text: //
  //  ASSupplementaryNodeSource.h
  //  Texture
  //
  //  Copyright (c) Facebook, Inc. and its affiliates.  All rights reserved.
  //  Changes after 4/13/2017 are: Copyright (c) Pinterest, Inc.  All rights reserved.
  //  Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
  //
  
  #import <Foundation/Foundation.h>
  #import "ASBlockTypes.h"
  #import "ASDimension.h"
  
  NS_ASSUME_NONNULL_BEGIN
  
  @protocol ASSupplementaryNodeSource <NSObject>
  
  @optional
  
  /**
   * A method to provide the node-block for the supplementary element.
   *
   * @param elementKind The kind of supplementary element.
   * @param index The index of the item.
   * @return A node block for the supplementary element.
   * @see collectionNode:nodeForSupplementaryElementOfKind:atIndexPath:
   */
  - (ASCellNodeBlock)nodeBlockForSupplementaryElementOfKind:(NSString *)elementKind atIndex:(NSInteger)index;
  
  /**
   * Asks the controller to provide a node to display for the given supplementary element.
   *
   * @param kind The kind of supplementary element.
   * @param index The index of the item.
   */
  - (ASCellNode *)nodeForSupplementaryElementOfKind:(NSString *)kind atIndex:(NSInteger)index;
  
  /**
   * A method to provide the size range used for measuring the supplementary
   * element of the given kind at the given index.
   *
   * @param elementKind The kind of supplementary element.
   * @param index The index of the item.
   * @return A size range used for asynchronously measuring the node.
   * @see collectionNode:constrainedSizeForSupplementaryElementOfKind:atIndexPath:
   */
  - (ASSizeRange)sizeRangeForSupplementaryElementOfKind:(NSString *)elementKind atIndex:(NSInteger)index;
  
  @end
  
  NS_ASSUME_NONNULL_END
  