package graph.cell;
import graph.rep.*;
import graph.*;
import java.awt.*;

/**
 * A hyper-edge or collection of edges.  A net is essentially
 * a dummy node that is not drawn on the screen, but has a
 * different semantic meaning.
 *
 * @see Node
 * @author Michael Shilman (michaels@eecs.berkeley.edu)
 * @version $Id$
 */
public class Net extends Node {
	/**
	 * An empty net.
	 */
	public Net() {
		super();
		rep = null;
		//rep.fill = Color.green;
	}
	
	/**
	 * Paint all the outgoing edges.
	 */
	public void paint(Graphics g) {
		//XXX  How do we do this?  I suppose the routing
		//XXX  algorithm will place us automatically...
		super.paint(g);
	}
	
	/**
	 * Make a new net which attaches two nodes.
	 */
	public static Net attach(Node n1, Node n2) throws GraphException {
		if(n1.parent != n2.parent) {
			throw(new GraphException("Nodes must be in same graph to be attached by a net!"));
		}
		Net n = new Net();
		n1.parent.add(n);
		n.x = (n1.x + n2.x)/2;
		n.y = (n1.y + n2.y)/2;
		n.w = (n1.w + n2.w)/2;
		n.h = (n1.h + n2.h)/2;
		n1.attach(n);
		n.attach(n2);
		return n;
	}
	
	/**
	 * Make a new net which attaches N nodes.
	 */
	public static Net attach(Node ns[]) throws GraphException {
		if(ns.length > 0) {
			Net n = new Net();
			ns[0].parent.add(n);
			for(int i = 0; i < ns.length; i++) {
				if(ns[i].parent != n.parent) {
					throw(new GraphException());
				}
				n.x += ns[i].x;
				n.y += ns[i].y;
				n.w += ns[i].w;
				n.h += ns[i].h;
				ns[i].attach(n);
			}
			n.x /= ns.length;
			n.y /= ns.length;
			n.w /= ns.length;
			n.h /= ns.length;
			return n;
		}
		return null;

	}
}