ASCollectionNode Class Reference

Inherits from ASDisplayNode : ASDealloc2MainObject
Conforms to ASRangeControllerUpdateRangeProtocol
Declared in ASCollectionNode.h

Overview

ASCollectionNode is a node based class that wraps an ASCollectionView. It can be used as a subnode of another node, and provide room for many (great) features and improvements later on.

– initWithCollectionViewLayout:

Initializes an ASCollectionNode

- (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout *)layout

Parameters

layout

The layout object to use for organizing items. The collection view stores a strong reference to the specified object. Must not be nil.

Discussion

Initializes and returns a newly allocated collection node object with the specified layout.

Declared In

ASCollectionNode.h

– initWithFrame:collectionViewLayout:

Initializes an ASCollectionNode

- (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout

Parameters

frame

The frame rectangle for the collection view, measured in points. The origin of the frame is relative to the superview in which you plan to add it. This frame is passed to the superclass during initialization.
layout

The layout object to use for organizing items. The collection view stores a strong reference to the specified object. Must not be nil.

Discussion

Initializes and returns a newly allocated collection node object with the specified frame and layout.

Declared In

ASCollectionNode.h

  view

Returns the corresponding ASCollectionView

@property (strong, nonatomic, readonly) ASCollectionView *view

Return Value

view The corresponding ASCollectionView.

Declared In

ASCollectionNode.h

  delegate

The object that acts as the asynchronous delegate of the collection view

@property (weak, nonatomic) id<ASCollectionDelegate> delegate

Discussion

The delegate must adopt the ASCollectionDelegate protocol. The collection view maintains a weak reference to the delegate object.

The delegate object is responsible for providing size constraints for nodes and indicating whether batch fetching should begin.

Note: This is a convenience method which sets the asyncDelegate on the collection node’s collection view.

Declared In

ASCollectionNode.h

  dataSource

The object that acts as the asynchronous data source of the collection view

@property (weak, nonatomic) id<ASCollectionDataSource> dataSource

Discussion

The datasource must adopt the ASCollectionDataSource protocol. The collection view maintains a weak reference to the datasource object.

The datasource object is responsible for providing nodes or node creation blocks to the collection view.

Note: This is a convenience method which sets the asyncDatasource on the collection node’s collection view.

Declared In

ASCollectionNode.h

  allowsSelection

A Boolean value that indicates whether users can select items in the collection node. If the value of this property is YES (the default), users can select items. If you want more fine-grained control over the selection of items, you must provide a delegate object and implement the appropriate methods of the UICollectionNodeDelegate protocol.

@property (nonatomic, assign) BOOL allowsSelection

Declared In

ASCollectionNode.h

  allowsMultipleSelection

A Boolean value that determines whether users can select more than one item in the collection node. This property controls whether multiple items can be selected simultaneously. The default value of this property is NO. When the value of this property is YES, tapping a cell adds it to the current selection (assuming the delegate permits the cell to be selected). Tapping the cell again removes it from the selection.

@property (nonatomic, assign) BOOL allowsMultipleSelection

Declared In

ASCollectionNode.h

– tuningParametersForRangeType:

Tuning parameters for a range type in full mode.

- (ASRangeTuningParameters)tuningParametersForRangeType:(ASLayoutRangeType)rangeType

Parameters

rangeType

The range type to get the tuning parameters for.

Return Value

A tuning parameter value for the given range type in full mode.

Declared In

ASCollectionNode.h

– setTuningParameters:forRangeType:

Set the tuning parameters for a range type in full mode.

- (void)setTuningParameters:(ASRangeTuningParameters)tuningParameters forRangeType:(ASLayoutRangeType)rangeType

Parameters

tuningParameters

The tuning parameters to store for a range type.
rangeType

The range type to set the tuning parameters for.

Declared In

ASCollectionNode.h

– tuningParametersForRangeMode:rangeType:

Tuning parameters for a range type in the specified mode.

- (ASRangeTuningParameters)tuningParametersForRangeMode:(ASLayoutRangeMode)rangeMode rangeType:(ASLayoutRangeType)rangeType

Parameters

rangeMode

The range mode to get the running parameters for.
rangeType

The range type to get the tuning parameters for.

Return Value

A tuning parameter value for the given range type in the given mode.

Declared In

ASCollectionNode.h

– setTuningParameters:forRangeMode:rangeType:

Set the tuning parameters for a range type in the specified mode.

- (void)setTuningParameters:(ASRangeTuningParameters)tuningParameters forRangeMode:(ASLayoutRangeMode)rangeMode rangeType:(ASLayoutRangeType)rangeType

Parameters

tuningParameters

The tuning parameters to store for a range type.
rangeMode

The range mode to set the running parameters for.
rangeType

The range type to set the tuning parameters for.

Declared In

ASCollectionNode.h

– scrollToItemAtIndexPath:atScrollPosition:animated:

Scrolls the collection to the given item.

- (void)scrollToItemAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(UICollectionViewScrollPosition)scrollPosition animated:(BOOL)animated

Parameters

indexPath

The index path of the item.
scrollPosition

Where the item should end up after the scroll.
animated

Whether the scroll should be animated or not.

This method must be called on the main thread.

Declared In

ASCollectionNode.h

– registerSupplementaryNodeOfKind:

Registers the given kind of supplementary node for use in creating node-backed supplementary elements.

- (void)registerSupplementaryNodeOfKind:(NSString *)elementKind

Parameters

elementKind

The kind of supplementary node that will be requested through the data source.

Discussion

Use this method to register support for the use of supplementary nodes in place of the default registerClass:forSupplementaryViewOfKind:withReuseIdentifier: and registerNib:forSupplementaryViewOfKind:withReuseIdentifier: methods. This method will register an internal backing view that will host the contents of the supplementary nodes returned from the data source.

Declared In

ASCollectionNode.h

– performBatchAnimated:updates:completion:

Perform a batch of updates asynchronously, optionally disabling all animations in the batch. This method must be called from the main thread. The data source must be updated to reflect the changes before the update block completes.

- (void)performBatchAnimated:(BOOL)animated updates:(nullable __attribute ( ( noescape ) ) void ( ^ ) ( ))updates completion:(nullable void ( ^ ) ( BOOL finished ))completion

Parameters

animated

NO to disable animations for this batch
updates

The block that performs the relevant insert, delete, reload, or move operations.
completion

A completion handler block to execute when all of the operations are finished. This block takes a single Boolean parameter that contains the value YES if all of the related animations completed successfully or NO if they were interrupted. This parameter may be nil. If supplied, the block is run on the main thread.

Declared In

ASCollectionNode.h

– performBatchUpdates:completion:

Perform a batch of updates asynchronously, optionally disabling all animations in the batch. This method must be called from the main thread. The data source must be updated to reflect the changes before the update block completes.

- (void)performBatchUpdates:(nullable __attribute ( ( noescape ) ) void ( ^ ) ( ))updates completion:(nullable void ( ^ ) ( BOOL finished ))completion

Parameters

updates

The block that performs the relevant insert, delete, reload, or move operations.
completion

A completion handler block to execute when all of the operations are finished. This block takes a single Boolean parameter that contains the value YES if all of the related animations completed successfully or NO if they were interrupted. This parameter may be nil. If supplied, the block is run on the main thread.

Declared In

ASCollectionNode.h

– waitUntilAllUpdatesAreCommitted

Blocks execution of the main thread until all section and item updates are committed to the view. This method must be called from the main thread.

- (void)waitUntilAllUpdatesAreCommitted

Declared In

ASCollectionNode.h

– insertSections:

Inserts one or more sections.

- (void)insertSections:(NSIndexSet *)sections

Parameters

sections

An index set that specifies the sections to insert.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– deleteSections:

Deletes one or more sections.

- (void)deleteSections:(NSIndexSet *)sections

Parameters

sections

An index set that specifies the sections to delete.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– reloadSections:

Reloads the specified sections.

- (void)reloadSections:(NSIndexSet *)sections

Parameters

sections

An index set that specifies the sections to reload.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– moveSection:toSection:

Moves a section to a new location.

- (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection

Parameters

section

The index of the section to move.
newSection

The index that is the destination of the move for the section.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– insertItemsAtIndexPaths:

Inserts items at the locations identified by an array of index paths.

- (void)insertItemsAtIndexPaths:(NSArray<NSIndexPath*> *)indexPaths

Parameters

indexPaths

An array of NSIndexPath objects, each representing an item index and section index that together identify an item.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– deleteItemsAtIndexPaths:

Deletes the items specified by an array of index paths.

- (void)deleteItemsAtIndexPaths:(NSArray<NSIndexPath*> *)indexPaths

Parameters

indexPaths

An array of NSIndexPath objects identifying the items to delete.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– reloadItemsAtIndexPaths:

Reloads the specified items.

- (void)reloadItemsAtIndexPaths:(NSArray<NSIndexPath*> *)indexPaths

Parameters

indexPaths

An array of NSIndexPath objects identifying the items to reload.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– moveItemAtIndexPath:toIndexPath:

Moves the item at a specified location to a destination location.

- (void)moveItemAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath

Parameters

indexPath

The index path identifying the item to move.
newIndexPath

The index path that is the destination of the move for the item.

Discussion

This method must be called from the main thread. The data source must be updated to reflect the changes before this method is called.

Declared In

ASCollectionNode.h

– reloadDataWithCompletion:

Reload everything from scratch, destroying the working range and all cached nodes.

- (void)reloadDataWithCompletion:(nullable void ( ^ ) ( ))completion

Parameters

completion

block to run on completion of asynchronous loading or nil. If supplied, the block is run on the main thread.

Discussion

Warning: This method is substantially more expensive than UICollectionView’s version.

Declared In

ASCollectionNode.h

– reloadData

Reload everything from scratch, destroying the working range and all cached nodes.

- (void)reloadData

Discussion

Warning: This method is substantially more expensive than UICollectionView’s version.

Declared In

ASCollectionNode.h

– relayoutItems

Triggers a relayout of all nodes.

- (void)relayoutItems

Discussion

This method invalidates and lays out every cell node in the collection view.

Declared In

ASCollectionNode.h

  indexPathsForSelectedItems

The index paths of the selected items, or @c nil if no items are selected.

@property (nonatomic, readonly, nullable) NSArray<NSIndexPath*> *indexPathsForSelectedItems

Declared In

ASCollectionNode.h

– selectItemAtIndexPath:animated:scrollPosition:

Selects the item at the specified index path and optionally scrolls it into view. If the allowsSelection property is NO, calling this method has no effect. If there is an existing selection with a different index path and the allowsMultipleSelection property is NO, calling this method replaces the previous selection. This method does not cause any selection-related delegate methods to be called.

- (void)selectItemAtIndexPath:(nullable NSIndexPath *)indexPath animated:(BOOL)animated scrollPosition:(UICollectionViewScrollPosition)scrollPosition

Parameters

indexPath

The index path of the item to select. Specifying nil for this parameter clears the current selection.
animated

Specify YES to animate the change in the selection or NO to make the change without animating it.
scrollPosition

An option that specifies where the item should be positioned when scrolling finishes. For a list of possible values, see UICollectionViewScrollPosition.

Discussion

This method must be called from the main thread.

Declared In

ASCollectionNode.h

– deselectItemAtIndexPath:animated:

Deselects the item at the specified index. If the allowsSelection property is NO, calling this method has no effect. This method does not cause any selection-related delegate methods to be called.

- (void)deselectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated

Parameters

indexPath

The index path of the item to select. Specifying nil for this parameter clears the current selection.
animated

Specify YES to animate the change in the selection or NO to make the change without animating it.

Discussion

This method must be called from the main thread.

Declared In

ASCollectionNode.h

– numberOfItemsInSection:

Retrieves the number of items in the given section.

- (NSInteger)numberOfItemsInSection:(NSInteger)section

Parameters

section

The section.

Return Value

The number of items.

Declared In

ASCollectionNode.h

  numberOfSections

The number of sections.

@property (nonatomic, readonly) NSInteger numberOfSections

Declared In

ASCollectionNode.h

  visibleNodes

Similar to -visibleCells.

@property (nonatomic, readonly) NSArray<__kindofASCellNode*> *visibleNodes

Return Value

an array containing the nodes being displayed on screen. This must be called on the main thread.

Declared In

ASCollectionNode.h

– nodeForItemAtIndexPath:

Retrieves the node for the item at the given index path.

- (nullable __kindof ASCellNode *)nodeForItemAtIndexPath:(NSIndexPath *)indexPath

Parameters

indexPath

The index path of the requested item.

Return Value

The node for the given item, or @c nil if no item exists at the specified path.

Declared In

ASCollectionNode.h

– indexPathForNode:

Retrieve the index path for the item with the given node.

- (nullable NSIndexPath *)indexPathForNode:(ASCellNode *)cellNode

Parameters

cellNode

A node for an item in the collection node.

Return Value

The indexPath for this item.

Declared In

ASCollectionNode.h

  indexPathsForVisibleItems

Retrieve the index paths of all visible items.

@property (nonatomic, readonly) NSArray<NSIndexPath*> *indexPathsForVisibleItems

Return Value

an array containing the index paths of all visible items. This must be called on the main thread.

Declared In

ASCollectionNode.h

– indexPathForItemAtPoint:

Retrieve the index path of the item at the given point.

- (nullable NSIndexPath *)indexPathForItemAtPoint:(CGPoint)point

Parameters

point

The point of the requested item.

Return Value

The indexPath for the item at the given point. This must be called on the main thread.

Declared In

ASCollectionNode.h

– cellForItemAtIndexPath:

Retrieve the cell at the given index path.

- (nullable UICollectionViewCell *)cellForItemAtIndexPath:(NSIndexPath *)indexPath

Parameters

indexPath

The index path of the requested item.

Return Value

The cell for the given index path. This must be called on the main thread.

Declared In

ASCollectionNode.h

– contextForSection:

Retrieves the context object for the given section, as provided by the data source in the @c collectionNode:contextForSection: method.

- (nullable id<ASSectionContext>)contextForSection:(NSInteger)section

Parameters

section

The section to get the context for.

Return Value

The context object, or @c nil if no context was provided.

TODO: This method currently accepts @c section in the view index space, but it should be in the node index space. To get the context in the view index space (e.g. for subclasses of @c UICollectionViewLayout, the user will call the same method on @c ASCollectionView.

Declared In

ASCollectionNode.h