power_notifications.py

#!/usr/bin/env python
"""Send desktop notifications when AC power status changes."""

from __future__ import print_function

import dbus
from dbus.mainloop import glib
import gobject

onMessage="Power plugged in!"
offMessage="Power unplugged!"
onImage="/run/current-system/sw/share/icons/breeze-dark/devices/64/battery.svg"
offImage="/run/current-system/sw/share/icons/breeze-dark/devices/64/battery.svg"


def mkCallback(bus):

    bus_obj = bus.get_object(
        'org.freedesktop.Notifications',
        '/org/freedesktop/Notifications',
    )
    notifications_iface = dbus.Interface(
        bus_obj,
        dbus_interface='org.freedesktop.Notifications',
    )

    def notify(msg,
               app_name="",
               icon="",
               summary="",
               actions=(),
               hints=(),
               timeout=5000,  # milliseconds
               ):
        # print(msg)
        notify.last_msg_id = notifications_iface.Notify(
            app_name,
            notify.last_msg_id,
            icon,
            summary,
            msg,
            actions,
            hints,
            timeout,
        )
    notify.last_msg_id = 0

    def callback(*args):
        # print("callback called: ", args)
        if len(args) == 3:
            (dev, data, sig) = args

        online = data.get('Online')
        if online is None:
            print("??????? I AM CONFUSION ???????")
        elif online:
            notify(msg=onMessage, icon=onImage)
        else:
            notify(msg=offMessage, icon=offImage)
    return callback


def main():
    dbus.set_default_main_loop(glib.DBusGMainLoop())

    system_bus = dbus.SystemBus()
    session_bus = dbus.SessionBus()

    system_bus.add_signal_receiver(
        handler_function=mkCallback(session_bus),
        signal_name="PropertiesChanged",
        dbus_interface="org.freedesktop.DBus.Properties",
        bus_name=None,  # Sender?
        path='/org/freedesktop/UPower/devices/line_power_AC0',
    )

    loop = gobject.MainLoop()
    loop.run()


if __name__ == '__main__':
    main()