Add button to center of UITabBarController

TabBar Center Button

//
//  CenterButtonTabBarController.swift
//  FashionCritic
//
//  Created by Lee Irvine on 1/5/18.
//  Copyright © 2018 kezzi.co. All rights reserved.
//

import UIKit

class CenterButtonTabBarController: UITabBarController {
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        self.view.bringSubview(toFront: self.tabBar)
        self.addCenterButton()
    }

    private func addCenterButton() {
        let button = UIButton(type: .custom)
        let square = self.tabBar.frame.size.height
        button.frame = CGRect(x: 0, y: 0, width: square, height: square)
        button.center = self.tabBar.center

        self.view.addSubview(button)
        self.view.bringSubview(toFront: button)

        button.addTarget(self, action: #selector(didTouchCenterButton(_:)), for: .touchUpInside)
    }

    @objc
    private func didTouchCenterButton(_ sender: AnyObject) {
        print("!!")
    }

}