#!/bin/bash
# Wallpaper changer for Xfce 4.6-${HOME}/Pictures/:/usr/share/backgrounds/
#
# Usage:
#
# Changer {monitor {interval {source1{:source2{:...}}}}}
#
# Where:
#    Changer  is the name you give to the script
#    monitor  is the device number of the monitor for which you want to rotate the background images.
#         Default: 0 (Which is the only possibility if you have only one monitor on your system.)
#    interval is the amount of time a backdrop should be displayed before it's replaced.
#         Default: Set as ${Display_Time}, below (One minute in this instance.)
#    source     is a colon-separated list of directories (which may have sub-directories) containing 
#         the images to be used as backdrops.
#         Default: Set in ${Wallpapers}, below. (/Wallpapers/ in this instance.)
#         (Try Wallpapers="${2:-${HOME}/Pictures/:/usr/share/backgrounds/"} to use your Pictures
#         directory and the system backdrop images.)
#
# Note: Some debugging output can be produced by setting ${debug} to a non-null value. (See near the end of
#    of this code where the setting of that value is commented out.)
#
# This script may be used as a command by copying it into the ~/Desktop directory. (Xfce will generate a
# script icon, and execute the script when you double-click on the icon.) The default values you set will
# be used unless you create an actual Changer.desktop file to run the script with some arguments. But, if
# you want to try it out before installing it, just run it from a terminal with whatever test arguments you
# want to try. (I found "./Changer 0 5s "${HOME}/Pictures:/usr/share/backgrounds/nature" useful.)
#
# Function to do the actual work
wallpaper_loop() {
# Default the display time to one minute if not specified
  Display_Time="${1:-1m}"
# Default the background directory list to /Wallpapers/
  Wallpapers="${2:-/Wallpapers/}"
  [ -n "${debug}" ] && echo "Starting wallpaper_loop of \"${Wallpapers}\" for ${Display_Time}" 
# Make sure that the property we want to change is actually a property
  PROPERTY="/backdrop/screen0/monitor${MONITOR:-0}/image-path"
  IMAGE_PATH="$(xfconf-query -c xfce4-desktop -p ${PROPERTY})"
  [ $? -ne 0 ] && echo "${PROPERTY} is not a recognized xfconf-query parameter." && exit 1
# Clean up any old wallpaper lists
  if [ -n "${debug}" ]
  then
    LIST="$(find /tmp/ -maxdepth 1 -name wallpaper_list_${MONITOR:-0}*)"
    [ -n "${LIST}" ] && echo "Deleting the following temporary file: ${LIST}"
  fi
  rm -f /tmp/wallpaper_list_${MONITOR:-0}*
# Get a new temporary file name for the new list
  LIST=$(mktemp /tmp/wallpaper_list_${MONITOR:-0}_XXXX)
  [ -n "${LIST}" ] && echo "Creating the following temporary file: ${LIST}"
# Create the new list.
  IFS=":"
  for dir in ${Wallpapers}
  do
    [ ! -d "${dir}" ] && echo "\"${dir}\" is not a directory. Skipping." && bad=$((${bad}+1)) && continue
    [ -n "${debug}" ] && echo "  Adding ${dir} to ${LIST}"
    find "${dir}" -type f -printf "%h/%f\n" >> ${LIST}
  done
  [ -n "${bad}" ] && echo "Aborting because of bad directory name(s)."&& exit 1
# Since the file names may contain blanks or other special characters
# set the field delimiter to a new line
  IFS=$'\n'
# Start an infinite loop
  while true
  do
# Get a random file name
    NAME="$(shuf -n 1 ${LIST} 2>/dev/null)"
    [ $? -ne 0 ] && exit 1
# Verify that the file is a JPEG or PNG file
    [ -z "$(file "${NAME}" | grep -iwE '(jpeg|png)')" ] && continue
# Set it as the background image
    xfconf-query -c xfce4-desktop -p ${PROPERTY} -s ${NAME}
# and do it again after displaying it for ${Display_Time} 
    sleep ${Display_Time}
  done
}
# Uncomment the next line for debugging output
#debug=y
#
# Minor housekeeping
#
# Default to changing the background on the first monitor unless passed an argument
MONITOR=${1:-0}
shift
# Make sure the system variable, DISPLAY, is defined
if [ -z "$DISPLAY" ]
then
  export DISPLAY=":0.0"
fi
# Pass any remaining arguments to the loop function
wallpaper_loop "$@"

Settings -> Desktop -> Background
 	Image list: selected
 	+ (to add images to the list)
 		Browsed to /home/c/d/.wallpapers
 			Ctrl+A to select all
 			Add
	Style:  Zoomed

#!/bin/bash
#: Title: shuffle-wallpaper-xfce4
#: Author: Neal T. Bailey <nealbailey@hotmail.com>
#: Date: 01/18/2011
#: Purpose: Randomly set a wallpaper (XFCE v4+)
#
#: Usage: ./shuffle-wallpaper-xfce4.sh [options]
#: Options: -d, --debug - print to stdout/log
#: 	    -v, --version - print version info
#:	    -h, --help - print help synopsis
#:	    -p, --path [dir] - define image path 
#:
#  Notes: This script is best when run in a cron job to randomly set background images
#         on a scheduled.
#
#  Example: 
#  $ crontab -e
#
#  Add this line into user crontab to change background every 30 minutes
#  */30 * * * * /home/neal.bailey/shuffle-wallpaper-xfce4.sh
#

# Allows script to run as a cron job
export DISPLAY=:0.0

# Metadata
scriptname=${0##*/}
description="Apply random a background image"
usage="$scriptname [-d|-v|-h|-p]"
optionusage="-d:\tEnable debug logging\n  -v:\tPrint version info\n  -h:\tPrint help (this screen)\n  -p:\tImage path [dir]\n"
date_of_creation=2011-01-18
version=1.0
author="Neal T. Bailey"

# Default Values
DEBUG=0
LOG="$0.debug"
LINE_PREFIX="[$(date +%m/%d/%Y' '%H:%M)]"
base="$HOME/Pictures" # wallpapers

# Functions
usage() #@ DESCRIPTION: print usage information
{       #@ USAGE: usage
  printf "%s - %s\n" "$scriptname" "$description"
  printf "Usage: %s\n" "$usage"
  printf "%s  $optionusage"
}

version() #@ DESCRIPTION: print version information
{         #@ USAGE: version
  printf "%s (v%s)\n" "$scriptname" "$version"
  printf "by %s, %d\n" "$author"  "${date_of_creation%%-*}"
}

# Options the program will accept
optstring=p:dhv 

while getopts $optstring opt
do
  case $opt in
    p) base=$OPTARG ;;
    d) DEBUG=$(( $DEBUG + 1 )) ;;
    h) usage; exit ;;
    v) version; exit ;;
    *) exit 1 ;;
  esac
done

shift "$(( $OPTIND - 1 ))"

# Sanity checks
if [ ! -d "$base" ] || [ ! -e "$base" ]; then
	echo "error: $base doesn't exist or isn't a directory!"
	exit 1
fi 

# Change the default IFS from \n\t\0 to ;
IFS=';'

 if [ "$DEBUG" -gt 0 ]; then
	echo "$LINE_PREFIX $0 began processing." > "$LOG"	
 fi

# Populate array with jpg/png files and append the new IFS (;) to each result
images=( $(find "$base" -printf %p\; -iname *jpg -or -iname *.png) )

# Get the upper bounds of the array
ubound=${#images[@]}

 if [ "$DEBUG" -gt 0 ]; then
	echo "$LINE_PREFIX Enumerating images in $base." | tee -a "$LOG"
	echo "$LINE_PREFIX find ~/Pictures -printf %p\; -iname *jpg -or -iname *.png" | tee -a "$LOG"
	echo "$LINE_PREFIX Search returned $ubound images." | tee -a "$LOG"
 fi

 if [ "$ubound" -eq 0 ]; then
	status="There were no images found. Cannot continue operation."
	echo "$status."
	exit 1
 fi

# Pick a random wallpaper
selected="${images[RANDOM % ubound]}"

 if [ "$DEBUG" -gt 0 ]; then
	echo "$LINE_PREFIX Selected random image $selected." | tee -a "$LOG"
 fi

# Set the wallpaper
xfconf-query -c xfce4-desktop -p /backdrop/screen0/monitor0/image-path -s "$selected" 2>>"$LOG"

 if [ "$DEBUG" -gt 0 ]; then
	echo "$LINE_PREFIX Instructing xfce to set new wallpaper." | tee -a "$LOG"
	echo "$LINE_PREFIX xfconf-query -c xfce4-desktop -p /backdrop/screen0/monitor0/image-path -s $selected" | tee -a "$LOG"
 fi

echo "Operation completed successfully."
exit 0