react-native-macos/React/Fabric/Utils/RNGenericDelegateSplitter.h

44 строки
1.8 KiB
Objective-C

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
/**
* General purpose implementation of Delegate Splitter (or Multicast) pattern which allows subscribing multiple
* `receiving` objects to single `sending` object (which normally does not support that feature by itself).
*
* In the case where only one receiving object is registered, using Splitter has zero performance overhead because the
* receiver is being subscribed directly. In the case where more than one receiving objects are registered, using
* Splitter introduces some performance overhead.
*/
@interface RNGenericDelegateSplitter<DelegateT> : NSObject
@property (nonatomic, copy, nullable) void (^delegateUpdateBlock)(DelegateT _Nullable delegate);
/*
* Creates an object with a given block that will be used to connect a `sending` object with a given `receiving` object.
* The class calls the block every time after each delegate adding or removing procedure, and it calls it twice: the
* first time with `nil` and the second time with actual delegate. This is required to establish a proper connection
* between sending and receiving objects (to reset caches storing information about supported (or not) optional
* methods).
*/
- (instancetype)initWithDelegateUpdateBlock:(void (^)(DelegateT _Nullable delegate))block;
/*
* Adds and removes a delegate.
* The delegates will be called in order of registration.
* If a delegate returns a value, the value from the last call will be passed to the `sending` object.
*/
- (void)addDelegate:(DelegateT)delegate;
- (void)removeDelegate:(DelegateT)delegate;
@end
NS_ASSUME_NONNULL_END