UITextField with image and padding

TextFieldWithImage.swift

import UIKit

@IBDesignable
class TextFieldWithImage: UITextField {

    override func leftViewRect(forBounds bounds: CGRect) -> CGRect {
        return super.leftViewRect(forBounds: bounds)
    }

    @IBInspectable var leftImage: UIImage? {
        didSet {
            updateView()
        }
    }
    @IBInspectable var leftPadding: CGFloat = 0 {
        didSet {
            updateView()
        }
    }
    @IBInspectable var rightPadding: CGFloat = 0 {
        didSet {
            updateView()
        }
    }
    @IBInspectable var imageMaxHeight: CGFloat = 0 {
        didSet {
            updateView()
        }
    }

    @IBInspectable var color: UIColor = UIColor.lightGray {
        didSet {
            updateView()
        }
    }

    func updateView() {
        if let image = leftImage {
            leftViewMode = UITextField.ViewMode.always

            let containerSize = calculateContainerViewSize(for: image)
            let containerView = UIView(frame: CGRect(x: 0, y: 0, width: containerSize.width, height: containerSize.height))

            let imageView = UIImageView(frame: .zero)
            containerView.addSubview(imageView)
            setImageViewConstraints(imageView, in: containerView)

            setImageViewProperties(imageView, image: image)

            leftView = containerView
        } else {
            leftViewMode = UITextField.ViewMode.never
            leftView = nil
        }

        attributedPlaceholder = NSAttributedString(string: placeholder != nil ? placeholder! : "",
                attributes: [NSAttributedString.Key.foregroundColor: color])
    }

    private func calculateContainerViewSize(for image: UIImage) -> CGSize {
        let imageRatio = image.size.height / image.size.width
        let adjustedImageMaxHeight = imageMaxHeight > self.frame.height ? self.frame.height : imageMaxHeight

        var imageSize = CGSize()
        if image.size.height > adjustedImageMaxHeight {
            imageSize.height = adjustedImageMaxHeight
            imageSize.width = imageSize.height / imageRatio
        }

        let paddingWidth = leftPadding + rightPadding

        let containerSize = CGSize(width: imageSize.width + paddingWidth, height: imageSize.height)
        return containerSize
    }

    private func setImageViewConstraints(_ imageView: UIImageView, in containerView: UIView) {
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.topAnchor.constraint(equalTo: containerView.topAnchor).isActive = true
        imageView.bottomAnchor.constraint(equalTo: containerView.bottomAnchor).isActive = true
        imageView.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -rightPadding).isActive = true
        imageView.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: leftPadding).isActive = true
    }

    private func setImageViewProperties(_ imageView: UIImageView, image: UIImage) {
        imageView.contentMode = .scaleAspectFit
        imageView.image = image
        imageView.tintColor = color
    }
}