Introduce ASCellLayoutMode (TextureGroup#1273)

* Introduce ASCellLayoutMode

* Some smaller improvements

* Improve logic around _superPerformBatchUpdates:completion:

* Add comment about default values for ASCellLayoutModeNone

* Always call _superReloadData:completion: within UICollectionView

* Add initial range test for ASCellLayoutModeNone

Source/ASCollectionNode+Beta.h

@@ -33,21 +33,23 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nullable, nonatomic, weak) id<ASBatchFetchingDelegate> batchFetchingDelegate;
 
 /**
- * When this mode is enabled, ASCollectionView matches the timing of UICollectionView as closely as possible, 
- * ensuring that all reload and edit operations are performed on the main thread as blocking calls. 
+ * When this mode is enabled, ASCollectionView matches the timing of UICollectionView as closely as
+ * possible, ensuring that all reload and edit operations are performed on the main thread as
+ * blocking calls.
  *
- * This mode is useful for applications that are debugging issues with their collection view implementation. 
- * In particular, some applications do not properly conform to the API requirement of UICollectionView, and these 
- * applications may experience difficulties with ASCollectionView. Providing this mode allows for developers to 
- * work towards resolving technical debt in their collection view data source, while ramping up asynchronous 
- * collection layout.
+ * This mode is useful for applications that are debugging issues with their collection view
+ * implementation. In particular, some applications do not properly conform to the API requirement
+ * of UICollectionView, and these applications may experience difficulties with ASCollectionView.
+ * Providing this mode allows for developers to work towards resolving technical debt in their
+ * collection view data source, while ramping up asynchronous collection layout.
  *
- * NOTE: Because this mode results in expensive operations like cell layout being performed on the main thread, 
- * it should be used as a tool to resolve data source conformance issues with Apple collection view API.
+ * NOTE: Because this mode results in expensive operations like cell layout being performed on the
+ * main thread, it should be used as a tool to resolve data source conformance issues with Apple
+ * collection view API.
  *
- * @default defaults to NO.
+ * @default defaults to ASCellLayoutModeNone.
  */
-@property (nonatomic) BOOL usesSynchronousDataLoading;
+@property (nonatomic) ASCellLayoutMode cellLayoutMode;
 
 /**
  *  Returns YES if the ASCollectionNode contents are completely synchronized with the underlying collection-view layout.
@@ -72,8 +74,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)endUpdatesAnimated:(BOOL)animated completion:(nullable void (^)(BOOL))completion ASDISPLAYNODE_DEPRECATED_MSG("Use -performBatchUpdates:completion: instead.");
 
-- (void)invalidateFlowLayoutDelegateMetrics;
-
 @end
 
 NS_ASSUME_NONNULL_END

Source/ASCollectionNode.mm

@@ -42,7 +42,7 @@ @interface _ASCollectionPendingState : NSObject {
 @property (nonatomic) BOOL allowsSelection; // default is YES
 @property (nonatomic) BOOL allowsMultipleSelection; // default is NO
 @property (nonatomic) BOOL inverted; //default is NO
-@property (nonatomic) BOOL usesSynchronousDataLoading;
+@property (nonatomic) ASCellLayoutMode cellLayoutMode;
 @property (nonatomic) CGFloat leadingScreensForBatching;
 @property (nonatomic, weak) id <ASCollectionViewLayoutInspecting> layoutInspector;
 @property (nonatomic) BOOL alwaysBounceVertical;
@@ -193,7 +193,7 @@ - (void)didLoad
     view.inverted                       = pendingState.inverted;
     view.allowsSelection                = pendingState.allowsSelection;
     view.allowsMultipleSelection        = pendingState.allowsMultipleSelection;
-    view.usesSynchronousDataLoading     = pendingState.usesSynchronousDataLoading;
+    view.cellLayoutMode                 = pendingState.cellLayoutMode;
     view.layoutInspector                = pendingState.layoutInspector;
     view.showsVerticalScrollIndicator   = pendingState.showsVerticalScrollIndicator;
     view.showsHorizontalScrollIndicator = pendingState.showsHorizontalScrollIndicator;
@@ -628,21 +628,21 @@ - (void)setBatchFetchingDelegate:(id<ASBatchFetchingDelegate>)batchFetchingDeleg
   return _batchFetchingDelegate;
 }
 
-- (BOOL)usesSynchronousDataLoading
+- (ASCellLayoutMode)cellLayoutMode
 {
   if ([self pendingState]) {
-    return _pendingState.usesSynchronousDataLoading; 
+    return _pendingState.cellLayoutMode;
   } else {
-    return self.view.usesSynchronousDataLoading;
+    return self.view.cellLayoutMode;
   }
 }
 
-- (void)setUsesSynchronousDataLoading:(BOOL)usesSynchronousDataLoading
+- (void)setCellLayoutMode:(ASCellLayoutMode)cellLayoutMode
 {
   if ([self pendingState]) {
-    _pendingState.usesSynchronousDataLoading = usesSynchronousDataLoading; 
+    _pendingState.cellLayoutMode = cellLayoutMode;
   } else {
-    self.view.usesSynchronousDataLoading = usesSynchronousDataLoading;
+    self.view.cellLayoutMode = cellLayoutMode;
   }
 }