Connector.java

/*
 * @(#)Connector.java 5.1
 *
 */

package CH.ifa.draw.framework;

import java.awt.Graphics;
import java.awt.Point;
import java.awt.Rectangle;
import java.io.Serializable;

import CH.ifa.draw.util.Storable;

/**
 * Connectors know how to locate a connection point on a figure.
 * A Connector knows its owning figure and can determine either
 * the start or the endpoint of a given connection figure. A connector
 * has a display box that describes the area of a figure it is
 * responsible for. A connector can be visible but it doesn't have
 * to be.<br>
 * <hr>
 * <b>Design Patterns</b><P>
 * <img src="images/red-ball-small.gif" width=6 height=6 alt=" o ">
 * <b><a href=../pattlets/sld004.htm>Strategy</a></b><br>
 * Connector implements the strategy to determine the connections points.<br>
 * <img src="images/red-ball-small.gif" width=6 height=6 alt=" o ">
 * <b><a href=../pattlets/sld016.htm>Factory Method</a></b><br>
 * Connectors are created by the Figure's factory method connectorAt.
 * <hr>
 *
 * @see Figure#connectorAt
 * @see ConnectionFigure
 */
public interface Connector extends Serializable, Storable {

	/**
	 * Finds the start point for the connection.
	 */
	public abstract Point findStart(ConnectionFigure connection);

	/**
	 * Finds the end point for the connection.
	 */
	public abstract Point findEnd(ConnectionFigure connection);

	/**
	 * Gets the connector's owner.
	 */
	public abstract Figure owner();

	/**
	 * Gets the display box of the connector.
	 */
	public abstract Rectangle displayBox();

	/**
	 * Tests if a point is contained in the connector.
	 */
	public abstract boolean containsPoint(int x, int y);

	/**
	 * Draws this connector. Connectors don't have to be visible
	 * and it is OK leave this method empty.
	 */
	public abstract void draw(Graphics g);

}