How to get all views in hierarchy in my touch position - Swift

Question

How to get all UIViews at my touch position?

In image below I need to get all UIViews in touches with the yellow line.

Snippet from UI hierarchy:

I looking for a similar function to SpriteKit where we use to get all nodes at point with

self.nodes(at: touch.location(in: self))

Answer 1

You have to traverse all views in the hierachy like:

extension UIView {
    func allViews(for touch: UITouch) -> [UIView] {
        return self.allViews(at: touch.location(in: self))
    }

    func allViews(at point: CGPoint) -> [UIView] {
        var stack = [UIView]()
        var result = [UIView]()

        stack.append(self)
        while let view = stack.popLast() {
            let localPoint = view.convert(point, from: self)

            if view.bounds.contains(localPoint) {
                result.append(view)
            }
            stack.append(contentsOf: view.subviews)
        }
        return result
    }
}

You can either start with any super view which contains all appropriate views (e.g the view of a view controller) or the window. The point for the second method must be relative to the bounds of the view which is represented by self.

Answer 2

This can be achieved in two steps:

1. get all views starting from a certain view

   func descendants(of view: UIView) -> [UIView] {
       return view.subviews + view.subviews.flatMap(descendants(of:))
   }
   

2. filter the view that contain the touch point:

   let touchLocation = touchGesture.location(in: nil)
   let matchingViews = descendants(of: UIApplication.shared.keyWindow!)
       .filter { $0.convert($0.bounds, to: nil).contains(touchLocation) }