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POEternal scrolling UITableView
 

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    <p>I'm trying to create a UITableView with dates, shouldn't be very exciting, I know. It starts around the current date, but the user should be able to scroll down (the future) <em>and up (the past)</em> as far as he/she wants. This results in a potentially infinite number of rows. So what's the way to go about creating this?</p> <p>Returning <code>NSIntegerMax</code> as the number of rows already crashes the app, but even if it wouldn't, that still doesn't account for being able to scroll <em>up</em>. I could start half way of course, but eventually there's a maximum. </p> <p>Any ideas how to do or fake this? Can I update/reload the table somehow without the user noticing, so I never run into a border?</p> <p><strong>SOLUTION:</strong><br> I went with @ender's suggestion and made a table with a fixed amount of cells. But instead of reloading it when the user scrolls to near the edges of the fixed cells, I went with reloading the table when the scrolling grinds to a halt. To accomodate with a user scrolling great distances without stopping, I just increased the row count to 1000, putting the ROW_CENTER constant to 500. This is the method that takes care of updating the rows.</p> <pre><code>- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { NSArray *visible = [self.tableView indexPathsForVisibleRows]; NSIndexPath *upper = [visible objectAtIndex:0]; NSIndexPath *lower = [visible lastObject]; // adjust the table to compensate for the up- or downward scrolling NSInteger upperDiff = ROW_CENTER - upper.row; NSInteger lowerDiff = lower.row - ROW_CENTER; // the greater difference marks the direction we need to compensate NSInteger magnitude = (lowerDiff &gt; upperDiff) ? lowerDiff : -upperDiff; self.offset += magnitude; CGFloat height = [self tableView:self.tableView heightForRowAtIndexPath:lower]; CGPoint current = self.tableView.contentOffset; current.y -= magnitude * height; [self.tableView setContentOffset:current animated:NO]; NSIndexPath *selection = [self.tableView indexPathForSelectedRow]; [self.tableView reloadData]; if (selection) { // reselect a prior selected cell after the reload. selection = [NSIndexPath indexPathForRow:selection.row - magnitude inSection:selection.section]; [self.tableView selectRowAtIndexPath:selection animated:NO scrollPosition:UITableViewScrollPositionNone]; } } </code></pre> <p>The magic breaks when a user scrolls to the edge of the table without stopping, but with the table view <code>bounces</code> property disabled, this merely feels like a minor glitch, yet totally acceptable. As always, thanks StackOverflow!</p>
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