Bug 414976 - Support RELATION_NODE_CHILD_OF for ARIA tree views, patch=aaronlev, r=me, a=mtschrep

accessible/src/base/nsAccessibilityUtils.cpp

@@ -304,6 +304,81 @@ nsAccUtils::GetAncestorWithRole(nsIAccessible *aDescendant, PRUint32 aRole)
   return nsnull;
 }
 
+void
+nsAccUtils::GetARIATreeItemParent(nsIAccessible *aStartTreeItem, nsIContent *aStartContent,
+                                  nsIAccessible **aTreeItemParentResult)
+{
+  *aTreeItemParentResult = nsnull;
+  nsAutoString levelStr;
+  PRInt32 level = 0;
+  if (aStartContent->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::aria_level, levelStr)) {
+    // This is a tree that uses aria-level to define levels, so find the first previous
+    // sibling accessible where level is defined to be less than the current level
+    PRInt32 success;
+    level = levelStr.ToInteger(&success);
+    if (level > 1 && NS_SUCCEEDED(success)) {
+      nsCOMPtr<nsIAccessible> currentAccessible = aStartTreeItem, prevAccessible;
+      while (PR_TRUE) {
+        currentAccessible->GetPreviousSibling(getter_AddRefs(prevAccessible));
+        currentAccessible.swap(prevAccessible);
+        nsCOMPtr<nsIAccessNode> accessNode = do_QueryInterface(currentAccessible);
+        if (!accessNode) {
+          break; // Reached top of tree, no higher level found
+        }
+        PRUint32 role;
+        currentAccessible->GetFinalRole(&role);
+        if (role != nsIAccessibleRole::ROLE_OUTLINEITEM)
+          continue;
+        nsCOMPtr<nsIDOMNode> treeItemNode;
+        accessNode->GetDOMNode(getter_AddRefs(treeItemNode));
+        nsCOMPtr<nsIContent> treeItemContent = do_QueryInterface(treeItemNode);
+        if (treeItemContent &&
+            treeItemContent->GetAttr(kNameSpaceID_None,
+                                     nsAccessibilityAtoms::aria_level, levelStr)) {
+          if (levelStr.ToInteger(&success) < level && NS_SUCCEEDED(success)) {
+            NS_ADDREF(*aTreeItemParentResult = currentAccessible);
+            return;
+          }
+        }
+      }
+    }
+  }
+
+  // Possibly a tree arranged by using role="group" to organize levels
+  // In this case the parent of the tree item will be a group and the
+  // previous sibling of that should be the tree item parent.
+  // Or, if the parent is something other than a tree we will return that.
+  nsCOMPtr<nsIAccessible> parentAccessible;
+  aStartTreeItem->GetParent(getter_AddRefs(parentAccessible));
+  if (!parentAccessible)
+    return;
+  PRUint32 role;
+  parentAccessible->GetFinalRole(&role);
+  if (role != nsIAccessibleRole::ROLE_GROUPING) {
+    NS_ADDREF(*aTreeItemParentResult = parentAccessible);
+    return; // The container for the tree items
+  }
+  nsCOMPtr<nsIAccessible> prevAccessible;
+  parentAccessible->GetPreviousSibling(getter_AddRefs(prevAccessible));
+  if (!prevAccessible)
+    return;
+  prevAccessible->GetFinalRole(&role);
+  if (role == nsIAccessibleRole::ROLE_TEXT_LEAF) {
+    // XXX Sometimes an empty text accessible is in the hierarchy here,
+    // although the text does not appear to be rendered, GetRenderedText() says that it is
+    // so we need to skip past it to find the true previous sibling
+    nsCOMPtr<nsIAccessible> tempAccessible = prevAccessible;
+    tempAccessible->GetPreviousSibling(getter_AddRefs(prevAccessible));
+    if (!prevAccessible)
+      return;
+    prevAccessible->GetFinalRole(&role);
+  }
+  if (role == nsIAccessibleRole::ROLE_OUTLINEITEM) {
+    // Previous sibling of parent group is a tree item -- this is the conceptual tree item parent
+    NS_ADDREF(*aTreeItemParentResult = prevAccessible);
+  }
+}
+
 nsresult
 nsAccUtils::ScrollSubstringTo(nsIFrame *aFrame,
                               nsIDOMNode *aStartNode, PRInt32 aStartIndex,

accessible/src/base/nsAccessibilityUtils.h

@@ -147,6 +147,19 @@ public:
    static already_AddRefed<nsIAccessible>
      GetAncestorWithRole(nsIAccessible *aDescendant, PRUint32 aRole);
 
+   /**
+     * For an ARIA tree item , get the accessible that represents its conceptual parent.
+     * This method will use the correct method for the given way the tree is constructed.
+     * The conceptual parent is what the user sees as the parent, not the DOM or accessible parent.
+     * @param aStartTreeItem  The tree item to get the parent for
+     * @param aStartTreeItemContent  The content node for the tree item
+     * @param The tree item's parent, or null if none
+     */
+   static void
+     GetARIATreeItemParent(nsIAccessible *aStartTreeItem,
+                           nsIContent *aStartTreeItemContent,
+                           nsIAccessible **aTreeItemParent);
+
   /**
    * Helper method to scroll range into view, used for implementation of
    * nsIAccessibleText::scrollSubstringTo().

accessible/src/base/nsAccessible.cpp

@@ -2674,6 +2674,11 @@ NS_IMETHODIMP nsAccessible::GetAccessibleRelated(PRUint32 aRelationType, nsIAcce
     {
       relatedNode =
         do_QueryInterface(nsAccUtils::FindNeighbourPointingToNode(content, nsAccessibilityAtoms::aria_owns));
+      if (!relatedNode && mRoleMapEntry && mRoleMapEntry->role == nsIAccessibleRole::ROLE_OUTLINEITEM) {
+        // This is an ARIA tree that doesn't use owns, so we need to get the parent the hard way
+        nsAccUtils::GetARIATreeItemParent(this, content, aRelated);
+        return NS_OK;
+      }
       break;
     }
   case nsIAccessibleRelation::RELATION_CONTROLLED_BY:

accessible/src/xul/nsXULTreeAccessible.cpp

@@ -1236,10 +1236,7 @@ NS_IMETHODIMP nsXULTreeitemAccessible::GetAccessibleRelated(PRUint32 aRelationTy
   if (IsDefunct())
     return NS_ERROR_FAILURE;
 
-  //currentlly only for ATK. and in the future, we'll sync MSAA and ATK same. 
-  //that's why ATK specific code shows here
   *aRelated = nsnull;
-#ifdef MOZ_ACCESSIBILITY_ATK
   if (aRelationType == nsIAccessibleRelation::RELATION_NODE_CHILD_OF) {
     PRInt32 columnIndex;
     if (NS_SUCCEEDED(mColumn->GetIndex(&columnIndex)) && columnIndex == 0) {
@@ -1256,12 +1253,9 @@ NS_IMETHODIMP nsXULTreeitemAccessible::GetAccessibleRelated(PRUint32 aRelationTy
       }
     }
     return NS_OK;
-  } else { 
-#endif
-    return nsAccessible::GetAccessibleRelated(aRelationType, aRelated);
-#ifdef MOZ_ACCESSIBILITY_ATK
   }
-#endif
+
+  return nsAccessible::GetAccessibleRelated(aRelationType, aRelated);
 }
 
 // attribute AString nsIAccessibleTreeItem::cachedName