Question

How do you know what is the current page/view displayed inside an UIPageViewController?

I have overridden the viewDidAppear method of my child views, so that they send an id to the parent view in their viewDidAppear method.

However, the problem is this: i cannot reliably use that id as id for the displayed page. because if the user turns the page but halfway through decides to stop the turning and put the page back, viewDidAppear will already have been called. (the view is visible behind the curled page).

Maybe i should only switch to a new id if the current view disappears. But I wonder if there is not a more simple way to return the view that is currently visible?

Answer 1

You should manually keep track of the current page.

The delegate method pageViewController:didFinishAnimating:previousViewControllers:transitionCompleted: will tell you when to update that variable. The last argument of the method transitionCompleted: can tell you whether a user completed a page turn transition or not.

Then, you can get the currently presented View Controller by doing

self.viewControllers?.first