#!/bin/sh -e

# Copyright (c) 2016 The crouton Authors. All rights reserved.

# Use of this source code is governed by a BSD-style license that can be

# found in the LICENSE file.

. "`dirname "$0"`/../installer/functions"

# Default button numbers

u=4

d=5

l=6

r=7

# Do horizontal scrolling by default

x=1

# Set the default scaling and constant values

xs='0.2'

xc='0.01'

ys='0.2'

yc='0.05'

#

USAGE="${0##*/} [-x] [-r] [-a #.#] [-b #.#] [-c #.#] [-d #.#]

Runs the mousewheel daemon.

Options:

-r Reverse the direction of scrolling.

-x Disable horizontal scrolling.

-a Sets the X scrolling scaling factor (default: $xs).

-b Sets the X scrolling constant additive (default: $xc).

-c Sets the Y scrolling scaling factor (default: $ys).

-d Sets the Y scrolling constant additive (default: $yc)."

# Process options

while getopts 'a:b:c:d:rx' opt; do

case "$opt" in

a) xs="$OPTARG";;

b) xc="$OPTARG";;

c) ys="$OPTARG";;

d) yc="$OPTARG";;

r) z=$u; u=$d; d=$z; z=$l; l=$r; r=$z;;

x) x='0';;

\?) echo "$USAGE" 1>&2; exit 1;;

esac

done

if [ $# -ge "$OPTIND" ]; then

echo "$USAGE" 1>&2

exit 1;

fi

# Operate on the Chromium OS X11 server

eval "`host-x11`"

# Only let one instance *really* run at a time

mkdir -m 775 -p "$CROUTONLOCKDIR"

exec 3>"$CROUTONLOCKDIR/wheel"

flock 3

# Monitor xinput2 events, reacting only to scroll events (axes 2 and 3).

# Accumulate the x and y scrolls, but reduce the acceleration so it doesn't go

# crazy. After a threshold, simulate the wheel presses using xte.

# Use xev to detect window changes and disable mouse wheel events when aura is

# focused.

# The goal of this system is to avoid having to launch any processes on a

# per-event basis, both to improve latency and performance.

{

croutonxi2event &

xi="$!"

aura="`croutonwmtools list ni | awk '/aura_root/ {print $NF}'`"

xev -id "$aura" &

trap "kill $! $xi 2>/dev/null || true" INT TERM HUP 0

wait

} | unbuffered_awk '

# Test if x is a non-zero real number (i.e. not nan, inf, "", or 0)

function isnonzero(x) {

return (x != "") && (x != 0) && (x != "nan") && (x != "inf")

}

# Disable when aura is visible and enable when it is not

/VisibilityUnobscured$/ {

w = 1

x = 0

y = 0

}

/VisibilityFullyObscured$/ {

w = 0

}

!w && /^EVENT type 17/ {

# Valuators start at $10; >=10 valuators implies a trackpad

if ($19 != "") {

dx = $14

dy = $15

tp = 1

} else {

dx = $12

dy = $13

tp = 0

}

if ('"$x"' && isnonzero(dx)) {

if (dx > 0) {

if (x < 0) x = 0

x += tp ? log(dx) * '"$xs"' + '"$xc"' : 1

} else {

if (x > 0) x = 0

x -= tp ? log(-dx) * '"$xs"' + '"$xc"' : 1

}

while (x >= 1) {

output("mouseclick '"$r"'")

x -= 1

}

while (x <= -1) {

output("mouseclick '"$l"'")

x += 1

}

}

if (isnonzero(dy)) {

if (dy > 0) {

if (y < 0) y = 0

y += tp ? log(dy) * '"$ys"' + '"$yc"' : 1

} else {

if (y > 0) y = 0

y -= tp ? log(-dy) * '"$ys"' + '"$yc"' : 1

}

while (y >= 1) {

output("mouseclick '"$u"'")

y -= 1

}

while (y <= -1) {

output("mouseclick '"$d"'")

y += 1

}

}

}

' | xte &

trap "pkill -P $$ 2>/dev/null || true" INT TERM HUP 0

wait

exit 0