Swiftgram/Source/Details/ASCollectionElement.mm
Adlai Holler 83111de0cc Add first-pass view model support to collection node. #trivial (#356)
* Add first-pass view model support for collection node. Much more to come!

* Address issues

* Update the gorram license header

* Dear lord
2017-06-12 16:50:33 -07:00

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//
// ASCollectionElement.mm
// Texture
//
// 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 /ASDK-Licenses directory of this source tree. An additional
// grant of patent rights can be found in the PATENTS file in the same directory.
//
// Modifications to this file made after 4/13/2017 are: Copyright (c) 2017-present,
// Pinterest, Inc. Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
#import <AsyncDisplayKit/ASCollectionElement.h>
#import <AsyncDisplayKit/ASCellNode+Internal.h>
#import <mutex>
@interface ASCollectionElement ()
/// Required node block used to allocate a cell node. Nil after the first execution.
@property (nonatomic, strong) ASCellNodeBlock nodeBlock;
@end
@implementation ASCollectionElement {
std::mutex _lock;
ASCellNode *_node;
}
- (instancetype)initWithViewModel:(id)viewModel
nodeBlock:(ASCellNodeBlock)nodeBlock
supplementaryElementKind:(NSString *)supplementaryElementKind
constrainedSize:(ASSizeRange)constrainedSize
owningNode:(id<ASRangeManagingNode>)owningNode
traitCollection:(ASPrimitiveTraitCollection)traitCollection
{
NSAssert(nodeBlock != nil, @"Node block must not be nil");
self = [super init];
if (self) {
_viewModel = viewModel;
_nodeBlock = nodeBlock;
_supplementaryElementKind = [supplementaryElementKind copy];
_constrainedSize = constrainedSize;
_owningNode = owningNode;
_traitCollection = traitCollection;
}
return self;
}
- (ASCellNode *)node
{
std::lock_guard<std::mutex> l(_lock);
if (_nodeBlock != nil) {
ASCellNode *node = _nodeBlock();
_nodeBlock = nil;
if (node == nil) {
ASDisplayNodeFailAssert(@"Node block returned nil node!");
node = [[ASCellNode alloc] init];
}
node.owningNode = _owningNode;
node.collectionElement = self;
ASTraitCollectionPropagateDown(node, _traitCollection);
node.viewModel = _viewModel;
_node = node;
}
return _node;
}
- (ASCellNode *)nodeIfAllocated
{
std::lock_guard<std::mutex> l(_lock);
return _node;
}
- (void)setTraitCollection:(ASPrimitiveTraitCollection)traitCollection
{
ASCellNode *nodeIfNeedsPropagation;
{
std::lock_guard<std::mutex> l(_lock);
if (! ASPrimitiveTraitCollectionIsEqualToASPrimitiveTraitCollection(_traitCollection, traitCollection)) {
_traitCollection = traitCollection;
nodeIfNeedsPropagation = _node;
}
}
if (nodeIfNeedsPropagation != nil) {
ASTraitCollectionPropagateDown(nodeIfNeedsPropagation, traitCollection);
}
}
@end