BendpointConnectionRouter.java

/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.draw2d;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.draw2d.geometry.Point;
import org.eclipse.draw2d.geometry.PointList;
import org.eclipse.draw2d.geometry.PrecisionPoint;

/**
 * Routes {@link Connection}s through a <code>List</code> of {@link Bendpoint Bendpoints}.
 */
public class BendpointConnectionRouter
	extends AbstractRouter
{

private Map constraints = new HashMap(11);

private static final PrecisionPoint A_POINT = new PrecisionPoint();

/**
 * Gets the constraint for the given {@link Connection}.  
 *
 * @param connection The connection whose constraint we are retrieving
 * @return The constraint
 */
public Object getConstraint(Connection connection) {
	return constraints.get(connection);
}

/**
 * Removes the given connection from the map of constraints.
 *
 * @param connection The connection to remove
 */
public void remove(Connection connection) {
	constraints.remove(connection);
}

/**
 * Routes the {@link Connection}.  Expects the constraint to be a List
 * of {@link org.eclipse.draw2d.Bendpoint Bendpoints}.
 *
 * @param conn The connection to route
 */
public void route(Connection conn) {
	PointList points = conn.getPoints();
	points.removeAllPoints();

	List bendpoints = (List)getConstraint(conn);
	if (bendpoints == null)
		bendpoints = Collections.EMPTY_LIST;

	Point ref1, ref2;

	if (bendpoints.isEmpty()) {
		ref1 = conn.getTargetAnchor().getReferencePoint();
		ref2 = conn.getSourceAnchor().getReferencePoint();
	} else {
		ref1 = new Point(((Bendpoint)bendpoints.get(0)).getLocation());
		conn.translateToAbsolute(ref1);
		ref2 = new Point(((Bendpoint)bendpoints.get(bendpoints.size() - 1)).getLocation());
		conn.translateToAbsolute(ref2);
	}

	A_POINT.setLocation(conn.getSourceAnchor().getLocation(ref1));
	conn.translateToRelative(A_POINT);
	points.addPoint(A_POINT);

	for (int i = 0; i < bendpoints.size(); i++) {
		Bendpoint bp = (Bendpoint)bendpoints.get(i);
		points.addPoint(bp.getLocation());
	}

	A_POINT.setLocation(conn.getTargetAnchor().getLocation(ref2));
	conn.translateToRelative(A_POINT);
	points.addPoint(A_POINT);
	conn.setPoints(points);
}

/**
 * Sets the constraint for the given {@link Connection}.
 *
 * @param connection The connection whose constraint we are setting
 * @param constraint The constraint
 */
public void setConstraint(Connection connection, Object constraint) {
	constraints.put(connection, constraint);
}

}