Refactor inhibit_sleep handling on linux to catch errors earlier

printrun/power/__init__.py

@@ -36,29 +36,29 @@ else:
     import dbus
 
     try:
-        bus = dbus.SessionBus()
-
-        def inhibit_sleep(reason):
-            if inhibit_sleep.handler is None:
+        inhibit_sleep_handler = None
         bus = dbus.SessionBus()
         try:
             # GNOME uses the right object path, try it first
             service_name = "org.freedesktop.ScreenSaver"
             proxy = bus.get_object(service_name,
                                    "/org/freedesktop/ScreenSaver")
-                    inhibit_sleep.handler = dbus.Interface(proxy, service_name)
+            inhibit_sleep_handler = dbus.Interface(proxy, service_name)
         except dbus.DBusException:
             # KDE uses /ScreenSaver object path, let's try it as well
             proxy = bus.get_object(service_name,
                                    "/ScreenSaver")
-                    inhibit_sleep.handler = dbus.Interface(proxy, service_name)
-            inhibit_sleep.token = inhibit_sleep.handler.Inhibit("printrun", reason)
-        inhibit_sleep.handler = None
+            inhibit_sleep_handler = dbus.Interface(proxy, service_name)
+
+        def inhibit_sleep(reason):
+            global inhibit_sleep_handler
+            inhibit_sleep.token = inhibit_sleep_handler.Inhibit("printrun", reason)
 
         def deinhibit_sleep():
-            if inhibit_sleep.handler is None:
+            global inhibit_sleep_handler
+            if inhibit_sleep_handler is None:
                 return
-            inhibit_sleep.handler.UnInhibit(inhibit_sleep.token)
+            inhibit_sleep_handler.UnInhibit(inhibit_sleep.token)
             inhibit_sleep.token = None
     except dbus.DBusException, e:
         print "dbus unavailable:", e.message