Swiftgram/AsyncDisplayKit/Layout/ASStaticLayoutSpec.mm

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/*
* 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 "ASStaticLayoutSpec.h"
#import "ASLayoutSpecUtilities.h"
#import "ASLayoutOptions.h"
#import "ASInternalHelpers.h"
#import "ASLayout.h"
#import "ASStaticLayoutable.h"
@implementation ASStaticLayoutSpec
+ (instancetype)staticLayoutSpecWithChildren:(NSArray *)children
{
return [[self alloc] initWithChildren:children];
}
- (instancetype)init
{
return [self initWithChildren:@[]];
}
- (instancetype)initWithChildren:(NSArray *)children
{
if (!(self = [super init])) {
return nil;
}
self.children = children;
return self;
}
- (ASLayout *)measureWithSizeRange:(ASSizeRange)constrainedSize
{
CGSize size = {
constrainedSize.max.width,
constrainedSize.max.height
};
NSMutableArray *sublayouts = [NSMutableArray arrayWithCapacity:self.children.count];
for (id<ASLayoutable> child in self.children) {
CGSize autoMaxSize = {
constrainedSize.max.width - child.layoutPosition.x,
constrainedSize.max.height - child.layoutPosition.y
};
ASSizeRange childConstraint = ASRelativeSizeRangeEqualToRelativeSizeRange(ASRelativeSizeRangeUnconstrained, child.sizeRange)
? ASSizeRangeMake({0, 0}, autoMaxSize)
: ASRelativeSizeRangeResolve(child.sizeRange, size);
ASLayout *sublayout = [child measureWithSizeRange:childConstraint];
sublayout.position = child.layoutPosition;
[sublayouts addObject:sublayout];
}
size.width = constrainedSize.min.width;
for (ASLayout *sublayout in sublayouts) {
size.width = MAX(size.width, sublayout.position.x + sublayout.size.width);
}
size.height = constrainedSize.min.height;
for (ASLayout *sublayout in sublayouts) {
size.height = MAX(size.height, sublayout.position.y + sublayout.size.height);
}
return [ASLayout layoutWithLayoutableObject:self
size:ASSizeRangeClamp(constrainedSize, size)
sublayouts:sublayouts];
}
- (void)setChild:(id<ASLayoutable>)child forIdentifier:(NSString *)identifier
{
ASDisplayNodeAssert(NO, @"ASStackLayoutSpec only supports setChildren");
}
- (id<ASLayoutable>)childForIdentifier:(NSString *)identifier
{
ASDisplayNodeAssert(NO, @"ASStackLayoutSpec only supports children");
return nil;
}
@end
@implementation ASStaticLayoutSpec (Debugging)
#pragma mark - ASLayoutableAsciiArtProtocol
- (NSString *)debugBoxString
{
return [ASLayoutSpec asciiArtStringForChildren:self.children parentName:[self asciiArtName]];
}
@end