vincentbernat.i3wm-configuration/bin/xss-lock

#!/bin/bash

me="$(readlink -f "$0")"
timeout=600
notify=$((timeout/30))
display=$(systemd-escape -- "$DISPLAY")

configure() {
    xset s $((timeout - notify)) $notify
    xset dpms $((timeout * 2)) $((timeout * 22 / 10)) $((timeout * 24 / 10))
}
unconfigure() {
    xset s 0
    xset dpms 0 0 0
}

case "$1" in
    start)
        configure
        exec xss-lock --session=${XDG_SESSION_ID} --notifier="$me notify" --transfer-sleep-lock "$me" lock
        ;;
    dim|notify)
        echo "notify: start (idle: $(xprintidle))"
        systemctl --user kill -s STOP redshift@${display}.service
        trap "systemctl --user kill -s CONT redshift@${display}.service" EXIT
        trap 'echo notify: user activity; kill %% 2> /dev/null; exit 0' HUP  # user activity
        trap 'echo notify: locker started; kill %% 2> /dev/null; exit 0' TERM # locker started
        outputs=($(xrandr --current | sed -n 's/\([^ ]*\) connected .*/\1/p'))
        for out in ${outputs[@]}; do
            xrandr --output $out --brightness 0.2
        done
        sleep infinity &
        wait
        echo "notify: end"
        ;;
    lock)
        echo "lock: lock screen (idle: $(xprintidle))"
        # Something may have mendled with screensaver settings
        configure
        # Pause music player and notifications
        playerctl -a pause
        dunstctl set-paused true
        # Then, lock screen
        i3lock -n -e -i $HOME/.cache/i3/current-wallpaper.png -t -f
        echo "lock: unlock screen"
        # Resume notifications
        dunstctl set-paused false
        ;;
esac