Swiftgram/AsyncDisplayKit/Details/ASCollectionViewFlowLayoutInspector.h
Michael Schneider 35c860c183 Refactor usage of ASCollectionViewLayoutInspecting
- Fix not using itemSize of UICollectionViewFlowLayout
- Move automatic constrained size calculation to the ASCollectionViewFlowLayoutInspector
- Provide a null layout inspector for throwing exceptions if a custom
  UICollectionView is given but no ASCollectionViewLayoutInspecting
- Fix not checking for optional layout inspecting data source methods
  are implemented or not
- Improving tests around ASCollectionViewLayoutInspecting
2016-07-13 16:36:48 -07:00

82 lines
2.7 KiB
Objective-C

//
// ASCollectionViewFlowLayoutInspector.h
// AsyncDisplayKit
//
// Copyright (c) 2014-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.
//
#pragma once
#import <Foundation/Foundation.h>
#import <AsyncDisplayKit/ASDimension.h>
@class ASCollectionView;
@protocol ASCollectionDataSource;
@protocol ASCollectionDelegate;
NS_ASSUME_NONNULL_BEGIN
@protocol ASCollectionViewLayoutInspecting <NSObject>
/**
* Asks the inspector to provide a constarained size range for the given collection view node.
*/
- (ASSizeRange)collectionView:(ASCollectionView *)collectionView constrainedSizeForNodeAtIndexPath:(NSIndexPath *)indexPath;
/**
* Asks the inspector to provide a constrained size range for the given supplementary node.
*/
- (ASSizeRange)collectionView:(ASCollectionView *)collectionView constrainedSizeForSupplementaryNodeOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath;
/**
* Asks the inspector for the number of supplementary sections in the collection view for the given kind.
*/
- (NSUInteger)collectionView:(ASCollectionView *)collectionView numberOfSectionsForSupplementaryNodeOfKind:(NSString *)kind;
/**
* Asks the inspector for the number of supplementary views for the given kind in the specified section.
*/
- (NSUInteger)collectionView:(ASCollectionView *)collectionView supplementaryNodesOfKind:(NSString *)kind inSection:(NSUInteger)section;
@optional
/**
* Allow the inspector to respond to delegate changes.
*
* @discussion A great time to update perform selector caches!
*/
- (void)didChangeCollectionViewDelegate:(id<ASCollectionDelegate>)delegate;
/**
* Allow the inspector to respond to dataSource changes.
*
* @discussion A great time to update perform selector caches!
*/
- (void)didChangeCollectionViewDataSource:(id<ASCollectionDataSource>)dataSource;
@end
/**
* Simple "Null Object" inspector for non-flow layouts that does throws exceptions if methods are called
* from <ASCollectionViewLayoutInspecting>
*/
@interface ASCollectionViewNullLayoutInspector : NSObject <ASCollectionViewLayoutInspecting>
@end
/**
* A layout inspector implementation specific for the sizing behavior of UICollectionViewFlowLayouts
*/
@interface ASCollectionViewFlowLayoutInspector : NSObject <ASCollectionViewLayoutInspecting>
@property (nonatomic, weak, readonly) UICollectionViewFlowLayout *layout;
- (instancetype)initWithCollectionView:(ASCollectionView *)collectionView flowLayout:(UICollectionViewFlowLayout *)flowLayout;
@end
NS_ASSUME_NONNULL_END