showAnnotations when rotation changes

Question

I have a SplitViewController with a mapview on as the detailViewController.

I add multiple annotations to the mapview. After adding them I call the showAnnotations:animated: method to zoom in/out the map so that all the annotations are shown in the visible portion of the map.

mapView.showAnnotations(mapView.annotations, animated: true)

Now I need the map to refocus itself when the orientation changes because the mapview's visible area reduces when you turn the iPad to portrait. So I call the same showAnnotations:animated: method in viewWillTransitionToSize:withTransitionCoordinator: method which fires when the orientation changes. But it doesn't work as expected.

override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
    mapView.showAnnotations(mapView.annotations, animated: true)
}

How do I make it refocus when orientation changes?

Demo project

Answer 1

Calling the showAnnotations within the viewDidLayoutSubviews method works perfectly.

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    mapView.showAnnotations(mapView.annotations, animated: true)
}