/*
    * TouchGraph LLC. Apache-Style Software License
    *
    *
    * Copyright (c) 2001-2002 Alexander Shapiro. All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer. 
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:  
   *       "This product includes software developed by 
   *        TouchGraph LLC (http://www.touchgraph.com/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "TouchGraph" or "TouchGraph LLC" must not be used to endorse 
   *    or promote products derived from this software without prior written 
   *    permission.  For written permission, please contact 
   *    alex@touchgraph.com
   *
   * 5. Products derived from this software may not be called "TouchGraph",
   *    nor may "TouchGraph" appear in their name, without prior written
   *    permission of alex@touchgraph.com.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL TOUCHGRAPH OR ITS CONTRIBUTORS BE 
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 
   * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
   * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
   * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   */
  
  package com.touchgraph.graphlayout;
  
  import java.awt.*;
  
  /***  Edge.
    *
    * @author   Alexander Shapiro
    * @version  1.21  $Id: Edge.java,v 1.1.1.1 2004/02/06 08:44:05 keesj Exp $
    */
  public class Edge {
  
      public static Color DEFAULT_COLOR = Color.decode("#0000B0");
      public static Color MOUSE_OVER_COLOR = Color.pink;
      public static int DEFAULT_LENGTH = 40;
  
      public Node from; //Should be private, changing from effects "from" Node
      public Node to;   //Should be private, changing from effects "to" Node
      protected Color col;
      protected int length;
      protected boolean visible;
      protected String id = null;
  
    // ............
  
      /*** Constructor with two Nodes and a length.
        */
      public Edge(Node f, Node t, int len) {
          from = f;
          to = t;
          length = len;
          col = DEFAULT_COLOR;
          visible = false;
      }
  
      /*** Constructor with two Nodes, which uses a default length.
        */
      public Edge(Node f, Node t) {
          this(f, t, DEFAULT_LENGTH);
      }
  
     // setters and getters ...............
     
      public static void setEdgeDefaultColor( Color color ) { DEFAULT_COLOR = color; }
      public static void setEdgeMouseOverColor( Color color ) { MOUSE_OVER_COLOR = color; }
      public static void setEdgeDefaultLength( int length ) { DEFAULT_LENGTH = length; }
  
     /*** Returns the starting "from" node of this edge as Node. */
      public Node getFrom() { return from; }
      
     /*** Returns the terminating "to" node of this edge as Node. */
     public Node getTo() { return to; }
     
    /*** Returns the color of this edge as Color. */
     public Color getColor() {
         return col;
     }
 
    /*** Set the color of this Edge to the Color <tt>color</tt>. */
     public void setColor( Color color ) {
         col = color;
     }
 
    /*** Returns the ID of this Edge as a String. */
     public String getID()
     {
         return id;
     }
 
    /*** Set the ID of this Edge to the String <tt>id</tt>. */
     public void setID( String id )
     {
         this.id=id;
     }
 
    /*** Returns the length of this Edge as a double. */
     public int getLength() {
         return length;
     }
 
    /*** Set the length of this Edge to the int <tt>len</tt>. */
     public void setLength(int len) {
         length=len;
     }
 
    /*** Set the visibility of this Edge to the boolean <tt>v</tt>. */
     public void setVisible( boolean v) {
         visible = v;
     } 
 
    /*** Return the visibility of this Edge as a boolean. */
     public boolean isVisible() {
         return visible;
     } 
 
     public Node getOtherEndpt(Node n) { //yields false results if Node n is not an endpoint
         if (to != n) return to;
         else return from;
     }
 
     /*** Switches the endpoints of the edge */
     public void reverse() {
         Node temp = to;
         to = from;
         from = temp;
     }
 
     public boolean intersects(Dimension d) {
         int x1 = (int) from.drawx;
         int y1 = (int) from.drawy;
         int x2 = (int) to.drawx;
         int y2 = (int) to.drawy;
 
         return (((x1>0 || x2>0) && (x1<d.width  || x2<d.width)) &&
                   ((y1>0 || y2>0) && (y1<d.height || y2<d.height) ));
 
     }
 
     public double distFromPoint(double px, double py) {
         double x1= from.drawx;
         double y1= from.drawy;
         double x2= to.drawx;
         double y2= to.drawy;
 
         if (px<Math.min(x1, x2)-8 || px>Math.max(x1, x2)+8 ||
             py<Math.min(y1, y2)-8 || py>Math.max(y1, y2)+8)
             return 1000;
 
         double dist = 1000;
         if (x1-x2!=0) dist = Math.abs((y2-y1)/(x2-x1)*(px - x1) + (y1 - py));
         if (y1-y2!=0) dist = Math.min(dist, Math.abs((x2-x1)/(y2-y1)*(py - y1) + (x1 - px)));
 
         return dist;
     }
 
     public boolean containsPoint(double px, double py) {
         return distFromPoint(px,py)<10;
     }
 
     public static void paintArrow(Graphics g, int x1, int y1, int x2, int y2, Color c) {
         //Forget hyperbolic bending for now
 
         g.setColor(c);
 
         int x3=x1;
         int y3=y1;
 
         double dist=Math.sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1));
         if (dist>10) {
             double adjustDistRatio = (dist-10)/dist;
             x3=(int) (x1+(x2-x1)*adjustDistRatio);
             y3=(int) (y1+(y2-y1)*adjustDistRatio);
         }
 
         x3=(int) ((x3*4+x1)/5.0);
         y3=(int) ((y3*4+y1)/5.0);
 
         g.drawLine(x3,   y3,   x2, y2);
         g.drawLine(x1,   y1,   x3, y3);
         g.drawLine(x1+1, y1,   x3, y3);
         g.drawLine(x1+2, y1,   x3, y3);
         g.drawLine(x1+3, y1,   x3, y3);
         g.drawLine(x1+4, y1,   x3, y3);
         g.drawLine(x1-1, y1,   x3, y3);
         g.drawLine(x1-2, y1,   x3, y3);
         g.drawLine(x1-3, y1,   x3, y3);
         g.drawLine(x1-4, y1,   x3, y3);
         g.drawLine(x1,   y1+1, x3, y3);
         g.drawLine(x1,   y1+2, x3, y3);
         g.drawLine(x1,   y1+3, x3, y3);
         g.drawLine(x1,   y1+4, x3, y3);
         g.drawLine(x1,   y1-1, x3, y3);
         g.drawLine(x1,   y1-2, x3, y3);
         g.drawLine(x1,   y1-3, x3, y3);
         g.drawLine(x1,   y1-4, x3, y3);
     }
 
     public void paint(Graphics g, TGPanel tgPanel) {
         Color c = (tgPanel.getMouseOverE()==this) ? MOUSE_OVER_COLOR : col;
 
         int x1=(int) from.drawx;
         int y1=(int) from.drawy;
         int x2=(int) to.drawx;
         int y2=(int) to.drawy;
         if (intersects(tgPanel.getSize())) paintArrow(g, x1, y1, x2, y2, c);
     }
 
 } // end com.touchgraph.graphlayout.Edge