Andrew,
Maybe this will help you:
http://ryanhomer.com/blog/2007/05/31/
detecting-when-your-cocoa-application-is-idle/
> On Apr 11, 2007, at 3:00 PM, Andrew James wrote:
>
>> Hi,
>>
>> Is there a method to hook into the system to detect when the
>> system has been idle for a certain period of time, not just the
>> application its self but the whole system.
>>
>> Like i want to run a method when the system has been idle for n
>> minutes
>
> There is a "private" API called CGSSecondsSinceLastInputEvent that
> returns the number of seconds since the last input has been
> received. I use this in a small utility that I have developed and
> it works under Tiger (10.4.{6,7,8,9}).
>
> Being a private API you should be aware of the fact that your
> application could be incompatible with other OS X versions (past
> and future).
>
> The prototype is: double CGSSecondsSinceLastInputEvent(long evType);
> CGSSecondsSinceLastInputEvent(-1) would do the trick.
>
> Hope this helps.
>
> See you,
> Fabio
