/*
 * @(#)PolyLineConnector.java
 *
 * Project:		JHotdraw - a GUI framework for technical drawings
 *				http://www.jhotdraw.org
 *				http://jhotdraw.sourceforge.net
 * Copyright:	© by the original author(s) and all contributors
 * License:		Lesser GNU Public License (LGPL)
 *				http://www.opensource.org/licenses/lgpl-license.html
 */

package org.jhotdraw.figures;

import java.awt.*;
import org.jhotdraw.framework.*;
import org.jhotdraw.standard.*;
import org.jhotdraw.util.*;

/**
 * PolyLineConnector finds connection points on a
 * PolyLineFigure.
 *
 * @see PolyLineFigure
 *
 * @version <$CURRENT_VERSION$>
 */
public class PolyLineConnector extends ChopBoxConnector {

	/*
	 * Serialization support.
	 */
	private static final long serialVersionUID = 6018435940519102865L;

	public PolyLineConnector() {
		super();
	}

	/**
	 * Constructs a connector with the given owner figure.
	 */
	public PolyLineConnector(Figure owner) {
		super(owner);
	}

	protected Point chop(Figure target, Point from) {
		PolyLineFigure p = (PolyLineFigure)owner();
		// *** based on PolygonFigure's heuristic
		Point ctr = p.center();
		int cx = -1;
		int cy = -1;
		long len = Long.MAX_VALUE;

		// Try for points along edge

		for (int i = 0; i < p.pointCount()-1; i++) {
			Point p1 = p.pointAt(i);
			Point p2 = p.pointAt(i+1);
			Point chop = Geom.intersect(p1.x,
								 p1.y,
								 p2.x,
								 p2.y,
								 from.x,
								 from.y,
								 ctr.x,
								 ctr.y);
			if (chop != null) {
				long cl = Geom.length2(chop.x, chop.y, from.x, from.y);
				if (cl < len) {
					len = cl;
					cx = chop.x;
					cy = chop.y;
				}
			}
		}
		// if none found, pick closest vertex
		//if (len ==  Long.MAX_VALUE) {
		{ // try anyway
			for (int i = 0; i < p.pointCount(); i++) {
				Point pp = p.pointAt(i);
				long l = Geom.length2(pp.x, pp.y, from.x, from.y);
				if (l < len) {
					len = l;
					cx = pp.x;
					cy = pp.y;
				}
			}
		}
		return new Point(cx, cy);
	}
}

