Preserves the scroll position on refresh

This sample demonstrates a functionality of top item position persistence. This persistence is based on topVisible element's index (offset) which is stored in URL ($location). So when you do some scrolls you see that 'offset' param is persisted via URL hash. Then you refresh the page and after that the $index value (and leftmost column in the example) changes, but the item which used to be on top stays on top.