!/usr/bin/perl
# By PJ Balsley & Nick Berry
# Purpose: Change Gnome desktop wallpaper.
#    Put in your crontab, to change once a day.
#    0 0 * * * ~/bin/wp-changer.pl
# Version 0.4
use strict;

#- Values -#
   my $debug = "0";     ##  0 = off, 1 = on
   my $gnome_file = "/desktop/gnome/background/picture_filename";
   my $wallpaper = "$ENV{'HOME'}/Documents/My-stuff/Wallpaper";


#- Execption directories -#
   my @execption = ("800x600",
                "1024x768",
                "1280x800",
                "1600x1200",
                "2560x1024",
                "1280x1024"
                );

#- Generate execpt string -#
   my $expect = undef;
   my $ex = undef;
   foreach $ex (@execption) {
        chomp($ex);
        if($expect) {
           $expect .= " -a \! -wholename '*$ex*'";
        } else {
           $expect = "\! -wholename '*$ex*'";
        }
   }


#- Find background images -#
   my @ls = `find $wallpaper $expect -type f -print`;
   if ($debug == "1") { print "find $wallpaper $expect -type f -print\n"; }


#- Pick one randomly -#
   my $randfile = &random(@ls);
   my $currentfile = `grep \"$randfile\" $ENV{"HOME"}/.gconf/desktop/gnome/background/\%gconf.xml`;
   while ($currentfile) {
      if ($debug == "1") { print "Randomize matched the same wallpaper ($randfile), randomizing again.\n"; }
      $randfile = &random(@ls);
      $currentfile = `grep \"$randfile\" $ENV{"HOME"}/.gconf/desktop/gnome/background/\%gconf.xml`;
   }


#- Change the Gnome background value -#
   system("gconftool-2 -t string -s $gnome_file \"$randfile\"");
   if ($debug == "1") { print "gconftool-2 -t string -s $gnome_file \"$randfile\"\n"; }


#- Sub Routines -#
#----------------#
sub random(@ls) {
        #- randomly pick a picture. -#

        my $randnum = rand(@ls);
        $randnum = int $randnum;
        my $randfile = $ls[$randnum];
        chomp($randfile);

        return $randfile;
}