Code

void AlignNodeTo(DiagramNode node, DiagramNode to)
{
	node.Move(to.Bounds.X, node.Bounds.Y);

	// find all nodes in the same lane as the aligned one
	var nodesInLane = new List<DiagramNode>();
	foreach (var n in diagram.Nodes)
	{
		if (n.LayoutTraits[SwimlaneLayoutTraits.Lane].Equals(
			node.LayoutTraits[SwimlaneLayoutTraits.Lane]))
			nodesInLane.Add(n);
	}

	// if a node intersect the aligned one, move it to the right of it
	foreach (var n in nodesInLane)
		if (n != node && n.Intersects(node))
			n.Move(node.Bounds.Right, n.Bounds.Y);

	nodesInLane.Sort((n1, n2) =>
		n1.Bounds.X.CompareTo(n2.Bounds.X));

	// shift remaining nodes to the right to remove overlaps
	for (int i = 1; i < nodesInLane.Count; i++)
	{
		var n1 = nodesInLane[i - 1];
		var n2 = nodesInLane[i];
		if (n2.Bounds.Left <= n1.Bounds.Right)
			n2.Move(n1.Bounds.Right + 5, n2.Bounds.Y);