Fabric: Implementaion of RCTScrollableProtocol for RCTScrollViewComponentView

Summary: We need this only until Fabric has own command-execution pipeline.

Reviewed By: mdvacca

Differential Revision: D15501202

fbshipit-source-id: aad77660ada43e429722b13d1da2f998a1726c73

React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.h

@@ -7,6 +7,7 @@
 
 #import <UIKit/UIKit.h>
 
+#import <React/RCTScrollableProtocol.h>
 #import <React/RCTViewComponentView.h>
 #import <React/RNGenericDelegateSplitter.h>
 
@@ -46,4 +47,13 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
+/*
+ * RCTScrollableProtocol is a protocol which RCTScrollViewManager uses to communicate with all kinds of `UIScrollView`s.
+ * Until Fabric has own command-execution pipeline we have to support that to some extent. The implementation shouldn't
+ * be perfect though because very soon we will migrate that to the new commands infra and get rid of this.
+ */
+@interface RCTScrollViewComponentView (ScrollableProtocol) <RCTScrollableProtocol>
+
+@end
+
 NS_ASSUME_NONNULL_END

React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm

@@ -218,3 +218,42 @@ using namespace facebook::react;
 }
 
 @end
+
+@implementation RCTScrollViewComponentView (ScrollableProtocol)
+
+- (CGSize)contentSize
+{
+  return _contentSize;
+}
+
+- (void)scrollToOffset:(CGPoint)offset
+{
+  [self scrollToOffset:offset animated:YES];
+}
+
+- (void)scrollToOffset:(CGPoint)offset animated:(BOOL)animated
+{
+  [self.scrollView setContentOffset:offset animated:animated];
+}
+
+- (void)scrollToEnd:(BOOL)animated
+{
+  // Not implemented.
+}
+
+- (void)zoomToRect:(CGRect)rect animated:(BOOL)animated
+{
+  // Not implemented.
+}
+
+- (void)addScrollListener:(NSObject<UIScrollViewDelegate> *)scrollListener
+{
+  [self.scrollViewDelegateSplitter addDelegate:scrollListener];
+}
+
+- (void)removeScrollListener:(NSObject<UIScrollViewDelegate> *)scrollListener
+{
+  [self.scrollViewDelegateSplitter removeDelegate:scrollListener];
+}
+
+@end