How do I focus UIView? - ios

Question

I want to implement functions like radio buttons. More specifically, I want to implement the ability to select only one UIView from several UIViews. This is similar to the Focus Engine on tvOS.
While searching of relevant this, I noticed that UIKit supports Focus-based Navigation. But I am not sure if this supports exactly what I want. There is also a lack of additional relevant examples.
I would like to hear some help and advice on related features. Is the Focus-based Navigation suitable for the purpose I was pursuing? And are there any other good ways to implement the functionality I want to implement?

Answer 1

#Paulw Thank you for your kind help.
The following steps solved the problem!
I have used a simple way that effects a specified UIView among multiple UIViews.
import UIKit
class ViewController: UIViewController {
var selectView: UIView?
override func viewDidLoad() {
super.viewDidLoad()
selectView = self.view
let viw = UIView(frame: CGRect(x: 100, y: 100, width: 150, height: 150))
viw.backgroundColor = UIColor.white
viw.layer.cornerRadius = 10
self.view.addSubview(viw)
let objectView = ObjectView()
objectView.frame.size = CGSize(width: 150, height: 150)
objectView.backgroundColor = UIColor.clear
self.view.addSubview(objectView)
let tapObject = UITapGestureRecognizer(target: self, action: #selector(handleTap(sender:)))
objectView.addGestureRecognizer(tapObject)
let tapObjects = UITapGestureRecognizer(target: self, action: #selector(handleTap(sender:)))
viw.addGestureRecognizer(tapObjects)
let tapRootView = UITapGestureRecognizer(target: self, action: #selector(handleTap(sender:)))
self.view.addGestureRecognizer(tapRootView)
}
#objc func handleTap(sender: UITapGestureRecognizer) {
if sender.state == .ended {
if selectView != self.view {
selectView?.layer.shadowColor = UIColor.clear.cgColor
}
selectView = sender.view
if selectView != self.view {
sender.view?.layer.shadowOffset = .zero
sender.view?.layer.shadowOpacity = 0.5
sender.view?.layer.shadowColor = UIColor.black.cgColor
}
}
}
}