Swiftgram/AsyncDisplayKit/Layout/ASOverlayLayoutNode.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 "ASOverlayLayoutNode.h"
#import "ASAssert.h"
#import "ASBaseDefines.h"
#import "ASLayoutNodeSubclass.h"
@implementation ASOverlayLayoutNode
{
ASLayoutNode *_overlay;
ASLayoutNode *_node;
}
+ (instancetype)newWithNode:(ASLayoutNode *)node overlay:(ASLayoutNode *)overlay
{
ASOverlayLayoutNode *n = [super new];
if (n) {
ASDisplayNodeAssertNotNil(node, @"Node that will be overlayed on shouldn't be nil");
n->_overlay = overlay;
n->_node = node;
}
return n;
}
+ (instancetype)new
{
ASDISPLAYNODE_NOT_DESIGNATED_INITIALIZER();
}
/**
First layout the contents, then fit the overlay on top of it.
*/
- (ASLayout *)calculateLayoutThatFits:(ASSizeRange)constrainedSize
{
ASLayout *contentsLayout = [_node calculateLayoutThatFits:constrainedSize];
NSMutableArray *layoutChildren = [NSMutableArray arrayWithObject:[ASLayoutChild newWithPosition:{0, 0} layout:contentsLayout]];
if (_overlay) {
ASLayout *overlayLayout = [_overlay calculateLayoutThatFits:{contentsLayout.size, contentsLayout.size}];
[layoutChildren addObject:[ASLayoutChild newWithPosition:{0, 0} layout:overlayLayout]];
}
return [ASLayout newWithNode:self size:contentsLayout.size children:layoutChildren];
}
@end