iPad: Keeping a selected table view cell on screen

Question

On the iPad I show a UIPopover when the user selects cells in a UITableView. The cell stays selected until the popover is dismissed.

When the user rotates the device from portrait to landscape orientation and the selected cell was on the lower part of the screen, it will disappear after the rotation and the popover ends up pointing at another (indifferent) cell.

How can I make sure that the selected cell in a UITableView stays on screen when rotating from portrait to landscape orientation?

Update: Combining Caleb's and kviksilver's codes, the following is a working solution:

-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    CGRect activeCellRect = [self.tableView rectForRowAtIndexPath:self.indexPath];
    if ((activeCellRect.origin.y + activeCellRect.size.height) >
        (self.view.frame.origin.y + self.view.frame.size.height))
    {
        // If a row ends up off screen after a rotation, bring it back
        // on screen.
        [self.tableView scrollToRowAtIndexPath:self.indexPath
                              atScrollPosition:UITableViewScrollPositionBottom
                                      animated:YES];
    }
}

Update 2, on repositioning the UIPopover: After the scroll command it is necessary to send a reloadData message to the table view. Then the rectForRowAtIndexPath: method will correctly report the new position of the cell (otherwise it will not, as it is not updated properly after the scroll-command)!

kviksilver kviksilver · Accepted Answer · 2011-06-18T13:26:26

On orientation change try checking indexPathsForVisibleRows to see if your cell is visible and then using scrollToRowAtIndexPath if not.. something like:

-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation{
    if (![[self.tableView indexPathsForVisibleRows] containsObject:[self.tableView indexPathForSelectedRow]]) {
        [self.tableView scrollToRowAtIndexPath:[self.tableView indexPathForSelectedRow] atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
    }
}

iPad: Keeping a selected table view cell on screen

2 Answers