Relation list properties for Accessibility Object Model phase 1

third_party/WebKit/Source/modules/accessibility/AXObject.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 374 matching lines @@
     AOMRelationProperty property) const {
   Element* element = this->GetElement();
   if (!element)
     return nullptr;
 
   AccessibleNode* target =
       AccessibleNode::GetPropertyOrARIAAttribute(element, property);
   return target ? target->element() : nullptr;
 }
 
+bool AXObject::HasAOMProperty(AOMRelationListProperty property,
+                              HeapVector<Member<Element>>& result) const {
+  Element* element = this->GetElement();
+  if (!element)
+    return false;
+
+  return AccessibleNode::GetProperty(element, property, result);
+}
+
+bool AXObject::HasAOMPropertyOrARIAAttribute(
+    AOMRelationListProperty property,
+    HeapVector<Member<Element>>& result) const {
+  Element* element = this->GetElement();
+  if (!element)
+    return false;
+
+  return AccessibleNode::GetPropertyOrARIAAttribute(element, property, result);
+}
+
 bool AXObject::HasAOMPropertyOrARIAAttribute(AOMBooleanProperty property,
                                              bool& result) const {
   Element* element = this->GetElement();
   if (!element)
     return false;
 
   bool is_null = true;
   result =
       AccessibleNode::GetPropertyOrARIAAttribute(element, property, is_null);
   return !is_null;
@@ skipping 563 matching lines @@
 
   // Step 2A from: http://www.w3.org/TR/accname-aam-1.1
   // If you change this logic, update AXNodeObject::nameFromLabelElement, too.
   if (!in_aria_labelled_by_traversal &&
       IsHiddenForTextAlternativeCalculation()) {
     *found_text_alternative = true;
     return String();
   }
 
   // Step 2B from: http://www.w3.org/TR/accname-aam-1.1
+  // AOM version
+  // If you change this logic, update AXNodeObject::nameFromLabelElement, too.
+  if (!in_aria_labelled_by_traversal && !already_visited) {
+    name_from = kAXNameFromRelatedElement;
+    if (name_sources) {
+      name_sources->push_back(
+          NameSource(*found_text_alternative, aria_labeledbyAttr));

[aboxhall, 2017/07/06 05:37:14]

Hm, I think we should have a different source for AOM properties (and should
there be an AOM version for aria_label as well?)

[dmazzoni, 2017/07/06 06:34:25]

For aria-label and almost every other place in the code where we were
previously getting an ARIA attribute, we're now calling
GetAOMPropertyOrARIAAttribute,
which allows us to not duplicate all of that code.

I'd be totally open to being more explicit about the AOM in developer tools,
but I think it's beyond the scope of this change since we haven't been doing
it for other properties yet.

Considering AOM in general is still experimental and subject to change, we
may also want to consider holding off on adding "extra" dev tools support,
and defer that until we're closer to wanting to ship this.

[aboxhall, 2017/07/06 06:55:15]

Makes sense!

+      name_sources->back().type = name_from;
+    }
+
+    HeapVector<Member<Element>> elements;
+    if (HasAOMProperty(AOMRelationListProperty::kLabeledBy, elements)) {
+      // Operate on a copy of |visited| so that if |nameSources| is not null,
+      // the set of visited objects is preserved unmodified for future
+      // calculations.
+      AXObjectSet visited_copy = visited;
+      text_alternative =
+          TextFromElements(true, visited_copy, elements, related_objects);
+      if (!text_alternative.IsNull()) {
+        if (name_sources) {
+          NameSource& source = name_sources->back();
+          source.type = name_from;
+          source.related_objects = *related_objects;
+          source.text = text_alternative;
+          *found_text_alternative = true;
+        } else {
+          *found_text_alternative = true;
+          return text_alternative;
+        }
+      } else if (name_sources) {
+        name_sources->back().invalid = true;
+      }
+    }
+  }
+
+  // Step 2B from: http://www.w3.org/TR/accname-aam-1.1
+  // ARIA version
   // If you change this logic, update AXNodeObject::nameFromLabelElement, too.
   if (!in_aria_labelled_by_traversal && !already_visited) {
     const QualifiedName& attr =
         HasAttribute(aria_labeledbyAttr) && !HasAttribute(aria_labelledbyAttr)
             ? aria_labeledbyAttr
             : aria_labelledbyAttr;
     name_from = kAXNameFromRelatedElement;
     if (name_sources) {
       name_sources->push_back(NameSource(*found_text_alternative, attr));
       name_sources->back().type = name_from;
@@ skipping 1112 matching lines @@
 }
 
 DEFINE_TRACE(AXObject) {
   visitor->Trace(children_);
   visitor->Trace(parent_);
   visitor->Trace(cached_live_region_root_);
   visitor->Trace(ax_object_cache_);
 }
 
 }  // namespace blink