title: Presenting a ViewController over another ViewController
body: <p>I've got a pretty lengthy question today, as it takes some amount of explaining. Let's start with an example.</p>
  
  <hr>
  
  <h2>Example</h2>
  
  <p>Let's say I have three view controllers: </p>
  
  <ol>
  <li>FullSizeViewController</li>
  <li>FirstViewController</li>
  <li>SecondViewController</li>
  </ol>
  
  <p>FullSizeViewController, as the name states, is intended to take the space of the whole screen. FirstViewController and SecondViewController, on the other hand, should only take up about 3/4 of the height of the screen. Here's a few pictures to illustrate.</p>
  
  <p><img src="https://i.stack.imgur.com/OEZAe.png" alt="FullSizeViewController"></p>
  
  <p>Here we have FullSizeViewController. Nothing special, just two buttons - "First" &amp; "Second". If you haven't already caught on by now, those two buttons should toggle each of the respective view controllers, as shown below.</p>
  
  <p><img src="https://i.stack.imgur.com/mnWNY.png" alt="FirstViewContoller"></p>
  
  <hr>
  
  <h2>The Issue</h2>
  
  <p>I'm having the main issues with this? How would I be able to</p>
  
  <ol>
  <li>Animate the view controllers from the bottom</li>
  <li>Change the size of the two smaller view controllers</li>
  <li>Still allow interaction with the FullSizeViewController even as a small view controller is open on top of its main content, but not the two toggle buttons?</li>
  </ol>
  
  <hr>
  
  <h2>What I've Tried</h2>
  
  <p>Since I'm not too sure how to do this, I haven't tried all that much, but I have tried one thing.</p>
  
  <p>In the IBAction connected to the "First" button:</p>
  
  <pre><code>let firstVC: FirstViewController = self.storyboard?.instantiateViewControllerWithIdentifier("FirstViewController")! as FirstViewController
          self.presentViewController(firstVC, animated: true, completion: nil)
  </code></pre>
  
  <p>In viewDidLoad of FirstViewController:</p>
  
  <pre><code>self.view.frame.size = CGSizeMake(UIScreen.mainScreen().bounds.size.width, UIScreen.mainScreen().bounds.size.height - 68)
  </code></pre>
  
  <hr>
  
  <p>tl;dr How can I achieve <a href="http://gyazo.com/a84d0cd66ed3ec9f1b9dd6e0294383dc" rel="nofollow noreferrer">this</a>?</p>