How to add SwipeGesture to tableView with 0 cells in Swift

Question

I need to add a left swipe gesture recognizer to my CommentVC. My CommentVC includes a tableView, so if I have 0 cells in CommentVC then I am unable to swipe back.

My code: with this code I can swipe only if there at least one cell in that area of that tableview. But I need to swipe if there is no cell as well. How can I achieve that? Please guide me.

class CommentVC: UIViewController, UIGestureRecognizerDelegate {

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationController?.interactivePopGestureRecognizer?.delegate = self    
    self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true
    
    let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(self.respondToSwipeGesture))
    swipeRight.direction = UISwipeGestureRecognizer.Direction.left
    self.tableView.addGestureRecognizer(swipeRight)
}

@objc func respondToSwipeGesture(gesture: UIGestureRecognizer) {
    if let swipeGesture = gesture as? UISwipeGestureRecognizer {
        switch swipeGesture.direction {
        case UISwipeGestureRecognizer.Direction.left:
            print("Swiped left")
            self.navigationController?.popViewController(animated: true)
        default:
            break
        }
    }
}

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true
}

}

Answer 1

I just tried this and its completely worked. i have just changed one line

self.tableView.addGestureRecognizer(swipeRight)

above line i have replaced above line with this line. then able to swipe with no cells and with cells in tableview i have added a UISwipeGestureRecognizer to the superview that contains the UITableView

self.view.addGestureRecognizer(swipeRight)

this is total code:

class CommentVC: UIViewController, UIGestureRecognizerDelegate {

override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.interactivePopGestureRecognizer?.delegate = self    
self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true

let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(self.respondToSwipeGesture))
swipeRight.direction = UISwipeGestureRecognizer.Direction.left
self.view.addGestureRecognizer(swipeRight)

}

@objc func respondToSwipeGesture(gesture: UIGestureRecognizer) {
if let swipeGesture = gesture as? UISwipeGestureRecognizer {
    switch swipeGesture.direction {
    case UISwipeGestureRecognizer.Direction.left:
        print("Swiped left")
        self.navigationController?.popViewController(animated: true)
    default:
        break
    }
}
}

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}

}

Answer 2

By your question, I suppose touchView in your code is a UITableView.

If so, you can simply add a generic background view to the table view, then add the same gesture recognizer to the background view.

    // assuming touchView is of type UITableView, and its frame is equal to self.view.bounds
    self.touchView.backgroundView = UIView()
    self.touchView.backgroundView?.addGestureRecognizer(swipeRight)