Swiftgram/AsyncDisplayKit/Details/ASIndexedNodeContext.mm
Michael Schneider 12e4e5b048 [Layout] Improve Layout System Abstraction (#2941)
* Improve Layout Abstraction

* Address naming comments

- Rename ASPrimitiveTraitEnvironment to ASTraitEnvironment
- Rename ASPrimitiveTraitCollectionPropagateDown to ASTraitCollectionPropagateDown
- Rename progagateNewPrimitiveTraitCollection: to propagateNewTraitCollection:
2017-02-03 13:04:20 -08:00

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//
// ASIndexedNodeContext.mm
// AsyncDisplayKit
//
// Created by Huy Nguyen on 2/28/16.
//
// 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/ASIndexedNodeContext.h>
#import <AsyncDisplayKit/ASCellNode+Internal.h>
#import <mutex>
@interface ASIndexedNodeContext ()
/// Required node block used to allocate a cell node. Nil after the first execution.
@property (nonatomic, strong) ASCellNodeBlock nodeBlock;
@end
@implementation ASIndexedNodeContext {
std::mutex _lock;
ASCellNode *_node;
}
- (instancetype)initWithNodeBlock:(ASCellNodeBlock)nodeBlock
indexPath:(NSIndexPath *)indexPath
supplementaryElementKind:(nullable NSString *)supplementaryElementKind
constrainedSize:(ASSizeRange)constrainedSize
environment:(id<ASTraitEnvironment>)environment
{
NSAssert(nodeBlock != nil && indexPath != nil, @"Node block and index path must not be nil");
self = [super init];
if (self) {
_nodeBlock = nodeBlock;
_indexPath = indexPath;
_supplementaryElementKind = [supplementaryElementKind copy];
_constrainedSize = constrainedSize;
_traitEnvironment = environment;
}
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! Index path: %@", _indexPath);
node = [[ASCellNode alloc] init];
}
node.cachedIndexPath = _indexPath;
node.supplementaryElementKind = _supplementaryElementKind;
node.owningNode = (ASDisplayNode *)_traitEnvironment;
ASTraitCollectionPropagateDown(node, [_traitEnvironment primitiveTraitCollection]);
_node = node;
}
return _node;
}
- (ASCellNode *)nodeIfAllocated
{
std::lock_guard<std::mutex> l(_lock);
return _node;
}
+ (NSArray<NSIndexPath *> *)indexPathsFromContexts:(NSArray<ASIndexedNodeContext *> *)contexts
{
NSMutableArray *result = [NSMutableArray arrayWithCapacity:contexts.count];
for (ASIndexedNodeContext *ctx in contexts) {
[result addObject:ctx.indexPath];
}
return result;
}
@end