protected function addCriteriaToPositionQuery($query)
    {
        // Find products in the same category
        $products = ProductCategoryQuery::create()
            ->filterByCategoryId($this->getDefaultCategoryId())
            ->filterByDefaultCategory(true)
            ->select('product_id')
            ->find();

        if ($products != null) {
            $query->filterById($products, Criteria::IN);
        }
    }