create-background-xml

#!/bin/bash

function element()
{
  echo "${1}<${2}>${3}</${2}>"
}

function starttime()
{
  starttime=`date --utc +%Y\ %m\ %d\ %H\ %M\ %S`

  echo "  <starttime>"
  element "    " year `cut --delimiter=\  --fields=1 <<< ${starttime}`
  element "    " month `cut --delimiter=\  --fields=2 <<< ${starttime}`
  element "    " day `cut --delimiter=\  --fields=3 <<< ${starttime}`
  element "    " hour `cut --delimiter=\  --fields=4 <<< ${starttime}`
  element "    " minute `cut --delimiter=\  --fields=5 <<< ${starttime}`
  element "    " second `cut --delimiter=\  --fields=6 <<< ${starttime}`
  echo "  </starttime>"
}

function static()
{
  echo "  <static>"
  element "    " duration ${1}
  element "    " file "${2}"
  echo "  </static>"
}

function transition()
{
  echo "  <transition>"
  element "    " duration ${1}
  element "    " from "${2}"
  element "    " to "${3}"
  echo "  </transition>"
}

staticDuration=${1:-290}
transitionDuration=${2:-10}

temporaryFile=`mktemp`
find . -type f \( -iname *.gif -o -iname *.jp*g -o -iname *.png \) | cut --characters=2- | sort > ${temporaryFile}
readarray -t backgrounds < ${temporaryFile}
rm --force ${temporaryFile}

backgroundsSize=${#backgrounds[*]}

echo "<background>"
starttime

for ((fromIndex = 0 ; ${fromIndex} < ${backgroundsSize} ; fromIndex++))
do
  toIndex=$((${fromIndex} + 1))

  from="${PWD}${backgrounds[${fromIndex}]}"

  if [ ${toIndex} -gt ${backgroundsSize} ]
  then
    to="${PWD}${backgrounds[0]}"
  else
    to="${PWD}${backgrounds[${toIndex}]}"
  fi

  static ${staticDuration} "${from}"
  transition ${transitionDuration} "${from}" "${to}"
done

echo "</background>"

exit 0