Change X virtual desktop by parking mouse on the edge

deskflip.sh

#! /bin/sh -Cefu

. /usr/local/bin/fortify.sh

# test0, xwinpos
. /usr/local/bin/mashlib.sh

margin=10
timeout=2
sleepwait=0.1
flipwait=0.4
while getopts :m:t:s:f: opt ; do
    case $opt in
        (m)
            margin=$OPTARG
            ;;
        (t)
            timeout=$OPTARG
            ;;
        (s)
            sleepwait=$OPTARG
            ;;
        (f)
            flipwait=$OPTARG
            ;;
        ('?')
            echo 'usage: deskflip [-m MARGIN] [-t TIMEOUT] [-s SLEEPWAIT] [-f FLIPWAIT]' >&2
            exit 2
            ;;
    esac
done

test_move_timeout()
{
    status=$( echo "( $now - $last_move_time ) > $timeout" | bc -l)
    test0 $status
}

test_flip_timeout()
{
    status=$( echo "( $now - $last_margin_time ) > $flipwait" | bc -l)
    test0 $status
}

xwinpos -root
rmargin=$(( w - margin ))
now=$( sleepenh 0 || true )
num_desks=$( xdotool get_num_desktops )
last_desk=$(( num_desks - 1 ))
last_move_time=$now
last_margin_time=$now
X=0
Y=0
while true ; do
    then_X=$X
    then_Y=$Y
    eval $( xdotool getmouselocation --shell )
    if test0 $X == $then_X '&&' $Y == $then_Y ; then
        if test_move_timeout ; then
            break
        fi
    else
        last_move_time=$now
    fi
    if test0 $X '<' $margin '||' $X '>' $rmargin ; then
        if test_flip_timeout ; then
            this_desktop=$( xdotool get_desktop )
            if test0 $X '<' $margin '&&' $this_desktop '>' 0 ; then
                xdotool set_desktop $(( this_desktop - 1 ))
                last_margin_time=$now
            elif test0 $X '>' $rmargin '&&' $this_desktop '<' $last_desk ; then
                xdotool set_desktop $(( this_desktop + 1 ))
                last_margin_time=$now
            fi
        fi
    else
        last_margin_time=$now
    fi
    now=$( sleepenh $now $sleepwait || true )
done