[WIP] UIView to check is visible on screen. Not perfect solution

UIView+isPossiblyVisible.swift

extension UIView {
    func isPossiblyVisible() -> Bool {
        guard isHidden == false,
            alpha > 0,
            bounds != .zero,
            let window = window, // In a window's view hierarchy
            window.isKeyWindow, // Does not consider cases covered by another transparent window
            window.hitTest(convert(center, to: nil), with: nil) != self
            else { return false }

        // Checck subviews
        let invisibleSubviews: Bool = {
            for subview in subviews {
                if subview.isPossiblyVisible() {
                    return false
                }
            }
            return true // Including no subviews
        }()

        // No subview and no color, its not visible
        if invisibleSubviews {
            if (backgroundColor == nil || backgroundColor == .clear)
                && (layer.backgroundColor == nil || layer.backgroundColor?.alpha == 0){
                return false
            }
        }

        // What about special CALayer cases?

        return true // maybe, not 100% sure XD
    }
}