Fix accessibilityElement accessibility frame

Summary:
Changelog: [internal]

`accessibilityElement.accessibilityFrame` returns CGRect in screen's coordinate space. Screen coordinate space changes whenever user scrolls. Therefore they have to be computed whenever on demand rather than precomputed.

Reviewed By: mdvacca

Differential Revision: D27118793

fbshipit-source-id: c48a2b9fc3f25b6ae797104371a2627193f4f79a

React/Fabric/Mounting/ComponentViews/Text/RCTAccessibilityElement.h

@@ -0,0 +1,16 @@
+/*
+ * 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
+
+@interface RCTAccessibilityElement : UIAccessibilityElement
+
+@end
+
+NS_ASSUME_NONNULL_END

React/Fabric/Mounting/ComponentViews/Text/RCTAccessibilityElement.mm

@@ -0,0 +1,18 @@
+/*
+ * 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 "RCTAccessibilityElement.h"
+
+@implementation RCTAccessibilityElement
+
+- (CGRect)accessibilityFrame
+{
+  UIView *container = (UIView *)self.accessibilityContainer;
+  return UIAccessibilityConvertFrameToScreenCoordinates(container.bounds, container);
+}
+
+@end

React/Fabric/Mounting/ComponentViews/Text/RCTParagraphComponentAccessibilityProvider.mm

@@ -13,6 +13,7 @@
 #import <react/renderer/textlayoutmanager/RCTTextLayoutManager.h>
 #import <react/renderer/textlayoutmanager/TextLayoutManager.h>
 
+#import "RCTAccessibilityElement.h"
 #import "RCTConversions.h"
 #import "RCTFabricComponentsPlugins.h"
 #import "RCTLocalizationProvider.h"
@@ -61,7 +62,8 @@ using namespace facebook::react;
     accessibilityLabel = RCTNSStringFromString(_attributedString.getString());
   }
   // add first element has the text for the whole textview in order to read out the whole text
-  UIAccessibilityElement *firstElement = [[UIAccessibilityElement alloc] initWithAccessibilityContainer:_view];
+  UIAccessibilityElement *firstElement =
+      [[RCTAccessibilityElement alloc] initWithAccessibilityContainer:_view.superview];
   firstElement.isAccessibilityElement = YES;
   firstElement.accessibilityTraits = UIAccessibilityTraitStaticText;
   firstElement.accessibilityLabel = accessibilityLabel;