title: How do I recalculate UICollectionViewFlowLayout on orientation change?
body: <p>In portrait, all my CollectionViewCells are aligned properly.</p>
  
  <p><a href="https://i.stack.imgur.com/oU77s.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oU77s.png" alt="enter image description here"></a></p>
  
  <p>When switched to Landscape the cells are now spaced out more.</p>
  
  <p><a href="https://i.stack.imgur.com/xu68P.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xu68P.png" alt="enter image description here"></a></p>
  
  <p>What would be the proper way to recalculate <code>UICollectionViewFlowLayout's</code> <code>minimumInterimSpacing</code> and <code>itemSize</code> on orientation changes? I'd like to display 6 columns in landscape.</p>