Phalcon\Paginator\Pager\Range\Sliding::getRange PHP Method

    public function getRange()
    {
        $page = $this->pager->getCurrentPage();
        $pages = $this->pager->getLastPage();
        $chunk = $this->chunkLength;
        if ($chunk > $pages) {
            $chunk = $pages;
        }
        $chunkStart = (int) ($page - floor($chunk / 2));
        $chunkEnd = (int) ($page + (ceil($chunk / 2) - 1));
        if ($chunkStart < 1) {
            $adjust = 1 - $chunkStart;
            $chunkStart = 1;
            $chunkEnd = $chunkEnd + $adjust;
        }
        if ($chunkEnd > $pages) {
            $adjust = $chunkEnd - $pages;
            $chunkStart = $chunkStart - $adjust;
            $chunkEnd = $pages;
        }
        return range($chunkStart, $chunkEnd);
    }