2015-08-12 16:55:12 -07:00

80 lines
2.6 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/ASDimension.h>
#import <AsyncDisplayKit/ASStackLayoutDefines.h>
@class ASLayout;
/**
* The ASLayoutable protocol declares a method for measuring the layout of an object. A class must implement the method
* so that instances of that class can be used to build layout trees. The protocol also provides information
* about how an object should be laid out within an ASStackLayoutSpec.
*/
@protocol ASLayoutable <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, should this object grow?
* Used when attached to a stack layout.
*/
@property (nonatomic, readwrite) BOOL flexGrow;
/**
* @abstract If the sum of childrens' stack dimensions is greater than the maximum size, should this object shrink?
* Used when attached to a stack layout.
*/
@property (nonatomic, readwrite) BOOL flexShrink;
/**
* @abstract Specifies the initial size in the stack dimension for this object.
* Default to ASRelativeDimensionUnconstrained.
* Used when attached to a stack layout.
*/
@property (nonatomic, readwrite) ASRelativeDimension flexBasis;
/**
* @abstract Orientation of the object along cross axis, overriding alignItems
* 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;
/**
* @abstract Calculate a layout based on given size range.
*
* @param constrainedSize The minimum and maximum sizes the receiver should fit in.
*
* @return An ASLayout instance defining the layout of the receiver and its children.
*/
- (ASLayout *)measureWithSizeRange:(ASSizeRange)constrainedSize;
@end