Displayed row numbers

I'm using v2.0 grid. Is there a method to get the number(s) of the rows displayed after scrolling? For example, if I have 100 records in the grid and 10 are visible at the time, after scrolling down additional 10 records I would like to know that records 11-20 are displayed.

you need to set obj.setRowHeaderWidth("0");

Enable row selectors (hidden by default) -

obj.setSelectorVisible(true);
    obj.setSelectorText(function(i){return this.getRowPosition(i)+1});
    obj.setSelectorWidth(28);