Black screen when changing root view controller in AppDelegate

Question

I am trying to change the root view controller from the app delegate's didFinishLaunchingWithOptions, depending on whether the user is logged in or not. Once I get past this condition, I am using the following code to change root view controllers:

self.window = UIWindow(frame: UIScreen.main.bounds)
self.window?.rootViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "SWRevealViewController") as! SWRevealViewController

self.window?.makeKeyAndVisible()

However, when I launch the app (with a valid logged in user) the simulator first shows the log in screen (old root view controller) for a second, then the screen goes black for about 30 seconds to a minute, before finally showing the desired view controller.

The view controller structure in storyboard is as follows:

SWRevealViewController -> Navigation Controller -> Desired View Controller (new root)

The reason for beginning with SWRevealViewController is because the slide menu is lost otherwise.

Any ideas of what might be going on?

Answer 1

I found a way to produce a similar result to the one I desired. It involves not changing the root view controller at all, and having it present an "artificial root view controller" after launch:

if let currentRoot = self.window?.rootViewController {
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let artificialRoot = storyboard.instantiateViewController(withIdentifier: "SWRevealViewController")
    currentRoot.present(artificialRoot, animated: false, completion: nil)
}

Although not ideal, the results of this implementation are by far better than the implementation in the question description.