wlroots lock screen manager

lockmgr.sh

#!/bin/bash

set -e

SELF="$(readlink -f "$0")"

###   _____ _____ _   _ ______ _____ _____
###  /  __ \  _  | \ | ||  ___|_   _|  __ \
###  | /  \/ | | |  \| || |_    | | | |  \/
###  | |   | | | | . ` ||  _|   | | | | __
###  | \__/\ \_/ / |\  || |    _| |_| |_\ \
###   \____/\___/\_| \_/\_|    \___/ \____/
###

SIMULATION_MODE=0

# The FIFO / named pipe used for IPC between the lockmgr and swayidle
FIFO="/tmp/wlroots_lockmgr"

# Common swaylock arguments.
LOCK_ARGS="--show-failed-attempts --hide-keyboard-layout --indicator-caps-lock"

# Set **ONE** of the following variables to set the background image / color of the lock screen:
#
# LOCK_COLOR="#000000"
# LOCK_IMG="/path/to/your/lock/wallpaper"
# LOCK_IMG_DIR="/path/to/a/dir/from/which/to/pick/a/random/wallpaper"
#
# Black screen by default
LOCK_COLOR="#000000"

# swayidle configuration with some changes:
#   - the timeout can now be relative to the last timeout
#   - the command is now comma (`,`) seperated list of commands to execute. Commands in this
#     context are not shell commands, but functions inside this script. All command functions
#     have a `cmd_` prefix.
#
#     New functions can be added by implementing new `cmd_<command name>` functions.

SWAYIDLE_COMMANDS=(
    "timeout  60  mgr_reset,notify"
    "timeout +5   lock               resume grace_unlock"
    "timeout +3   grace_end"
    "timeout +30  dpms_off           resume dpms_on"
    "before-sleep lock"
    "lock         lock"
    "unlock       unlock"
)

###   _____ ________  ______  ___  ___   _   _______  _____
###  /  __ \  _  |  \/  ||  \/  | / _ \ | \ | |  _  \/  ___|
###  | /  \/ | | | .  . || .  . |/ /_\ \|  \| | | | |\ `--.
###  | |   | | | | |\/| || |\/| ||  _  || . ` | | | | `--. \
###  | \__/\ \_/ / |  | || |  | || | | || |\  | |/ / /\__/ /
###   \____/\___/\_|  |_/\_|  |_/\_| |_/\_| \_/___/  \____/
###

# This will store the swayidle PID in the future
CHILD_PID=-1

ALLOW_GRACE_UNLOCK=0

cmd_mgr_reset() {
    msg1 "Starting lock chain"
    ALLOW_GRACE_UNLOCK=1
}

cmd_notify() {
    msg2 "Notifying the user"
    notify-send "Sleepy..." "I am about to lock your screen because of inactivity. Please do something if you don't want that to happen!"
}

cmd_lock() {
    if pidof swaylock > /dev/null; then
        msg2 "Screen is already locked --> Doing nothing"
        return 0
    fi

    msg2 "Locking the screen"
    extra_args=""
    [ -n "$LOCK_COLOR"   ] && extra_args="-c '$LOCK_COLOR'"
    [ -n "$LOCK_IMG"     ] && extra_args="-i '$LOCK_IMG'"
    [ -n "$LOCK_IMG_DIR" ] && extra_args="-i '$LOCK_IMG_DIR/$(ls "$LOCK_IMG_DIR" | sort -R | tail -n 1)'"

    # `--daemonize` should always be passed unless you feel like
    # messing around with the IPC logic if this script :)
    if (( SIMULATION_MODE == 1 )); then
        msg3 "swaylock --daemonize $LOCK_ARGS $extra_args"
    else
        swaylock --daemonize $LOCK_ARGS $extra_args
    fi
}

# Workaround helper for https://github.com/swaywm/swayidle/issues/54
_disable_grace_delayed() {
    sleep 2
    $SELF grace_end
}

cmd_manual_lock() {
    msg1 "Manually lock triggered"

    sleep .5

    msg2 "Setting swayidle status to idle"
    if ps -p $CHILD_PID &> /dev/null; then
        kill -SIGUSR1 $CHILD_PID
    fi

    _disable_grace_delayed &
}

cmd_grace_unlock() {
    if (( ALLOW_GRACE_UNLOCK == 1 )); then
        msg2 "Unlocking because activity within the grace period"
        if pidof swaylock > /dev/null; then
            killall -SIGUSR1 swaylock
        fi
    else
        msg2 "The grace period has passed --> No automatic unlock"
    fi
}

cmd_grace_end() {
    msg2 "The grace period ends now!"
    ALLOW_GRACE_UNLOCK=0
}

cmd_dpms_off() {
    msg2 "DPMS off"
    if (( SIMULATION_MODE == 1 )); then
        return 0
    fi
    case ${XDG_CURRENT_DESKTOP:-sway} in
        Hyprland|hyprland)
            hyprctl dispatch dpms off
            ;;
        sway|Sway)
            swaymsg "output * dpms off"
            ;;
        *)
            error "DPMS control for $XDG_CURRENT_DESKTOP is not yet supported!"
            ;;
    esac
}

cmd_dpms_on() {
    msg2 "DPMS on"
    if (( SIMULATION_MODE == 1 )); then
        return 0
    fi
    case ${XDG_CURRENT_DESKTOP:-sway} in
        Hyprland|hyprland)
            hyprctl dispatch dpms on
            ;;
        sway|Sway)
            swaymsg "output * dpms on"
            ;;
        *)
            error "DPMS control for $XDG_CURRENT_DESKTOP is not yet supported!"
            ;;
    esac
}

# Could be used to manually terminate the lockmgr
cmd_exit() {
    msg1 "Exit requested --> terminating"
    exit 0
}

###   _     _____ _____
###  | |   |  _  |  __ \
###  | |   | | | | |  \/
###  | |   | | | | | __
###  | |___\ \_/ / |_\ \
###  \_____/\___/ \____/
###

msg1() {
    echo -e "\x1b[1;35m[\x1b[0m$(date '+%F %T')\x1b[1;35m]\x1b[0m \x1b[1;32m=>\x1b[0m $*"
}

msg2() {
    echo -e "\x1b[1;35m[\x1b[0m$(date '+%F %T')\x1b[1;35m]\x1b[0m \x1b[1;34m   - \x1b[0m $*"
}

msg3() {
    echo -e "\x1b[1;35m[\x1b[0m$(date '+%F %T')\x1b[1;35m]\x1b[0m \x1b[1;36m    -- \x1b[0m $*"
}

warn() {
    echo -e "\x1b[1;35m[\x1b[0m$(date '+%F %T')\x1b[1;35m]\x1b[0m \x1b[1;33mWARN:\x1b[0m $*"
}

error() {
    echo -e "\x1b[1;35m[\x1b[0m$(date '+%F %T')\x1b[1;35m]\x1b[0m \x1b[1;31mERROR:\x1b[0m $*"
}

###  ___  ___  ___  _____ _   _
###  |  \/  | / _ \|_   _| \ | |
###  | .  . |/ /_\ \ | | |  \| |
###  | |\/| ||  _  | | | | . ` |
###  | |  | || | | |_| |_| |\  |
###  \_|  |_/\_| |_/\___/\_| \_/
###

cleanup() {
    msg1 "Begin cleanup"
    if [ -e $FIFO ]; then
        msg2 "Deleting named pipe $FIFO"
        rm -f $FIFO
    fi
    if ps -p $CHILD_PID &> /dev/null; then
        msg2 "Terminating swayidle child process $CHILD_PID"
        kill -SIGTERM $CHILD_PID
    fi
    msg2 "Cleanup DONE"
}

add_time() {
    t=$1
    [[ ${t:0:1} == '+' || ${t:0:1} == '-' ]] && (( t = $last_time ${t:0:1} ${t:1} ))
    last_time=$t
    swayidle_cmd+=($t)
}

dispatch_main() {
    if [ ! -p $FIFO ]; then
        warn "FIFO $FIFO does not exist. The manager does not seem to be running. Doing nothing."
        exit 1
    fi
    echo $1 > $FIFO
}

manager_main() {
    if [ -e $FIFO ]; then
        cat <<EOF
        FIFO $FIFO already exists.

            Only one instance of $0 may run at a time. However,
            the existence of $FIFO indicates that another
            instance is already running.

            Please manually delete $FIFO, if you are sure that
            the other instance of $0 has exited / crashed.
EOF
        exit 1
    fi

    msg1 "Startup"

    # Set the cleanup exit hook
    trap cleanup EXIT

    # Prepare FIFO
    msg2 "Creating named pipe $FIFO"
    mkfifo $FIFO

    # Building swayidle command
    msg2 "Building swayidle command:"
    swayidle_cmd=(swayidle -w)
    last_time=0
    for i in "${SWAYIDLE_COMMANDS[@]}"; do
        c=($i)
        swayidle_cmd+=(${c[0]})
        case "${c[0]}" in
            timeout)
                add_time ${c[1]}
                swayidle_cmd+=("$SELF '${c[2]}'")
                if [[ "${c[3]}" == 'resume' ]]; then
                    swayidle_cmd+=(resume)
                    swayidle_cmd+=("$SELF '${c[4]}'")
                fi
                ;;
            before-sleep|after-resume|lock|unlock)
                swayidle_cmd+=("$SELF '${c[1]}'")
                ;;
            idlehint)
                add_time ${c[1]}
                ;;
            *)
                error "Unknown command '${c[0]}'"
                exit 1
                ;;
        esac
    done

    # Start swayidle
    "${swayidle_cmd[@]}" &
    CHILD_PID=$!
    msg2 "Started swayidle: PID=$CHILD_PID"

    # Main loop
    msg2 "Starting main loop"
    while true; do
        # Read from the FIFO with a timeout
        read -st 1 cmd <> $FIFO || cmd=''

        # Check if the FIFO was deleted
        if [ ! -p $FIFO ]; then
            warn "FIFO $FIFO was deleted. --> Exiting"
            exit 1
        fi

        # Empty command / timeout?
        [ -z "$cmd" ] && continue

        # Commands may be chained via `,`
        for i in ${cmd//,/ }; do
            # Exec command if known
            if [[ "$(LC_ALL=C type -t "cmd_$i")" == 'function' ]]; then
                cmd_$i
            else
                warn "Unknown command '$i' --> ignoring"
            fi
        done
    done
}

if [ -n "$1" ]; then
    dispatch_main "$1"
else
    manager_main
fi