Wired the activity continuation code in, it all works spiffingly well

The region is extracted from the activity and the map updated to display
it as appropriate.

Ready for writeup

38-handoff/MapOff/MapOff/AppDelegate.swift

@@ -32,7 +32,9 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
   }
 
   func application(application: UIApplication, continueUserActivity userActivity: NSUserActivity, restorationHandler: ([AnyObject]!) -> Void) -> Bool {
-    println("Continuing...")
+    if let rootVC = window?.rootViewController {
+      restorationHandler([rootVC])
+    }
     return true
   }
 

38-handoff/MapOff/MapOff/ViewController.swift

@@ -20,11 +20,12 @@ import MapKit
 class ViewController: UIViewController, MKMapViewDelegate {
 
   @IBOutlet weak var mapView: MKMapView!
+  let activityType = "com.shinobicontrols.MapOff.viewport"
 
   override func viewDidLoad() {
     super.viewDidLoad()
     // Do any additional setup after loading the view, typically from a nib.
-    let activityType = "com.shinobicontrols.MapOff.viewport"
+
     if userActivity?.activityType != activityType {
       userActivity?.invalidate()
       userActivity = NSUserActivity(activityType: activityType)
@@ -34,11 +35,24 @@ class ViewController: UIViewController, MKMapViewDelegate {
     mapView.delegate = self
   }
 
+  // MARK:- UIResponder Activity Handling
   override func updateUserActivityState(activity: NSUserActivity) {
     let regionData = NSData(bytes: &mapView.region, length: sizeof(MKCoordinateRegion))
     activity.userInfo = ["region" : regionData]
   }
 
+  override func restoreUserActivityState(activity: NSUserActivity) {
+    if activity.activityType == activityType {
+      // Extract the data
+      let regionData = activity.userInfo!["region"] as NSData
+      // Need an empty coordinate region to populate
+      var region = MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: 0.0, longitude: 0.0),
+                                        span: MKCoordinateSpan(latitudeDelta: 0.0, longitudeDelta: 0.0))
+      regionData.getBytes(&region, length: sizeof(MKCoordinateRegion))
+      mapView.setRegion(region, animated: true)
+    }
+  }
+
   // MARK:- MKMapViewDelegate
   func mapView(mapView: MKMapView!, regionDidChangeAnimated animated: Bool) {
     userActivity?.needsSave = true