Storyboard view designed properly with Auto Layout and Trait Variations in Interface Builder of Xcode 8 has wrong size in Simulator and Device

Question

I've been working on iOS apps for many years before a longer pause. On my new project I decided to try the new features of the Interface Builder and Storyboards (Swift 3, Xcode 8.2.1). So I've got a working app with precisely defined constraints for all supported devices, following the "regular" and "compact" width/height paradigm. Everything seemed to work and I loved the approach.

I was finalising the first views (and their controllers) for the iPad simulator before I decided to run the app also on an iPhone simulator to check for the layout. It turns out that all works as expected but for ONE view.

This view has the following behaviour:

• If in the Storyboard canvas (and even the Assistance Editor, which looks the same for me, by the way) I selected "view as iPad 9,7" and run the iPad simulator (of the same screen size), the layout works the way it should.
• If in the Storyboard canvas I selected "view as iPhone 5" and run the iPhone 5 simulator, the layout works the way it should.
• If however I select "view as iPhone 5" and run the app on the iPad simulator OR any other false combination, the following happens:

Once the view appears (custom segue, or default push. All the views are inside a navigation controller) it shows the content scaled down/up to the size of the preview size I selected on the Storyboard. Then it animates (scaling from the top left corner) to fill the screen. For instance: If I select "view as iPhone 5" and run on an iPad, the view appears in the left top corner of the iPad simulator having the size of an iPhone 5. Then it scales up to fill the screen having the exact layout I want.

One should add that inside this one view, the layout for all devices looks the same, merely scaled down/up. So it really just comes down to wrong view size.

This all happens ONLY to one of my views, which I all have designed and laid out (constraints) the same way. This happens EVERY TIME, and it happens on the simulator and on real devices.

I was trying various suggestions from the web for the last week and I failed to find any topic (on Stack Overflow) that was able to help me.

I'm lost. I'm glad for any suggestions!

Thank you.

Answer 1

After removing everything from my view step by step and building every single step I found that I had a self.view.layoutIfNeeded() inside my viewDidLoad() which was inside an animation block animating a single subview, but for some reason lead to aforementioned issues. Removing it solved the issue.