JGraphDistanceCostFunction.java :  » Graphic-Library » jgraph » com » jgraph » algebra » cost » Java Open Source

/*
 * $Id: JGraphDistanceCostFunction.java,v 1.1 2009/09/25 15:14:15 david Exp $
 * Copyright (c) 2001-2005, Gaudenz Alder
 * 
 * All rights reserved. 
 * 
 * This file is licensed under the JGraph software license, a copy of which
 * will have been provided to you in the file LICENSE at the root of your
 * installation directory. If you are unable to locate this file please
 * contact JGraph sales for another copy.
 */
package com.jgraph.algebra.cost;

import java.awt.geom.Point2D;

import org.jgraph.graph.CellMapper;
import org.jgraph.graph.CellView;
import org.jgraph.graph.EdgeView;

/**
 * This class implements a priority queue.
 */
public class JGraphDistanceCostFunction implements JGraphCostFunction {
  
  protected CellMapper mapper = null;

  public JGraphDistanceCostFunction(CellMapper mapper) {
    this.mapper = mapper;
  }
  
  /**
   *
   */
  public double getCost(Object cell) {
    if (mapper != null) {
      CellView view = mapper.getMapping(cell, false);
      return getLength(view);
    } else {
      return 1.0;
    }
  }

  /**
   *
   */
  public static double getLength(CellView view) {
    double cost = 1.0;
    if (view instanceof EdgeView) {
      EdgeView edge = (EdgeView) view;
      Point2D last = null, current = null;
      for (int i = 0; i < edge.getPointCount(); i++) {
        current = edge.getPoint(i);
        if (last != null)
          cost += last.distance(current);
        last = current;
      }
    }
    return cost;
  }
}