Selection follows focus/activedescendant in single selection containers

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

Index: third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp b/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
index c425d319cef09becd3e2ef032be455727988e426..1b6e85114762795b16851bf679002ff13da36cb3 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
@@ -1255,6 +1255,35 @@ AXObjectImpl* AXObjectImpl::ParentObjectUnignored() const {
   return parent;
 }
 
+// Container widgets are those that a user tabs into and arrows around
+// sub-widgets
+bool AXObjectImpl::IsContainerWidget() const {
+  switch (RoleValue()) {
+    case kComboBoxRole:
+    case kGridRole:
+    case kListBoxRole:
+    case kMenuBarRole:
+    case kMenuRole:
+    case kRadioGroupRole:
+    case kSpinButtonRole:
+    case kTabListRole:
+    case kToolbarRole:
+    case kTreeGridRole:
+    case kTreeRole:
+      return true;
+    default:
+      return false;
+  }
+}
+
+AXObjectImpl* AXObjectImpl::ContainerWidget() const {

[dmazzoni, 2017/05/19 19:54:04]

Should this check for the right type of container?

I.e. if you're on an option it should only walk
up to a container listbox, not a grid or toolbar.

Also, even though the spec seems to imply that
containers can have descendants anywhere, in many
cases the descendants have to be immediate children
for it to work on most platforms.

So the listitem has to be an immediate child of the
list, for example, or a group in some cases. You
can't have another non-presentational object in-between.

+  AXObjectImpl* ancestor = ParentObjectUnignored();
+  while (ancestor && !ancestor->IsContainerWidget())
+    ancestor = ancestor->ParentObjectUnignored();
+
+  return ancestor;
+}
+
 void AXObjectImpl::UpdateChildrenIfNecessary() {
   if (!HasChildren())
     AddChildren();