5.1.0

Breaking Changes

• Added methods to the IGListAdapterDelegate to include callback methods for any time a cell will appear or did disappear from the screen. This can be used in conjunction with the IGListAdapterDelegateAnnouncer to listen globally for cell lifecycle events. Any implementer of IGListAdapterDelegate must update to include these methods. Jesse Seidman (fa50aa1), (d1d6f9d), (03049f7)

• Added willCrash delegate methods in order to capture incoming crashes in IGListKit for analysis. Any implementer of IGListAdapterUpdaterDelegate and/or IGListUpdatingDelegate must update to include these methods. Hoà V. DINH (da1050e)

Enhancements

• Replaced CocoaPods with SPM as the new dependency manager of IGListKit.xcodeproj when running unit tests. Tim Oliver (2964f06)

• Added handling for new collection view cell dequeue behavior in iOS 18 Maxime Ollivier (4bad7d52)

• Added support for Swift Concurrency Mark Davis (0ec2d52)

• Exposed an option to disable layout cache invalidation when new items are inserted Constantine Fry (700905e)

• Exposed IGListCollectionViewLayoutInvalidationContext as a public interface (1560956)

• Annotated main API classes with NS_SWIFT_UI_ACTOR in preparation of moving to Swift 6 Cory Wilhite (a28d835)

• Added autoDeselectEnabled on IGListAdapter to free each section-controller from having to do this and avoid bugs Maxime Ollivier (fec6b0e)

• Added associatedListAdapters as a property of UIViewController to track IGListAdapter instances bound to that view controller. Maxime Ollivier (9c0ef52)

• Added assert when a section's diffIdentifier changed before an update starts, which could manifest in a few different crashes Maxime Ollivier (64ba471)

• Added support for iOS 13 Context Menus with contextMenuConfigurationForItemAt method. Jérôme B. (23daf6d).

Fixes

• A crash that could periodically occur when collection view layout attributes were nil (6e91299)

• A crash that could occur when reloading the same cell index multiple times Maxime Ollivier (0c25779)

• A crash in IGListCollectionViewLayout that could occur if a nil indexPath value was provided (5ee2207)

5.0.0

5.0.0 is finally here! 🎉🎊🥳

This version brings all of the enhancements Instagram has been adding to IGListKit over the years since 4.0.0. We're incredibly excited for everyone to try it out and let us know what they think. If you encounter any issues, please let us know by opening a GitHub ticket. Thank you so much to all of the internal and external contributors who submitted code, reported issues and everything else that made this release possible.

Breaking Changes

• Changed iOS deployment target to 11.0 and macOS deployment target to 10.13 Kent Sutherland (#1573)

• Removed unneeded diffing functions IGListDiffExperiment(...) and IGListDiffPathsExperiment(...). Maxime Ollivier (254c041)

• ListSectionController.collectionContext and ListGenericSectionController.object are now implicitly-unwrapped optionals in Swift. Nate Stedman (a6526ce)

• The argument of IGListGenericSectionController's -didUpdateToObject: is now generic, not id. Nate Stedman (a6526ce)

• Updated IGListUpdatingDelegate, including a new method to safely perform [IGListAdapter setDataSource:] and changes to -performUpdateWithCollectionViewBlock that allows section-controllers to be created before the diffing (and therefore use a more accurate toObjects array) Maxime Ollivier (43af883)

// OLD
- (void)performUpdateWithCollectionViewBlock:(IGListCollectionViewBlock)collectionViewBlock
                                 fromObjects:(nullable NSArray<id <IGListDiffable>> *)fromObjects
                              toObjectsBlock:(nullable IGListToObjectBlock)toObjectsBlock
                                    animated:(BOOL)animated
                       objectTransitionBlock:(IGListObjectTransitionBlock)objectTransitionBlock
                                  completion:(nullable IGListUpdatingCompletion)completion;

// NEW
- (void)performUpdateWithCollectionViewBlock:(IGListCollectionViewBlock)collectionViewBlock
                                    animated:(BOOL)animated
                            sectionDataBlock:(IGListTransitionDataBlock)sectionDataBlock
                       applySectionDataBlock:(IGListTransitionDataApplyBlock)applySectionDataBlock
                                  completion:(nullable IGListUpdatingCompletion)completion;

// NEW
- (void)performDataSourceChange:(IGListDataSourceChangeBlock)block;

• Removed allowsBackgroundReloading from IGListAdapterUpdater because it's causing performance issues and other bugs. Maxime Ollivier (032e1b0)

• Introducing allowsBackgroundDiffing on IGListAdapterUpdater! This property lets the updater perform the diffing on a background thread. Originally introduced by Ryan Nystrom a while back. Maxime Ollivier (9a11f6)

• Updated scrollToObject: method in IGListAdapter to include a new parameter additionalOffset to handle shifting the final scroll position by some vertical or horizontal offset depending on the scroll direction. This allows the object to be shown at the correct position when it is scrolled to in a list with sticky headers. Anna Tang (f2166c3)

// OLD
- (void)scrollToObject:(id)object
    supplementaryKinds:(nullable NSArray<NSString *> *)supplementaryKinds
       scrollDirection:(UICollectionViewScrollDirection)scrollDirection
        scrollPosition:(UICollectionViewScrollPosition)scrollPosition
              animated:(BOOL)animated;

// NEW
- (void)scrollToObject:(id)object
    supplementaryKinds:(nullable NSArray<NSString *> *)supplementaryKinds
       scrollDirection:(UICollectionViewScrollDirection)scrollDirection
        scrollPosition:(UICollectionViewScrollPosition)scrollPosition
      additionalOffset:(CGPoint)additionalOffset
              animated:(BOOL)animated;

• Unshipped the IGListExperimentSkipViewSectionControllerMap experiment as it was no longer being used. Maxime Ollivier (99e24af)

• Unshipped the IGListExperimentSkipPerformUpdateIfPossible experiment since it wasn't considered safe enough. Maxime Ollivier (b3a22ad)

Enhancements

• Added traitCollection property to IGListAdapter in order to access the current trait collection of the underlying collection view. Sash Zats (53a96a9)

• Added viewForSupplementaryElementOfKind:atIndex:sectionController: to IGListAdapter. ryanmathews (c708a10)

• Replaced usage of method_exchangeImplementations with class_replaceMethod for increased performance. Saagar Jha (#1583)

• Added shouldDeselectItemAtIndex: to IGListSectionController. bladeofky (b22a10e)

• Added shouldSelectItemAtIndex: to IGListSectionController. dirtmelon (#1479)

• Added Mac Catalyst support. Petro Rovenskyy (#1487)

• Introduce IGListSwiftKit, with Swift refinements for dequeueReusableCellOfClass methods. Koen Punt (#1388).

• Added APPLICATION_EXTENSION_API_ONLY support for IGListDiffKit Peter Meyers (#1422)

• Improved performance by deferring requesting objects from the IGListAdapterDataSource until just before diffing is executed. If n updates are coalesced into one, this results in just a single request for objects from the data source. Shipped with experiment IGListExperimentDeferredToObjectCreation from Ryan Nystrom. Maxime Ollivier (7fc4384)

• Improved performance by using reloadData when there are too many diffing updates. Shipped with experiment IGListExperimentReloadDataFallback from Ryan Nystrom. Maxime Ollivier (86ecc60)

• Small performance improvement by replacing NSSet with NSArray during the data update to avoid unnecessary hashing, especially when dealing with lots of large objects with non trivial hashes. Maxime Ollivier (c0cf10d)

• Lazy initialize the -emptyViewForListAdapter: Maxime Ollivier (29d4640)

• Updated IGListAdapterUpdater to be safer, more performant, and better organized! Maxime Ollivier (247e7ca)

  • Safely handles [IGListAdapter setDataSource:] by also invalidating the UICollectionView data.
  • Safely handles [IGListAdapter setCollectionView:] by cancelling on-going transactions.
  • Safely handles returning nil IGListSectionController from IGListAdapterDataSource by dumping objects that don't have a controller before the diffing.
  • Checks that the UICollectionView section count matches the IGListAdapter before committing the update, otherwise fallback to a reload.
  • Schedules an update block (dispatch_async) only when needed, instead of scheduling on every single call to -performUpdateWithCollectionViewBlock.
  • Wraps each update in a transaction that can be easily cancelled.
  • Uses methods instead of blocks to make the callstack easier to read in crash reports.
  • Unblocks IGListExperimentBackgroundDiffing

• The IGListExperimentFixCrashOnReloadObjects experiment succeeded and has officially been implemented into IGListKit. Maxime Ollivier (99e24af)

• Added IGListExperimentKeepPointerToCollectionViewDataSource experiment as a potential solution for certain crashes being periodically observed.

• Added IGListExperimentDisableAnimationOnUpdates experiment to optionally disable update animations in IGListAdapter instances. [(eeb5208)](https://github.com/In...

4.0.0

4.0.0

4.0.0 is here! 🎉🎊🥳

This version has a number of improvements we've been working on for the last year. We're excited for everyone get their hands on the new improvements and features. Thanks so much to all who contributed code, submitted issues, and contributed to discussions around this release!

Breaking Changes

• Added Swift annotation name to IGListAdapterDelegate which removes IG prefix. The new name for Swift clients is ListAdapterDelegate. Andrea Antonioni (#1116)

• Remove support for iOS 8 Ian Perry (#1381)

• IGListKit has been split into IGListKit and IGListDiffKit for Xcode and Carthage builds. Cocoapods continues to use an all-inclusive IGListKit podspec. Nate Stedman (#1377)

• Remove coalescanceTime from IGListAdapterUpdate, since it increase crash rate. Zhisheng Huang (2f76e8c)

• All IGListBindingSectionControllerSelectionDelegate methods are now required. Bofei Zhu (#1186)

• Renamed [IGListAdapterUpdatingDelegate listAdapterUpdater:willPerformBatchUpdatesWithCollectionView:] to [IGListAdapterUpdatingDelegate listAdapterUpdater:willPerformBatchUpdatesWithCollectionView:fromObjects:toObjects:listIndexSetResult:] to include more supporting info on updated objects. Jeremy Cohen (b200dda)

• Renamed [IGListAdapterUpdatingDelegatelistAdapterUpdater:collectionView:willCrashWithException:fromObjects:toObjects:updates:] to [ IGListAdapterUpdatingDelegatelistAdapterUpdater:collectionView:willCrashWithException:fromObjects:toObjects:diffResult:updates:] to include diff result info. Zhisheng Huang (039e77e)

• Remove IGListStackedSectionController. Hanton Yang (#1355)

Enhancements

• Added IGListCollectionScrollingTraits for exposing UICollectionView scrolling traits to section controllers via IGListCollectionContext. Adam Stern (b4c8ea1)

• IGListBindingSectionController no longer asserts when reloading the entire section. A warning message is now logged if the entire section is going to be reloaded. Jeff Bailey (#1213)

• Added preferItemReloadsForSectionReloads in IGListAdapterUpdater so that the item updates are invoked with the proper collectionView animation, instead of using the delete+insert section operation when the number of items is unchanged. Zhisheng Huang (f699ea0)

• Created IGListAdapterPerformanceDelegate for IGListAdapter to be able to measure how long some operations take across all section controllers. For example, how long it takes to dequeue a cell. Maxime Ollivier (4662454)

• Update CocoaPods integration to use the CocoaPods specs CDN Koen Punt (#1386)

• Remove useless system version code Kinarobin (#1386)

Fixes

• Fixed bug with layouts inconsistency in updateAnimated:completion of IGListBindingSectionController. Qinghua Hong (#1285)

• Fixed bug with -[IGListAdapter scrollToObject:supplementaryKinds:scrollDirection:scrollPosition:animated:] where the content inset(bottom/right) of the collection view was incorrectly being applied to the final offset and was inconsistent with the content inset(top/left) of the collection view being applied. Qinghua Hong (#1284)

• Fixed crash when the data source is nil before calling -[IGListAdapterUpdater performUpdateWithCollectionViewBlock:fromObjects:toObjectsBlock:animated:objectTransitionBlock:completion:]. Zhisheng Huang (6cdd112)

• Experimental fix to get the UICollectionView for batch updating immediately before applying the update. Ryan Nystrom (583efb9)

• Fixed bug with IGListDiff.mm where arrays of NSIndexPath, instead of NSIndexPath, were incorrectly set as objects for the IndexPathMaps. Bofei Zhu (#1205)

• [IGListAdapterUpdater performBatchUpdatesWithCollectionViewBlock:] and [IGListAdapterUpdater performReloadDataWithCollectionViewBlock:] clean state and run completion blocks if their UICollectionView is nil. Brandon Darin (290d592)

• Ensuring view models with duplicate diff identifiers are removed when view models are first requested by IGListBindingSectionController Adam Stern (a1ee4c1)

• Fixed [IGListAdapterUpdater reloadItemInCollectionView:fromIndexPath:toIndexPath:] does not call delegate when not inside a batch update. Bofei Zhu (#1211)

• Log instead of assert for duplicate diff identifiers to make code testable. Adam Stern (bee2178)

• Removed nibName argument from IGListReusableViewIdentifier. Trung Duc (#1223)

• Fixed crash when using -[IGListCollectionContext dequeueReusableCellOfClass:withReuseIdentifier:forSectionController:atIndex:] Jeremy Lawrence (3b19cfb)

• Added missing method override to IGListBindingSectionController that updates the internal viewModels array after moving a cell. Dennis Müller (#1262)

• Fixed logic flaw in [IGListCollectionViewLayout shouldInvalidateLayoutForBoundsChange:]. Allen Hsu (#1236)

• Fixed crash when calling [UICollectionView layoutAttributesForSupplementaryElementOfKind...] with IGListCollectionViewLayout and the section controller doesn't actually return a supplementary view Maxime Ollivier (cddb297)

• Added IGListExperimentAvoidLayoutOnScrollToObject to avoid creating off-screen cells when calling [IGListAdapter scrollToObject ...]. Maxime Ollivier (6faddd9)

• Added IGListExperimentFixIndexPathImbalance to test fixing a crash when inserting and deleting the same NSIndexPath multiple times. Maxime Ollivier (7824698)

3.4.0

3.4.0

Enhancements

• Relicensed IGListKit to MIT. Ryan Nystrom (000bc36)

• Experimental performance improvement from deferring -[IGListAdapterDataSource objectsForListAdapter:] calls until just before diffing. Ryan Nystrom (3059c5e)

3.3.0

3.3.0

Enhancements

• Add support for UICollectionView's interactive reordering in iOS 9+. Updates include -[IGListSectionController canMoveItemAtIndex:] to enable the behavior, -[IGListSectionController moveObjectFromIndex:toIndex:] called when items within a section controller were moved through reordering, -[IGListAdapterDataSource listAdapter:moveObject:from:to] called when section controllers themselves were reordered (only possible when all section controllers contain exactly 1 object), and -[IGListUpdatingDelegate moveSectionInCollectionView:fromIndex:toIndex] to enable custom updaters to conform to the reordering behavior. The update also includes two new examples ReorderableSectionController and ReorderableStackedViewController to demonstrate how to enable interactive reordering in your client app. Jared Verdi (#976)

• 5x improvement to diffing performance when result is only inserts or deletes. Ryan Nystrom (afd2d29)

• Can always show sticky header although section data is empty. Marcus Wu (#1129)

• Added -[IGListCollectionContext dequeueReusableCellOfClass:withReuseIdentifier:forSectionController:atIndex:] to allow for registering cells of the same class with different reuse identifiers. Jeremy Lawrence (f47753e)

Fixes

• Fixed Xcode 9.3 build errors. Sho Ikeda (#1143)

• Copy objects when retrieving from datasource to prevent modification of models in binding section controller. Kashish Goel (#1109)

• Fixed footer is sticky when stickyHeader is true aelam (#1094)

• Updated IGListCollectionViewLayout to rely on layoutAttributesClass instead of vanilla UICollectionViewLayoutAttributes Cole Potrocky #1135

• -[IGListSectionController didSelectItemAtIndex:] is now called when a scrollViewDelegate or collectionViewDelegate is set. Ryan Nystrom (#1108)

• Fixed binding section controllers failing to update their cells when the section controller's section changes. Chrisna Aing (#1144)

3.2.0

Enhancements

• Added -[IGListSectionController didHighlightItemAtIndex:] and -[IGListSectionController didUnhighlightItemAtIndex:] APIs to support UICollectionView cell highlighting. Kevin Delannoy (#933)

• Added -didDeselectSectionController:withObject: to IGListSingleSectionControllerDelegate Darren Clark (#954)

• Added a new listener API to be notified when IGListAdapter finishes updating. Add listeners via -[IGListAdapter addUpdateListener:] with objects conforming to the new IGListAdapterUpdateListener protocol. Ryan Nystrom (5cf01cc)

• Updated project settings for iOS 11. Ryan Nystrom (#942)

• Added support UICollectionElementKindSectionFooter for IGListCollectionViewLayout. Igor Vasilenko (#1017)

• Added experiment to make -[IGListAdapter visibleSectionControllers:] a bit faster. Maxime Ollivier (82a2a2e)

• Added support -[UIScrollView adjustedContentInset] for iOS 11. Guoyin Li (#1020)

• Added new transitionDelegate API to give IGListSectionControllers control to customize initial and final UICollectionViewLayoutAttributes. Includes automatic integration with IGListCollectionViewLayout. Sue Suhan Ma (26924ec)

• Reordered position of intercepted selector in IGListAdapterProxy's isInterceptedSelector method to reduce overall consumption of compare. zhongwuzw (#1055)

• Made IGListTransitionDelegate inherited from NSObject. Igor Vasilenko (#1075)

Fixes

• Duplicate objects for initial data source setup filtered out. Mikhail Vashlyaev (#993

• Weakly reference the UICollectionView in coalescence so that it can be released if the rest of system is destroyed. Ryan Nystrom (d322c2e)

• Fix bug with -[IGListAdapter scrollToObject:supplementaryKinds:scrollDirection:scrollPosition:animated:] where the content inset of the collection view was incorrectly being applied to the final offset. Ryan Nystrom (b2860c3)

• Avoid crash when invalidating the layout while inside `-[UICollectionView performBatchUpdates:completion:]. Ryan Nystrom (d9a89c9)

• Duplicate view models in IGListBindingSectionController gets filtered out. Weyert de Boer (#916)

• Check object type on lookup to prevent crossing types if different objects collide with their identifiers. Ryan Nystrom (296baf5)

3.1.1

3.1.1

Fixes

• Prevent a crash when IGListBindingSectionControllerDelegate objects do not implement the optional deselection API. Ryan Nystrom (#921)

3.1.0

This release closes the 3.1.0 milestone.

Enhancements

• Added debug descriptions for 'IGListBindingSectionController' when printing to lldb via po [IGListDebugger dump]. Candance Smith (#856)

Fixes

• Prevent a crash when update queued immediately after item batch update. Ryan Nystrom (3dc6060)

• Return correct -[IGListAdapter visibleSectionControllers] when section has no items, but has supplementary views. Mani Ghasemlou (#643)

• Call [CATransaction commit] before calling completion block in IGListAdapterUpdater to prevent animation issues. Maxime Ollivier (6f946b2)

• Fix scrollToObject:supplementaryKinds:... not scrolling when section is empty but does have supplymentary views. Gulam Moledina (#808)

• Better support for non-top positions in scrollToObject: API. Gulam Moledina (#861)

Enhancements

• Added -[IGListSectionController didDeselectItemAtIndex:] API to support default UICollectionView cell deselection. Ryan Nystrom (6540f96)

• Added -[IGListCollectionContext selectItemAtIndex:] Select an item through IGListCollectionContext like -[IGListCollectionContext deselectItemAtIndex:]. Marvin Nazari (#874)

• Added horizontal scrolling support to IGListCollectionViewLayout. Peter Edmonston (#857)

• Added support for scrollViewDidEndDecelerating to IGListAdapter. Phil Larson (#899)

• Automatically disable [UICollectionView isPrefetchingEnabled] when setting a collection view on an adapter. Ryan Nystrom (#889)

3.0.0

This release closes the 3.0.0 milestone.

Breaking Changes

• Added Swift annotation names which remove IG prefixes from class names, C functions, and other APIs. Note, this only affects Swift clients. Robert Payne (#593)

Example:

// OLD
class MySectionController : IGListSectionController { ... }

// NEW
class MySectionController : ListSectionController { ... }

// OLD
IGListDiff([], [], .equality)

// NEW
ListDiff(oldArray: [], newArray: [], .equality)

• Updated didSelect delegate call in IGListSingleSectionControllerDelegate to include object. Sherlouk (#397)

// OLD
- (void)didSelectSingleSectionController:(IGListSingleSectionController *)sectionController;

// NEW
- (void)didSelectSectionController:(IGListSingleSectionController *)sectionController
                        withObject:(id)object;

• IGListUpdatingDelegate now conforms to NSObject, bringing it in line with other framework protocols. Adlai Holler (#435)

• Changed hasChanges methods in IGListIndexPathResult and IGListIndexSetResult to read-only properties. Bofei Zhu (#453)

• Replaced IGListGridCollectionViewLayout with IGListCollectionViewLayout. Ryan Nystrom (#482, #450)

• Renamed IGListAdapterUpdaterDelegate method to listAdapterUpdater:didPerformBatchUpdates:collectionView:. Vincent Peng (#491)

• Moved section controller mutations to IGListBatchContext, provided as a parameter when calling -performBatchAnimated:updates:completion on a section controller's collectionContext. All updates (insert, delete, reload item/section controller) must now be done inside a batch update block. Ryan Nystrom (a15ea08)

// OLD
[self.collectionContext performBatchAnimated:YES updates:^{
  self.expanded = YES;
  [self.collectionContext insertInSectionController:self atIndexes:[NSIndexSet indexSetWithIndex:1]];
} completion:nil];

// NEW
[self.collectionContext performBatchAnimated:YES updates:^(id<IGListBatchContext> batchContext) {
  self.expanded = YES;
  [batchContext insertInSectionController:self atIndexes:[NSIndexSet indexSetWithIndex:1]];
} completion:nil];

// OLD
[self.collectionContext reloadSectionController:self];

// NEW
[self.collectionContext performBatchAnimated:YES updates:^(id<IGListBatchContext> batchContext) {
  [batchContext reloadSectionController:self];
} completion:nil];

• -[IGListCollectionContext containerSize] no longer accounts for the content inset of the collection view when returning a size. If you require that behavior, you can now use -[IGListCollectionContext insetContainerSize]. Ryan Nystrom (623ff2a)

• IGListCollectionView has been completely removed in favor of using plain old UICollectionView. See discussion at #409 for details. Jesse Squires (2284ce3)

• IGListBatchUpdateData replaced its NSSet properties with NSArray instead. Ryan Nystrom (#616)

• IGListUpdatingDelegate now requires method -reloadItemInCollectionView:fromIndexPath:toIndexPath: to handle reloading cells between index paths. Ryan Nystrom (#657)

• -[IGListCollectionContext sectionForSectionController:] has been removed and replaced with the NSInteger sectionIndex property on IGListSectionController. Andrew Monshizadeh #671

Enhancements

• Added an initializer on IGListAdapter that does not take a workingRangeSize and defaults it to 0. BasThomas (#686)

• Added -[IGListAdapter visibleCellsForObject:] API. Sherlouk (#442)

• Added -[IGListAdapter sectionControllerForSection:] API. Adlai-Holler (#477)

• You can now manually move items (cells) within a section controller, ex: [self.collectionContext moveInSectionController:self fromIndex:0 toIndex:1]. Ryan Nystrom (#418)

• Invalidate the layout of a section controller and control the transition with UIView animation APIs. Ryan Nystrom (#499)

• Added -[IGListAdapter visibleIndexPathsForSectionController:] API. Malecks (#465)

• Added IGListBindingSectionController which automatically binds view models to cells and animates updates at the cell level. Ryan Nystrom (#494)

• Added IGListGenericSectionController to take advantage of Objective-C (and Swift) generics and automatically store strongly-typed references to the object powering your section controller. Ryan Nystrom (301f147)

• Added a debug option for IGListKit that you can print to lldb via po [IGListDebugger dump]. Ryan Nystrom (#617)

Fixes

• Gracefully handle a nil section controller returned by an IGListAdapterDataSource. Ryan Nystrom (#488)

• Fix bug where emptyView's hidden status is not updated after the number of items is changed with insertInSectionController:atIndexes: or related methods. Peter Edmonston (#395)

• Fix bug where IGListStackedSectionController's children need to know numberOrItems before didUpdate is called. (#348)

• Fix bug where -[UICollectionViewCell ig_setStackedSectionControllerIndex:] should use OBJC_ASSOCIATION_COPY_NONATOMIC for NSNumber. PhilCai (#424)

• Fix potential bug with suppressing animations (by passing NO) during -[IGListAdapter performUpdatesAnimated: completion:] where user would see UI glitches/flashing. Jesse Squires (019c990)

• Fix bug where scroll position would be incorrect in call to -[IGListAdapter scrollToObject:supplementaryKinds:scrollDirection:scrollPosition:animated: with scrollDirection/scrollPosition of UICollectionViewScrollDirectionVertical/UICollectionViewScrollPositionCenteredVertically or UICollectionViewScrollDirectionHorizontal/UICollectionViewScrollPositionCenteredHorizontally and with a collection view with nonzero contentInset. David Yamnitsky (5cc0fcd)

• Fix a crash when reusing collection views between embedded IGListAdapters. Ryan Nystrom (#517)

• Only collect batch updates when explicitly inside the batch update block, execute them otherwise. Fixes dropped updates. Ryan Nystrom (#494)

• Remove objects that return nil diff identifiers before updating. Ryan Nystrom (af984ca)

• Fix a potential crash when a section is moved and deleted at the same time. Ryan Nystrom (#577)

• Prevent section controllers and supplementary sources from returning negative sizes that crash UICollectionViewFlowLayout. Ryan Nystrom (#583)

• Add nullability annotations to a few more headers. Adlai Holler (#626)

• Fix a crash when inserting or deleting from the same index within the same batch-update application. Ryan Nystrom (#616)

• IGListSectionType protocol was removed and its methods were absorted into the IGListSectionController base class with default implementations. Ryan Nystrom ([3102852](https://github.com/Inst...

2.1.0

This release closes the 2.1.0 milestone.

Enhancements

• Added support for macOS. Note: this is only for the Diffing components. There is no support for IGListAdapter, IGListSectionController, and other components at this time. Guilherme Rambo (#235)
• Added a macOS example project. Guilherme Rambo (#337)
• Disables prefetchEnabled by default on IGListCollectionView. Sven Bacia (#323)
• Working ranges now work with IGListStackedSectionController. Ryan Nystrom (#356)
• Added CocoaPods subspec for diffing, IGListKit/Diffing and an installation guide. Sherlouk (#368)
• Added allowsBackgroundReloading flag (default YES) to IGListAdapterUpdater so users can configure this behavior as needed. Adlai-Holler (#375)
• -[IGListAdapter updater] is now public (read-only). Adlai-Holler (#379)

Fixes

• Avoid UICollectionView crashes when queueing a reload and insert/delete on the same item as well as reloading an item in a section that is animating. Ryan Nystrom (#325)
• Prevent adapter data source from deallocating after queueing an update. Ryan Nystrom (4cc91a2)
• Fix out-of-bounds bug when child section controllers in a stack remove cells. Ryan Nystrom (#358)
• Fix a grid layout bug when item has full-width and iter-item spacing is not zero. Bofei Zhu (#361)