bug278039 Add a11y description for XUL column

r  = pkwarren
sr = Henry.Jia

accessible/src/atk/nsMaiInterfaceTable.cpp

@@ -428,16 +428,12 @@ getRowDescriptionCB(AtkTable *aTable, gint aRow)
                        accWrap->GetMaiInterface(MAI_INTERFACE_TABLE));
     NS_ENSURE_TRUE(maiTable, nsnull);
 
-    const char *description = maiTable->GetRowDescription();
-    if (!description) {
-        nsAutoString autoStr;
-        nsresult rv = accTable->GetRowDescription(aRow, autoStr);
-        NS_ENSURE_SUCCESS(rv, nsnull);
+    nsAutoString autoStr;
+    nsresult rv = accTable->GetRowDescription(aRow, autoStr);
+    NS_ENSURE_SUCCESS(rv, nsnull);
 
-        maiTable->SetRowDescription(autoStr);
-        description = maiTable->GetRowDescription();
-    }
-    return description;
+    maiTable->SetRowDescription(autoStr);
+    return maiTable->GetRowDescription();
 }
 
 AtkObject*

accessible/src/atk/nsMaiInterfaceTable.h

@@ -55,22 +55,22 @@ public:
     virtual const GInterfaceInfo *GetInterfaceInfo();
 
     const char *GetColumnDescription() {
-        return NS_ConvertUCS2toUTF8(mColumnDescription).get(); 
+        return mColumnDescription.get(); 
     }
     void SetColumnDescription(nsAString &aString) {
-        mColumnDescription = aString;
+        CopyUTF16toUTF8(aString, mColumnDescription);
     }
 
     const char *GetRowDescription() {
-        return NS_ConvertUCS2toUTF8(mRowDescription).get(); 
+        return mRowDescription.get(); 
     }
     void SetRowDescription(nsAString &aString) {
-        mRowDescription = aString;
+        CopyUTF16toUTF8(aString, mRowDescription);
     }
 
 private:
-    nsString mColumnDescription;
-    nsString mRowDescription;
+    nsCString mColumnDescription;
+    nsCString mRowDescription;
 };
 
 #endif /* __MAI_INTERFACE_TABLE_H__ */

accessible/src/atk/nsXULTreeAccessibleWrap.cpp

@@ -319,7 +319,12 @@ NS_IMETHODIMP nsXULTreeAccessibleWrap::GetRowExtentAt(PRInt32 aRow, PRInt32 aCol
 
 NS_IMETHODIMP nsXULTreeAccessibleWrap::GetColumnDescription(PRInt32 aColumn, nsAString & _retval)
 {
-  return NS_ERROR_NOT_IMPLEMENTED;
+  nsCOMPtr<nsIAccessibleTable> columnHeader;
+  nsresult rv = GetColumnHeader(getter_AddRefs(columnHeader));
+  if (NS_SUCCEEDED(rv) && columnHeader) {
+    return columnHeader->GetColumnDescription(aColumn, _retval);
+  }
+  return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP nsXULTreeAccessibleWrap::GetRowDescription(PRInt32 aRow, nsAString & _retval)
@@ -533,7 +538,12 @@ NS_IMETHODIMP nsXULTreeColumnsAccessibleWrap::GetRowExtentAt(PRInt32 aRow, PRInt
 
 NS_IMETHODIMP nsXULTreeColumnsAccessibleWrap::GetColumnDescription(PRInt32 aColumn, nsAString & _retval)
 {
-  return NS_ERROR_NOT_IMPLEMENTED;
+  nsCOMPtr<nsIAccessible> column;  
+  nsresult rv = CellRefAt(0, aColumn, getter_AddRefs(column));
+  if (NS_SUCCEEDED(rv) && column) {
+    return column->GetName(_retval);
+  }
+  return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP nsXULTreeColumnsAccessibleWrap::GetRowDescription(PRInt32 aRow, nsAString & _retval)