title: How to use new method in IOS 8 to find screenwidth when view size changes
body: <p>There is the following method in IOS 8 that is supposed to be used when a view's orientation changes:</p>
  
  <pre><code>override func viewWillTransitionToSize(size: CGSize,
      withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
  
  }
  </code></pre>
  
  <p>How can I use this to find the new width of the screen (I am making a keyboard app) when the screen rotates?</p>