title: With multiple UITableViews in a single UIScrollview, how to only load cell data for visible cells
body: <p>I have 3 uitableviews in a single uiscrollview. Each uitableview is full length and not scrollable so that the outer uiscrollview scrolls them together. This works fine except the uitableviews believe all cells are visible so that all are created up front. Even this is acceptable except each call has an image view (a thumbnail) that is loaded asynchronously from a url. I am trying to figure out how to limit the image loading to only visible cells but still allow the user to scroll the outer uiscrollview (thus mimicking the uitableview behavior).</p>
  
  <p>The alternative design of a single table with cells that show 3 cells each doesn't work (based on other design requirements) so I am stuck with some way to limit the image downloads. The largest number of cells will be 125 or so. The uiscrollview delegate doesn't seem to have enough calls to allow updating cells on the fly but I could be wrong. Any ideas? </p>