How to read the interface orientation: portrait or landscape?

Swift version: 5.10

Paul Hudson @twostraws May 28th 2019

Apple generally doesn’t want developers to think about things like “portrait” and “landscape” because devices come in a range of sizes, and in the case of iPad you get slide over and split view on top. However, sometimes it’s just useful, particularly on iPhone where the difference between portrait and landscape is huge.

If you just want to read the current interface orientation you can do so using UIApplication.shared.statusBarOrientation, which will contain a value such as .portraitUpsideDown. Alternatively, you can use its isLandscape and isPortrait properties to check for both values of landscape or both values of portrait at once.

If you want your interface to adapt every time the user moves between landscape and portrait, you should check UIApplication.shared.statusBarOrientation inside the willTransition(to:) method, which is triggered when the trait collection of your app changes.

Something like this ought to do the trick:

override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
    coordinator.animate(alongsideTransition: { context in
        if UIApplication.shared.statusBarOrientation.isLandscape {
            // activate landscape changes
        } else {
            // activate portrait changes
        }
    })
}