Scroll past section header upon tapping section index? - ios

Question

I've implemented a UITableView that has section headers above each section. I've designed the table with the Grouped style so the headers scroll with the table instead of fixing to the top. I have also added a section index so users can tap/swipe to jump to a specific section. The problem is doing so jumps to that section but it shows the section header at the top. In this case that's undesirable - I want to scroll so the very top of the first cell is at the top of the screen, with that section header not visible.
How can you scroll just past the section header when the user taps an icon in the section index for UITableView?

Answer 1

Just try this
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 section:desiredSectionIndex];
[tableView scrollToRowAtIndexPath: indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];

Answer 2

Found a solution. Perhaps there is a cleaner solution but this is working well for me.
Return -1 to prevent the table view from scrolling to any section when that method is called. Just before the return, add the logic to scroll to the desired location by getting and modifying the frame of the next cell.
- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index {
CGRect nextRowRect = [tableView rectForRowAtIndexPath:[NSIndexPath indexPathForRow:1 inSection:index]];
nextRowRect.origin.y -= tableView.rowHeight;
nextRowRect.size.height += tableView.frame.size.height - tableView.contentInset.top - tableView.contentInset.bottom - tableView.rowHeight;
[tableView scrollRectToVisible:nextRowRect animated:NO];
return -1; //prevent auto scroll
}