IGListKit/Source/IGListSupplementaryViewSource.h
FBShipIt cdc796746a Initial commit
fbshipit-source-id: c38b897b9e2b87c782e0e01b0145d9189dc7f9d8
2016-10-11 10:12:17 -04:00

54 lines
2 KiB
Objective-C

/**
* Copyright (c) 2016-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
/**
Implement the methods of this protocol to provide information about a list's supplementary views. This data is used in
IGListAdapter which then configures and maintains a UICollectionView. The supplementary API reflects that in
UICollectionView, UICollectionViewLayout, and UICollectionViewDataSource.
*/
@protocol IGListSupplementaryViewSource <NSObject>
/**
Asks the SupplementaryViewSource for an array of supported element kinds.
@return An array of element kind strings that the supplementary source handles.
*/
- (NSArray<NSString *> *)supportedElementKinds;
/**
Asks the SupplementaryViewSource for a configured supplementary view for the specified kind and index.
@param elementKind The kind of supplementary view being requested
@param index The index for the row being requested.
@discussion This is your opportunity to do any supplementary view setup and configuration.
@warning You should never allocate new views in this method. Instead deque a view from the `IGListCollectionContext`.
*/
- (__kindof UICollectionReusableView *)viewForSupplementaryElementOfKind:(NSString *)elementKind
atIndex:(NSInteger)index;
/**
Asks the SupplementaryViewSource for the size of a supplementary view for the given kind and index path.
@param elementKind The kind of supplementary view.
@param index The index of the requested row.
@return The size for the supplementary view.
*/
- (CGSize)sizeForSupplementaryViewOfKind:(NSString *)elementKind
atIndex:(NSInteger)index;
@end
NS_ASSUME_NONNULL_END