ComponentKit/Core/ComponentTree/CKTreeNodeComponentKey.h

/*
 *  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 <Foundation/Foundation.h>

#import <ComponentKit/CKDefines.h>
#import <RenderCore/RCEqualityHelpers.h>

#if CK_NOT_SWIFT

#include <vector>

NS_ASSUME_NONNULL_BEGIN

struct CKTreeNodeComponentKey {
  constexpr static NSUInteger const kCounterParentOffset = 0;
  constexpr static NSUInteger const kCounterOwnerOffset = 1;

  enum class Type {
    owner,
    parent,
  };

  const char *componentTypeName;
  NSUInteger counter;
  _Nullable id identifier;
  std::vector<id<NSObject>> keys;

  auto operator==(const CKTreeNodeComponentKey& other) const -> bool {
    return componentTypeName == other.componentTypeName &&
      counter == other.counter &&
      RCObjectIsEqual(identifier, other.identifier) &&
      RCKeyVectorsEqual(keys, other.keys);
  }

  auto type() const -> Type {
    return counter % 2 == kCounterParentOffset ? Type::parent : Type::owner;
  }

  static auto startOffsetForType(Type type) -> NSUInteger {
    switch (type) {
      case Type::owner:
        return kCounterOwnerOffset;
      case Type::parent:
        return kCounterParentOffset;
    }
  }
};

@class CKTreeNode;

struct CKTreeNodeComponentKeyToNode {
  CKTreeNodeComponentKey key;
  CKTreeNode *node;
};

NS_ASSUME_NONNULL_END

#endif