Reorder cells of UICollectionView

Question

Consider a UICollectionView with flow layout and horizontal direction. By default, cells are ordered from top to bottom, left to right. Like this:

Answer 1

You have an object that implements the UICollectionViewDataSource protocol. Inside collectionView:cellForItemAtIndexPath: simply return the correct item that you want to return. I don't understand where there would be a problem.

Edit: ok, I see the problem. Here is the solution: http://www.skeuo.com/uicollectionview-custom-layout-tutorial , specifically steps 17 to 25. It's not a huge amount of work, and can be reused very easily.