#!/bin/sh
#
# A simple shell script to stop Firefox using CPU and paging in RAM
#
# John C. McCabe-Dansted, 2009
# Permission is given to use this file under any version of the GPL or LGPL.
#
# Bugs: 1) Only checks if one Firefox window is minimised, others may be
#     unminimized, but this will still leave Firefox halted and unresponsive
#     until the window this is actually checking is unminimized
#
#       2) Do not minimize Firefox while downloading, or the download will
#     time out.
#
#       3) This script itself will use a tiny bit of CPU and RAM while polling
#     xwininfo to determine whether Firefox is minimised. You may want to tune
#     DELAY. Note that Firefox will be unresponsive for up to DELAY seconds
#     after being unminimised.

DELAY=1 # in seconds

main () {
WinID=$1
PID=$3

echo WinID: $WinID
echo PID:   $PID

set_running () {
		if [ "$active" = "yes" ]
		then
			kill -s CONT $PID
		else
			kill -s STOP $PID
		fi
}

set_nice () {
		if [ "$active" = "yes" ]
		then
			renice +0 $PID
		else
			renice +19 $PID
		fi
}

kill -s CONT $PID
running=yes
while true
do
	if xwininfo -id $WinID | grep 'Map State: IsUnMapped' > /dev/null
	then 
		#Minimized
		active=no
	else 
		active=yes
	fi
	if [ "$active" = no ]
	then
		sleep 0.1
                kill -s STOP $PID
		sleep 0.5
                if ! kill -s CONT $PID
		then
			exit
		fi
	else
		sleep $DELAY
		
	fi
	

	#echo $active
	if [ ! "$running" = "$active" ]
	then
		set_nice
		running="$active"
	fi
done
}

main `wmctrl -l -p | grep " - Mozilla Firefox$"`