     @available(iOS 9, *)
     func SELdidTogglePrivateMode() {
         privateMode = !privateMode
+    }
+}
+
+// MARK: - App Notifications
+extension TabTrayController {
+    func SELappWillResignActiveNotification() {
+        if privateMode {
+            collectionView.alpha = 0
+        }
+    }
+
+    func SELappDidBecomeActiveNotification() {
+        // Re-show any components that might have been hidden because they were being displayed
+        // as part of a private mode tab
+        UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseInOut, animations: {
+            self.collectionView.alpha = 1
+        },
+        completion: nil)
     }
 }
 

                privateMode = true
            }
        }
    }

    override func traitCollectionDidChange(previousTraitCollection: UITraitCollection?) {

        fatalError("init(coder:) has not been implemented")
    }

    deinit {
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIApplicationWillResignActiveNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIApplicationWillEnterForegroundNotification, object: nil)
    }

// MARK: View Controller Callbacks
    override func viewDidLoad() {
        super.viewDidLoad()
