Speaking from experience I would personally only adjust your layout based upon deviceDidRotateSelector notifications.
I have an updatePortrait method and an updateLandscape method and call whichever is necessary.

When to use layoutSubview in iOS
We are trying to figure out what the library file count restriction is for items under a folder.

We can see here:

http://technet.microsoft.com/en-us/library/cc262787(v=office.15).aspx#ListLibrary

Documents :: 30,000,000 per library >> You can create very large document libraries by nesting folders, or using standard views and site hierarchy. This value may vary depending on how documents and folders are organized, and by the type and size of documents stored.

Does that mean there is a file count limit of some sort under folders for a library?
