#!/usr/bin/env bash
# -------------------------------------------------
#  Get monitors configuration from monitor.xml and apply it for current user session.
#  In case of multiple definitions in monitor.xml only first one is used.
#
#  See http://bernaerts.dyndns.org/linux/74-ubuntu/309-ubuntu-dual-display-monitor-position-lost
#  for instructions
#
#  Parameters :
#    $1 : waiting time in sec. before forcing configuration (optional)
#
#  Revision history :
#    19/04/2014, V1.0 - Creation by N. Bernaerts
#    10/07/2014, V1.1 - Wait 5 seconds for X to fully initialize
#    01/09/2014, V1.2 - Correct NULL file bug (thanks to Ivan Harmady) and handle rotation
#    07/10/2014, V1.3 - Add monitors size and rate handling (idea from jescalante)
#    08/10/2014, V1.4 - Handle primary display parameter
#    08/12/2014, V1.5 - Waiting time in seconds becomes a parameter
#    06/05/2020, V1.6 - Handle scale parameter
# -------------------------------------------------

esc() { printf "%s\n" "$1" | sed -e "s/'/'\"'\"'/g" -e "1s/^/'/" -e "\$s/\$/'/" }

# monitor.xml path
MONITOR_XML="$HOME/Documents/monitors.xml"

# get number of declared monitors
NUM=$(xmllint --xpath 'count(//monitors/configuration['1']/logicalmonitor)' "${MONITOR_XML}")

# loop thru declared monitors to create the command line parameters
for (( i=1; i<=$NUM; i++)); do
  # get attributes of current monitor (name and x & y positions)
  NAME=$(xmllint --xpath 'string(//monitors/configuration['1']/logicalmonitor['$i']/monitor/monitorspec/connector/text())' "${MONITOR_XML}" 2>/dev/null)
  POS_X=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/x/text()' "${MONITOR_XML}" 2>/dev/null)
  POS_Y=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/y/text()' "${MONITOR_XML}" 2>/dev/null)
  SCALE=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/scale/rate/text()' "${MONITOR_XML}" 2>/dev/null)
#   ROTATE=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/rotation/text()' $MONITOR_XML 2>/dev/null)
  WIDTH=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/monitor/mode/width/text()' "${MONITOR_XML}" 2>/dev/null)
  HEIGHT=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/monitor/mode/height/text()' "${MONITOR_XML}" 2>/dev/null)
  RATE=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/monitor/mode/rate/text()' "${MONITOR_XML}" 2>/dev/null)
  PRIMARY=$(xmllint --xpath '//monitors/configuration['1']/logicalmonitor['$i']/primary/text()' "${MONITOR_XML}" 2>/dev/null)

  RES="${WIDTH} ${HEIGHT}" 
  MODELINE=$(cvt $(echo "${RES}") | grep -e "Modeline [^(]" | sed -r 's/.*Modeline (.*)/\1/')
  MODERES=$(echo "${MODELINE}" | grep -o -P '(?<=").*(?=")')

  # if position is defined for current monitor, add its position and orientation to command line parameters
  [ -n "${POS_X}" ] && PARAM_ARR=("${PARAM_ARR[@]}" "--output" "${NAME}" "--pos" "${POS_X}x${POS_Y}" "--mode" "${MODERES}" "--rate" "${RATE}")
  [ -n "${SCALE}" ] && PARAM_ARR=("${PARAM_ARR[@]}" "--scale" "${SCALE}")

  # addmodes before so they can set
  eval "xrandr" "--newmode ${MODELINE[@]}"
  xrandr "--addmode" "${NAME}" "${MODERES}"
  
  # if monitor is defined as primary, adds it to command line parameters
  [ "${PRIMARY}" = "yes" ] && PARAM_ARR=("${PARAM_ARR[@]}" "--primary")
done

# if needed, wait for some seconds (for X to finish initialisation)
[ -n "$1" ] && sleep $1

# position all monitors
xrandr "${PARAM_ARR[@]}"