From d4af736985eef11621c4dae605a42bce16aa9c4a Mon Sep 17 00:00:00 2001
From: appleguy <scottgoodson@gmail.com>
Date: Sun, 2 Apr 2017 12:11:44 -0700
Subject: [PATCH] [ASCollectionView] Improve interop to silence invalid layout
 warnings, fix supplementary passthrough. (#3178)

* [ASCollectionView] Improve interop to silence invalid layout warnings, fix supplementary passthrough.

Before this change, passthrough of supplementary elements didn't work properly -- it would get rehosted into the blank ASCellNode.

* [ASCollectionView] Ensure that IGListKit-handled supplementary views are sent through ASRangeController.

* [ASCellNode] When .shouldUseUIKitCell == YES, don't remove the subviews of the .contentView
---
 Source/ASCollectionView.mm          | 10 +++++-----
 Source/Details/ASRangeController.mm | 10 ++++++++--
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/Source/ASCollectionView.mm b/Source/ASCollectionView.mm
index f997359b7b..d8ab5c0a1c 100644
--- a/Source/ASCollectionView.mm
+++ b/Source/ASCollectionView.mm
@@ -924,7 +924,9 @@ static NSString * const kReuseIdentifier = @"_ASCollectionReuseIdentifier";
   ASCellNode *cell = [self nodeForItemAtIndexPath:indexPath];
   if (cell.shouldUseUIKitCell) {
     if ([_asyncDelegate respondsToSelector:@selector(collectionView:layout:sizeForItemAtIndexPath:)]) {
-      return [(id)_asyncDelegate collectionView:collectionView layout:collectionViewLayout sizeForItemAtIndexPath:indexPath];
+      CGSize size = [(id)_asyncDelegate collectionView:collectionView layout:collectionViewLayout sizeForItemAtIndexPath:indexPath];
+      cell.style.preferredSize = size;
+      return size;
     }
   }
   ASCollectionElement *e = [_dataController.visibleMap elementForItemAtIndexPath:indexPath];
@@ -972,13 +974,11 @@ static NSString * const kReuseIdentifier = @"_ASCollectionReuseIdentifier";
 
   BOOL shouldDequeueExternally = _asyncDataSourceFlags.interopViewForSupplementaryElement && (_asyncDataSourceFlags.interopAlwaysDequeue || node.shouldUseUIKitCell);
   if (shouldDequeueExternally) {
+    // This codepath is used for both IGListKit mode, and app-level UICollectionView interop.
     view = [(id<ASCollectionDataSourceInterop>)_asyncDataSource collectionView:collectionView viewForSupplementaryElementOfKind:kind atIndexPath:indexPath];
   } else {
-    view = [self dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:kReuseIdentifier forIndexPath:indexPath];
-  }
-
-  if (!node.shouldUseUIKitCell) {
     ASDisplayNodeAssert(node != nil, @"Supplementary node should exist.  Kind = %@, indexPath = %@, collectionDataSource = %@", kind, indexPath, self);
+    view = [self dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:kReuseIdentifier forIndexPath:indexPath];
   }
 
   if (node) {
diff --git a/Source/Details/ASRangeController.mm b/Source/Details/ASRangeController.mm
index 024c99384b..5bc4cfb191 100644
--- a/Source/Details/ASRangeController.mm
+++ b/Source/Details/ASRangeController.mm
@@ -12,7 +12,7 @@
 
 #import <AsyncDisplayKit/_ASHierarchyChangeSet.h>
 #import <AsyncDisplayKit/ASAssert.h>
-#import <AsyncDisplayKit/ASCellNode.h>
+#import <AsyncDisplayKit/ASCellNode+Internal.h>
 #import <AsyncDisplayKit/ASCollectionElement.h>
 #import <AsyncDisplayKit/ASDisplayNodeExtras.h>
 #import <AsyncDisplayKit/ASDisplayNodeInternal.h> // Required for interfaceState and hierarchyState setter methods.
@@ -444,7 +444,13 @@ static UIApplicationState __ApplicationState = UIApplicationStateActive;
   ASDisplayNodeAssertMainThread();
   ASDisplayNodeAssert(node, @"Cannot move a nil node to a view");
   ASDisplayNodeAssert(contentView, @"Cannot move a node to a non-existent view");
-  
+
+  if (node.shouldUseUIKitCell) {
+    // When using UIKit cells, the ASCellNode is just a placeholder object with a preferredSize.
+    // In this case, we should not disrupt the subviews of the contentView.
+    return;
+  }
+
   if (node.view.superview == contentView) {
     // this content view is already correctly configured
     return;