swift - Simultaneous gesture recognition for specific gestures

Question

I'm trying to enable simultaneous gesture recognition but only for the UIPinchGestureRecognizer and UIRotationGestureRecognizer gestures. I don't want it to work for any other gestures. If I set the following property to true it allows all gestures to be recognized simultaneously, how can I limit it to just rotating and scaling?

func gestureRecognizer(UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true
}

Answer 1

Make sure your class implements UIGestureRecognizerDelegate

class YourViewController: UIViewController, UIGestureRecognizerDelegate ...

---

Set the gesture's delegate to self

yourGesture.delegate = self

---

Add delegate function to your class

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    if (gestureRecognizer is UIPanGestureRecognizer || gestureRecognizer is UIRotationGestureRecognizer) {
        return true
    } else {
        return false
    }
}