BaseNavigationController+UIGestureRecognizerDelegate.swift

extension BaseNavigationController: UIGestureRecognizerDelegate {

    func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        guard gestureRecognizer == interactivePopGestureRecognizer else {
            return true // default value
        }

        // Disable pop gesture in three situations:

        // 1) the view controller doesn't support being popped or doesn't want to be popped right now
        if let viewController = visibleViewController as? BaseViewControllerDelegate, viewController.preventInteractivePopGesture() {
            return false
        }

        // 2) when there is only one view controller on the stack
        // 3) when the pop animation is in progress
        return viewControllers.count > 1 && self.duringPushAnimation == false
    }
}