UIView + AllowTouchesOutsideOfBounds.swift

public extension UIView {
    
    private struct ExtendedTouchAssociatedKey {
        static var outsideOfBounds = "viewExtensionAllowTouchesOutsideOfBounds"
    }
    
    
    var allowTouchesOutsideOfBounds:Bool {
        get {
            return objc_getAssociatedObject(self, &ExtendedTouchAssociatedKey.outsideOfBounds) as? Bool ?? false
        }
        set {
            UIView.swizzlePoinInsideIfNeeded()
            objc_setAssociatedObject(self, &ExtendedTouchAssociatedKey.outsideOfBounds, newValue, .OBJC_ASSOCIATION_RETAIN)
        }
    }
    
    func hasSubviewAllowingTouchesOutsideOfBounds(at point:CGPoint) -> Bool {

        if allowTouchesOutsideOfBounds && self.bounds.contains(point) {
            return true
        }
        return subviews.contains(where: { (subview) -> Bool in
            let converted = self.convert(point, to: subview)
            return subview.hasSubviewAllowingTouchesOutsideOfBounds(at: converted)
        })
        
    }
    
    static private var swizzledMethods:Bool = false

    @objc func _point(inside point: CGPoint, with event: UIEvent?) -> Bool {
        return _point(inside:point,with:event) || hasSubviewAllowingTouchesOutsideOfBounds(at: point)
    }

    static private func swizzlePoinInsideIfNeeded() {
        if swizzledMethods {
            return
        }
        swizzledMethods = true
        let aClass: AnyClass! = UIView.self
        let originalSelector = #selector(point(inside:with:))
        let swizzledSelector = #selector(_point(inside:with:))
        swizzle(forClass: aClass, originalSelector: originalSelector, swizzledSelector: swizzledSelector)
    }

}