Changing the default focus in UISplitViewController

Question

In an UISplitViewController, by default, the focus is set to be on the TableView. Is there a way for me to override it so that the focus is on the DetailViewController instead?

Can I change the focus to be on the button instead of the TableView cell when starting up the app?

Answer 1

Found the solution:

override weak var preferredFocusEnvironments: [UIFocusEnvironment] {
    get {
        let controllerToFocus = viewControllers[1] as? ViewController
        return [(controllerToFocus?.view)]
}

And we need to call setNeedsFocusUpdate() and updateFocusIfNeeded():

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(true)

    self.setNeedsFocusUpdate()
    self.updateFocusIfNeeded()
}