Unoccluded UITextField Extension (Text Field Delegate)

UIViewController-UnocculdedTextField-TextField-Delegate.swift

import UIKit
import ObjectiveC

struct AssociatedKeys {
    static var activeTextField: UInt8 = 0
}

extension UIViewController : UITextFieldDelegate {
    
    private(set) var activeTextField: UITextField? {
        get {
            return objc_getAssociatedObject(self, &AssociatedKeys.activeTextField) as? UITextField
        }
        set(newValue) {
            objc_setAssociatedObject(self, &AssociatedKeys.activeTextField, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
        }
    }
    
    public func textFieldDidBeginEditing(_ textField: UITextField) {
        self.activeTextField = textField
    }
    
    public func textFieldDidEndEditing(_ textField: UITextField, reason: UITextFieldDidEndEditingReason) {
        self.activeTextField = nil
    }
    
    public func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return false
    }
    
}