Making use of NSUserDefaults - Remember Checklist on app close / susp…

…ension

AllListsViewController.swift

@@ -1,12 +1,25 @@
 import UIKit
 
-class AllListsViewController: UITableViewController, ListDetailViewControllerDelegate {
+class AllListsViewController: UITableViewController, ListDetailViewControllerDelegate, UINavigationControllerDelegate {
 
   var dataModel: DataModel!
 
   override func viewDidLoad() {
     super.viewDidLoad()
   }
+
+  override func viewDidAppear(animated: Bool) {
+    super.viewDidAppear(animated)
+
+    navigationController?.delegate = self
+
+    let index = NSUserDefaults.standardUserDefaults().integerForKey("ChecklistIndex")
+
+    if index != -1 {
+      let checklist = dataModel.lists[index]
+      performSegueWithIdentifier("ShowChecklist", sender: checklist)
+    }
+  }
 
   override func didReceiveMemoryWarning() {
     super.didReceiveMemoryWarning()
@@ -27,6 +40,8 @@ class AllListsViewController: UITableViewController, ListDetailViewControllerDel
   }
 
   override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
+    NSUserDefaults.standardUserDefaults().setInteger(indexPath.row, forKey: "ChecklistIndex")
+
     let checklist = dataModel.lists[indexPath.row]
     performSegueWithIdentifier("ShowChecklist", sender: checklist)
   }
@@ -95,4 +110,11 @@ class AllListsViewController: UITableViewController, ListDetailViewControllerDel
 
     presentViewController(navigationController, animated: true, completion: nil)
   }
+
+  func navigationController(navigationController: UINavigationController, willShowViewController viewController: UIViewController, animated: Bool) {
+
+    if viewController === self {
+      NSUserDefaults.standardUserDefaults().setInteger(-1, forKey: "ChecklistIndex")
+    }
+  }
 }