y nAX: Move selectedTextRange off of the main-thread

https://bugs.webkit.org/show_bug.cgi?id=263940 rdar://117568720 Reviewed by Andres Gonzalez. We currently use the main thread to get the selectedTextRange when in isolated tree mode. In the effort to completely sever ITM, this should be cached to be served on the AX thread. This patch caches that value on text input objects, and updates the property every time text selection changes. This update is debounced to account for text selection in-progress and minimize computation. * LayoutTests/accessibility/content-editable-as-textarea.html: * LayoutTests/accessibility/textbox-role-reports-selection.html: * Source/WebCore/accessibility/AXObjectCache.cpp: (WebCore::AXObjectCache::AXObjectCache): (WebCore::AXObjectCache::~AXObjectCache): (WebCore::AXObjectCache::postTextStateChangeNotification): (WebCore::AXObjectCache::updateIsolatedTree): (WebCore::AXObjectCache::selectedTextRangeTimerFired): * Source/WebCore/accessibility/AXObjectCache.h: * Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp: (WebCore::AXIsolatedObject::initializeProperties): (WebCore::AXIsolatedObject::selectedTextRange const): Deleted. * Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h: * Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp: (WebCore::AXIsolatedTree::updateNodeProperties): * Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h: * Source/WebCore/accessibility/mac/AXObjectCacheMac.mm: (WebCore::AXObjectCache::platformSelectedTextRangeDebounceInterval const): Canonical link: https://commits.webkit.org/270340@main
WebKit · Nov 7, 2023 · ae0dcb5 · ae0dcb5
1 parent e2dca80
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diff --git a/LayoutTests/accessibility/content-editable-as-textarea.html b/LayoutTests/accessibility/content-editable-as-textarea.html
@@ -57,12 +57,15 @@
         var sel = window.getSelection();
         sel.addRange(range);
 
-        testOutput += `Selected text range: ${textArea.selectedTextRange}\n`;
-        testOutput += `Selected text: ${textArea.stringAttributeValue("AXSelectedText")}\n`;
+        setTimeout(async () => {
+            await waitFor(() => textArea.selectedTextRange == "{0, 3}");
+            testOutput += `Selected text range: ${textArea.selectedTextRange}\n`;
+            testOutput += `Selected text: ${textArea.stringAttributeValue("AXSelectedText")}\n`;
 
-        // Send a value change.
-        document.getElementById("content").focus();
-        eventSender.keyDown(targetCharacter, []);
+            // Send a value change.
+            document.getElementById("content").focus();
+            eventSender.keyDown(targetCharacter, []);
+        }, 0);
     }
 </script>
 </body>

diff --git a/LayoutTests/accessibility/textbox-role-reports-selection.html b/LayoutTests/accessibility/textbox-role-reports-selection.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <script src="../resources/js-test.js"></script>
+<script src="../resources/accessibility-helper.js"></script>
 </head>
 <body>
 This tests that the AXSelection property is correctly reported for non-native text boxes.<br>
@@ -22,7 +23,7 @@
             debug("FAIL: " + actual + " should be " + expected + ", got " + actualValue + (message ? " (" + message + ")" : ""));
     }
 
-    function assertCorrectAXSelection(element, selection, message) {
+    async function assertCorrectAXSelection(element, selection, message) {
         element.focus();
         var selectionValues = /\{(\d+), (\d+)\}/.exec(selection);
         var selectionStart = eval(selectionValues[1]);
@@ -31,20 +32,28 @@
 
         window.getSelection().setBaseAndExtent(element.firstChild, selectionStart, element.firstChild, selectionEnd);
         var axElement = accessibilityController.focusedElement;
-        axSelection = axElement.selectedTextRange;
+        await waitFor(() => {
+            axSelection = axElement.selectedTextRange;
+            return axSelection == selection;
+        });
         assertEvaluatesTo("axSelection", selection, message);
     }
 
     if (window.testRunner && window.accessibilityController) {
+        window.jsTestIsAsync = true;
         var ariaTextBox = document.getElementById("ariaTextBox");
         var textLength = ariaTextBox.textContent.length;
-
-        assertCorrectAXSelection(ariaTextBox, "{0, 0}", "Collapsed selection at start");
-        assertCorrectAXSelection(ariaTextBox, "{" + textLength + ", 0}", "Collapsed selection at end");
-        assertCorrectAXSelection(ariaTextBox, "{15, 0}", "Collapsed selection in the middle");
-        assertCorrectAXSelection(ariaTextBox, "{15, 2}", "Non-collapsed selection in the middle");
-        assertCorrectAXSelection(ariaTextBox, "{0, 15}", "Non-collapsed selection at the start");
-        assertCorrectAXSelection(ariaTextBox, "{15, "+ (textLength - 15) + "}", "Non-collapsed selection at the end");
+
+        setTimeout(async () => {
+            await assertCorrectAXSelection(ariaTextBox, "{0, 0}", "Collapsed selection at start");
+            await assertCorrectAXSelection(ariaTextBox, "{" + textLength + ", 0}", "Collapsed selection at end");
+            await assertCorrectAXSelection(ariaTextBox, "{15, 0}", "Collapsed selection in the middle");
+            await assertCorrectAXSelection(ariaTextBox, "{15, 2}", "Non-collapsed selection in the middle");
+            await assertCorrectAXSelection(ariaTextBox, "{0, 15}", "Non-collapsed selection at the start");
+            await assertCorrectAXSelection(ariaTextBox, "{15, "+ (textLength - 15) + "}", "Non-collapsed selection at the end");
+
+            finishJSTest();
+        }, 0);
     }
 
 </script>

diff --git a/Source/WebCore/accessibility/AXObjectCache.cpp b/Source/WebCore/accessibility/AXObjectCache.cpp
@@ -244,6 +244,7 @@ AXObjectCache::AXObjectCache(Document& document)
 #if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
     , m_buildIsolatedTreeTimer(*this, &AXObjectCache::buildIsolatedTree)
     , m_geometryManager(AXGeometryManager::create(*this))
+    , m_selectedTextRangeTimer(*this, &AXObjectCache::selectedTextRangeTimerFired, platformSelectedTextRangeDebounceInterval())
 #endif
 {
     AXTRACE(makeString("AXObjectCache::AXObjectCache 0x"_s, hex(reinterpret_cast<uintptr_t>(this))));
@@ -279,6 +280,8 @@ AXObjectCache::~AXObjectCache()
         object->detach(AccessibilityDetachmentType::CacheDestroyed);
 
 #if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
+    m_selectedTextRangeTimer.stop();
+
     if (m_pageID) {
         if (auto tree = AXIsolatedTree::treeForPageID(*m_pageID))
             tree->setPageActivityState({ });
@@ -1997,6 +2000,12 @@ void AXObjectCache::postTextStateChangeNotification(AccessibilityObject* object,
     if (object) {
         const AXTextStateChangeIntent& newIntent = (intent.type == AXTextStateChangeTypeUnknown || (m_isSynchronizingSelection && m_textSelectionIntent.type != AXTextStateChangeTypeUnknown)) ? m_textSelectionIntent : intent;
         postTextStateChangePlatformNotification(object, newIntent, selection);
+
+#if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
+        m_lastDebouncedTextRangeObject = object->objectID();
+        if (!m_selectedTextRangeTimer.isActive())
+            m_selectedTextRangeTimer.restart();
+#endif
     }
 #if PLATFORM(MAC)
     onSelectedTextChanged(selection);
@@ -4200,6 +4209,9 @@ void AXObjectCache::updateIsolatedTree(const Vector<std::pair<RefPtr<Accessibili
         case AXPopoverTargetChanged:
             tree->updateNodeProperties(*notification.first, { AXPropertyName::SupportsExpanded, AXPropertyName::IsExpanded });
             break;
+        case AXSelectedTextChanged:
+            tree->updateNodeProperty(*notification.first, AXPropertyName::SelectedTextRange);
+            break;
         case AXSortDirectionChanged:
             tree->updateNodeProperty(*notification.first, AXPropertyName::SortDirection);
             break;
@@ -4877,6 +4889,25 @@ AXTextChange AXObjectCache::textChangeForEditType(AXTextEditType type)
 }
 #endif
 
+#if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
+void AXObjectCache::selectedTextRangeTimerFired()
+{
+    if (!accessibilityEnabled())
+        return;
+
+    m_selectedTextRangeTimer.stop();
+
+    if (m_lastDebouncedTextRangeObject.isValid()) {
+        for (auto* axObject = objectForID(m_lastDebouncedTextRangeObject); axObject; axObject = axObject->parentObject()) {
+            if (axObject->isTextControl())
+                postNotification(axObject, nullptr, AXSelectedTextChanged);
+        }
+    }
+
+    m_lastDebouncedTextRangeObject = { };
+}
+#endif
+
 } // namespace WebCore
 
 #endif // ENABLE(ACCESSIBILITY)
diff --git a/Source/WebCore/accessibility/AXObjectCache.h b/Source/WebCore/accessibility/AXObjectCache.h
@@ -586,6 +586,11 @@ class AXObjectCache : public CanMakeWeakPtr<AXObjectCache>, public CanMakeChecke
     bool enqueuePasswordValueChangeNotification(AccessibilityObject*);
     void passwordNotificationPostTimerFired();
 
+#if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
+    void selectedTextRangeTimerFired();
+    Seconds platformSelectedTextRangeDebounceInterval() const;
+#endif
+
     void deferRowspanChange(AccessibilityObject*);
     void handleChildrenChanged(AccessibilityObject&);
     void handleAllDeferredChildrenChanged();
@@ -707,6 +712,8 @@ class AXObjectCache : public CanMakeWeakPtr<AXObjectCache>, public CanMakeChecke
     Timer m_buildIsolatedTreeTimer;
     bool m_deferredRegenerateIsolatedTree { false };
     Ref<AXGeometryManager> m_geometryManager;
+    DeferrableOneShotTimer m_selectedTextRangeTimer;
+    AXID m_lastDebouncedTextRangeObject;
 #endif
     bool m_isSynchronizingSelection { false };
     bool m_performingDeferredCacheUpdate { false };

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp b/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp
@@ -335,6 +335,9 @@ void AXIsolatedObject::initializeProperties(const Ref<AccessibilityObject>& axOb
     if (descriptor.length())
         setProperty(AXPropertyName::ExtendedDescription, descriptor.isolatedCopy());
 
+    if (object.isTextControl())
+        setProperty(AXPropertyName::SelectedTextRange, object.selectedTextRange());
+
     // These properties are only needed on the AXCoreObject interface due to their use in ATSPI,
     // so only cache them for ATSPI.
 #if PLATFORM(ATSPI)
@@ -1261,18 +1264,6 @@ bool AXIsolatedObject::isNativeTextControl() const
     return false;
 }
 
-CharacterRange AXIsolatedObject::selectedTextRange() const
-{
-    if (shouldReturnEmptySelectedText())
-        return { };
-
-    return Accessibility::retrieveValueFromMainThread<CharacterRange>([this] () -> CharacterRange {
-        if (auto* object = associatedAXObject())
-            return object->selectedTextRange();
-        return { };
-    });
-}
-
 int AXIsolatedObject::insertionPointLineNumber() const
 {
     return Accessibility::retrieveValueFromMainThread<int>([this] () -> int {

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h b/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h
@@ -342,7 +342,7 @@ class AXIsolatedObject final : public AXCoreObject {
 #endif
 
     // CharacterRange support.
-    CharacterRange selectedTextRange() const final;
+    CharacterRange selectedTextRange() const final { return propertyValue<CharacterRange>(AXPropertyName::SelectedTextRange); }
     int insertionPointLineNumber() const final;
     CharacterRange doAXRangeForLine(unsigned) const final;
     String doAXStringForRange(const CharacterRange&) const final;

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp b/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp
@@ -643,6 +643,9 @@ void AXIsolatedTree::updateNodeProperties(AXCoreObject& axObject, const Vector<A
         case AXPropertyName::CellScope:
             propertyMap.set(AXPropertyName::CellScope, axObject.cellScope().isolatedCopy());
             break;
+        case AXPropertyName::SelectedTextRange:
+            propertyMap.set(AXPropertyName::SelectedTextRange, axObject.selectedTextRange());
+            break;
         case AXPropertyName::SetSize:
             propertyMap.set(AXPropertyName::SetSize, axObject.setSize());
             break;

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h b/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h
@@ -203,6 +203,7 @@ enum class AXPropertyName : uint16_t {
     RowIndexRange,
     ScreenRelativePosition,
     SelectedChildren,
+    SelectedTextRange,
     SetSize,
     SortDirection,
     SpeechHint,

diff --git a/Source/WebCore/accessibility/mac/AXObjectCacheMac.mm b/Source/WebCore/accessibility/mac/AXObjectCacheMac.mm
@@ -762,6 +762,13 @@ static bool isTestAXClientType(AXClientType client)
 #endif
 }
 
+#if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
+Seconds AXObjectCache::platformSelectedTextRangeDebounceInterval() const
+{
+    return 100_ms;
+}
+#endif
+
 // TextMarker and TextMarkerRange funcstions.
 // FIXME: TextMarker and TextMarkerRange should become classes wrapping the system objects.