How to check whether running on Lion or Snow Leopard

Question

In my Cocoa application I would like to let the user take the app full screen on Lion. To do this I would like to add the following:

if (check for lion or above) {
    [mywindow setCollectionBehavior:NSWindowCollectionBehaviorFullScreenPrimary];
}

I am adding this conditionally for Lion because NSWindowCollectionBehaviorFullScreenPrimary is only available from 10.7. What is the best way towards the check for lion or above?

Answer 1

You should read documentation about the Gestalt function.

SInt32 MacVersion;

if( Gestalt( gestaltSystemVersion, &MacVersion ) == noErr )
{
    if( MacVersion == 0x1050 ) /* Mac OS X 10.5.0 */
    {}
    else
    {}
}

Or you can use the SysCTL API