A page control subclass with customizable dots

PageControl.swift

import UIKit

@IBDesignable
final class PageControl: UIPageControl {

    @IBInspectable var activeImage: UIImage?
    @IBInspectable var inactiveImage: UIImage?

    private func updateDotImages() {
        for (i, subview) in enumerate(subviews) {
            if let dot = subview as? UIImageView {
                dot.image = (i == currentPage) ? activeImage : inactiveImage
            }
        }
    }

    override var currentPage: Int {
        didSet {
            updateDotImages()
        }
    }
}