IGListKit/Source/Internal/IGListStackedSectionControllerInternal.h
Ryan Nystrom a15ea08614 Move section controller mutation API to object provided in update block
Summary:
We constantly have random bugs pop up when mutations are made outside of a batch update. This change restricts the mutation API to a batch context object (which is just an `IGListAdapter`) so they can only be done **inside an update block**.

- Fixed open source project
- Confirmed open source examples build
- Updated all of Instagram.app to use this API
- Changelog breaking changes entry

Fixes #392

Reviewed By: jessesquires

Differential Revision: D4754129

fbshipit-source-id: 11d32a0fac3e50c9edbb01e92a8a0c7b8a43cf2d
2017-03-22 12:46:49 -07:00

44 lines
1.8 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 <IGListKit/IGListDisplayDelegate.h>
#import "IGListStackedSectionController.h"
@interface IGListStackedSectionController ()
<
IGListBatchContext,
IGListCollectionContext,
IGListDisplayDelegate,
IGListScrollDelegate,
IGListWorkingRangeDelegate
>
@property (nonatomic, strong, readonly) NSOrderedSet<__kindof IGListSectionController<IGListSectionType> *> *sectionControllers;
/// An array the length of the total number of items in the stack, pointing to a section controller for the item index.
@property (nonatomic, copy) NSArray<IGListSectionController<IGListSectionType> *> *sectionControllersForItems;
/// An array of index offsets for each item in the flattened stack.
@property (nonatomic, copy) NSArray<NSNumber *> *sectionControllerOffsets;
/// A cached collection of the number of items summed from each section controller in the stack.
@property (nonatomic, assign) NSInteger flattenedNumberOfItems;
/// A counted set of the visible section controllers, used to forward granular display events to child section controllers
@property (nonatomic, strong, readonly) NSCountedSet *visibleSectionControllers;
/// Temporary batch context so the stack controller can transform child indices within the stack before updating.
@property (nonatomic, strong) id<IGListBatchContext> forwardingBatchContext;
- (IGListSectionController <IGListSectionType> *)sectionControllerForObjectIndex:(NSInteger)itemIndex;
- (NSInteger)offsetForSectionController:(IGListSectionController<IGListSectionType> *)sectionController;
- (void)reloadData;
@end