third-party/net.sf.jung2/src/main/java/edu/uci/ics/jung/algorithms/layout/RadialTreeLayout.java

   1 /*
   2  * Copyright (c) 2005, the JUNG Project and the Regents of the University of
   3  * California All rights reserved.
   4  *
   5  * This software is open-source under the BSD license; see either "license.txt"
   6  * or http://jung.sourceforge.net/license.txt for a description.
   7  *
   8  * Created on Jul 9, 2005
   9  */
  10
  11 package edu.uci.ics.jung.algorithms.layout;
  12 import java.awt.Dimension;
  13 import java.awt.geom.Point2D;
  14 import java.util.HashMap;
  15 import java.util.Map;
  16
  17 import edu.uci.ics.jung.graph.Forest;
  18
  19 /**
  20  * A radial layout for Tree or Forest graphs.
  21  *
  22  * @author Tom Nelson
  23  *
  24  */
  25 public class RadialTreeLayout<V,E> extends TreeLayout<V,E> {
  26
  27     protected Map<V,PolarPoint> polarLocations;
  28
  29     /**
  30      * Creates an instance for the specified graph with default X and Y distances.
  31      */
  32     public RadialTreeLayout(Forest<V,E> g) {
  33         this(g, DEFAULT_DISTX, DEFAULT_DISTY);
  34     }
  35
  36     /**
  37      * Creates an instance for the specified graph and X distance with
  38      * default Y distance.
  39      */
  40     public RadialTreeLayout(Forest<V,E> g, int distx) {
  41         this(g, distx, DEFAULT_DISTY);
  42     }
  43
  44     /**
  45      * Creates an instance for the specified graph, X distance, and Y distance.
  46      */
  47     public RadialTreeLayout(Forest<V,E> g, int distx, int disty) {
  48         super(g, distx, disty);
  49     }
  50
  51         @Override
  52     protected void buildTree() {
  53             super.buildTree();
  54             this.polarLocations = new HashMap<V, PolarPoint>();
  55         setRadialLocations();
  56     }
  57
  58     @Override
  59     public void setSize(Dimension size) {
  60         this.size = size;
  61         buildTree();
  62     }
  63
  64     @Override
  65     protected void setCurrentPositionFor(V vertex) {
  66         locations.get(vertex).setLocation(m_currentPoint);
  67     }
  68
  69         @Override
  70     public void setLocation(V v, Point2D location)
  71     {
  72         Point2D c = getCenter();
  73         Point2D pv = new Point2D.Double(location.getX() - c.getX(),
  74                 location.getY() - c.getY());
  75         PolarPoint newLocation = PolarPoint.cartesianToPolar(pv);
  76         PolarPoint currentLocation = polarLocations.get(v);
  77         if (currentLocation == null)
  78                 polarLocations.put(v, newLocation);
  79         else
  80                 currentLocation.setLocation(newLocation);
  81      }
  82
  83         /**
  84          * Returns the map from vertices to their locations in polar coordinates.
  85          */
  86         public Map<V,PolarPoint> getPolarLocations() {
  87                 return polarLocations;
  88         }
  89
  90         @Override
  91     public Point2D transform(V v) {
  92                 PolarPoint pp = polarLocations.get(v);
  93                 double centerX = getSize().getWidth()/2;
  94                 double centerY = getSize().getHeight()/2;
  95                 Point2D cartesian = PolarPoint.polarToCartesian(pp);
  96                 cartesian.setLocation(cartesian.getX()+centerX,cartesian.getY()+centerY);
  97                 return cartesian;
  98         }
  99
 100         private Point2D getMaxXY() {
 101                 double maxx = 0;
 102                 double maxy = 0;
 103                 for(Point2D p : locations.values()) {
 104                         maxx = Math.max(maxx, p.getX());
 105                         maxy = Math.max(maxy, p.getY());
 106                 }
 107                 return new Point2D.Double(maxx,maxy);
 108         }
 109
 110         private void setRadialLocations() {
 111                 Point2D max = getMaxXY();
 112                 double maxx = max.getX();
 113                 double maxy = max.getY();
 114                 maxx = Math.max(maxx, size.width);
 115                 double theta = 2*Math.PI/maxx;
 116
 117                 double deltaRadius = size.width/2/maxy;
 118                 for(Map.Entry<V, Point2D> entry : locations.entrySet()) {
 119                         V v = entry.getKey();
 120                         Point2D p = entry.getValue();
 121                         PolarPoint polarPoint = new PolarPoint(p.getX()*theta, (p.getY() - this.distY)*deltaRadius);
 122                         polarLocations.put(v, polarPoint);
 123                 }
 124         }
 125 }