Peter 9bc996374f Add 'submodules/AsyncDisplayKit/' from commit '02bedc12816e251ad71777f9d2578329b6d2bef6'
git-subtree-dir: submodules/AsyncDisplayKit
git-subtree-mainline: d06f423e0ed3df1fed9bd10d79ee312a9179b632
git-subtree-split: 02bedc12816e251ad71777f9d2578329b6d2bef6
2019-06-11 18:42:43 +01:00

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2.6 KiB
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//
// ASOverlayLayoutSpec.mm
// Texture
//
// Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
// Changes after 4/13/2017 are: Copyright (c) Pinterest, Inc. All rights reserved.
// Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
//
#import <AsyncDisplayKit/ASOverlayLayoutSpec.h>
#import <AsyncDisplayKit/ASLayoutSpec+Subclasses.h>
#import <AsyncDisplayKit/ASAssert.h>
#import <AsyncDisplayKit/ASCollections.h>
static NSUInteger const kUnderlayChildIndex = 0;
static NSUInteger const kOverlayChildIndex = 1;
@implementation ASOverlayLayoutSpec
#pragma mark - Class
+ (instancetype)overlayLayoutSpecWithChild:(id<ASLayoutElement>)child overlay:(id<ASLayoutElement>)overlay NS_RETURNS_RETAINED
{
return [[self alloc] initWithChild:child overlay:overlay];
}
#pragma mark - Lifecycle
- (instancetype)initWithChild:(id<ASLayoutElement>)child overlay:(id<ASLayoutElement>)overlay
{
if (!(self = [super init])) {
return nil;
}
self.child = child;
self.overlay = overlay;
return self;
}
#pragma mark - Setter / Getter
- (void)setChild:(id<ASLayoutElement>)child
{
ASDisplayNodeAssertNotNil(child, @"Child that will be overlayed on shouldn't be nil");
[super setChild:child atIndex:kUnderlayChildIndex];
}
- (id<ASLayoutElement>)child
{
return [super childAtIndex:kUnderlayChildIndex];
}
- (void)setOverlay:(id<ASLayoutElement>)overlay
{
ASDisplayNodeAssertNotNil(overlay, @"Overlay cannot be nil");
[super setChild:overlay atIndex:kOverlayChildIndex];
}
- (id<ASLayoutElement>)overlay
{
return [super childAtIndex:kOverlayChildIndex];
}
#pragma mark - ASLayoutSpec
/**
First layout the contents, then fit the overlay on top of it.
*/
- (ASLayout *)calculateLayoutThatFits:(ASSizeRange)constrainedSize
restrictedToSize:(ASLayoutElementSize)size
relativeToParentSize:(CGSize)parentSize
{
ASLayout *contentsLayout = [self.child layoutThatFits:constrainedSize parentSize:parentSize];
contentsLayout.position = CGPointZero;
ASLayout *rawSublayouts[2];
int i = 0;
rawSublayouts[i++] = contentsLayout;
if (self.overlay) {
ASLayout *overlayLayout = [self.overlay layoutThatFits:ASSizeRangeMake(contentsLayout.size)
parentSize:contentsLayout.size];
overlayLayout.position = CGPointZero;
rawSublayouts[i++] = overlayLayout;
}
const auto sublayouts = [NSArray<ASLayout *> arrayByTransferring:rawSublayouts count:i];
return [ASLayout layoutWithLayoutElement:self size:contentsLayout.size sublayouts:sublayouts];
}
@end