iOS - how to move table cell up while editing

-(BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
    CGPoint pointInTable = [textField.superview convertPoint:textField.frame.origin toView:_tableview];
    CGPoint contentOffset = _tableview.contentOffset;
    
    contentOffset.y = (pointInTable.y - textField.inputAccessoryView.frame.size.height);
    
    NSLog(@"contentOffset is: %@", NSStringFromCGPoint(contentOffset));    
    [_tableview setContentOffset:contentOffset animated:YES];    
    return YES;
}


-(BOOL)textFieldShouldEndEditing:(UITextField *)textField
{
    [textField resignFirstResponder];    
    if ([textField.superview.superview isKindOfClass:[UITableViewCell class]])
    {
        CGPoint buttonPosition = [textField convertPoint:CGPointZero
                                                  toView: _tableview];
        NSIndexPath *indexPath = [_tableview indexPathForRowAtPoint:buttonPosition];
        
        [_tableview scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionMiddle animated:TRUE];
    }
    
    return YES;
}