                     
                     // within range of center container
                     if currentYOffset.constant < (verticalSnapThresholdFraction * view.frame.size.height) {
-                        showContainer(.Center)
+                        showEmbeddedView(.Center)
                     }
                         
                         // within range of top container
                     else if currentYOffset.constant > ((1.0 - verticalSnapThresholdFraction) * view.frame.size.height) {
-                        showContainer(.Top)
+                        showEmbeddedView(.Top)
                     }
                         
                         // center region: depends on inertia direction
                     else {
                         // pulled down
                         if previousNonZeroDirectionChange.dy > 0.0 {
-                            showContainer(.Top)
+                            showEmbeddedView(.Top)
                         }
                             
                             // pulled up
                         else {
-                            showContainer(.Center)
+                            showEmbeddedView(.Center)
                         }
                     }
                 }

    
    // delegate to handle containers events
    func onDone(sender: AnyObject)
    func onShowContainer(position: Position, sender: AnyObject)
}

public class SwipeNavigationController: UIViewController {

                        // pulled up
                        if previousNonZeroDirectionChange.dy < 0.0 {
                            
                            showEmbeddedView(.Bottom)
                        }
                            
                            // pulled down
                        else {
                            showEmbeddedView(.Center)
                        }
                    }
                }
