Merge commit '89156ebbc750a2d28b8d4594ccad62ef4c73127e'

AsyncDisplayKit/ASCollectionView.mm

@@ -78,6 +78,8 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
   ASDisplayNodeAssertMainThread();
   node.layoutAttributes = _layoutAttributes;
   _node = node;
+  self.backgroundColor = node.backgroundColor;
+  self.clipsToBounds = node.clipsToBounds;
   [node __setSelectedFromUIKit:self.selected];
   [node __setHighlightedFromUIKit:self.highlighted];
 }
@@ -121,6 +123,15 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
   self.layoutAttributes = layoutAttributes;
 }
 
+/**
+ * Keep our node filling our content view.
+ */
+- (void)layoutSubviews
+{
+  [super layoutSubviews];
+  self.node.frame = self.contentView.bounds;
+}
+
 @end
 
 #pragma mark -
@@ -282,7 +293,15 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
 {
   if (!(self = [super initWithFrame:frame collectionViewLayout:layout]))
     return nil;
-  
+
+  // Disable UICollectionView prefetching.
+  // Experiments done by Instagram show that this option being YES (default)
+  // when unused causes a significant hit to scroll performance.
+  // https://github.com/Instagram/IGListKit/issues/318
+  if (AS_AT_LEAST_IOS10) {
+    self.prefetchingEnabled = NO;
+  }
+
   _layoutController = [[ASCollectionViewLayoutController alloc] initWithCollectionView:self];
   
   _rangeController = [[ASRangeController alloc] init];
@@ -614,6 +633,10 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
 
 - (NSIndexPath *)convertIndexPathFromCollectionNode:(NSIndexPath *)indexPath waitingIfNeeded:(BOOL)wait
 {
+  if (indexPath == nil) {
+    return nil;
+  }
+  
   // If this is a section index path, we don't currently have a method
   // to do a mapping.
   if (indexPath.item == NSNotFound) {
@@ -751,7 +774,8 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
 
 - (void)performBatchUpdates:(void (^)())updates completion:(void (^)(BOOL))completion
 {
-  [self performBatchAnimated:YES updates:updates completion:completion];
+  // We capture the current state of whether animations are enabled if they don't provide us with one.
+  [self performBatchAnimated:[UIView areAnimationsEnabled] updates:updates completion:completion];
 }
 
 - (void)registerSupplementaryNodeOfKind:(NSString *)elementKind