I recently decided that Gnome is not the best desktop for my little EeePC netbook with a little 10.5" screen. So I'm playing around with a window manager that mainly just maximizes everything. I've tried Ratpoison, I've tried wmii, and now I'm trying Awesome.
I have a lot of customizations to do, but one thing that was missing was a way to suspend the netbook when the laptop lid is closed. I could manually run acpitool -s in a shell, or pm-suspend, but it's best handled by DBus, as intended.
Now, a simple way to have DBus do the work is using dbus-send, like so:
dbus-send --print-reply \ --system \ --dest=org.freedesktop.UPower \ /org/freedesktop/UPower \ org.freedesktop.UPower.Suspend
The hard part is subscribing to the lid close event, so I'm not polling all the time, exactly what DBus was written to prevent. I had a Python script for this, but the API was changed in Squeeze to use the UPower daemon and API.
I had to do some poking around to figure out how to update it, but I just got it working, so I thought I'd share.
#!/usr/bin/python import dbus, gobject, sys from dbus.mainloop.glib import DBusGMainLoop pow_prop_iface = None pow_iface = None def handle_lidclose(*args): closed = pow_prop_iface.Get('', 'LidIsClosed') if closed: print "lid is closed, suspending" pow_iface.Suspend() else: print "lid is open" def main(): global pow_prop_iface, pow_iface DBusGMainLoop(set_as_default=True) bus = dbus.SystemBus() power_proxy = bus.get_object('org.freedesktop.UPower', '/org/freedesktop/UPower') pow_prop_iface = dbus.Interface(power_proxy, 'org.freedesktop.DBus.Properties') pow_iface = dbus.Interface(power_proxy, 'org.freedesktop.UPower') print "Registering a signal receiver for upower events..." bus.add_signal_receiver(handle_lidclose, dbus_interface="org.freedesktop.UPower", signal_name="Changed") loop = gobject.MainLoop() loop.run() if __name__ == '__main__': main()
Now I just run it in the background from my .xsession script at X11 login, and it's sitting there waiting for any change in UPower status. Works like a charm.