Navigation bar large title custom y offset - iOS 11

LargeTitleCustomOffset.swift

import UIKit

class  LargeTitleCustomOffset: UINavigationBar {
    
    let labelcolor = UIColor(red: 36.0/255.0, green: 38.0/255.0, blue: 47.0/255.0, alpha: 1.0)

    override func draw(_ rect: CGRect) {
        super.draw(rect)
        
        self.backgroundColor = UIColor.white
        let largeView = "_UINavigationBarLargeTitleView"
        
        for view in self.subviews {
            if largeView.contains(String(describing: type(of: view))) {
                for v in view.subviews {
                    if String(describing: type(of: v)) == "UILabel" {
                        var titleLabel = v as! UILabel
                        var labelRect = titleLabel.frame
                        let labelInsets = UIEdgeInsets(top: 10, left: 13, bottom: 0, right: 0)
                        let attrText = NSMutableAttributedString(string: "Custom title", attributes: [NSAttributedStringKey.font: UIFont(name: "SFProDisplay-Heavy", size: 30)!, NSAttributedStringKey.foregroundColor: self.labelcolor])
                        
                        labelRect.origin.y += 20
                        let newLabel = UILabel(frame: labelRect)
                        newLabel.attributedText = attrText
                        titleLabel.text = ""
                      
                        // disable offset if normal title state is on
                        if labelRect.origin.y > 0 {
                            titleLabel = newLabel
                            titleLabel.drawText(in: UIEdgeInsetsInsetRect(labelRect, labelInsets))
                        }
                    }
                }
            }
        }
    }
}