How to notice if a UITableViewCell has left the visible area?

I'm stuck with the problem that I want to know in my UITableView if a specific UITableViewCell, let's say the first, is still visible or already off the visible area. I would also be ok to know if the cell of interest is now beeing reused at an other index开发者_JAVA技巧Path of the table.

One of my - later and frustrated approaches - was to have a thread that knows the first cell object and frequently pings it to check if a value I did set in the cell changed. Obviously a not so good solution.

Andy ideas how to do this right?

Remember that UITableView is UIScrollView subclass and its delegate also confirms to UIScrollViewDelegate protocol as well.

So in your table delegate you can implement scrollViewDidScroll: method and check contentOffset - if it's more then first cell height then first cell is not visible. You can also get the array off all currently visible cells using -visibleCells method, but I think knowing contentOffset should be enough.