How to Create a Draggable Floating View in Swift

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var draggableView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.draggableView.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(handler)))
    }

    @objc func handler(gesture: UIPanGestureRecognizer){
        let location = gesture.location(in: self.view)
        let draggedView = gesture.view
        draggedView?.center = location

        if gesture.state == .ended {
            if self.draggableView.frame.midX >= self.view.layer.frame.width / 2 {
                UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: .curveEaseIn, animations: {
                    self.draggableView.center.x = self.view.layer.frame.width - 40
                }, completion: nil)
            } else {
                UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: .curveEaseIn, animations: {
                    self.draggableView.center.x = 40
                }, completion: nil)
            }
        }
    }
}