How to detect device's orientation in Swift

There are two ways to detect a device's orientation:

1). The UIDevice.current.orientation property (instance of UIDeviceOrientation class:
- isFlat: when the device is held upward (toward the sky) or downward (toward the ground)
- isLandscape: when the device is held upright and the home button is on the right/left
- isPortrait: when the device is held upright and the home button is at the bottom/top

2). The UIApplication.shared.statusBarOrientation property:
- isLandscape
- isPortrait

Using Swift 3, the status bar is hidden by default in my app. However, the isLandscape and isPortrait still work correctly.

Which one should we use?
It depends on circumstances. In my case, I want to enable swipe gesture in portrait mode but disable it in landscape mode so UIApplication.shared.statusBarOrientation.isLandscape is the right one. If my device is firstly in landscape mode and then i put it on the table (face up), the swipe gesture should still be disable. The UIDevice.current.orientation.isLandscape property would return false and then the user would be able to swipe.