Code

void distributeLinks(DiagramNode node)
{
	DiagramLinkList links = node.getOutgoingLinks();
	int numLinks = links.size();
	if (numLinks == 0)
		return;

	Rectangle2D.Float rect = node.getBounds();
	float available = rect.width;
	float padding = available / (numLinks + 1);
	float currentX = rect.x + padding;
	for (int l = 0; l < numLinks; l++)
	{
		DiagramLink link = links.get(l);
		Point2D.Float point = link.getStartPoint();
		point.x = currentX;
		point.y = (float)rect.getMaxY();
		currentX += padding;
		link.updateFromPoints();
	}
}

void distributeLinks()
{
	for (DiagramNode node : diagram.getNodes())
		distributeLinks(node);
}

Rectangle2D defBounds = new Rectangle2D.Float(10, 10, 30, 20);

void treeLayout()
{
	diagram.clearAll();
	DiagramNode root = diagram.getFactory().createShapeNode(defBounds);
	buildTree(root, 3);

	TreeLayout layout = new TreeLayout();
	layout.setLevelDistance(30);
	layout.arrange(diagram);

	distributeLinks();
}

void buildTree(DiagramNode parent, int depth)
{
	for (int i = 0; i < 3; i++)
	{
		DiagramNode child = diagram.getFactory().createShapeNode(defBounds);
		diagram.getFactory().createDiagramLink(parent,  child);
		if (depth >= 0)
			buildTree(child, depth - 1);
	}
}