iOS 9-10 iPhone Popover Example

//Add this to a view controller 

let button = UIButton(frame: CGRect(x: 0, y: 0, width: 75, height: 20))
var bbItem : UIBarButtonItem!

extension SettingsViewController : UIPopoverPresentationControllerDelegate {
    
    fileprivate func _setupPopoverTest() {
        bbItem = UIBarButtonItem(customView: button)
        button.setTitle("Popover", for: .normal)
        button.setTitleColor(.black, for: .normal)
        button.addTarget(self, action: #selector(showPopover), for: .touchUpInside)
        self.navigationItem.setRightBarButton(bbItem, animated: true)
        
    }
    
    func showPopover() {
        let vc = UIViewController()
        vc.modalPresentationStyle = .popover
        vc.view.backgroundColor = UIColor.magenta
        vc.preferredContentSize = CGSize(width: 200, height: 200)
        vc.popoverPresentationController?.delegate = self
        vc.popoverPresentationController?.permittedArrowDirections = .up
        //        vc.popoverPresentationController?.barButtonItem = bbItem
        vc.popoverPresentationController?.sourceView = button
        vc.popoverPresentationController?.sourceRect = button.bounds
        
        self.present(vc, animated: false, completion: nil)
    }
    
    func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
        return .none
    }
}