Uipageviewcontroller - Making a slider

Question

I’m using a UIPageViewController. It displays contents and is exchanged page through a NSTimer. Basically like the slider of content in highlights on the sites. The problem is that I need to identify exactly which way the user is moving the same.

I want to remember that in many of the cases I researched users answered in which way I can define the direction or by the methods:

func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController?

func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController?

When in fact I need to directly "capture" this event so I can add define properties according to the direction.

Obs.: If by any chance someone has any more suggestions of another component to use in cases like this, it will be well accepted.