getnextwindidinactvclass

#!/usr/bin/env bash
# 
# File:
#   getnextwindidinactvclass
# 
# Description:
#   Get the ID of the next window in the class of the active window.
# 
# Options:
#   -n [name]    return only IDs of windows with titles partially matched by
#                [name]
# 
# Returns:
#   ID of the next window in class; ID of the active window if no other windows
#   in the class exist
# 

while getopts n: OPT; do
  case "${OPT}" in
    n) OPT_WIND_NAME="${OPTARG}"
       ;;
  esac
done
shift $((OPTIND - 1))

getActvWindId() {
  echo "$(xprop -root _NET_ACTIVE_WINDOW | cut -d ' ' -f 5 | rev | cut -c 2- | \
      rev | sed 's/^0x/0x0/')"
}

ACTV_WIND_ID="$(getActvWindId)"

getWindIdsInClass() {
  echo "$(wmctrl -lx | awk -v class="${1}" '$3 ~ class {print $1}')"
}

getWindClassById() {
  echo "$(xprop -id "${1}" WM_CLASS | sed -n \
      's/[^"]*"\([^"]*\)",\s"\([^"]*\)"/\1.\2/p')"
}

CLASS_WIND_IDS=($(getWindIdsInClass "$(getWindClassById "${ACTV_WIND_ID}")"))

if [ -n "${OPT_WIND_NAME}" ]; then
  getWindNameById() {
    echo "$(xprop -id "${1}" WM_NAME 2>/dev/null | sed -n \
        's/[^"]*"\(.*\)./\1/p')"
  }

  for windId in "${CLASS_WIND_IDS[@]}"; do
    windName="$(getWindNameById "${windId}")"
    if [[ "${windName}" = *"${OPT_WIND_NAME}"* ]]; then
      clssWindIdsTmp+=("${windId}")
    fi
  done

  CLASS_WIND_IDS=("${clssWindIdsTmp[@]}")
fi

for indx in ${!CLASS_WIND_IDS[@]}; do
  if [ "${CLASS_WIND_IDS[${indx}]}" = "${ACTV_WIND_ID}" ]; then
    clssWindIdsActvWindIdPos="${indx}"
    break
  fi
done

if [ "${clssWindIdsActvWindIdPos}" -eq $(("${#CLASS_WIND_IDS[@]}" - 1)) ]; then
  echo "${CLASS_WIND_IDS[0]}"
else
  echo "${CLASS_WIND_IDS[$((clssWindIdsActvWindIdPos + 1))]}"
fi