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I have swipeable tableview cells. The intention is to let the user swipe rows left or right completely (swipe out completely), and the swiped row gets removed from the table (like how Inbox by Gmail works). Everything works fine, but I had a question.

func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? 
 let swipeRightAction = UIContextualAction(style: .destructive, title: "", handler: (ac:UIContextualAction, view:UIView, success:(Bool) -> Void) in
 let item = self.myItems[indexPath.row]
 self.swipeRight(item) //do something
 self.myItems.remove(at: indexPath.row)
 success(true)
 )

 return UISwipeActionsConfiguration(actions: [swipeRightAction])
 

How can I set the threshold/distance (how much the user has to swipe before the action is taken)? Currently, the user has to swipe half way, before the row gets swiped out. Can I change this point so the user only needs to swipe a little (say 20% of the way) to swipe out the row?

There is no direct configuration method for it.

Solution

But you can build it yourself:

• add a UIPanGestureRecognizer to the table


• allow simultaneous recognitions of gestures


• when a swipe ends check for direction and compute percentage out of the translation


• determine the affected table row


• delete it

Code

A swipe of the cells to the left by 20%, leading to the deletion of a row, would look like this in the code:

class ViewController: UITableViewController, UIGestureRecognizerDelegate {

 override func viewDidLoad() 
 super.viewDidLoad()
 ...
 let swipeGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(onSwiped(_:)))
 swipeGestureRecognizer.delegate = self
 self.tableView.addGestureRecognizer(swipeGestureRecognizer)
 

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

 @objc private func onSwiped(_ gestureRecognizer: UIPanGestureRecognizer) 
 if gestureRecognizer.state == .ended 
 let translation = gestureRecognizer.translation(in: self.view)
 guard translation.x < 0 else return 
 let width = self.tableView.bounds.width
 let percentage = -translation.x / width
 print("swiped left percentage:(percentage)")
 if percentage > 0.2 
 let location = gestureRecognizer.location(in: self.tableView)
 if let indexPath = self.tableView.indexPathForRow(at: location) 
 print("delete row: (indexPath.row)")
 self.dataSource.remove(at: indexPath.row)
 self.tableView.reloadData()
 
 
 
 

Demo