Where can I learn about DeviceKit-Power

[Patrick Doyle]

I stumbled across a wiki page
(https://wiki.ubuntu.com/DebuggingGNOMEPowerManager) that mentioned
that Ubuntu 9.10 uses DeviceKit-Power instead of HAL.  What caught my
eye on that page was that HAL offered 4 options for manipulating the
power state of the machine: Reboot, Shutdown, Hibernate, and Suspend,
while DeviceKit-Power offered only 2 options: Suspend and Hibernate.

This caught my eye because I was recently trying to figure out how to
configure my 9.10 box (a Mythbuntu box) to gracefully shut down when
somebody pressed the front panel power switch.  I tried using the
Settings>Power Management>General menu (in xfce) and found that it had
2 options: "Suspend" and "Hibernate", where everything I've read has
said that there should also be a "Shut Down" option.  Now I've
stumbled across web page that suggests there might be a correlation to
DeviceKit-Power.

So now I'm wondering where I can learn more about DeviceKit-Power.

My good buddy Google has pointed me at freedesktop.org with pages that
describe the reference manual for DeviceKit (and/or DeviceKit-Power).
While those are interesting, they don't include any sort of
explanatory information.  Google has also pointed me at a lot of posts
where everybody and his/her brother announce and/or blogged about how
DeviceKit was replacing HAL and was much better, but again, not real
explanatory information and nothing that I've found that explains what
happened to the handling of "shut down" type events.

So I figured I'd ask you folks... can you give my buddy Google and me
some tips on where I/we can l learn more about DeviceKit-Power.

--wpd