Shuffle & Cleanup Stuff (#3080)

Source/ASSectionController.h

@@ -0,0 +1,69 @@
+//
+//  ASSectionController.h
+//  AsyncDisplayKit
+//
+//  Created by Adlai Holler on 1/19/17.
+//  Copyright © 2017 Facebook. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * A protocol that your section controllers should conform to,
+ * in addition to IGListSectionType, in order to be used with AsyncDisplayKit.
+ *
+ * @note Your supplementary view source should conform to @c ASSupplementaryNodeSource.
+ */
+@protocol ASSectionController <NSObject>
+
+/**
+ * A method to provide the node block for the item at the given index.
+ * The node block you return will be run asynchronously off the main thread,
+ * so it's important to retrieve any objects from your section _outside_ the block
+ * because by the time the block is run, the array may have changed.
+ *
+ * @param index The index of the item.
+ * @return A block to be run concurrently to build the node for this item.
+ * @see collectionNode:nodeBlockForItemAtIndexPath:
+ */
+- (ASCellNodeBlock)nodeBlockForItemAtIndex:(NSInteger)index;
+
+@optional
+
+/**
+ * Asks the section controller whether it should batch fetch because the user is
+ * near the end of the current data set.
+ *
+ * @discussion Use this method to conditionally fetch batches. Example use cases are: limiting the total number of
+ * objects that can be fetched or no network connection.
+ *
+ * If not implemented, the assumed return value is @c YES.
+ */
+- (BOOL)shouldBatchFetch;
+
+/**
+ * Asks the section controller to begin fetching more content (tail loading) because
+ * the user is near the end of the current data set.
+ *
+ * @param context A context object that must be notified when the batch fetch is completed.
+ *
+ * @discussion You must eventually call -completeBatchFetching: with an argument of YES in order to receive future
+ * notifications to do batch fetches. This method is called on a background queue.
+ */
+- (void)beginBatchFetchWithContext:(ASBatchContext *)context;
+
+/**
+ * A method to provide the size range used for measuring the item
+ * at the given index.
+ *
+ * @param index The index of the item.
+ * @return A size range used for asynchronously measuring the node at this index.
+ * @see collectionNode:constrainedSizeForItemAtIndexPath:
+ */
+- (ASSizeRange)sizeRangeForItemAtIndex:(NSInteger)index;
+
+@end
+
+NS_ASSUME_NONNULL_END