Passing touches between stacked UIWindows?

Question

I have two windows -- a front one, and a back one. The front one is used to overlay some stuff on top of the back one. I want to be able to capture touches on some parts of

Answer 1

I had a similar issue: the additional UIWindow should have a transparent view on it with some intractable subviews. All touches outside of those intractable views must be passed through.

I ended up using modified version of Anna's code that uses view's tag instead of type checking. This way view subclass creation is not required:

class PassTroughWindow: UIWindow {
    var passTroughTag: Int?

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {

        let hitView = super.hitTest(point, with: event)

        if let passTroughTag = passTroughTag {
            if passTroughTag == hitView?.tag {
                return nil
            }
        }
        return hitView
    }
}

Assuming you have a window and root view controller created you you could use it like this:

let window: PassTroughWindow 
//Create or obtain window

let passTroughTag = 42

window.rootViewController.view.tag = passTroughTag
window.passTroughTag = passTroughTag

//Or with a view:
let untouchableView: UIView // Create it
untouchableView.tag = passTroughTag
window.addSubview(untouchableView)