From a05d3119adc8a97b66b76ea86e3f8d65135f9d5d Mon Sep 17 00:00:00 2001
From: Nick Velloff <nickvelloff@users.noreply.github.com>
Date: Wed, 22 Jun 2016 16:21:10 -0700
Subject: [PATCH] [WIP] Trigger new batch fetch for collection view after
 layout transitions (#1697)

[Table / Collection] Trigger new batch fetch after programmatic scrolls, or layout transitions.
---
 AsyncDisplayKit/ASCollectionView.mm          | 6 ++++++
 AsyncDisplayKit/ASTableView.mm               | 5 +++++
 AsyncDisplayKit/Details/ASRangeController.h  | 7 +++++++
 AsyncDisplayKit/Details/ASRangeController.mm | 1 +
 4 files changed, 19 insertions(+)

diff --git a/AsyncDisplayKit/ASCollectionView.mm b/AsyncDisplayKit/ASCollectionView.mm
index 821e21ddca..a7ab280e25 100644
--- a/AsyncDisplayKit/ASCollectionView.mm
+++ b/AsyncDisplayKit/ASCollectionView.mm
@@ -1002,6 +1002,7 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
 - (NSArray *)visibleNodeIndexPathsForRangeController:(ASRangeController *)rangeController
 {
   ASDisplayNodeAssertMainThread();
+  
   // Calling visibleNodeIndexPathsForRangeController: will trigger UIKit to call reloadData if it never has, which can result
   // in incorrect layout if performed at zero size.  We can use the fact that nothing can be visible at zero size to return fast.
   BOOL isZeroSized = CGRectEqualToRect(self.bounds, CGRectZero);
@@ -1065,6 +1066,11 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
   _performingBatchUpdates = NO;
 }
 
+- (void)didCompleteUpdatesInRangeController:(ASRangeController *)rangeController
+{
+  [self _checkForBatchFetching];
+}
+
 - (void)rangeController:(ASRangeController *)rangeController didInsertNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
   ASDisplayNodeAssertMainThread();
diff --git a/AsyncDisplayKit/ASTableView.mm b/AsyncDisplayKit/ASTableView.mm
index b8a174bbdd..871589b49d 100644
--- a/AsyncDisplayKit/ASTableView.mm
+++ b/AsyncDisplayKit/ASTableView.mm
@@ -968,6 +968,11 @@ static NSString * const kCellReuseIdentifier = @"_ASTableViewCell";
   }
 }
 
+- (void)didCompleteUpdatesInRangeController:(ASRangeController *)rangeController
+{
+  [self _checkForBatchFetching];
+}
+
 - (void)rangeController:(ASRangeController *)rangeController didInsertNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
   ASDisplayNodeAssertMainThread();
diff --git a/AsyncDisplayKit/Details/ASRangeController.h b/AsyncDisplayKit/Details/ASRangeController.h
index 2de7e3ce4f..c79124a961 100644
--- a/AsyncDisplayKit/Details/ASRangeController.h
+++ b/AsyncDisplayKit/Details/ASRangeController.h
@@ -146,6 +146,13 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)rangeController:(ASRangeController * )rangeController didEndUpdatesAnimated:(BOOL)animated completion:(void (^)(BOOL))completion;
 
+/**
+ * Completed updates to cell node addition and removal.
+ *
+ * @param rangeController Sender.
+ */
+- (void)didCompleteUpdatesInRangeController:(ASRangeController *)rangeController;
+
 /**
  * Called for nodes insertion.
  *
diff --git a/AsyncDisplayKit/Details/ASRangeController.mm b/AsyncDisplayKit/Details/ASRangeController.mm
index 436cb8f409..6c84935540 100644
--- a/AsyncDisplayKit/Details/ASRangeController.mm
+++ b/AsyncDisplayKit/Details/ASRangeController.mm
@@ -333,6 +333,7 @@ static UIApplicationState __ApplicationState = UIApplicationStateActive;
   [modifiedIndexPaths sortUsingSelector:@selector(compare:)];
   NSLog(@"Range update complete; modifiedIndexPaths: %@", [self descriptionWithIndexPaths:modifiedIndexPaths]);
 #endif
+  [_delegate didCompleteUpdatesInRangeController:self];
 }
 
 #pragma mark - Notification observers