class ViewConrtoller: UIViewController { override func viewDidLoad() { super.viewDidLoad() view.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(onDrage(_:)))) } @objc func onDrage(_ sender:UIPanGestureRecognizer) { let percentThreshold:CGFloat = 0.3 let translation = sender.translation(in: view) let newX = ensureRange(value: view.frame.minX + translation.x, minimum: 0, maximum: view.frame.maxX) let progress = progressAlongAxis(newX, view.bounds.width) view.frame.origin.x = newX //Move view to new position if sender.state == .ended { let velocity = sender.velocity(in: view) if velocity.x >= 300 || progress > percentThreshold { self.dismiss(animated: true) //Perform dismiss } else { UIView.animate(withDuration: 0.2, animations: { self.view.frame.origin.x = 0 // Revert animation }) } } sender.setTranslation(.zero, in: view) }
}
func progressAlongAxis(_ pointOnAxis: CGFloat, _ axisLength: CGFloat) -> CGFloat { let movementOnAxis = pointOnAxis / axisLength let positiveMovementOnAxis = fmaxf(Float(movementOnAxis), 0.0) let positiveMovementOnAxisPercent = fminf(positiveMovementOnAxis, 1.0) return CGFloat(positiveMovementOnAxisPercent) } func ensureRange<T>(value: T, minimum: T, maximum: T) -> T where T : Comparable { return min(max(value, minimum), maximum) }