iPhone - how to scroll two UITableViews symmetrically

Question

In my app, I have two tableViews side by side. When the user scrolls on, I would like the second one to scroll at the same time, so it looks almost like one table with two d

Answer 1

also, the tableview that got scrolled by the user should not be sent setContentOffset: message in scrollViewDidScroll, since it will get the app into endless cycle. so additional UIScrollViewDelegate methods should be implemented in order to solve the problem:

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    beingScrolled_ = nil;
}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{    
    if(beingScrolled_ == nil)
        beingScrolled_ = scrollView;
}

and modifying Inspire48's version scrollViewDidScroll: accordingly:

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    UIScrollView *otherScrollView = (scrollView == self.tableView1) ? self.tableView2 : self.tableView1;
    if(otherScrollView != beingScrolled)
    {
        [otherScrollView setContentOffset:[scrollView contentOffset] animated:NO];
    }
}

where beingScrolled_ is an ivar of type UIScrollView