Bug 395223 - positional description incorrect for headings, r=aaronlev, a=dsicore

accessible/src/base/nsAccessibilityUtils.cpp

@@ -67,6 +67,8 @@ void
 nsAccUtils::GetAccAttr(nsIPersistentProperties *aAttributes, nsIAtom *aAttrName,
                        nsAString& aAttrValue)
 {
+  aAttrValue.Truncate();
+
   nsCAutoString attrName;
   aAttrName->ToUTF8String(attrName);
   aAttributes->GetStringProperty(attrName, aAttrValue);

accessible/src/base/nsAccessible.cpp

@@ -2230,7 +2230,7 @@ nsAccessible::GroupPosition(PRInt32 *aGroupLevel,
   // If 'level' attribute doesn't make sense element then it isn't represented
   // via IAccessible::attributes and groupLevel of groupPosition method is 0.
   // Elements that expose 'level' attribute only (like html headings elements)
-  // don't support this method and all arguements are equealed 0.
+  // don't support this method and all arguements are equalled 0.
 
   NS_ENSURE_ARG_POINTER(aGroupLevel);
   NS_ENSURE_ARG_POINTER(aSimilarItemsInGroup);

accessible/src/msaa/nsAccessibleWrap.cpp

@@ -333,14 +333,21 @@ nsAccessibleWrap::get_accDescription(VARIANT varChild,
 
   nsAutoString description;
 
-  // Try nsIAccessible::groupPosition to make a positional description string.
-  PRInt32 groupLevel;
-  PRInt32 similarItemsInGroup;
-  PRInt32 positionInGroup;
+  // Try to get group attributes to make a positional description string. We
+  // can't use nsIAccessible::groupPosition because the method isn't supposed
+  // to work with elements exposing 'level' attribute only (like HTML headings).
+  nsCOMPtr<nsIPersistentProperties> attributes;
+  nsresult rv = xpAccessible->GetAttributes(getter_AddRefs(attributes));
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (!attributes)
+    return NS_ERROR_FAILURE;
+
+  PRInt32 groupLevel = 0;
+  PRInt32 itemsInGroup = 0;
+  PRInt32 positionInGroup = 0;
+  nsAccUtils::GetAccGroupAttrs(attributes, &groupLevel, &positionInGroup,
+                               &itemsInGroup);
 
-  nsresult rv = xpAccessible->GroupPosition(&groupLevel, &similarItemsInGroup,
-                                            &positionInGroup);
-  if (NS_SUCCEEDED(rv)) {
   if (positionInGroup > 0) {
     if (groupLevel > 0) {
       // XXX: How do we calculate the number of children? Now we append
@@ -378,24 +385,27 @@ nsAccessibleWrap::get_accDescription(VARIANT varChild,
       if (numChildren) {
         nsTextFormatter::ssprintf(description,
                                   NS_LITERAL_STRING("L%d, %d of %d with %d").get(),
-                                    groupLevel, positionInGroup,
-                                    similarItemsInGroup + 1, numChildren);
+                                  groupLevel, positionInGroup, itemsInGroup,
+                                  numChildren);
       } else {
         nsTextFormatter::ssprintf(description,
                                   NS_LITERAL_STRING("L%d, %d of %d").get(),
-                                    groupLevel, positionInGroup,
-                                    similarItemsInGroup + 1);
+                                  groupLevel, positionInGroup, itemsInGroup);
       }
     } else { // Position has no level
       nsTextFormatter::ssprintf(description,
                                 NS_LITERAL_STRING("%d of %d").get(),
-                                  positionInGroup, similarItemsInGroup + 1);
+                                positionInGroup, itemsInGroup);
+    }
+  } else if (groupLevel > 0) {
+    nsTextFormatter::ssprintf(description, NS_LITERAL_STRING("L%d").get(),
+                              groupLevel);
   }
 
+  if (!description.IsEmpty()) {
     *pszDescription = ::SysAllocString(description.get());
     return S_OK;
   }
-  }
 
   xpAccessible->GetDescription(description);
   if (!description.IsEmpty()) {