This is a small project used to demostrate how to implement UIWindow's
rootViewController transitions with a little piece of code.
You can found the original article for this article here.
Sometimes during the lifecycle of an application you may need to change the
rootViewController of your main
UIWindow ; a typical case maybe the transition between the initial on-boarding and the home of the app (ie. a
In order to handle this edge case you may want to create a top controller (typically an
UINavigationController with invisible navigation bar) which enable you to push your new container using a standard push animation.
While basically it works fine, the addition of a container used only to handle this single operation is a bit awful to see.
A way better solution is to apply an animated transition (push/pop or slide) to the
rootViewController set so you will get an animate switch from the current view controller to the new one.
In fact, even if not exposed, you can and its really simple to accomplish via
The following code implements a new function as extension of
UIWindow class; it takes two arguments: the destination controller and options.
As you may imagine the destination controller is the controller you want to set as new
rootViewController, while options is struct used to group some typical CoreAnimation settings: the animation direction (pop/push/slide from top or bottom), the animation curve (linear, ease in/out), the duration of the animation (by default is 0.25s) and an optional UIView instance used to fade in/out between the old and new view.
Once implemented you can use the only function exposed to all UIWindow instances called
public func setRootViewController(_ controller: UIViewController, options: TransitionOptions = TransitionOptions())
controller: the destination view controller to set as new
TransitionOptionswith the following properties:
duration: duration of the animation (expressed in
TimeInterval, seconds, default is
direction: direction of the transition (
toBottom, default is
style: animation curve (
easeInOut, default is
background: background view set for fade in-out into the old/new controller (by default is
The following code change the
rootViewController using a ease out - slide up animation of 0.4 seconds.
let wnd = UIApplication.shared.keyWindow var options = UIWindow.TransitionOptions() options.direction = .toTop options.duration = 0.4 options.style = .easeOut wnd?.setRootViewController(newVC, options: options)
If you just need of a simple push (like
UINavigationController's push) you can call it without the
The following demo is available inside the project's demo application.
You can install UIWindowTransitions using CocoaPods, Carthage and Swift package manager
use_frameworks! pod 'UIWindowTransitions'
Swift Package Manager
Add UIWindowTransitions as dependency in your
import PackageDescription let package = Package(name: "YourPackage", dependencies: [ .Package(url: "https://github.com/malcommac/UIWindowTransitions.git", majorVersion: 0), ] )
Credits & License
UIWindowTransitions was created by Daniele Margutti.
As open source creation any help is welcome!
The code of this library is licensed under MIT License; you can use it in commercial products without any limitation.