How to dynamically resize UITableViewCell based on UITableView scrolling?

Question

I have tried looking for an answer to this question but so far I haven't got any luck.

Context

I have a UITableView inside a standard UIViewController (NOT a UITableViewController..). I have subclassed UITableViewCell and all the cells in the tableview are from the same class.

Requirement

I would like to find an efficient way to resize the cells based on the scrolling of the tableview. For example, when the cell is at the bottom of the visible list, the height is X. When the cell moves up on the screen, its height should proportionally increase to 2X.

Additional Info

I am close to just ditch the UITableView way and start making my own control that would implement such a feat by subclassing a UIScrollView. However, I would like to see if it is possible before going this path. I did see some very interesting SO posts but nothing that would put me on the right path.

Any hint or help would be highly appreciated.

Answer 1

You would need to respond to the scroll view delegate method scrollViewDidScroll: and implement it to record the cell at the top of the table view and reload the table view. Then your table view delegate method tableView:heightForRowAtIndexPath: sets the cell height by the relationship between the index path and the top cell index path.

Your main issue is performance while reloading the table view all the time.

If you wanted to roll your own solution it would be along the lines of the above description anyway, but you would be able to be more efficient than the table view as the table view will call the tableView:heightForRowAtIndexPath: method once for every row for every reload in order to calculate the total height of the table content.