ActionableTextField.swift

//: A UIKit based Playground for presenting user interface
  
import UIKit
import PlaygroundSupport

typealias EmptyClosure = () -> Void

class ActionableTextField: UITextField {
    
    private var cancelAction: EmptyClosure?
    private var doneAction: EmptyClosure?
    
    func addToolbarWithActions(cancel: EmptyClosure? = nil, done: EmptyClosure? = nil) {
        cancelAction = cancel
        doneAction = done
        
        let toolbar = UIToolbar(frame: CGRect(x: 0,
                                                    y: 0,
                                                    width: UIScreen.main.bounds.width,
                                                    height: 50))
        toolbar.barStyle = UIBarStyle.default
        toolbar.items = [
            UIBarButtonItem(title: "Cancel",
                            style: .plain,
                            target: self,
                            action: #selector(cancel(sender:))),
            UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil),
            UIBarButtonItem(title: "Done",
                            style: .plain,
                            target: self,
                            action: #selector(done(sender:)))
        ]
        toolbar.sizeToFit()
        inputAccessoryView = toolbar
    }
    
    @objc
    private func cancel(sender: AnyObject) {
        cancelAction?()
    }
    
    @objc
    private func done(sender: AnyObject) {
        doneAction?()
    }
    
}

class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        let label = ActionableTextField()
        label.frame = CGRect(x: 150, y: 200, width: 200, height: 20)
        label.text = "Hello World!"
        label.textColor = .black
        label.addToolbarWithActions { [unowned label] in
            // TBD
            label.text = "cancelled"
        } done: {
            label.text = "done"
        }

        
        view.addSubview(label)
        self.view = view
    }
}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()