AX: aria-hidden=true should be ignored on the body and html elements

https://bugs.webkit.org/show_bug.cgi?id=269523 rdar://123049663 Reviewed by Chris Fleizach. To prevent authors from hiding all content from assistive technologies, aria-hidden should not be respected on document root elements (`html`, `body`, or top-level `svg`s). w3c/aria#1880 * LayoutTests/accessibility/body-element-aria-hidden-expected.txt: Added. * LayoutTests/accessibility/body-element-aria-hidden.html: Added. * LayoutTests/accessibility/html-element-aria-hidden-expected.txt: Added. * LayoutTests/accessibility/html-element-aria-hidden.html: Added. * LayoutTests/platform/ios/TestExpectations: Enable new tests. * Source/WebCore/accessibility/AXCoreObject.h: * Source/WebCore/accessibility/AccessibilityObject.cpp: (WebCore::AccessibilityObject::isARIAHidden const): (WebCore::AccessibilityObject::tagName const): (WebCore::AccessibilityObject::setIsIgnoredFromParentDataForChild): * Source/WebCore/accessibility/AccessibilityObject.h: * Source/WebCore/accessibility/atspi/AccessibilityObjectAtspi.cpp: (WebCore::AccessibilityObjectAtspi::attributes const): * Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp: (WebCore::AXIsolatedObject::tagName const): Deleted. * Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h:
JonWBedard · Apr 15, 2024 · 6cedd71 · 6cedd71
1 parent 993b286
commit 6cedd71
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Showing 11 changed files with 74 additions and 17 deletions.
diff --git a/LayoutTests/accessibility/body-element-aria-hidden-expected.txt b/LayoutTests/accessibility/body-element-aria-hidden-expected.txt
@@ -0,0 +1,8 @@
+This test ensures that aria-hidden='true' is not respected on the body element.
+
+PASS: accessibilityController.accessibleElementById('button').role.toLowerCase().includes('button') === true
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+Submit
diff --git a/LayoutTests/accessibility/body-element-aria-hidden.html b/LayoutTests/accessibility/body-element-aria-hidden.html
@@ -0,0 +1,21 @@
+<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
+<html>
+<head>
+<script src="../resources/accessibility-helper.js"></script>
+<script src="../resources/js-test.js"></script>
+</head>
+<body aria-hidden="true">
+
+<button id="button">Submit</button>
+
+<script>
+var output = "This test ensures that aria-hidden='true' is not respected on the body element.\n\n";
+
+if (window.accessibilityController) {
+    output += expect("accessibilityController.accessibleElementById('button').role.toLowerCase().includes('button')", "true");
+    debug(output);
+}
+</script>
+</body>
+</html>
+
diff --git a/LayoutTests/accessibility/html-element-aria-hidden-expected.txt b/LayoutTests/accessibility/html-element-aria-hidden-expected.txt
@@ -0,0 +1,8 @@
+This test ensures that aria-hidden='true' is not respected on the html element.
+
+PASS: accessibilityController.accessibleElementById('button').role.toLowerCase().includes('button') === true
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+Submit
diff --git a/LayoutTests/accessibility/html-element-aria-hidden.html b/LayoutTests/accessibility/html-element-aria-hidden.html
@@ -0,0 +1,21 @@
+<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
+<html aria-hidden="true">
+<head>
+<script src="../resources/accessibility-helper.js"></script>
+<script src="../resources/js-test.js"></script>
+</head>
+<body>
+
+<button id="button">Submit</button>
+
+<script>
+var output = "This test ensures that aria-hidden='true' is not respected on the html element.\n\n";
+
+if (window.accessibilityController) {
+    output += expect("accessibilityController.accessibleElementById('button').role.toLowerCase().includes('button')", "true");
+    debug(output);
+}
+</script>
+</body>
+</html>
+
diff --git a/LayoutTests/platform/ios/TestExpectations b/LayoutTests/platform/ios/TestExpectations
@@ -2300,6 +2300,7 @@ accessibility/aria-braillelabel.html [ Pass ]
 accessibility/aria-brailleroledescription.html [ Pass ]
 accessibility/aria-checked-mixed-value.html [ Pass ]
 accessibility/aria-describedby-on-input.html [ Pass ]
+accessibility/body-element-aria-hidden.html [ Pass ]
 accessibility/display-contents/aria-hidden.html [ Pass ]
 accessibility/aria-multiline.html [ Pass ]
 accessibility/aria-readonly-updates-after-dynamic-change.html [ Pass ]
@@ -2325,6 +2326,7 @@ accessibility/empty-text-under-element-cached.html [ Pass ]
 accessibility/heading-level.html [ Pass ]
 accessibility/hidden-label.html [ Pass ]
 accessibility/hidden-slot.html [ Pass ]
+accessibility/html-element-aria-hidden.html [ Pass ]
 accessibility/html5-required-attribute.html [ Pass ]
 accessibility/iframe-tree-update-with-dirty-layout.html [ Pass ]
 accessibility/iframe-with-role.html [ Pass ]

diff --git a/Source/WebCore/accessibility/AXCoreObject.h b/Source/WebCore/accessibility/AXCoreObject.h
@@ -1272,7 +1272,6 @@ class AXCoreObject : public ThreadSafeRefCountedAndCanMakeThreadSafeWeakPtr<AXCo
     bool isAncestorOfObject(const AXCoreObject*) const;
 
     virtual String nameAttribute() const = 0;
-    virtual AtomString tagName() const = 0;
 
     virtual std::optional<SimpleRange> simpleRange() const = 0;
     virtual VisiblePositionRange visiblePositionRange() const = 0;

diff --git a/Source/WebCore/accessibility/AccessibilityObject.cpp b/Source/WebCore/accessibility/AccessibilityObject.cpp
@@ -3987,12 +3987,19 @@ bool AccessibilityObject::isARIAHidden() const
         return false;
 
     auto* node = this->node();
+    auto* element = dynamicDowncast<Element>(node);
+    AtomString tag = element ? element->localName() : nullAtom();
+    // https://github.com/w3c/aria/pull/1880
+    // To prevent authors from hiding all content from assistive technology users, do not respect
+    // aria-hidden on html, body, or document-root svg elements.
+    if (tag == bodyTag || tag == htmlTag || (tag == SVGNames::svgTag && !element->parentNode()))
+        return false;
+
     if (auto* assignedSlot = node ? node->assignedSlot() : nullptr) {
         if (equalLettersIgnoringASCIICase(assignedSlot->attributeWithDefaultARIA(aria_hiddenAttr), "true"_s))
             return true;
     }
-
-    return equalLettersIgnoringASCIICase(getAttribute(aria_hiddenAttr), "true"_s);
+    return element && equalLettersIgnoringASCIICase(element->attributeWithDefaultARIA(aria_hiddenAttr), "true"_s);
 }
 
 // ARIA component of hidden definition.
@@ -4174,10 +4181,8 @@ AccessibilityObject* AccessibilityObject::radioGroupAncestor() const
 
 AtomString AccessibilityObject::tagName() const
 {
-    if (Element* element = this->element())
-        return element->localName();
-
-    return nullAtom();
+    auto* element = this->element();
+    return element ? element->localName() : nullAtom();
 }
 
 bool AccessibilityObject::isStyleFormatGroup() const
@@ -4441,7 +4446,7 @@ void AccessibilityObject::setIsIgnoredFromParentDataForChild(AccessibilityObject
 
     AccessibilityIsIgnoredFromParentData result = AccessibilityIsIgnoredFromParentData(this);
     if (!m_isIgnoredFromParentData.isNull()) {
-        result.isAXHidden = (m_isIgnoredFromParentData.isAXHidden || equalLettersIgnoringASCIICase(child->getAttribute(aria_hiddenAttr), "true"_s)) && !child->isFocused();
+        result.isAXHidden = (m_isIgnoredFromParentData.isAXHidden || child->isARIAHidden());
         result.isPresentationalChildOfAriaRole = m_isIgnoredFromParentData.isPresentationalChildOfAriaRole || ariaRoleHasPresentationalChildren();
         result.isDescendantOfBarrenParent = m_isIgnoredFromParentData.isDescendantOfBarrenParent || !canHaveChildren();
     } else {

diff --git a/Source/WebCore/accessibility/AccessibilityObject.h b/Source/WebCore/accessibility/AccessibilityObject.h
@@ -543,7 +543,7 @@ class AccessibilityObject : public AXCoreObject, public CanMakeWeakPtr<Accessibi
     String nameAttribute() const final;
     int getIntegralAttribute(const QualifiedName&) const;
     bool hasTagName(const QualifiedName&) const;
-    AtomString tagName() const override;
+    AtomString tagName() const;
     bool hasDisplayContents() const;
 
     std::optional<SimpleRange> simpleRange() const override;

diff --git a/Source/WebCore/accessibility/atspi/AccessibilityObjectAtspi.cpp b/Source/WebCore/accessibility/atspi/AccessibilityObjectAtspi.cpp
@@ -864,7 +864,7 @@ HashMap<String, String> AccessibilityObjectAtspi::attributes() const
 
     RefPtr liveObject = dynamicDowncast<AccessibilityObject>(m_coreObject);
 
-    String tagName = m_coreObject->tagName();
+    String tagName = liveObject->tagName();
     if (!tagName.isEmpty())
         map.add("tag"_s, tagName);
 

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp b/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp
@@ -1377,12 +1377,6 @@ void AXIsolatedObject::decrement()
     });
 }
 
-AtomString AXIsolatedObject::tagName() const
-{
-    ASSERT_NOT_REACHED();
-    return AtomString();
-}
-
 bool AXIsolatedObject::isAccessibilityRenderObject() const
 {
     ASSERT_NOT_REACHED();

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h b/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h
@@ -338,7 +338,6 @@ class AXIsolatedObject final : public AXCoreObject {
     std::optional<AccessibilityChildrenVector> selectedChildren() final;
     void setSelectedChildren(const AccessibilityChildrenVector&) final;
     AccessibilityChildrenVector visibleChildren() final { return tree()->objectsForIDs(vectorAttributeValue<AXID>(AXPropertyName::VisibleChildren)); }
-    AtomString tagName() const final;
     void setChildrenIDs(Vector<AXID>&&);
     void updateChildrenIfNecessary() final;
     bool isDetachedFromParent() final;