[maemo-developers] [maemo-developers] How to determine if the screen has turned off?

[From: Aaron Levinson]

In the Maemo coding style and programming guidelines document on
maemo.org, it states the following:  "Avoid updating the GUI when the
application running on the background and when the screen has been turned
off. Remove unnecessary graphical elements or constantly updated screen
components."  Now, it appears that hildon_window_get_is_topmost() or
hildon_program_get_is_topmost() can be used to determine if an application
is running in the background, but how does one programmatically determine
if the screen has been turned off?  I see in the latest version of libosso
in SVN that there is a muali API that provides the ability to access the
information via a callback, but it is unclear how to determine this on 2.0
or 2.1.  Perhaps I can use XScreenSaverQueryInfo() ?

Thanks,
Aaron