How can you add a UIGestureRecognizer to a UIBarButtonItem as in the common undo/redo UIPopoverController scheme on iPad apps?

Question

Problem

In my iPad app, I cannot attach a popover to a button bar item only after press-and-hold events. But this seems to be standard for

Answer 1

@utopians answer in Swift 4.2

@objc func myAction(_ sender: UIBarButtonItem, forEvent event:UIEvent) {
    let longPressed:Bool = (event.allTouches?.first?.tapCount).map {$0 == 0} ?? false

    ... handle long press ...
}