Swiftgram/AsyncDisplayKit/ASCellNode.h

121 lines
4.6 KiB
Objective-C

/* 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.
*/
#import <AsyncDisplayKit/ASDisplayNode.h>
@class ASCellNode;
typedef NSUInteger ASCellNodeAnimation;
@protocol ASCellNodeDelegate <NSObject>
/**
* Notifies the delegate that the specified cell node has done a relayout that results in a new size.
* The notification is done on main thread.
*
* @param node A node informing the delegate about the relayout.
*
* @param newSize A new size that is resulted in the relayout.
*
* @param suggestedAnimation A constant that indicates how the delegate should animate. See UITableViewRowAnimation.
*/
- (void)node:(ASCellNode *)node didRelayoutToNewSize:(CGSize)newSize suggestedAnimation:(ASCellNodeAnimation)animation;
@end
/**
* Generic cell node. Subclass this instead of `ASDisplayNode` to use with `ASTableView` and `ASCollectionView`.
*/
@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
* indistinguishible 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 (nonatomic, assign) BOOL neverShowPlaceholders;
/*
* ASTableView uses these properties when configuring UITableViewCells that host ASCellNodes.
*/
//@property (atomic, retain) UIColor *backgroundColor;
@property (nonatomic) UITableViewCellSelectionStyle selectionStyle;
/*
* A Boolean value that indicates whether the node is selected.
*/
@property (nonatomic, assign) BOOL selected;
/*
* A Boolean value that indicates whether the node is highlighted.
*/
@property (nonatomic, assign) BOOL highlighted;
/*
* A delegate to be notified (on main thread) after a relayout that results in a new size.
*/
@property (nonatomic, weak) id<ASCellNodeDelegate> delegate;
/*
* A constant that is passed to the delegate to indicate how a relayout is to be animated.
*
* @see UITableViewRowAnimation
*/
@property (nonatomic, assign) ASCellNodeAnimation relayoutAnimation;
/*
* 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 *)touches withEvent:(UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event ASDISPLAYNODE_REQUIRES_SUPER;
/**
* Marks the node as needing layout. Convenience for use whether the view / layer is loaded or not. Safe to call from a background thread.
*
* If this node was measured, calling this method triggers an internal relayout: the calculated layout is invalidated,
* and the supernode is notified or (if this node is the root one) a full measurement pass is executed using the old constrained size.
*
* If the relayout causes a change in size, the delegate will be notified on main thread.
*
* This method can be called inside of an animation block (to animate all of the layout changes).
*/
- (void)setNeedsLayout;
@end
/**
* Simple label-style cell node. Read its source for an example of custom <ASCellNode>s.
*/
@interface ASTextCellNode : ASCellNode
/**
* Text to display.
*/
@property (nonatomic, copy) NSString *text;
@end