Swapping child views in a container view

Question

Let ContainerView be the parent container view with two child content views: NavigationView and ContentView.

Answer 1

For such kind of transition you can also use UIView.animateWith... animations.

For example, assume that rootContainerView is container and contentViewController currently active controller in container, then

func setContentViewController(contentViewController:UIViewController, animated:Bool = true) {
    if animated == true {
        addChildViewController(contentViewController)
        contentViewController.view.alpha = 0
        contentViewController.view.frame = rootContainerView.bounds
        rootContainerView.addSubview(contentViewController.view)
        self.contentViewController?.willMoveToParentViewController(nil)

        UIView.animateWithDuration(0.3, animations: {
            contentViewController.view.alpha = 1
            }, completion: { (_) in
                contentViewController.didMoveToParentViewController(self)

                self.contentViewController?.view.removeFromSuperview()
                self.contentViewController?.didMoveToParentViewController(nil)
                self.contentViewController?.removeFromParentViewController()
                self.contentViewController = contentViewController
        })
    } else {
        cleanUpChildControllerIfPossible()

        contentViewController.view.frame = rootContainerView.bounds
        addChildViewController(contentViewController)
        rootContainerView.addSubview(contentViewController.view)
        contentViewController.didMoveToParentViewController(self)
        self.contentViewController = contentViewController
    }
}

// MARK: - Private

private func cleanUpChildControllerIfPossible() {
    if let childController = contentViewController {
        childController.willMoveToParentViewController(nil)
        childController.view.removeFromSuperview()
        childController.removeFromParentViewController()
    }
}

this will provide u simple fade animations, u can also can try any UIViewAnimationOptions, transitions etc.