[ASTableView] Generate a new cell layout if existing ones are invalid (#942)

CHANGELOG.md

@@ -56,6 +56,7 @@
 - [ASDisplayNode] Fix an issue that causes a node to sometimes return an outdated calculated size or size range. [Huy Nguyen](https://github.com/nguyenhuy) [#808](https://github.com/TextureGroup/Texture/pull/808)
 - Add an experimental deallocation queue implementation that's more efficient. [Adlai Holler](https://github.com/Adlai-Holler)
 - Standardize property declaration style. [Adlai Holler](https://github.com/Adlai-Holler)
+- [ASTableView] Fix an issue that causes table view to use one of a cell's invalid layouts instead of generating a new one. [Huy Nguyen](https://github.com/nguyenhuy) [#942](https://github.com/TextureGroup/Texture/pull/942)
 
 ## 2.6
 - [Xcode 9] Updated to require Xcode 9 (to fix warnings) [Garrett Moon](https://github.com/garrettmoon)

Source/ASCollectionView.mm

@@ -664,11 +664,13 @@ static NSString * const kReuseIdentifier = @"_ASCollectionReuseIdentifier";
 - (CGSize)sizeForElement:(ASCollectionElement *)element
 {
   ASDisplayNodeAssertMainThread();
-  ASCellNode *node = element.node;
-  if (element == nil || node == nil) {
+  if (element == nil) {
     return CGSizeZero;
   }
 
+  ASCellNode *node = element.node;
+  ASDisplayNodeAssertNotNil(node, @"Node must not be nil!");
+
   BOOL useUIKitCell = node.shouldUseUIKitCell;
   if (useUIKitCell) {
     ASWrapperCellNode *wrapperNode = (ASWrapperCellNode *)node;

Source/ASTableView.mm

@@ -919,8 +919,14 @@ static NSString * const kCellReuseIdentifier = @"_ASTableViewCell";
 
 - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
 {
-  ASCellNode *node = [_dataController.visibleMap elementForItemAtIndexPath:indexPath].node;
-  CGFloat height = node.calculatedSize.height;
+  CGFloat height = 0.0;
+
+  ASCollectionElement *element = [_dataController.visibleMap elementForItemAtIndexPath:indexPath];
+  if (element != nil) {
+    ASCellNode *node = element.node;
+    ASDisplayNodeAssertNotNil(node, @"Node must not be nil!");
+    height = [node layoutThatFits:element.constrainedSize].size.height;
+  }
   
 #if TARGET_OS_IOS
   /**
@@ -1819,6 +1825,9 @@ static NSString * const kCellReuseIdentifier = @"_ASTableViewCell";
     const CGSize calculatedSize = [node layoutThatFits:constrainedSize].size;
     node.frame = { .size = calculatedSize };
 
+    // After the re-measurement, set the new constrained size to the node's backing colleciton element.
+    node.collectionElement.constrainedSize = constrainedSize;
+
     // If the node height changed, trigger a height requery.
     if (oldSize.height != calculatedSize.height) {
       [self beginUpdates];