UIPickerView, detect “rolling wheel” start and stop?

Question

I just discovered that if I do the following:

1. Click the button that animates a UIPickerView into my view
2. Quickly start the wheel rolling

Answer 1

Expanded @iluvatar_GR answer

extension UIView { 
func isScrolling () -> Bool {

    if let scrollView = self as? UIScrollView {
        if (scrollView.isDragging || scrollView.isDecelerating) {
            return true
        }
    }

    for subview in self.subviews {
        if ( subview.isScrolling() ) {
            return true
        }
    }
    return false
}
func waitTillDoneScrolling (completion: @escaping () -> Void) {
    var isMoving = true
    DispatchQueue.global(qos: .background).async {
    while isMoving == true {
        isMoving = self.isScrolling()
    }
        DispatchQueue.main.async {
            completion()}

    }
}
}