Query the subview hierarchy

UIView+Subviews.swift

extension UIView {
      func allSubviews<T: UIView>(of type: T.Type) -> [T] {
        let directSubviews = subviews.compactMap({ $0 as? T })
        var nested = [T]()

        for s in subviews {
            let ss = s.allSubviews(of: type)
            nested += ss
        }

        return directSubviews + nested
    }

    func firstSubview<T: UIView>(of type: T.Type) -> T? {
        if let directSubview = subviews.first(where: { $0 is T}) as? T {
            return directSubview
        }


        for s in subviews {
            guard let ss = s.firstSubview(of: type) else {
                continue
            }
            return ss
        }

        return nil
    }
}