/*******************************************************************************
 * Copyright (c) 2000, 2010 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 org.eclipse.draw2d.geometry.PointList;

/**
 * A Connection is a figure that connects two objects.
 */
public interface Connection extends IFigure {

	/**
	 * The connection router property. Used to signify that the ConnectionRouter
	 * has changed.
	 */
	String PROPERTY_CONNECTION_ROUTER = "connectionRouter"; //$NON-NLS-1$
	/**
	 * The points property. Used to signify the points in the Connection have
	 * changed.
	 */
	String PROPERTY_POINTS = "points"; //$NON-NLS-1$

	/**
	 * Returns the ConnectionRouter used to route this Connection. Does not
	 * return null.
	 * 
	 * @return The ConnectionRouter for this Connection
	 */
	ConnectionRouter getConnectionRouter();

	/**
	 * Sets the ConnectionRouter for this Connection.
	 * 
	 * @param router
	 *            The ConnectionRouter to set for this Connection
	 */
	void setConnectionRouter(ConnectionRouter router);

	/**
	 * Returns the ConnectionAnchor at the <b>source</b> end of this Connection.
	 * 
	 * @return The ConnectionAnchor at the <b>source</b> end of this Connection
	 */
	ConnectionAnchor getSourceAnchor();

	/**
	 * Returns the ConnectionAnchor at the <b>target</b> end of this Connection.
	 * 
	 * @return The ConnectionAnchor at the <b>target</b> end of this Connection
	 */
	ConnectionAnchor getTargetAnchor();

	/**
	 * Returns the routing constraint. May be <code>null</code>.
	 * 
	 * @return The routing constraint
	 */
	Object getRoutingConstraint();

	/**
	 * Sets the routing constraint used by the router.
	 * 
	 * @param cons
	 *            The routing constraint
	 */
	void setRoutingConstraint(Object cons);

	/**
	 * Sets the ConnectionAnchor to be used at the <i>source</i> end of this
	 * Connection.
	 * 
	 * @param anchor
	 *            The source anchor
	 */
	void setSourceAnchor(ConnectionAnchor anchor);

	/**
	 * Sets the ConnectionAnchor to be used at the <i>target</i> end of this
	 * Connection.
	 * 
	 * @param anchor
	 *            The target anchor
	 */
	void setTargetAnchor(ConnectionAnchor anchor);

	/**
	 * Returns the PointList containing the Points that make up this Connection.
	 * This may be returned by reference.
	 * 
	 * @return The points for this Connection
	 */
	PointList getPoints();

	/**
	 * Sets the PointList containing the Points that make up this Connection.
	 * 
	 * @param list
	 *            The points for this Connection
	 */
	void setPoints(PointList list);

}