title: Add multiple subviews to NSWindow in Swift
body: <p>I have a window with an outlet and a custom view (in my <code>.xib</code> file) which contains a button and a text field. When a button is pressed in the window I want to add an instance of the custom view into the window.</p>
  
  <p>Currently I have an outlet to the window and the custom view (<code>configWindow</code> and <code>customView</code>) and this action is called when the button is pressed:</p>
  
  <pre><code>@IBAction func addView(sender: NSButton) {
      configWindow.contentView.addSubview(customView)
      // Print the views in the window, see what's been added
      for i in configWindow.contentView.subviews {
          println(i)
      }
  }
  </code></pre>
  
  <p>This will only ever add one view to the window.</p>
  
  <p>Is this the right way to go about it, or should I be using a completely different approach?</p>