From a5f0b4fcafa7d2ef6bcebc607bd4bae8ab66fc39 Mon Sep 17 00:00:00 2001
From: Greg Pardo <greg.pardo@tesseractsensors.com>
Date: Thu, 15 Oct 2015 10:36:35 -0400
Subject: [PATCH] References #193 Allows for nil on focus (Focus can be
 elsewhere)

---
 RxCocoa/iOS/UICollectionView+Rx.swift | 30 ++++++++++++++++++---------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/RxCocoa/iOS/UICollectionView+Rx.swift b/RxCocoa/iOS/UICollectionView+Rx.swift
index d5ba452c..b0de1120 100644
--- a/RxCocoa/iOS/UICollectionView+Rx.swift
+++ b/RxCocoa/iOS/UICollectionView+Rx.swift
@@ -161,11 +161,11 @@ extension UICollectionView {
     /**
      Reactive wrapper for `delegate` message `collectionView:didUpdateFocusInContext:withAnimationCoordinator:`.
      */
-    public var rx_nextFocusedUpdated: ControlEvent<NSIndexPath> {
+    public var rx_nextFocusedUpdated: ControlEvent<NSIndexPath?> {
         let source = rx_delegate.observe("collectionView:didUpdateFocusInContext:withAnimationCoordinator:")
-            .map { a -> NSIndexPath in
+            .map { a -> NSIndexPath? in
                 let context = a[1] as! UICollectionViewFocusUpdateContext
-                return context.nextFocusedIndexPath! as NSIndexPath
+                return context.nextFocusedIndexPath!
         }
         
         return ControlEvent(source: source)
@@ -174,11 +174,11 @@ extension UICollectionView {
     /**
      Reactive wrapper for `delegate` message `collectionView:didUpdateFocusInContext:withAnimationCoordinator:`.
      */
-    public var rx_previousFocusedUpdated: ControlEvent<NSIndexPath> {
+    public var rx_previousFocusedUpdated: ControlEvent<NSIndexPath?> {
         let source = rx_delegate.observe("collectionView:didUpdateFocusInContext:withAnimationCoordinator:")
-            .map { a -> NSIndexPath in
+            .map { a -> NSIndexPath? in
                 let context = a[1] as! UICollectionViewFocusUpdateContext
-                return context.previouslyFocusedIndexPath! as NSIndexPath
+                return context.previouslyFocusedIndexPath!
         }
         
         return ControlEvent(source: source)
@@ -190,8 +190,13 @@ extension UICollectionView {
      
      It can be only used when one of the `rx_itemsWith*` methods is used to bind observable sequence.
      */
-    public func rx_modelForNextFocusedUpdated<T>() -> ControlEvent<T> {
-        let source: Observable<T> = rx_nextFocusedUpdated .map { indexPath in
+    public func rx_modelForNextFocusedUpdated<T>() -> ControlEvent<T?> {
+        let source: Observable<T?> = rx_nextFocusedUpdated .map { indexPath in
+            
+            guard let indexPath = indexPath else {
+                return nil
+            }
+            
             let dataSource: RxCollectionViewReactiveArrayDataSource<T> = castOrFatalError(self.rx_dataSource.forwardToDelegate(), message: "This method only works in case one of the `rx_itemsWith*` methods was used.")
             
             return dataSource.modelAtIndex(indexPath.item)!
@@ -206,8 +211,13 @@ extension UICollectionView {
      
      It can be only used when one of the `rx_itemsWith*` methods is used to bind observable sequence.
      */
-    public func rx_modelForPreviouslyFocusedUpdated<T>() -> ControlEvent<T> {
-        let source: Observable<T> = rx_previousFocusedUpdated .map { indexPath in
+    public func rx_modelForPreviouslyFocusedUpdated<T>() -> ControlEvent<T?> {
+        let source: Observable<T?> = rx_previousFocusedUpdated .map { indexPath in
+            
+            guard let indexPath = indexPath else {
+                return nil
+            }
+            
             let dataSource: RxCollectionViewReactiveArrayDataSource<T> = castOrFatalError(self.rx_dataSource.forwardToDelegate(), message: "This method only works in case one of the `rx_itemsWith*` methods was used.")
             
             return dataSource.modelAtIndex(indexPath.item)!