/* $Id: LayoutHelper.java 17858 2010-01-12 19:59:48Z linus $

  *****************************************************************************

  * Copyright (c) 2009 Contributors - see below

  * 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:

  *    mvw

  *****************************************************************************

  *

  * Some portions of this file was previously release using the BSD License:

  */

 // Copyright (c) 1996-2006 The Regents of the University of California. All

 // Rights Reserved. Permission to use, copy, modify, and distribute this

 // software and its documentation without fee, and without a written

 // agreement is hereby granted, provided that the above copyright notice

 // and this paragraph appear in all copies.  This software program and

 // documentation are copyrighted by The Regents of the University of

 // California. The software program and documentation are supplied "AS

 // IS", without any accompanying services from The Regents. The Regents

 // does not warrant that the operation of the program will be

 // uninterrupted or error-free. The end-user understands that the program

 // was developed for research purposes and is advised not to rely

 // exclusively on the program for any reason.  IN NO EVENT SHALL THE

 // UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,

 // SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,

 // ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF

 // THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF

 // SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY

 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE

 // PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF

 // CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,

 // UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 package org.argouml.uml.diagram.layout;

 import java.awt.Point;

 import java.awt.Rectangle;

 import java.awt.Polygon;

 /** LayoutHelper is a utility class which mainly returns various types

  *  of routing polygons for different kind of connection lines between

  *  two nodes. Specific layouters might use these methods to reuse certain

  *  kinds of diagram lines.

  *  @stereotype utility

 */

 public class LayoutHelper {

     /**

      * A constant bitmask for a direction.

      */

     public static final int NORTH = 0;

     /**

      * A constant bitmask for a direction.

      */

     public static final int NORTHEAST = 1;

     /**

      * A constant bitmask for a direction.

      */

     public static final int EAST = 2;

     /**

      * A constant bitmask for a direction.

      */

     public static final int SOUTHEAST = 4;

     /**

      * A constant bitmask for a direction.

      */

     public static final int SOUTH = 8;

     /**

      * A constant bitmask for a direction.

      */

     public static final int SOUTHWEST = 16;

     /**

      * A constant bitmask for a direction.

      */

     public static final int WEST = 32;

     /**

      * A constant bitmask for a direction.

      */

     public static final int NORTHWEST = 64;

     /**

      * @param rect the rectangle

      * @param direction the direction

      * @return the point on the perimeter

      */

     public static Point getPointOnPerimeter(Rectangle rect, int direction) {

         return getPointOnPerimeter(rect, direction, 0, 0);

     }

     /**

      * @param rect the rectangle

      * @param direction the direction

      * @param xOff the x offset

      * @param yOff the y offset

      * @return the point on the perimeter

      */

     public static Point getPointOnPerimeter(Rectangle rect, int direction,

                                             double xOff, double yOff) {

         double x = 0;

         double y = 0;

         if (direction == NORTH

                 || direction == NORTHEAST

                 || direction == NORTHWEST) {

             y = rect.getY();

         }

         if (direction == SOUTH

                 || direction == SOUTHWEST

                 || direction == SOUTHEAST) {

             y = rect.getY() + rect.getHeight();

         }

         if (direction == EAST

                 || direction == WEST) {

             y = rect.getY() + rect.getHeight() / 2.0;

         }

         if (direction == NORTHWEST

                 || direction == WEST

                 || direction == SOUTHWEST) {

             x = rect.getX();

         }

         if (direction == NORTHEAST

                 || direction == EAST

                 || direction == SOUTHEAST) {

             x = rect.getX() + rect.getWidth();

         }

         if (direction == NORTH || direction == SOUTH) {

             x = rect.getX() + rect.getWidth() / 2.0;

         }

         x += xOff;

         y += yOff;

         return new Point((int) x, (int) y);

     }

     /**

      * Get a routing polygon for a straightline between two points.

      *

      * @param start start of the line

      * @param end end of the line

      * @return the routing polygon between start and end

      */

     public static Polygon getRoutingPolygonStraightLine(Point start, Point end)

     {

         return getRoutingPolygonStraightLineWithOffset(start, end, 0);

     }

     /**

      * Get a routing polygon with a horizontal offset from the two points.

      *

      * @param start start of the line

      * @param end end of the line

      * @param offset the given offset

      * @return the routing polygon between start and end

      */

     public static Polygon getRoutingPolygonStraightLineWithOffset(Point start,

                                                 Point end, int offset) {

         Polygon newPoly = new Polygon();

         newPoly.addPoint((int) start.getX(), (int) start.getY());

         if (offset != 0) {

             double newY = 0.0;

             if (offset < 0) {

                 newY =

                     Math.min(start.getY() + offset, end.getY() + offset);

             }

             if (offset > 0) {

                 newY =

                     Math.max(start.getY() + offset, end.getY() + offset);

             }

             newPoly.addPoint((int) start.getX(), (int) newY);

             newPoly.addPoint((int) end.getX(), (int) newY);

         }

         newPoly.addPoint((int) end.getX(), (int) end.getY());

         return newPoly;

     }

 }