/* $Id: PathConvPercent2.java 17865 2010-01-12 20:45:26Z 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:

  *    tfmorris

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

  *

  * 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.ui;

 import java.awt.Point;

 import org.tigris.gef.base.PathConv;

 import org.tigris.gef.presentation.Fig;

 /**

  * Used to place labels as specific positions along a FigEdge. For example, a

  * label can be placed in the middle of a FigEdge by using 50%. This version

  * changes the behavior as it tries to avoid that the itemFig cuts through the

  * pathFig.

  *

  * @author abonner@ics.uci.edu

  */

 public class PathConvPercent2 extends PathConv {

     /**

      * The item Fig.

      */

     private Fig itemFig;

     /**

      * The percent.

      */

     private int percent;

     /**

      * The offset.

      */

     private int offset;

     /**

      * Constructor.

      *

      * @param theFig The Fig.

      * @param theItemFig The item Fig.

      * @param newPercent The percent.

      * @param newOffset The offset.

      */

     public PathConvPercent2(Fig theFig, Fig theItemFig, int newPercent,

             int newOffset) {

         super(theFig);

         itemFig = theItemFig;

         setPercentOffset(newPercent, newOffset);

     }

     /*

      * @see org.tigris.gef.base.PathConv#stuffPoint(java.awt.Point)

      */

     public void stuffPoint(Point res) {

         int figLength = _pathFigure.getPerimeterLength();

         if (figLength < 10) {

             res.setLocation(_pathFigure.getCenter());

             return;

         }

         int pointToGet = (figLength * percent) / 100;

         _pathFigure.stuffPointAlongPerimeter(pointToGet, res);

         applyOffsetAmount(_pathFigure.pointAlongPerimeter(pointToGet + 5),

                 _pathFigure.pointAlongPerimeter(pointToGet - 5), offset, res);

     }

     /**

      * Set the percent and offset again.

      *

      * @param newPercent The new percent.

      * @param newOffset The new offset.

      */

     public void setPercentOffset(int newPercent, int newOffset) {

         percent = newPercent;

         offset = newOffset;

     }

     /*

      * @see org.tigris.gef.base.PathConv#setClosestPoint(java.awt.Point)

      */

     public void setClosestPoint(Point newPoint) {

     }

     /*

      * @see org.tigris.gef.base.PathConv#applyOffsetAmount(java.awt.Point, java.awt.Point, int, java.awt.Point)

      */

     protected void applyOffsetAmount(

             Point p1, Point p2,

             int theOffset, Point res) {

         // slope of the line we're finding the normal to

         // is slope, and the normal is the negative reciprocal

         // slope is (p1.y - p2.y) / (p1.x - p2.x)

         // so recip is - (p1.x - p2.x) / (p1.y - p2.y)

         int recipnumerator = (p1.x - p2.x) * -1;

         int recipdenominator = (p1.y - p2.y);

         if (recipdenominator == 0 && recipnumerator == 0) {

             return;

         }

         // find the point offset on the line that gives a

         // correct offset

         double len =

             Math.sqrt(recipnumerator * recipnumerator

                 + recipdenominator * recipdenominator);

         int dx = (int) ((recipdenominator * theOffset) / len);

         int dy = (int) ((recipnumerator * theOffset) / len);

         res.x += Math.abs(dx);

         res.y -= Math.abs(dy);

         int width = itemFig.getWidth() / 2;

         if (recipnumerator != 0) {

             double slope = (double) recipdenominator / (double) recipnumerator;

             double factor = tanh(slope);

             res.x += (Math.abs(factor) * width);

         } else {

             res.x += width;

         }

     }

     /**

      * Calculate the tangens hyperbolicus.

      *

      * @param x The argument.

      * @return tangens hyberbolicus

      */

     private double tanh(double x) {

         return ((Math.exp(x) - Math.exp(-x)) / 2)

             / ((Math.exp(x) + Math.exp(-x)) / 2);

     }

     /**

      * The UID.

      */

     private static final long serialVersionUID = -8079350336685789199L;

 }