Swift Swipe Guester detector. Detect all four swipe directions. Swift 4

swift_swipe_detect.swift

//more info on https://stackoverflow.com/questions/24215117/how-to-recognize-swipe-in-all-4-directions
class BaseViewController: UIViewController {             

     override func viewDidLoad() {
         super.viewDidLoad()
         let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(swiped))
         swipeRight.direction = UISwipeGestureRecognizerDirection.right
         self.view.addGestureRecognizer(swipeRight)
         let swipeLeft = UISwipeGestureRecognizer(target: self, action: #selector(swiped))
         swipeLeft.direction = UISwipeGestureRecognizerDirection.left
         self.view.addGestureRecognizer(swipeLeft)
     }

     // Example Tabbar 5 pages
     @objc func swiped(_ gesture: UISwipeGestureRecognizer) {
         if gesture.direction == .left {
            if (self.tabBarController?.selectedIndex)! < 5 {
                self.tabBarController?.selectedIndex += 1
            }
         } else if gesture.direction == .right {
             if (self.tabBarController?.selectedIndex)! > 0 {
                 self.tabBarController?.selectedIndex -= 1
             }
         }
     }  
}