swap-lalt-lwin

#!/usr/bin/env bash 

# gsettings config names
SCHEMA='org.gnome.desktop.input-sources'
KEY='xkb-options'
OPTION='altwin:swap_lalt_lwin'

# toggle whether left alt and left win are switched
main() {
  # pull the current setting and make it a space-delimited list
  # I don't think config values will have spaces, but YOLO
  current="$(gsettings get "${SCHEMA}" "${KEY}" | tr -d "[]',")"

  # add alt-win setting to the end if it isn't already in the list
  if ! [[ ${current} == *${OPTION}* ]] ; then 
    new="${current} ${OPTION}"
    msg="Swapping Left Alt with Left Win"
  # otherwise, delete it from the list
  else 
    for val in ${current} ; do 
      if [[ "${val}" == "${OPTION}" ]] ; then
        continue
      fi
      new="${new} ${val}"
    done
    msg="Unswapping Left Alt with Left Win"
  fi

  # trim leading spaces from concatenation above
  new="$(echo "${new}" | sed -e 's/^[[:space:]]*//')"

  # format as gsettings value array 
  new="$(echo "['${new}']" | sed -e "s/ /\', \'/")"
  
  # write to dconf database
  gsettings set "${SCHEMA}" "${KEY}" "${new}"

  # send desktop notification
  notify-send -t 2000 'Left Alt/Win' "${msg}"
}

main