protected function getFileName($layoutSrc)
	{
		$filename = $this->getLayoutDir() . \DIRECTORY_SEPARATOR . $layoutSrc;
		if ( ! is_file($filename)) {
			throw new LayoutNotFound("File '$layoutSrc' was not found");
		}
		if ( ! is_readable($filename)) {
			throw new \RuntimeException("File '$layoutSrc' is not readable");
		}

		// security stuff
		$this->securityCheck($filename);

		return $filename;
	}