#pragma mark - textfield delegate
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
    CGPoint pointInTable = [textField.superview convertPoint:textField.frame.origin toView:self.tableView];
    CGPoint contentOffset = self.tableView.contentOffset;
    contentOffset.y = (pointInTable.y - textField.inputAccessoryView.frame.size.height);
    [self.tableView setContentOffset:contentOffset animated:YES];
    return YES;
}

- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
    [textField resignFirstResponder];
    if ([textField.superview.superview isKindOfClass:[UITableViewCell class]]) {
        UITableViewCell *cell = (UITableViewCell*)textField.superview.superview;
        NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
        [self.tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionMiddle animated:TRUE];
    }
    return YES;
}