AX: aria-describedby text can become stale after the targeted element…

… changes its subtree https://bugs.webkit.org/show_bug.cgi?id=273584 rdar://problem/127390465 Reviewed by Andres Gonzalez. When an object targeted by aria-describedby changes its subtree, we need to re-compute AXPropertyName::{AccessibilityText, ExtendedDescription} for the described object. We already did this for aria-labelledby relationships, so this patch hooks into the same method to check for describedby relationships too. * LayoutTests/accessibility/dynamic-aria-describedby-subtree-expected.txt: Added. * LayoutTests/accessibility/dynamic-aria-describedby-subtree.html: Added. * LayoutTests/platform/glib/TestExpectations: Skip new test. * LayoutTests/platform/ios/TestExpectations: Enable new test. * Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp: (WebCore::AXIsolatedTree::updateDependentProperties): Canonical link: https://commits.webkit.org/278318@main
WebKit · May 3, 2024 · 65862d8 · 65862d8
1 parent 53e1699
commit 65862d8
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diff --git a/LayoutTests/accessibility/dynamic-aria-describedby-subtree-expected.txt b/LayoutTests/accessibility/dynamic-aria-describedby-subtree-expected.txt
@@ -0,0 +1,11 @@
+This test ensures that we update an element's description when it's described-by changes subtree dynamically.
+
+PASS: accessibilityController.accessibleElementById('button').customContent === 'description: Always'
+PASS: accessibilityController.accessibleElementById('button').customContent === 'description: Sometimes Always'
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+Sometimes
+Always
+Press
diff --git a/LayoutTests/accessibility/dynamic-aria-describedby-subtree.html b/LayoutTests/accessibility/dynamic-aria-describedby-subtree.html
@@ -0,0 +1,32 @@
+<!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>
+
+<div id="tooltip" role="tooltip">
+  <div id="initially-hidden" style="display:none">Sometimes</div>Always
+</div>
+<button id="button" aria-describedby="tooltip">Press</button>
+
+<script>
+var output = "This test ensures that we update an element's description when it's described-by changes subtree dynamically.\n\n";
+
+if (window.accessibilityController) {
+    window.jsTestIsAsync = true;
+
+    output += expect("accessibilityController.accessibleElementById('button').customContent", "'description: Always'");
+    document.getElementById("initially-hidden").style.display = "block";
+    setTimeout(async function() {
+        output += await expectAsync("accessibilityController.accessibleElementById('button').customContent", "'description: Sometimes Always'");
+
+        debug(output);
+        finishJSTest();
+    }, 0);
+}
+</script>
+</body>
+</html>
+
diff --git a/LayoutTests/platform/glib/TestExpectations b/LayoutTests/platform/glib/TestExpectations
@@ -480,6 +480,9 @@ accessibility/shadow-dom-hit-test.html [ Skip ]
 # AccessibilityUIElement::isAttributeSupported needs to be updated to handle AXSelectedRows.
 accessibility/aria-table-selection-support.html [ Skip ]
 
+# AccessibilityUIElement::customContent is not implemented.
+accessibility/dynamic-aria-describedby-subtree.html [ Skip ]
+
 # Timing out since added in https://bugs.webkit.org/show_bug.cgi?id=263715
 accessibility/focus-inside-modal.html [ Skip ]
 # Timing out since added in https://bugs.webkit.org/show_bug.cgi?id=249283.

diff --git a/LayoutTests/platform/ios/TestExpectations b/LayoutTests/platform/ios/TestExpectations
@@ -2324,6 +2324,7 @@ accessibility/display-contents/element-roles.html [ Pass ]
 accessibility/display-contents/object-ordering.html [ Pass ]
 accessibility/display-contents/table.html [ Pass ]
 accessibility/display-flex-shadow-dom-accname.html [ Pass ]
+accessibility/dynamic-aria-describedby-subtree.html [ Pass ]
 accessibility/dynamic-text.html [ Pass ]
 accessibility/dynamically-ignored-canvas.html [ Pass ]
 accessibility/editable-webpage-focused-ui-element.html [ Pass ]

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp b/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp
@@ -771,14 +771,18 @@ void AXIsolatedTree::updateDependentProperties(AccessibilityObject& axObject)
 {
     ASSERT(isMainThread());
 
-    auto updateLabeledObjects = [this] (const AccessibilityObject& label) {
-        auto labeledObjects = label.labelForObjects();
-        for (const auto& labeledObject : labeledObjects) {
+    auto updateRelatedObjects = [this] (const AccessibilityObject& object) {
+        for (const auto& labeledObject : object.labelForObjects()) {
             if (RefPtr axObject = downcast<AccessibilityObject>(labeledObject.get()))
                 queueNodeUpdate(axObject->objectID(), NodeUpdateOptions::nodeUpdate());
         }
+
+        for (const auto& describedByObject : object.descriptionForObjects()) {
+            if (RefPtr axObject = downcast<AccessibilityObject>(describedByObject.get()))
+                queueNodeUpdate(axObject->objectID(), { { AXPropertyName::AccessibilityText, AXPropertyName::ExtendedDescription } });
+        }
     };
-    updateLabeledObjects(axObject);
+    updateRelatedObjects(axObject);
 
     // When a row gains or loses cells, the column count of the table can change.
     bool updateTableAncestorColumns = is<AccessibilityTableRow>(axObject);
@@ -798,7 +802,7 @@ void AXIsolatedTree::updateDependentProperties(AccessibilityObject& axObject)
             break;
         }
 
-        updateLabeledObjects(*ancestor);
+        updateRelatedObjects(*ancestor);
     }
 }