Getting device orientation in Swift

you can use:

override func didRotateFromInterfaceOrientation(fromInterfaceOrientation: UIInterfaceOrientation) {
    var text=""
    switch UIDevice.currentDevice().orientation{
    case .Portrait:
        text="Portrait"
    case .PortraitUpsideDown:
        text="PortraitUpsideDown"
    case .LandscapeLeft:
        text="LandscapeLeft"
    case .LandscapeRight:
        text="LandscapeRight"
    default:
        text="Another"
    }
    NSLog("You have moved: \(text)")        
}

SWIFT 3 UPDATE

override func didRotate(from fromInterfaceOrientation: UIInterfaceOrientation) {
    var text=""
    switch UIDevice.current.orientation{
    case .portrait:
        text="Portrait"
    case .portraitUpsideDown:
        text="PortraitUpsideDown"
    case .landscapeLeft:
        text="LandscapeLeft"
    case .landscapeRight:
        text="LandscapeRight"
    default:
        text="Another"
    }
    NSLog("You have moved: \(text)")        
}

or

override func willRotateToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
}

with Notification you can check: IOS8 Swift: How to detect orientation change?

NOTE : didRotateFromInterfaceOrientation is Deprecated Use
viewWillTransitionToSize for iOS 2.0 and later

In case of Face up and Face Down this will not work.
So we need to use the following.

if UIApplication.shared.statusBarOrientation.isLandscape {
     // activate landscape changes
} else {
     // activate portrait changes
}