[Accessibility] Do not exclude elements outside the window’s rect that are subviews of UIScrollView

Source/Details/_ASDisplayViewAccessiblity.mm

@@ -210,6 +210,17 @@ static void CollectAccessibilityElementsForContainer(ASDisplayNode *container, U
   [elements addObject:accessiblityElement];
 }
 
+/// Check if a view is a subviews of an UIScrollView. This is used to determine whether to enforce that
+/// accessibility elements must be on screen
+static BOOL recusivelyCheckSuperviewsForScrollView(UIView *view) {
+    if (!view) {
+        return NO;
+    } else if ([view isKindOfClass:[UIScrollView class]]) {
+        return YES;
+    }
+    return recusivelyCheckSuperviewsForScrollView(view.superview);
+}
+
 /// Collect all accessibliity elements for a given view and view node
 static void CollectAccessibilityElements(ASDisplayNode *node, NSMutableArray *elements)
 {
@@ -226,7 +237,6 @@ static void CollectAccessibilityElements(ASDisplayNode *node, NSMutableArray *el
   }));
 
   UIView *view = node.view;
-
   // If we don't have a window, let's just bail out
   if (!view.window) {
     return;
@@ -246,11 +256,13 @@ static void CollectAccessibilityElements(ASDisplayNode *node, NSMutableArray *el
   for (ASDisplayNode *subnode in node.subnodes) {
     // If a node is hidden or has an alpha of 0.0 we should not include it
     if (subnode.hidden || subnode.alpha == 0.0) {
-        continue;
+      continue;
     }
-    // If a subnode is outside of the view's window, exclude it
+
+    // If a subnode is outside of the view's window, exclude it UNLESS it is a subview of an UIScrollView.
+    // In this case UIKit will return the element even if it is outside of the window or the scrollView's visible rect (contentOffset + contentSize)
     CGRect nodeInWindowCoords = [node convertRect:subnode.frame toNode:nil];
-    if (!CGRectIntersectsRect(view.window.frame, nodeInWindowCoords)) {
+    if (!CGRectIntersectsRect(view.window.frame, nodeInWindowCoords) && !recusivelyCheckSuperviewsForScrollView(view)) {
       continue;
     }
 

Tests/ASDisplayViewAccessibilityTests.mm

@@ -20,6 +20,7 @@
 #import <AsyncDisplayKit/ASTextNode.h>
 #import <AsyncDisplayKit/ASConfiguration.h>
 #import <AsyncDisplayKit/ASConfigurationInternal.h>
+#import <AsyncDisplayKit/ASScrollNode.h>
 #import <AsyncDisplayKit/ASViewController.h>
 #import <OCMock/OCMock.h>
 #import "ASDisplayNodeTestsHelper.h"
@@ -382,6 +383,60 @@ - (void)testAccessibilityElementsNotInAppWindow {
   XCTAssertTrue([elements containsObject:partiallyOnScreenNodeY.view]);
 }
 
+- (void)testAccessibilityElementsNotInAppWindowButInScrollView {
+
+  UIWindow *window = [[UIWindow alloc] initWithFrame:CGRectMake(0, 0, 320, 568)];
+  ASScrollNode *node = [[ASScrollNode alloc] init];
+  node.automaticallyManagesSubnodes = YES;
+
+  ASViewController *vc = [[ASViewController alloc] initWithNode:node];
+  window.rootViewController = vc;
+  [window makeKeyAndVisible];
+  [window layoutIfNeeded];
+
+  CGSize windowSize = window.frame.size;
+  node.view.contentSize = CGSizeMake(window.frame.size.width, window.frame.size.height * 2.0);
+  ASTextNode *label = [[ASTextNode alloc] init];
+  label.attributedText = [[NSAttributedString alloc] initWithString:@"on screen"];
+  label.frame = CGRectMake(0, 0, 100, 20);
+
+  ASTextNode *partiallyOnScreenNodeY = [[ASTextNode alloc] init];
+  partiallyOnScreenNodeY.attributedText = [[NSAttributedString alloc] initWithString:@"partially on screen y"];
+  partiallyOnScreenNodeY.frame = CGRectMake(0, windowSize.height - 10, 100, 20);
+
+  ASTextNode *partiallyOnScreenNodeX = [[ASTextNode alloc] init];
+  partiallyOnScreenNodeX.attributedText = [[NSAttributedString alloc] initWithString:@"partially on screen x"];
+  partiallyOnScreenNodeX.frame = CGRectMake(windowSize.width - 10, 100, 100, 20);
+
+  ASTextNode *offScreenNodeY = [[ASTextNode alloc] init];
+  offScreenNodeY.attributedText = [[NSAttributedString alloc] initWithString:@"off screen y"];
+  offScreenNodeY.frame = CGRectMake(0, windowSize.height + 10, 100, 20);
+
+  ASTextNode *offScreenNodeX = [[ASTextNode alloc] init];
+  offScreenNodeX.attributedText = [[NSAttributedString alloc] initWithString:@"off screen x"];
+  offScreenNodeX.frame = CGRectMake(windowSize.width + 1, 200, 100, 20);
+
+  ASTextNode *offScreenNode = [[ASTextNode alloc] init];
+  offScreenNode.attributedText = [[NSAttributedString alloc] initWithString:@"off screen"];
+  offScreenNode.frame = CGRectMake(windowSize.width + 1, windowSize.height + 1, 100, 20);
+
+  [node addSubnode:label];
+  [node addSubnode:partiallyOnScreenNodeY];
+  [node addSubnode:partiallyOnScreenNodeX];
+  [node addSubnode:offScreenNodeY];
+  [node addSubnode:offScreenNodeX];
+  [node addSubnode:offScreenNode];
+
+  NSArray *elements = [node accessibilityElements];
+  XCTAssertTrue(elements.count == 6);
+  XCTAssertTrue([elements containsObject:label.view]);
+  XCTAssertTrue([elements containsObject:partiallyOnScreenNodeX.view]);
+  XCTAssertTrue([elements containsObject:partiallyOnScreenNodeY.view]);
+  XCTAssertTrue([elements containsObject:offScreenNodeY.view]);
+  XCTAssertTrue([elements containsObject:offScreenNodeX.view]);
+  XCTAssertTrue([elements containsObject:offScreenNode.view]);
+}
+
 - (void)testAccessibilitySort {
   ASDisplayNode *node1 = [[ASDisplayNode alloc] init];
   node1.accessibilityFrame = CGRectMake(0, 0, 50, 200);