Scrolling like WhatsApp Chat where scrolling to top, scrolling further shows "Archived Chats"

Question

Just not getting the proper search term, but my question is how can i achieve this tableview feature where i can scroll to top, but only on further scrolling to top, a row appears on top of the first row.

Similar feature where WhatsApp uses to show "Archived Chats", here scrolling to your chat list, further scrolling shows you Archived chats.

I am using swift 2.3

Thank you

Answer 1

Maybe a bit late, but here you have a workaround (objective-c) to replicate the whatsapp archived chats scroll further feature:

I use two booleans to determine if table view is at top position and if the archived chats row is visible.

@property (assign, nonatomic) BOOL isArchivedChatsRowVisible;
@property (assign, nonatomic) BOOL isScrollAtTop;

And with the scroll view delegate, using these bools, insert or remove a section for displaying the archive chats cell.

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    if (scrollView.contentOffset.y > 0 && self.isArchivedChatsRowVisible) {
        self.isScrollAtTop = NO;
        self.isArchivedChatsRowVisible = NO;
        [self.tableView beginUpdates];
        [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationFade];
        [self.tableView endUpdates];
    }

    if (self.isScrollAtTop && scrollView.contentOffset.y < 0 && !self.isArchivedChatsRowVisible) {
        self.isArchivedChatsRowVisible = YES;
        [self.tableView beginUpdates];
        [self.tableView insertSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationMiddle];
        [self.tableView endUpdates];
    }
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {      
    self.isScrollAtTop = scrollView.contentOffset.y > 0 ? NO : YES;
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
    if (scrollView.contentOffset.y > 0) {
        self.isScrollAtTop = NO;
    }
}

I hope it would be useful