react-native/ReactKit/Modules/RCTUIManager.h

// Copyright 2004-present Facebook. All Rights Reserved.

#import <UIKit/UIKit.h>

#import "RCTBridge.h"
#import "RCTBridgeModule.h"
#import "RCTInvalidating.h"
#import "RCTViewManager.h"

@class RCTRootView;

@protocol RCTScrollableProtocol;

/**
 * The RCTUIManager is the module responsible for updating the view hierarchy.
 */
@interface RCTUIManager : NSObject <RCTBridgeModule, RCTInvalidating>

@property (nonatomic, weak) id<RCTScrollableProtocol> mainScrollView;

/**
 * Allows native environment code to respond to "the main scroll view" events.
 * see `RCTUIManager`'s `setMainScrollViewTag`.
 */
@property (nonatomic, readwrite, weak) id<UIScrollViewDelegate> nativeMainScrollDelegate;

/**
 * Register a root view with the RCTUIManager. Theoretically, a single manager
 * can support multiple root views, however this feature is not currently exposed
 * and may eventually be removed.
 */
- (void)registerRootView:(RCTRootView *)rootView;

/**
 * Schedule a block to be executed on the UI thread. Useful if you need to execute
 * view logic after all currently queued view updates have completed.
 */
- (void)addUIBlock:(RCTViewManagerUIBlock)block;

/**
 * The view that is currently first responder, according to the JS context.
 */
+ (UIView *)JSResponder;

@end

/**
 * This category makes the current RCTUIManager instance available via the
 * RCTBridge, which is useful for RCTBridgeModules or RCTViewManagers that
 * need to access the RCTUIManager.
 */
@interface RCTBridge (RCTUIManager)

@property (nonatomic, readonly) RCTUIManager *uiManager;

@end