AX: Serve initial AXRelativeFrame for elements without cached frames …

…off of the main thread https://bugs.webkit.org/show_bug.cgi?id=268035 rdar://120764228 Reviewed by Tyler Wilcock. We only serve relative frames for objects on the secondary thread once they are cached during the Accessibility paint phase. This means that when we move to objects that were offscreen or haven't been painted, we have to use the main thread to serve the relative frame. This patch instead serves a rough frame from the AX thread initally, until the object's frame is cached during painting. This rough frame is constructed by using the frame rect of the element for its size, and it's closest painted ancestor for its position. As soon as the element's precise frame is cached duiring paint, this is updated. * LayoutTests/accessibility/mac/initial-relative-frame-cached-expected.txt: Added. * LayoutTests/accessibility/mac/initial-relative-frame-cached.html: Added. * LayoutTests/platform/mac-wk1/TestExpectations: * Source/WebCore/accessibility/AXObjectCache.cpp: (WebCore::AXObjectCache::setForceInitialFrameCaching): (WebCore::AXObjectCache::shouldServeInitialCachedFrame): * Source/WebCore/accessibility/AXObjectCache.h: (WebCore::AXObjectCache::forceInitialFrameCaching): * Source/WebCore/accessibility/AccessibilityObject.h: (WebCore::AccessibilityObject::frameRect const): (WebCore::AccessibilityObject::isNonLayerSVGObject const): * Source/WebCore/accessibility/AccessibilityRenderObject.cpp: (WebCore::AccessibilityRenderObject::isNonLayerSVGObject const): (WebCore::AccessibilityRenderObject::frameRect const): * Source/WebCore/accessibility/AccessibilityRenderObject.h: * Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp: (WebCore::AXIsolatedObject::initializeProperties): (WebCore::AXIsolatedObject::relativeFrame const): * Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h: * Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp: (WebCore::AXIsolatedTree::updateFrame): * Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h: * Source/WebKit/WebProcess/InjectedBundle/API/c/WKBundlePage.cpp: (WKAccessibilitySetForceInitialFrameCaching): * Source/WebKit/WebProcess/InjectedBundle/API/c/WKBundlePagePrivate.h: * Tools/WebKitTestRunner/InjectedBundle/AccessibilityController.cpp: (WTR::AccessibilityController::setForceInitialFrameCaching): * Tools/WebKitTestRunner/InjectedBundle/AccessibilityController.h: * Tools/WebKitTestRunner/InjectedBundle/Bindings/AccessibilityController.idl: Canonical link: https://commits.webkit.org/274472@main
WebKit · Feb 12, 2024 · e6c6fde · e6c6fde
1 parent 9c97e55
commit e6c6fde
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diff --git a/LayoutTests/accessibility/mac/initial-relative-frame-cached-expected.txt b/LayoutTests/accessibility/mac/initial-relative-frame-cached-expected.txt
@@ -0,0 +1,15 @@
+This test verifies that when initial rough frame caching is enabled, frames are eventually correct.
+
+heading1 has relative frame NSRect: {{8, 278}, {754, 37}}.
+image has relative frame NSRect: {{8, 336}, {100, 101}}.
+list has relative frame NSRect: {{8, 456}, {754, 37}}.
+listitem has relative frame NSRect: {{48, 456}, {714, 19}}.
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+Hello, world.
+
+
+List item 1
+List item 2
diff --git a/LayoutTests/accessibility/mac/initial-relative-frame-cached.html b/LayoutTests/accessibility/mac/initial-relative-frame-cached.html
@@ -0,0 +1,60 @@
+<!DOCTYPE html>
+<html>
+<head>
+<script src="../../resources/accessibility-helper.js"></script>
+<script src="../../resources/js-test.js"></script>
+</head>
+<body style="height: 1000px; width=1000px">
+
+<div style="height: 500px; overflow: auto;" id="scrollarea">
+    <div style="margin-top: 600px;" id="hidden-content">
+        <h1 id="heading1">Hello, world.</h1>
+
+        <img id="image" height=100 width=100 src="../resources/cake.png" alt="Cake in front of a glass door">
+
+        <ul id="list">
+            <li id="listitem">List item 1</li>
+            <li>List item 2</li>
+        </ul>
+    </div>
+</div>
+
+<script>
+let output = "This test verifies that when initial rough frame caching is enabled, frames are eventually correct.\n\n";
+
+if (window.accessibilityController) {
+    accessibilityController.setForceInitialFrameCaching(true);
+    window.jsTestIsAsync = true;
+
+    setTimeout(async function() {
+        // Scroll all content onscreen
+        let container = document.getElementById("scrollarea");
+        container.scrollTop = container.scrollHeight;
+
+        // Enable accessibility & trigger paint
+        accessibilityController.rootElement;
+
+        // Wait for the objects to be painted
+        await sleep(1000);
+
+        output += frameDebugString("heading1");
+        output += frameDebugString("image");
+        output += frameDebugString("list");
+        output += frameDebugString("listitem");
+
+        accessibilityController.setForceInitialFrameCaching(false);
+
+        debug(output);
+        finishJSTest();
+    }, 0);
+}
+
+
+function frameDebugString(id) {
+    let element = accessibilityController.accessibleElementById(id);
+    return `${id} has relative frame ${element.stringDescriptionOfAttributeValue('AXRelativeFrame')}.\n`;
+}
+
+</script>
+</body>
+</html>
diff --git a/LayoutTests/platform/mac-wk1/TestExpectations b/LayoutTests/platform/mac-wk1/TestExpectations
@@ -855,6 +855,9 @@ accessibility/mac/lazy-spellchecking.html [ Skip ]
 accessibility/mac/spellcheck-with-voiceover.html [ Skip ]
 accessibility/text-marker/text-marker-range-with-unordered-markers.html
 
+# AccessibilityController::setForceInitialFrameCaching not supported on WK1.
+accessibility/mac/initial-relative-frame-cached.html [ Skip ]
+
 # New API not supported in WK1
 accessibility/mac/intersection-with-selection-range.html [ Skip ]
 

diff --git a/Source/WebCore/accessibility/AXObjectCache.cpp b/Source/WebCore/accessibility/AXObjectCache.cpp
@@ -208,6 +208,7 @@ bool AXObjectCache::gForceDeferredSpellChecking = false;
 #if ENABLE(AX_THREAD_TEXT_APIS)
 bool AXObjectCache::gAccessibilityThreadTextApisEnabled = false;
 #endif
+bool AXObjectCache::gForceInitialFrameCaching = false;
 
 void AXObjectCache::enableAccessibility()
 {
@@ -234,7 +235,17 @@ void AXObjectCache::setEnhancedUserInterfaceAccessibility(bool flag)
 #endif
 }
 
+void AXObjectCache::setForceInitialFrameCaching(bool shouldForce)
+{
+    gForceInitialFrameCaching = shouldForce;
+}
+
 #if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
+bool AXObjectCache::shouldServeInitialCachedFrame()
+{
+    return !isTestClient() || forceInitialFrameCaching();
+}
+
 static const Seconds updateTreeSnapshotTimerInterval { 100_ms };
 #endif
 

diff --git a/Source/WebCore/accessibility/AXObjectCache.h b/Source/WebCore/accessibility/AXObjectCache.h
@@ -276,6 +276,12 @@ class AXObjectCache final : public CanMakeWeakPtr<AXObjectCache>, public CanMake
     static bool useAXThreadTextApis() { return gAccessibilityThreadTextApisEnabled && !isMainThread(); }
 #endif
 
+    static bool forceInitialFrameCaching() { return gForceInitialFrameCaching; }
+    WEBCORE_EXPORT static void setForceInitialFrameCaching(bool);
+#if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
+    static bool shouldServeInitialCachedFrame();
+#endif
+
     const Element* rootAXEditableElement(const Node*);
     bool nodeIsTextControl(const Node*);
 
@@ -678,6 +684,7 @@ class AXObjectCache final : public CanMakeWeakPtr<AXObjectCache>, public CanMake
     WEBCORE_EXPORT static bool gAccessibilityEnabled;
     WEBCORE_EXPORT static bool gAccessibilityEnhancedUserInterfaceEnabled;
     static bool gForceDeferredSpellChecking;
+    static bool gForceInitialFrameCaching;
 
 #if ENABLE(AX_THREAD_TEXT_APIS)
     static bool gAccessibilityThreadTextApisEnabled;

diff --git a/Source/WebCore/accessibility/AccessibilityObject.h b/Source/WebCore/accessibility/AccessibilityObject.h
@@ -770,6 +770,9 @@ class AccessibilityObject : public AXCoreObject, public CanMakeWeakPtr<Accessibi
     void setLastPresentedTextPrediction(Node&, CompositionState, const String&, size_t, bool);
 #endif // PLATFORM(IOS_FAMILY)
 
+    virtual FloatRect frameRect() const { return { }; }
+    virtual bool isNonLayerSVGObject() const { return false; }
+
 protected:
     AccessibilityObject() = default;
 

diff --git a/Source/WebCore/accessibility/AccessibilityRenderObject.cpp b/Source/WebCore/accessibility/AccessibilityRenderObject.cpp
@@ -90,6 +90,7 @@
 #include "RenderListMarker.h"
 #include "RenderMathMLBlock.h"
 #include "RenderMenuList.h"
+#include "RenderSVGInlineText.h"
 #include "RenderSVGRoot.h"
 #include "RenderSVGShape.h"
 #include "RenderTableCell.h"
@@ -862,7 +863,13 @@ LayoutRect AccessibilityRenderObject::boundingBoxRect() const
 
     return result;
 }
-
+
+bool AccessibilityRenderObject::isNonLayerSVGObject() const
+{
+    auto* renderer = this->renderer();
+    return renderer ? is<RenderSVGInlineText>(renderer) || is<LegacyRenderSVGModelObject>(renderer) : false;
+}
+
 bool AccessibilityRenderObject::supportsPath() const
 {
     return is<RenderText>(renderer()) || (renderer() && renderer()->isRenderOrLegacyRenderSVGShape());
@@ -2716,6 +2723,12 @@ void AccessibilityRenderObject::scrollTo(const IntPoint& point) const
     box->layer()->scrollableArea()->scrollToOffset(point);
 }
 
+FloatRect AccessibilityRenderObject::frameRect() const
+{
+    auto* box = dynamicDowncast<RenderBox>(renderer());
+    return box ? convertFrameToSpace(box->frameRect(), AccessibilityConversionSpace::Page) : FloatRect();
+}
+
 #if ENABLE(MATHML)
 bool AccessibilityRenderObject::isIgnoredElementWithinMathTree() const
 {

diff --git a/Source/WebCore/accessibility/AccessibilityRenderObject.h b/Source/WebCore/accessibility/AccessibilityRenderObject.h
@@ -57,6 +57,9 @@ class AccessibilityRenderObject : public AccessibilityNodeObject {
     static Ref<AccessibilityRenderObject> create(RenderObject*);
     virtual ~AccessibilityRenderObject();
 
+    FloatRect frameRect() const final;
+    bool isNonLayerSVGObject() const override;
+
     bool isAttachment() const override;
     bool isOffScreen() const override;
     bool hasBoldFont() const override;

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp b/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp
@@ -168,6 +168,7 @@ void AXIsolatedObject::initializeProperties(const Ref<AccessibilityObject>& axOb
     setProperty(AXPropertyName::IsKeyboardFocusable, object.isKeyboardFocusable());
     setProperty(AXPropertyName::BrailleRoleDescription, object.brailleRoleDescription().isolatedCopy());
     setProperty(AXPropertyName::BrailleLabel, object.brailleLabel().isolatedCopy());
+    setProperty(AXPropertyName::IsNonLayerSVGObject, object.isNonLayerSVGObject());
 
     RefPtr geometryManager = tree()->geometryManager();
     std::optional frame = geometryManager ? geometryManager->cachedRectForID(object.objectID()) : std::nullopt;
@@ -183,7 +184,8 @@ void AXIsolatedObject::initializeProperties(const Ref<AccessibilityObject>& axOb
     } else if (object.isMenuListPopup()) {
         // AccessibilityMenuListPopup's elementRect is hardcoded to return an empty rect, so preserve that behavior.
         setProperty(AXPropertyName::RelativeFrame, IntRect());
-    }
+    } else
+        setProperty(AXPropertyName::InitialFrameRect, object.frameRect());
 
     if (object.supportsCheckedState()) {
         setProperty(AXPropertyName::SupportsCheckedState, true);
@@ -1243,11 +1245,27 @@ FloatRect AXIsolatedObject::relativeFrame() const
     } else if (roleValue() == AccessibilityRole::Column || roleValue() == AccessibilityRole::TableHeaderContainer)
         return exposedTableAncestor() ? relativeFrameFromChildren() : FloatRect();
 
-    return Accessibility::retrieveValueFromMainThread<FloatRect>([this] () -> FloatRect {
-        if (auto* axObject = associatedAXObject())
-            return axObject->relativeFrame();
-        return { };
+    // Mock objects and SVG objects need use the main thread since they do not have render nodes and are not painted with layers, respectively.
+    // FIXME: Remove isNonLayerSVGObject when LBSE is enabled & SVG frames are cached.
+    if (!AXObjectCache::shouldServeInitialCachedFrame() || isMockObject() || isNonLayerSVGObject()) {
+        return Accessibility::retrieveValueFromMainThread<FloatRect>([this] () -> FloatRect {
+            if (auto* axObject = associatedAXObject())
+                return axObject->relativeFrame();
+            return { };
+        });
+    }
+
+    // InitialFrameRect stores the correct size, but not position, of the element before it is painted.
+    // We find the position of the nearest painted ancestor to use as the position until the object's frame
+    // is cached during painting.
+    auto* ancestor = Accessibility::findAncestor<AXIsolatedObject>(*this, false, [] (const auto& object) {
+        return object.hasCachedRelativeFrame();
     });
+    auto frameRect = rectAttributeValue<FloatRect>(AXPropertyName::InitialFrameRect);
+    if (ancestor && frameRect.location() == FloatPoint())
+        frameRect.setLocation(ancestor->relativeFrame().location());
+
+    return frameRect;
 }
 
 FloatRect AXIsolatedObject::relativeFrameFromChildren() const

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h b/Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.h
@@ -215,6 +215,7 @@ class AXIsolatedObject final : public AXCoreObject {
     bool isMeter() const final { return boolAttributeValue(AXPropertyName::IsMeter); };
     FloatPoint screenRelativePosition() const final;
     FloatRect relativeFrame() const final;
+    bool hasCachedRelativeFrame() const { return optionalAttributeValue<IntRect>(AXPropertyName::RelativeFrame).has_value(); }
 #if PLATFORM(MAC)
     FloatRect primaryScreenRect() const final;
 #endif
@@ -464,6 +465,7 @@ class AXIsolatedObject final : public AXCoreObject {
     bool isOnScreen() const final;
     bool isOffScreen() const final;
     bool isPressed() const final;
+    bool isNonLayerSVGObject() const { return boolAttributeValue(AXPropertyName::IsNonLayerSVGObject); }
     // FIXME: isVisible should be accurate for all objects, not just widgets, on COCOA.
     bool isVisible() const final { return boolAttributeValue(AXPropertyName::IsVisible); }
     bool isSelectedOptionActive() const final;

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp b/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp
@@ -1043,6 +1043,8 @@ void AXIsolatedTree::updateFrame(AXID axID, IntRect&& newFrame)
 
     AXPropertyMap propertyMap;
     propertyMap.set(AXPropertyName::RelativeFrame, WTFMove(newFrame));
+    // We can clear the initially-cached rough frame, since the object's frame has been cached
+    propertyMap.set(AXPropertyName::InitialFrameRect, FloatRect());
     Locker locker { m_changeLogLock };
     m_pendingPropertyChanges.append({ axID, WTFMove(propertyMap) });
 }

diff --git a/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h b/Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h
@@ -111,6 +111,7 @@ enum class AXPropertyName : uint16_t {
     HorizontalScrollBar,
     IdentifierAttribute,
     IncrementButton,
+    InitialFrameRect,
     InnerHTML,
     InternalLinkElement,
     InsideLink,
@@ -151,6 +152,7 @@ enum class AXPropertyName : uint16_t {
     IsMathToken,
     IsMeter,
     IsMultiSelectable,
+    IsNonLayerSVGObject,
     IsNonNativeTextControl,
     IsPlugin,
     IsPressed,

diff --git a/Source/WebKit/WebProcess/InjectedBundle/API/c/WKBundlePage.cpp b/Source/WebKit/WebProcess/InjectedBundle/API/c/WKBundlePage.cpp
@@ -346,6 +346,11 @@ bool WKAccessibilityEnhancedAccessibilityEnabled()
     return WebCore::AXObjectCache::accessibilityEnhancedUserInterfaceEnabled();
 }
 
+void WKAccessibilitySetForceInitialFrameCaching(bool shouldForce)
+{
+    WebCore::AXObjectCache::setForceInitialFrameCaching(shouldForce);
+}
+
 void WKBundlePageStopLoading(WKBundlePageRef pageRef)
 {
     WebKit::toImpl(pageRef)->stopLoading();

diff --git a/Source/WebKit/WebProcess/InjectedBundle/API/c/WKBundlePagePrivate.h b/Source/WebKit/WebProcess/InjectedBundle/API/c/WKBundlePagePrivate.h
@@ -103,6 +103,7 @@ WK_EXPORT void WKAccessibilityTestingInjectPreference(WKBundlePageRef, WKStringR
 WK_EXPORT void WKAccessibilitySetForceDeferredSpellChecking(bool);
 WK_EXPORT void WKAccessibilityEnableEnhancedAccessibility(bool);
 WK_EXPORT bool WKAccessibilityEnhancedAccessibilityEnabled();
+WK_EXPORT void WKAccessibilitySetForceInitialFrameCaching(bool);
 
 WK_EXPORT void WKBundlePageClickMenuItem(WKBundlePageRef, WKContextMenuItemRef);
 WK_EXPORT WKArrayRef WKBundlePageCopyContextMenuItems(WKBundlePageRef);

diff --git a/Tools/WebKitTestRunner/InjectedBundle/AccessibilityController.cpp b/Tools/WebKitTestRunner/InjectedBundle/AccessibilityController.cpp
@@ -73,6 +73,11 @@ void AccessibilityController::setForceDeferredSpellChecking(bool shouldForce)
     WKAccessibilitySetForceDeferredSpellChecking(shouldForce);
 }
 
+void AccessibilityController::setForceInitialFrameCaching(bool shouldForce)
+{
+    WKAccessibilitySetForceInitialFrameCaching(shouldForce);
+}
+
 void AccessibilityController::makeWindowObject(JSContextRef context)
 {
     setGlobalObjectProperty(context, "accessibilityController", this);

diff --git a/Tools/WebKitTestRunner/InjectedBundle/AccessibilityController.h b/Tools/WebKitTestRunner/InjectedBundle/AccessibilityController.h
@@ -61,6 +61,7 @@ class AccessibilityController : public JSWrappable {
 
     void setIsolatedTreeMode(bool);
     void setForceDeferredSpellChecking(bool);
+    void setForceInitialFrameCaching(bool);
 
     JSRetainPtr<JSStringRef> platformName();
 

diff --git a/Tools/WebKitTestRunner/InjectedBundle/Bindings/AccessibilityController.idl b/Tools/WebKitTestRunner/InjectedBundle/Bindings/AccessibilityController.idl
@@ -30,6 +30,7 @@ interface AccessibilityController {
     undefined setForceDeferredSpellChecking(boolean shouldForce);
     undefined setRetainedElement(AccessibilityUIElement axElement);
     AccessibilityUIElement retainedElement();
+    undefined setForceInitialFrameCaching(boolean shouldForce);
 
     readonly attribute DOMString platformName;
     readonly attribute AccessibilityUIElement rootElement;