How to detect edge swipes

Swift version: 5.4

Paul Hudson @twostraws May 28th 2019

Detecting pan gestures is easy enough with a regular UIPanGestureRecognizer, but there's a special gesture recognizer to use if you want to detect the user swiping from the edge of their screen. The example below demonstrates detecting the user swiping from the left edge of the screen:

override func viewDidLoad() {
    super.viewDidLoad()

    let edgePan = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(screenEdgeSwiped))
    edgePan.edges = .left

    view.addGestureRecognizer(edgePan)
}

@objc func screenEdgeSwiped(_ recognizer: UIScreenEdgePanGestureRecognizer) {
    if recognizer.state == .recognized {
        print("Screen edge swiped!")
    }
}