Migrating methods from AXLayoutObject to AxNodeObject.

 - Migrating IsDefault method
 - Migrating HasPopup method
 - Inverting control flow for NativeRoleIgnoringAria

Written collaboratively with Aboxhall and Meredithl.

Change-Id: Ic516fecf0f9e9d010e033ec46c8bd09df7869983
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2186874Reviewed-by: Alice Boxhall <aboxhall@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Chris Hall <chrishall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774035}

third_party/blink/renderer/modules/accessibility/ax_layout_object.cc

@@ -170,14 +170,8 @@ static bool IsImageOrAltText(LayoutBoxModelObject* box, Node* node) {
   return false;
 }
 
-ax::mojom::blink::Role AXLayoutObject::NativeRoleIgnoringAria() const {
-  // DOM role takes precedence over layout role.
-  // For example, <h4 style="display:table"> is a heading, not a table.
-  ax::mojom::blink::Role dom_role = AXNodeObject::NativeRoleIgnoringAria();
-  if (dom_role != ax::mojom::blink::Role::kGenericContainer &&
-      dom_role != ax::mojom::blink::Role::kUnknown)
-    return dom_role;
-
+ax::mojom::blink::Role AXLayoutObject::RoleFromLayoutObject(
+    ax::mojom::blink::Role dom_role) const {
   // Markup did not provide a specific role, so attempt to determine one
   // from the computed style.
   Node* node = layout_object_->GetNode();
@@ -230,6 +224,9 @@ ax::mojom::blink::Role AXLayoutObject::NativeRoleIgnoringAria() const {
   if (layout_object_->IsHR())
     return ax::mojom::blink::Role::kSplitter;
 
+  // TODO(accessibility): refactor this method to take no argument and instead
+  // default to returning kUnknownRole, the caller can then check for this and
+  // return a different value if they prefer.
   return dom_role;
 }
 
@@ -1634,42 +1631,6 @@ void AXLayoutObject::AriaDescribedbyElements(
                                        describedby);
 }
 
-ax::mojom::blink::HasPopup AXLayoutObject::HasPopup() const {
-  const AtomicString& has_popup =
-      GetAOMPropertyOrARIAAttribute(AOMStringProperty::kHasPopUp);
-  if (!has_popup.IsNull()) {
-    if (EqualIgnoringASCIICase(has_popup, "false"))
-      return ax::mojom::blink::HasPopup::kFalse;
-
-    if (EqualIgnoringASCIICase(has_popup, "listbox"))
-      return ax::mojom::blink::HasPopup::kListbox;
-
-    if (EqualIgnoringASCIICase(has_popup, "tree"))
-      return ax::mojom::blink::HasPopup::kTree;
-
-    if (EqualIgnoringASCIICase(has_popup, "grid"))
-      return ax::mojom::blink::HasPopup::kGrid;
-
-    if (EqualIgnoringASCIICase(has_popup, "dialog"))
-      return ax::mojom::blink::HasPopup::kDialog;
-
-    // To provide backward compatibility with ARIA 1.0 content,
-    // user agents MUST treat an aria-haspopup value of true
-    // as equivalent to a value of menu.
-    // And unknown value also return menu too.
-    if (EqualIgnoringASCIICase(has_popup, "true") ||
-        EqualIgnoringASCIICase(has_popup, "menu") || !has_popup.IsEmpty())
-      return ax::mojom::blink::HasPopup::kMenu;
-  }
-
-  // ARIA 1.1 default value of haspopup for combobox is "listbox".
-  if (RoleValue() == ax::mojom::blink::Role::kComboBoxMenuButton ||
-      RoleValue() == ax::mojom::blink::Role::kTextFieldWithComboBox)
-    return ax::mojom::blink::HasPopup::kListbox;
-
-  return AXObject::HasPopup();
-}
-
 // TODO : Aria-dropeffect and aria-grabbed are deprecated in aria 1.1
 // Also those properties are expected to be replaced by a new feature in
 // a future version of WAI-ARIA. After that we will re-implement them

third_party/blink/renderer/modules/accessibility/ax_layout_object.h

@@ -52,7 +52,6 @@ class MODULES_EXPORT AXLayoutObject : public AXNodeObject {
   LayoutObject* GetLayoutObject() const final { return layout_object_; }
   ScrollableArea* GetScrollableAreaIfScrollable() const final;
   ax::mojom::blink::Role DetermineAccessibilityRole() override;
-  ax::mojom::blink::Role NativeRoleIgnoringAria() const override;
 
   // If this is an anonymous node, returns the node of its containing layout
   // block, otherwise returns the node of this layout object.
@@ -137,7 +136,6 @@ class MODULES_EXPORT AXLayoutObject : public AXNodeObject {
   void AriaDescribedbyElements(AXObjectVector&) const override;
   void AriaOwnsElements(AXObjectVector&) const override;
 
-  ax::mojom::blink::HasPopup HasPopup() const override;
   bool SupportsARIADragging() const override;
   void Dropeffects(
       Vector<ax::mojom::blink::Dropeffect>& dropeffects) const override;
@@ -205,6 +203,17 @@ class MODULES_EXPORT AXLayoutObject : public AXNodeObject {
   // alert.
   AXObject* ErrorMessage() const override;
 
+  //
+  // Layout object specific methods.
+  //
+  // These methods may eventually migrate over to AXNodeObject.
+  //
+
+  // If we can't determine a useful role from the DOM node, attempt to determine
+  // a role from the layout object.
+  ax::mojom::blink::Role RoleFromLayoutObject(
+      ax::mojom::blink::Role dom_role) const override;
+
  private:
   bool IsTabItemSelected() const;
   AXObject* AccessibilityImageMapHitTest(HTMLAreaElement*,

third_party/blink/renderer/modules/accessibility/ax_node_object.cc

@@ -644,7 +644,7 @@ ax::mojom::blink::Role AXNodeObject::DetermineTableCellRole() const {
 // DataList(), aria-pressed, the parent's tag, role on an iframe, etc.
 ax::mojom::blink::Role AXNodeObject::NativeRoleIgnoringAria() const {
   if (!GetNode())
-    return ax::mojom::blink::Role::kUnknown;
+    return RoleFromLayoutObject(ax::mojom::blink::Role::kUnknown);
 
   // |HTMLAnchorElement| sets isLink only when it has kHrefAttr.
   if (GetNode()->IsLink()) {
@@ -678,7 +678,7 @@ ax::mojom::blink::Role AXNodeObject::NativeRoleIgnoringAria() const {
       parent = LayoutTreeBuilderTraversal::Parent(*parent);
     if (parent && IsA<HTMLDetailsElement>(parent))
       return ax::mojom::blink::Role::kDisclosureTriangle;
-    return ax::mojom::blink::Role::kUnknown;
+    return RoleFromLayoutObject(ax::mojom::blink::Role::kUnknown);
   }
 
   // Chrome exposes both table markup and table CSS as a tables, letting
@@ -773,7 +773,7 @@ ax::mojom::blink::Role AXNodeObject::NativeRoleIgnoringAria() const {
     return ax::mojom::blink::Role::kHeading;
 
   if (IsA<HTMLDivElement>(*GetNode()))
-    return ax::mojom::blink::Role::kGenericContainer;
+    return RoleFromLayoutObject(ax::mojom::blink::Role::kGenericContainer);
 
   if (IsA<HTMLMeterElement>(*GetNode()))
     return ax::mojom::blink::Role::kMeter;
@@ -860,14 +860,14 @@ ax::mojom::blink::Role AXNodeObject::NativeRoleIgnoringAria() const {
     return ax::mojom::blink::Role::kSection;
 
   if (GetNode()->HasTagName(html_names::kAddressTag))
-    return ax::mojom::blink::Role::kGenericContainer;
+    return RoleFromLayoutObject(ax::mojom::blink::Role::kGenericContainer);
 
   if (IsA<HTMLDialogElement>(*GetNode()))
     return ax::mojom::blink::Role::kDialog;
 
   // The HTML element.
   if (IsA<HTMLHtmlElement>(GetNode()))
-    return ax::mojom::blink::Role::kGenericContainer;
+    return RoleFromLayoutObject(ax::mojom::blink::Role::kGenericContainer);
 
   // Treat <iframe> and <frame> the same.
   if (IsA<HTMLIFrameElement>(*GetNode()) || IsA<HTMLFrameElement>(*GetNode())) {
@@ -920,7 +920,7 @@ ax::mojom::blink::Role AXNodeObject::NativeRoleIgnoringAria() const {
   if (IsFieldset())
     return ax::mojom::blink::Role::kGroup;
 
-  return ax::mojom::blink::Role::kUnknown;
+  return RoleFromLayoutObject(ax::mojom::blink::Role::kUnknown);
 }
 
 ax::mojom::blink::Role AXNodeObject::DetermineAccessibilityRole() {
@@ -1133,6 +1133,21 @@ bool AXNodeObject::IsControllingVideoElement() const {
       MediaControlElementsHelper::ToParentMediaElement(node));
 }
 
+bool AXNodeObject::IsDefault() const {
+  if (IsDetached())
+    return false;
+
+  // Checks for any kind of disabled, including aria-disabled.
+  if (Restriction() == kRestrictionDisabled ||
+      RoleValue() != ax::mojom::blink::Role::kButton) {
+    return false;
+  }
+
+  // Will only match :default pseudo class if it's the first default button in
+  // a form.
+  return GetElement()->MatchesDefaultPseudoClass();
+}
+
 bool AXNodeObject::ComputeIsEditableRoot() const {
   Node* node = GetNode();
   if (!node)
@@ -2155,6 +2170,42 @@ bool AXNodeObject::HasAriaAttribute() const {
   return false;
 }
 
+ax::mojom::blink::HasPopup AXNodeObject::HasPopup() const {
+  const AtomicString& has_popup =
+      GetAOMPropertyOrARIAAttribute(AOMStringProperty::kHasPopUp);
+  if (!has_popup.IsNull()) {
+    if (EqualIgnoringASCIICase(has_popup, "false"))
+      return ax::mojom::blink::HasPopup::kFalse;
+
+    if (EqualIgnoringASCIICase(has_popup, "listbox"))
+      return ax::mojom::blink::HasPopup::kListbox;
+
+    if (EqualIgnoringASCIICase(has_popup, "tree"))
+      return ax::mojom::blink::HasPopup::kTree;
+
+    if (EqualIgnoringASCIICase(has_popup, "grid"))
+      return ax::mojom::blink::HasPopup::kGrid;
+
+    if (EqualIgnoringASCIICase(has_popup, "dialog"))
+      return ax::mojom::blink::HasPopup::kDialog;
+
+    // To provide backward compatibility with ARIA 1.0 content,
+    // user agents MUST treat an aria-haspopup value of true
+    // as equivalent to a value of menu.
+    // And unknown value also return menu too.
+    if (EqualIgnoringASCIICase(has_popup, "true") ||
+        EqualIgnoringASCIICase(has_popup, "menu") || !has_popup.IsEmpty())
+      return ax::mojom::blink::HasPopup::kMenu;
+  }
+
+  // ARIA 1.1 default value of haspopup for combobox is "listbox".
+  if (RoleValue() == ax::mojom::blink::Role::kComboBoxMenuButton ||
+      RoleValue() == ax::mojom::blink::Role::kTextFieldWithComboBox)
+    return ax::mojom::blink::HasPopup::kListbox;
+
+  return AXObject::HasPopup();
+}
+
 // Returns the nearest block-level LayoutBlockFlow ancestor
 static LayoutBlockFlow* NonInlineBlockFlow(LayoutObject* object) {
   LayoutObject* current = object;

third_party/blink/renderer/modules/accessibility/ax_node_object.h

@@ -95,6 +95,7 @@ class MODULES_EXPORT AXNodeObject : public AXObject {
 
   // Check object role or purpose.
   bool IsControllingVideoElement() const;
+  bool IsDefault() const override;
   bool IsMultiline() const override;
   bool IsEditable() const override { return IsNativeTextControl(); }
   bool ComputeIsEditableRoot() const override;
@@ -158,6 +159,8 @@ class MODULES_EXPORT AXNodeObject : public AXObject {
   ax::mojom::blink::Role AriaRoleAttribute() const final;
   bool HasAriaAttribute() const override;
 
+  ax::mojom::blink::HasPopup HasPopup() const override;
+
   // AX name calculation.
   String GetName(ax::mojom::blink::NameFrom&,
                  AXObjectVector* name_objects) const override;
@@ -238,6 +241,17 @@ class MODULES_EXPORT AXNodeObject : public AXObject {
     return nullptr;
   }
 
+  //
+  // Layout object specific methods.
+  //
+
+  // If we can't determine a useful role from the DOM node, attempt to determine
+  // a role from the layout object.
+  virtual ax::mojom::blink::Role RoleFromLayoutObject(
+      ax::mojom::blink::Role dom_role) const {
+    return dom_role;
+  }
+
   FRIEND_TEST_ALL_PREFIXES(AccessibilityTest, SetNeedsToUpdateChildren);
   FRIEND_TEST_ALL_PREFIXES(AccessibilityTest, UpdateChildrenIfNecessary);