dbus_service.py

   1 #!/usr/bin/env python
   2 """
   3 A dbus service example currently providing a device called redshift, that runs
   4 redshift whenever it is not activated. This could be useful to temporarily
   5 disable redshift e.g. while watching a movie.
   6 """
   7
   8 import logging
   9
  10 import dbus
  11 import dbus.service
  12 from dbus.mainloop.glib import DBusGMainLoop
  13 from gi.repository import GObject
  14
  15 import onoff.common
  16 import onoff.dbusutils
  17 import onoff.process
  18
  19 logger = logging.getLogger("dbus_service")
  20
  21 class OnoffControl(dbus.service.Object):
  22     domain = "de.subdivi.onoff0"
  23     path = onoff.dbusutils.object_prefix
  24
  25     def __init__(self, bus, name, device):
  26         busname = dbus.service.BusName(self.domain, bus=bus)
  27         dbus.service.Object.__init__(self, busname, "%s/%s" % (self.path, name))
  28         self.device = device
  29         device.notify.add(self.changestate)
  30         self.usecount = 0
  31
  32     @dbus.service.signal(domain, signature="q")
  33     def changestate(self, st):
  34         logger.debug("emitting state %d", st)
  35
  36     @dbus.service.method(domain, out_signature="q")
  37     def state(self):
  38         return self.device.state
  39
  40     @dbus.service.method(domain, in_signature="q", out_signature="q")
  41     def activatetime(self, duration):
  42         logger.info("activatetime %d", duration)
  43         GObject.timeout_add(duration * 1000, self.unuse)
  44         return self.use()
  45
  46     @dbus.service.method(domain, in_signature="q", out_signature="qh")
  47     def activatefd(self, duration):
  48         logger.info("activatefd duration %d", duration)
  49         notifyfd, retfd = onoff.dbusutils.socketpair()
  50         def callback(fd, _):
  51             logger.info("fd %d completed", fd.fileno())
  52             fd.close()
  53             GObject.timeout_add(duration * 1000, self.unuse)
  54             return False
  55         GObject.io_add_watch(notifyfd, GObject.IO_HUP|GObject.IO_ERR, callback)
  56         return (self.use(), retfd)
  57
  58     def use(self):
  59         self.usecount += 1
  60         if self.usecount <= 1:
  61             self.device.activate()
  62         return self.device.state
  63
  64     def unuse(self):
  65         self.usecount -= 1
  66         if not self.usecount:
  67             self.device.deactivate()
  68         else:
  69             logger.debug("%d users left", self.usecount)
  70         return False
  71
  72
  73 def main():
  74     logging.basicConfig()
  75     logging.getLogger().setLevel(logging.DEBUG)
  76     DBusGMainLoop(set_as_default=True)
  77     bus = dbus.SessionBus()
  78     dev = onoff.process.OnoffProcess(["redshift"], 3)
  79     dev = onoff.common.InvertedDevice(dev)
  80     OnoffControl(bus, "redshift", dev)
  81     GObject.MainLoop().run()
  82
  83 if __name__ == "__main__":
  84     main()