text: //
  //  ASCellNode.h
  //  Texture
  //
  //  Copyright (c) Facebook, Inc. and its affiliates.  All rights reserved.
  //  Changes after 4/13/2017 are: Copyright (c) Pinterest, Inc.  All rights reserved.
  //  Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
  //
  
  #ifndef MINIMAL_ASDK
  
  #import <AsyncDisplayKit/ASDisplayNode.h>
  
  NS_ASSUME_NONNULL_BEGIN
  
  @class ASCellNode, ASTextNode;
  @protocol ASRangeManagingNode;
  
  typedef NSUInteger ASCellNodeAnimation;
  
  typedef NS_ENUM(NSUInteger, ASCellNodeVisibilityEvent) {
    /**
     * Indicates a cell has just became visible
     */
    ASCellNodeVisibilityEventVisible,
    /**
     * Its position (determined by scrollView.contentOffset) has changed while at least 1px remains visible.
     * It is possible that 100% of the cell is visible both before and after and only its position has changed,
     * or that the position change has resulted in more or less of the cell being visible.
     * Use CGRectIntersect between cellFrame and scrollView.bounds to get this rectangle
     */
    ASCellNodeVisibilityEventVisibleRectChanged,
    /**
     * Indicates a cell is no longer visible
     */
    ASCellNodeVisibilityEventInvisible,
    /**
     * Indicates user has started dragging the visible cell
     */
    ASCellNodeVisibilityEventWillBeginDragging,
    /**
     * Indicates user has ended dragging the visible cell
     */
    ASCellNodeVisibilityEventDidEndDragging,
  };
  
  /**
   * Generic cell node.  Subclass this instead of `ASDisplayNode` to use with `ASTableView` and `ASCollectionView`.
   
   * @note When a cell node is contained inside a collection view (or table view),
   * calling `-setNeedsLayout` will also notify the collection on the main thread
   * so that the collection can update its item layout if the cell's size changed.
   */
  @interface ASCellNode : ASDisplayNode
  
  /**
   * @abstract When enabled, ensures that the cell is completely displayed before allowed onscreen.
   *
   * @default NO
   * @discussion Normally, ASCellNodes are preloaded and have finished display before they are onscreen.
   * However, if the Table or Collection's rangeTuningParameters are set to small values (or 0),
   * or if the user is scrolling rapidly on a slow device, it is possible for a cell's display to
   * be incomplete when it becomes visible.
   *
   * In this case, normally placeholder states are shown and scrolling continues uninterrupted.
   * The finished, drawn content is then shown as soon as it is ready.
   *
   * With this property set to YES, the main thread will be blocked until display is complete for
   * the cell.  This is more similar to UIKit, and in fact makes AsyncDisplayKit scrolling visually
   * indistinguishable from UIKit's, except being faster.
   *
   * Using this option does not eliminate all of the performance advantages of AsyncDisplayKit.
   * Normally, a cell has been preloading and is almost done when it reaches the screen, so the
   * blocking time is very short.  If the rangeTuningParameters are set to 0, still this option
   * outperforms UIKit: while the main thread is waiting, subnode display executes concurrently.
   */
  @property BOOL neverShowPlaceholders;
  
  /*
   * The kind of supplementary element this node represents, if any.
   *
   * @return The supplementary element kind, or @c nil if this node does not represent a supplementary element.
   */
  @property (nullable, copy, readonly) NSString *supplementaryElementKind;
  
  /*
   * The layout attributes currently assigned to this node, if any.
   *
   * @discussion This property is useful because it is set before @c collectionView:willDisplayNode:forItemAtIndexPath:
   *   is called, when the node is not yet in the hierarchy and its frame cannot be converted to/from other nodes. Instead
   *   you can use the layout attributes object to learn where and how the cell will be displayed.
   */
  @property (nullable, copy, readonly) UICollectionViewLayoutAttributes *layoutAttributes;
  
  /**
   * A Boolean value that is synchronized with the underlying collection or tableView cell property.
   * Setting this value is equivalent to calling selectItem / deselectItem on the collection or table.
   */
  @property (getter=isSelected) BOOL selected;
  
  /**
   * A Boolean value that is synchronized with the underlying collection or tableView cell property.
   * Setting this value is equivalent to calling highlightItem / unHighlightItem on the collection or table.
   */
  @property (getter=isHighlighted) BOOL highlighted;
  
  /**
   * The current index path of this cell node, or @c nil if this node is
   * not a valid item inside a table node or collection node.
   */
  @property (nullable, copy, readonly) NSIndexPath *indexPath;
  
  /**
   * BETA: API is under development. We will attempt to provide an easy migration pathway for any changes.
   *
   * The view-model currently assigned to this node, if any.
   *
   * This property may be set off the main thread, but this method will never be invoked concurrently on the 
   */
  @property (nullable) id nodeModel;
  
  /**
   * Asks the node whether it can be updated to the given node model.
   *
   * The default implementation returns YES if the class matches that of the current view-model.
   */
  - (BOOL)canUpdateToNodeModel:(id)nodeModel;
  
  /**
   * The backing view controller, or @c nil if the node wasn't initialized with backing view controller
   * @note This property must be accessed on the main thread.
   */
  @property (nullable, nonatomic, readonly) UIViewController *viewController;
  
  
  /**
   * The table- or collection-node that this cell is a member of, if any.
   */
  @property (nullable, weak, readonly) id<ASRangeManagingNode> owningNode;
  
  /*
   * ASCellNode must forward touch events in order for UITableView and UICollectionView tap handling to work. Overriding
   * these methods (e.g. for highlighting) requires the super method be called.
   */
  - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
  - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
  - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
  - (void)touchesCancelled:(nullable NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
  
  /** 
   * Called by the system when ASCellNode is used with an ASCollectionNode.  It will not be called by ASTableNode.
   * When the UICollectionViewLayout object returns a new UICollectionViewLayoutAttributes object, the corresponding ASCellNode will be updated.
   * See UICollectionViewCell's applyLayoutAttributes: for a full description.
  */
  - (void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes;
  
  /**
   * @abstract Initializes a cell with a given view controller block.
   *
   * @param viewControllerBlock The block that will be used to create the backing view controller.
   * @param didLoadBlock The block that will be called after the view controller's view is loaded.
   *
   * @return An ASCellNode created using the root view of the view controller provided by the viewControllerBlock.
   * The view controller's root view is resized to match the calculated size produced during layout.
   *
   */
  - (instancetype)initWithViewControllerBlock:(ASDisplayNodeViewControllerBlock)viewControllerBlock didLoadBlock:(nullable ASDisplayNodeDidLoadBlock)didLoadBlock;
  
  /**
   * @abstract Notifies the cell node of certain visibility events, such as changing visible rect.
   *
   * @warning In cases where an ASCellNode is used as a plain node – i.e. not returned from the
   *   nodeBlockForItemAtIndexPath/nodeForItemAtIndexPath data source methods – this method will
   *   deliver only the `Visible` and `Invisible` events, `scrollView` will be nil, and
   *   `cellFrame` will be the zero rect.
   */
  - (void)cellNodeVisibilityEvent:(ASCellNodeVisibilityEvent)event inScrollView:(nullable UIScrollView *)scrollView withCellFrame:(CGRect)cellFrame;
  
  #pragma mark - UITableViewCell specific passthrough properties
  
  /* @abstract The selection style when a tap on a cell occurs
   * @default UITableViewCellSelectionStyleDefault
   * ASTableView uses these properties when configuring UITableViewCells that host ASCellNodes.
   */
  @property UITableViewCellSelectionStyle selectionStyle;
  
  /* @abstract The focus style when a cell is focused
   * @default UITableViewCellFocusStyleDefault
   * ASTableView uses these properties when configuring UITableViewCells that host ASCellNodes.
   */
  @property UITableViewCellFocusStyle focusStyle;
  
  /* @abstract The view used as the background of the cell when it is selected.
   * ASTableView uses these properties when configuring UITableViewCells that host ASCellNodes.
   * ASCollectionView uses these properties when configuring UICollectionViewCells that host ASCellNodes.
   */
  @property (nullable) UIView *selectedBackgroundView;
  
  /* @abstract The view used as the background of the cell.
   * ASTableView uses these properties when configuring UITableViewCells that host ASCellNodes.
   * ASCollectionView uses these properties when configuring UICollectionViewCells that host ASCellNodes.
   */
  @property (nullable) UIView *backgroundView;
  
  /* @abstract The accessory type view on the right side of the cell. Please take care of your ASLayoutSpec so that doesn't overlay the accessoryView
   * @default UITableViewCellAccessoryNone
   * ASTableView uses these properties when configuring UITableViewCells that host ASCellNodes.
   */
  @property UITableViewCellAccessoryType accessoryType;
  
  /* @abstract The inset of the cell separator line
   * ASTableView uses these properties when configuring UITableViewCells that host ASCellNodes.
   */
  @property UIEdgeInsets separatorInset;
  
  @end
  
  @interface ASCellNode (Unavailable)
  
  - (instancetype)initWithLayerBlock:(ASDisplayNodeLayerBlock)viewBlock didLoadBlock:(nullable ASDisplayNodeDidLoadBlock)didLoadBlock NS_UNAVAILABLE;
  
  - (instancetype)initWithViewBlock:(ASDisplayNodeViewBlock)viewBlock didLoadBlock:(nullable ASDisplayNodeDidLoadBlock)didLoadBlock NS_UNAVAILABLE;
  
  - (void)setLayerBacked:(BOOL)layerBacked AS_UNAVAILABLE("ASCellNode does not support layer-backing, although subnodes may be layer-backed.");
  
  @end
  
  
  /**
   * Simple label-style cell node.  Read its source for an example of custom <ASCellNode>s.
   */
  @interface ASTextCellNode : ASCellNode
  
  /**
   * Initializes a text cell with given text attributes and text insets
   */
  - (instancetype)initWithAttributes:(NSDictionary *)textAttributes insets:(UIEdgeInsets)textInsets;
  
  /**
   * Text to display.
   */
  @property (nullable, copy) NSString *text;
  
  /**
   * A dictionary containing key-value pairs for text attributes. You can specify the font, text color, text shadow color, and text shadow offset using the keys listed in NSString UIKit Additions Reference.
   */
  @property (copy) NSDictionary<NSAttributedStringKey, id> *textAttributes;
  
  /**
   * The text inset or outset for each edge. The default value is 15.0 horizontal and 11.0 vertical padding.
   */
  @property UIEdgeInsets textInsets;
  
  /**
   * The text node used by this cell node.
   */
  @property (readonly) ASTextNode *textNode;
  
  @end
  
  NS_ASSUME_NONNULL_END
  
  #endif
  