Shuffle & Cleanup Stuff (#3080)

Source/Layout/ASStackLayoutElement.h

@@ -0,0 +1,74 @@
+//
+//  ASStackLayoutElement.h
+//  AsyncDisplayKit
+//
+//  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>
+
+#import <AsyncDisplayKit/ASStackLayoutDefines.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ *  Layout options that can be defined for an ASLayoutElement being added to a ASStackLayoutSpec.
+ */
+@protocol ASStackLayoutElement <NSObject>
+
+/**
+ * @abstract Additional space to place before this object in the stacking direction.
+ * Used when attached to a stack layout.
+ */
+@property (nonatomic, readwrite) CGFloat spacingBefore;
+
+/**
+ * @abstract Additional space to place after this object in the stacking direction.
+ * Used when attached to a stack layout.
+ */
+@property (nonatomic, readwrite) CGFloat spacingAfter;
+
+/**
+ * @abstract If the sum of childrens' stack dimensions is less than the minimum size, how much should this component grow?
+ * This value represents the "flex grow factor" and determines how much this component should grow in relation to any
+ * other flexible children.
+ */
+@property (nonatomic, readwrite) CGFloat flexGrow;
+
+/**
+ * @abstract If the sum of childrens' stack dimensions is greater than the maximum size, how much should this component shrink?
+ * This value represents the "flex shrink factor" and determines how much this component should shink in relation to
+ * other flexible children.
+ */
+@property (nonatomic, readwrite) CGFloat flexShrink;
+
+/**
+ * @abstract Specifies the initial size in the stack dimension for this object.
+ * Defaults to ASDimensionAuto.
+ * Used when attached to a stack layout.
+ */
+@property (nonatomic, readwrite) ASDimension flexBasis;
+
+/**
+ * @abstract Orientation of the object along cross axis, overriding alignItems.
+ * Defaults to ASStackLayoutAlignSelfAuto.
+ * Used when attached to a stack layout.
+ */
+@property (nonatomic, readwrite) ASStackLayoutAlignSelf alignSelf;
+
+/**
+ *  @abstract Used for baseline alignment. The distance from the top of the object to its baseline.
+ */
+@property (nonatomic, readwrite) CGFloat ascender;
+
+/**
+ *  @abstract Used for baseline alignment. The distance from the baseline of the object to its bottom.
+ */
+@property (nonatomic, readwrite) CGFloat descender;
+
+@end
+
+NS_ASSUME_NONNULL_END