diff -r 000000000000 -r 6474c204b198 accessible/src/base/AccGroupInfo.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accessible/src/base/AccGroupInfo.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,114 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef AccGroupInfo_h_
+#define AccGroupInfo_h_
+
+#include "Accessible-inl.h"
+
+namespace mozilla {
+namespace a11y {
+
+/**
+ * Calculate and store group information.
+ */
+class AccGroupInfo
+{
+public:
+  ~AccGroupInfo() { MOZ_COUNT_DTOR(AccGroupInfo); }
+
+  /**
+   * Return 1-based position in the group.
+   */
+  uint32_t PosInSet() const { return mPosInSet; }
+
+  /**
+   * Return a number of items in the group.
+   */
+  uint32_t SetSize() const { return mSetSize; }
+
+  /**
+   * Return a direct or logical parent of the accessible that this group info is
+   * created for.
+   */
+  Accessible* ConceptualParent() const { return mParent; }
+
+  /**
+   * Update group information.
+   */
+  void Update();
+
+  /**
+   * Create group info.
+   */
+  static AccGroupInfo* CreateGroupInfo(Accessible* aAccessible)
+  {
+    mozilla::a11y::role role = aAccessible->Role();
+    if (role != mozilla::a11y::roles::ROW &&
+        role != mozilla::a11y::roles::OUTLINEITEM &&
+        role != mozilla::a11y::roles::OPTION &&
+        role != mozilla::a11y::roles::LISTITEM &&
+        role != mozilla::a11y::roles::MENUITEM &&
+        role != mozilla::a11y::roles::COMBOBOX_OPTION &&
+        role != mozilla::a11y::roles::RICH_OPTION &&
+        role != mozilla::a11y::roles::CHECK_RICH_OPTION &&
+        role != mozilla::a11y::roles::PARENT_MENUITEM &&
+        role != mozilla::a11y::roles::CHECK_MENU_ITEM &&
+        role != mozilla::a11y::roles::RADIO_MENU_ITEM &&
+        role != mozilla::a11y::roles::RADIOBUTTON &&
+        role != mozilla::a11y::roles::PAGETAB)
+      return nullptr;
+
+    AccGroupInfo* info = new AccGroupInfo(aAccessible, BaseRole(role));
+    return info;
+  }
+
+  /**
+   * Return a first item for the given container.
+   */
+  static Accessible* FirstItemOf(Accessible* aContainer);
+
+  /**
+   * Return next item of the same group to the given item.
+   */
+  static Accessible* NextItemTo(Accessible* aItem);
+
+protected:
+  AccGroupInfo(Accessible* aItem, a11y::role aRole);
+
+private:
+  AccGroupInfo() MOZ_DELETE;
+  AccGroupInfo(const AccGroupInfo&) MOZ_DELETE;
+  AccGroupInfo& operator =(const AccGroupInfo&) MOZ_DELETE;
+
+  static mozilla::a11y::role BaseRole(mozilla::a11y::role aRole)
+  {
+    if (aRole == mozilla::a11y::roles::CHECK_MENU_ITEM ||
+        aRole == mozilla::a11y::roles::PARENT_MENUITEM ||
+        aRole == mozilla::a11y::roles::RADIO_MENU_ITEM)
+      return mozilla::a11y::roles::MENUITEM;
+
+    if (aRole == mozilla::a11y::roles::CHECK_RICH_OPTION)
+      return mozilla::a11y::roles::RICH_OPTION;
+
+    return aRole;
+  }
+
+  /**
+   * Return true if the given parent and child roles should have their node
+   * relations reported.
+   */
+  static bool ShouldReportRelations(a11y::role aRole, a11y::role aParentRole);
+
+  uint32_t mPosInSet;
+  uint32_t mSetSize;
+  Accessible* mParent;
+  Accessible* mItem;
+  a11y::role mRole;
+};
+
+} // namespace mozilla
+} // namespace a11y
+
+#endif