Add debug tool to get shadowView from UIView

Reviewed By: nicklockwood

Differential Revision: D3058618

fb-gh-sync-id: 8e6c0ad328fa767f43438c9461b8374d1279931b
shipit-source-id: 8e6c0ad328fa767f43438c9461b8374d1279931b

React/Modules/RCTUIManager.m

@@ -905,6 +905,10 @@ RCT_EXPORT_METHOD(createView:(nonnull NSNumber *)reactTag
         [uiManager->_bridgeTransactionListeners addObject:view];
       }
       ((NSMutableDictionary<NSNumber *, UIView *> *)viewRegistry)[reactTag] = view;
+
+#if RCT_DEV
+      [view _DEBUG_setReactShadowView:shadowView];
+#endif
     }
   }];
 }

React/Views/UIView+React.h

@@ -9,6 +9,8 @@
 
 #import <UIKit/UIKit.h>
 
+@class RCTShadowView;
+
 #import "RCTComponent.h"
 
 //TODO: let's try to eliminate this category if possible
@@ -49,4 +51,11 @@
 - (void)reactDidMakeFirstResponder;
 - (BOOL)reactRespondsToTouch:(UITouch *)touch;
 
+/**
+ Tools for debugging
+ */
+#if RCT_DEV
+@property (nonatomic, strong, setter=_DEBUG_setReactShadowView:) RCTShadowView *_DEBUG_reactShadowView;
+#endif
+
 @end

React/Views/UIView+React.m

@@ -13,6 +13,7 @@
 
 #import "RCTAssert.h"
 #import "RCTLog.h"
+#import "RCTShadowView.h"
 
 @implementation UIView (React)
 
@@ -26,6 +27,21 @@
   objc_setAssociatedObject(self, @selector(reactTag), reactTag, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
 }
 
+#if RCT_DEBUG
+
+- (RCTShadowView *)_DEBUG_reactShadowView
+{
+  return objc_getAssociatedObject(self, _cmd);
+}
+
+- (void)_DEBUG_setReactShadowView:(RCTShadowView *)shadowView
+{
+  // Use assign to avoid keeping the shadowView alive it if no longer exists
+  objc_setAssociatedObject(self, @selector(_DEBUG_reactShadowView), shadowView, OBJC_ASSOCIATION_ASSIGN);
+}
+
+#endif
+
 - (BOOL)isReactRootView
 {
   return RCTIsReactRootView(self.reactTag);