#!/bin/sh

# this script takes a screenshot using xwd, gimp, and pngcrush.
# it is mostly a proof-of-concept for command-line gimp.
#

#TODO : add noxmessage option
#TODO : don't check if things exist if they aren't being run

if [ "${1}" = "-u" ] ; then
 NOPNGCRUSH="TRUE"
 export NOPNGCRUSH
fi

if [ "${1}" = "-h" ] ; then
 echo This script takes a screenshot as a png in the
 echo current working directory in the form of
 echo "HH-MM.SS_scrn.png". This format allows for a
 echo good chance of no conflicting files. It requires:
 echo X11, GIMP \& pngcrush to be installed. It also
 echo requires /tmp and the current working directory
 echo to be writeable. It, however does not require
 echo \"ImageMagick\" as the conversion is done in GIMP
 echo \(batch-mode\).
 echo
 echo "Title: gimp_scrn.sh"
 echo "Author: Greg Schenzel"
 echo "Liscence: GNU General Public Liscence v2"
 echo "Usage: $0 -u/-h"
 echo "  -u :: save png uncompressed (to bypass pngcrush"
 echo "        if not installed). you may also set"
 echo "        NOPNGCRUSH to \"TRUE\" in your environment."
 echo "  -h :: print this message."
 exit
fi

if [ ! -w /tmp ] ; then
 echo "FATAL: /tmp is not writeable."
 exit
fi

if [ ! -w ${PWD} ] ; then
 echo "FATAL: ${PWD} is not writeable."
 exit
fi

if ! whereis gimp ; then
 echo "GIMP not found."
 exit
fi

if ! whereis xwd ; then
 echo "XWD not found. (Is X11 installed?)."
 exit
fi

if ! whereis xmessage ; then
 echo "XMESSAGE not found. (Is X11 installed?)."
 exit
fi

if ! whereis pngcrush ; then
 echo "pngcrush not found."
 exit
fi


FILE=`whoami`_scrn
export FILE
RF1=/tmp/${FILE}.xwd
RF2=/tmp/${FILE}.png
RF3=$PWD/`date +%H-%M.%S_scrn.png`
export RF1 RF2 RF3

xwd -root > /tmp/${FILE}.xwd
gimp --no-interface --no-data --batch "(file-xwd-load 1 \"${RF1}\" \"${RF1}\")" "(file-png-save 1 0 (car (gimp-image-active-drawable 0)) \"${RF2}\" \"${RF2}\" 0 0 1 0 0 0 0)" "(gimp-quit 0)"
if [ "TRUE" = "${NOPNGCRUSH}" ]
 then cp ${RF2} ${RF3}
 else pngcrush -q ${RF2} ${RF3}
fi

rm ${RF1} ${RF2}

xmessage "The screenshot has completed."