How to display a popover UIAlertController from a UITableViewCell's UIContextualAction?

Question

I'd like to present a UIAlertController over a UIContextualAction 'button' in a UITableViewCell. My question is how to set the sourceRect for the specific selected action? I assume it's possible, the way the iOS Mail app allows you to select more options when you swipe left on a cell (see image).

Answer 1

When you setup your action, it has a view parameter. Use that to setup the action sheet.

override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
    let act1 = UIContextualAction(style: .normal, title: "Bar") { (action, view, completion) in
        completion(false)
    }

    let act2 = UIContextualAction(style: .normal, title: "Foo") { (action, view, completion) in
        let alert = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
        alert.addAction(UIAlertAction(title: "Option 1", style: .default) { (action) in
            completion(true)
        })
        alert.addAction(UIAlertAction(title: "Option 2", style: .default) { (action) in
            completion(false)
        })

        // This sets up the alert to show next to the button
        alert.popoverPresentationController?.sourceView = view
        alert.popoverPresentationController?.sourceRect = view.bounds

        self.present(alert, animated: true, completion: nil)
    }

    return UISwipeActionsConfiguration(actions: [act1, act2])
}

Of course this only works on an iPad since on an iPhone the alert will show from the bottom of the screen.