ChannelInfo::compareBySort

static function compareBySort(ChannelInfo $first, ChannelInfo $second)
{
	$firstSort = $first->sort;
	$firstGroupSort = -1;
	if($first->groupID !== '')
	{
		$firstGroup = ChannelTrackerManager::getGroupInfo($first->groupID);
		if($firstGroup !== null)
		{
			$firstGroupSort = $firstGroup->getSort();
		}
	}

	$secondSort = $second->sort;
	$secondGroupSort = -1;
	if($second->groupID !== '')
	{
		$secondGroup = ChannelTrackerManager::getGroupInfo($second->groupID);
		if($secondGroup !== null)
		{
			$secondGroupSort = $secondGroup->getSort();
		}
	}

	if($firstGroupSort > 0 && $secondGroupSort > 0 && $firstGroupSort !== $secondGroupSort)
	{
		return ($firstGroupSort - $secondGroupSort);
	}

	if($firstGroupSort > 0)
	{
		$firstSort += $firstGroupSort;
	}

	if($secondGroupSort > 0)
	{
		$secondSort += $secondGroupSort;
	}

	return ($firstSort - $secondSort);
}