Keyboard backlight timeout script

kbd_idle.py

#!/usr/bin/python3

# Needs packages python-dbus & python-gobject

# ~/scripts/kbd_idle.sh:
#   !/bin/sh

#   cd ~/scripts
#   exec python3 kbd_idle.py &

# Add to kde autostart

import sys
from time import sleep
import threading
import dbus
from dbus.mainloop.glib import DBusGMainLoop
from gi.repository import GLib

IDLE_TIMEOUT = 10 # Seconds

brightness = 0

def kbd_brightness_change_handler(x):
    global brightness
    brightness = x

def signal_listener_thread(loop):
    loop.run()

def main(argc, argv):
    DBusGMainLoop(set_as_default=True)
    loop = GLib.MainLoop()

    sesbus = dbus.SessionBus()
    sysbus = dbus.SystemBus()

    ss_proxy = sesbus.get_object("org.freedesktop.ScreenSaver", "/ScreenSaver")
    ss_iface = dbus.Interface(ss_proxy, "org.freedesktop.ScreenSaver")

    ksm_proxy = sesbus.get_object("org.kde.ksmserver", "/KSMServer")
    ksm_iface = dbus.Interface(ksm_proxy, "org.kde.KSMServerInterface")

    bl_proxy = sysbus.get_object("org.freedesktop.UPower", "/org/freedesktop/UPower/KbdBacklight")
    bl_iface = dbus.Interface(bl_proxy, "org.freedesktop.UPower.KbdBacklight")

    bl_iface.connect_to_signal("BrightnessChanged", kbd_brightness_change_handler)

    receiver = threading.Thread(target=signal_listener_thread, args=[loop])
    receiver.start()

    global brightness
    brightness = bl_iface.GetBrightness()
    prev_brightness = 0
    shutdown = False
    try:
        while not ksm_iface.isShuttingDown():
            sleep(0.5)
            idle_time = ss_iface.GetSessionIdleTime() / 1000 # ms
            if not shutdown and idle_time > IDLE_TIMEOUT:
                prev_brightness = bl_iface.GetBrightness()
                bl_iface.SetBrightness(0)
                shutdown = True
            elif shutdown and idle_time < IDLE_TIMEOUT:
                if not brightness:
                    bl_iface.SetBrightness(prev_brightness)
                shutdown = False
    except (SystemExit, KeyboardInterrupt):
        pass

    loop.quit()
    receiver.join()

    return 0


if __name__ == "__main__":
    sys.exit(main(len(sys.argv), sys.argv))