modules/base/src/main/java/javafx/collections/transformation/TransformationList.java

rev 9769 : 8139848: SortedList should provide a way to map source index to view index

*** 146,151 ****
--- 146,158 ----
              currentSource = tSource.source;
          }
          return idx;
      }
  
+     /**
+      * Maps the index of the direct source list's element to an index in this list.
+      * @param index the index in the source list
+      * @return the index of the element in this list
+      * @see #getSource(), #getSourceIndex()
+      */
+     public abstract int getViewIndex(int index);
  }