Shuffle & Cleanup Stuff (#3080)

Source/ASContextTransitioning.h

@@ -0,0 +1,75 @@
+//
+//  ASContextTransitioning.h
+//  AsyncDisplayKit
+//
+//  Created by Levi McCallum on 2/4/16.
+//
+//  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/ASDimension.h>
+
+@class ASDisplayNode;
+@class ASLayout;
+
+NS_ASSUME_NONNULL_BEGIN
+
+extern NSString * const ASTransitionContextFromLayoutKey;
+extern NSString * const ASTransitionContextToLayoutKey;
+
+@protocol ASContextTransitioning <NSObject>
+
+/**
+ @abstract Defines if the given transition is animated
+ */
+- (BOOL)isAnimated;
+
+/**
+ * @abstract Retrieve either the "from" or "to" layout
+ */
+- (nullable ASLayout *)layoutForKey:(NSString *)key;
+
+/**
+ * @abstract Retrieve either the "from" or "to" constrainedSize
+ */
+- (ASSizeRange)constrainedSizeForKey:(NSString *)key;
+
+/**
+ * @abstract Retrieve the subnodes from either the "from" or "to" layout
+ */
+- (NSArray<ASDisplayNode *> *)subnodesForKey:(NSString *)key;
+
+/**
+ * @abstract Subnodes that have been inserted in the layout transition
+ */
+- (NSArray<ASDisplayNode *> *)insertedSubnodes;
+
+/**
+ * @abstract Subnodes that will be removed in the layout transition
+ */
+- (NSArray<ASDisplayNode *> *)removedSubnodes;
+
+/**
+ @abstract The frame for the given node before the transition began.
+ @discussion Returns CGRectNull if the node was not in the hierarchy before the transition.
+ */
+- (CGRect)initialFrameForNode:(ASDisplayNode *)node;
+
+/**
+ @abstract The frame for the given node when the transition completes.
+ @discussion Returns CGRectNull if the node is no longer in the hierarchy after the transition.
+ */
+- (CGRect)finalFrameForNode:(ASDisplayNode *)node;
+
+/**
+ @abstract Invoke this method when the transition is completed in `animateLayoutTransition:`
+ @discussion Passing NO to `didComplete` will set the original layout as the new layout.
+ */
+- (void)completeTransition:(BOOL)didComplete;
+
+@end
+
+NS_ASSUME_NONNULL_END