selfedge.java

ALGAE是一个快速创建算法演示的框架。目前支持的算法实现语言包括java和c

package edu.odu.cs.zeil.AlgAE.Client.DataViewer.DataGraph;

import edu.odu.cs.zeil.AlgAE.Debug;
import edu.odu.cs.zeil.AlgAE.Direction;
import edu.odu.cs.zeil.AlgAE.Client.DataViewer.DataGraph.Edge;
import edu.odu.cs.zeil.AlgAE.Client.DataViewer.DataGraph.Edgeable;
import edu.odu.cs.zeil.AlgAE.Client.GraphicsInfo;
import java.awt.Color;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Polygon;


  
/**
 *  A self edge is an edge that from a node to itself.
 *
 *
 *  @see NullEdge
 *  @see LinearEdge
 */

public class SelfEdge extends Edge
{

  SelfEdge(Edgeable srcdest, int direction, Color colour, String edgeLabel)
  {
    //pre: srcdest != null
    super (srcdest, srcdest, direction, colour, edgeLabel);
  }
  


  
  Point entryPoint()
  {
    return exitPoint();
  }
  
  


  void draw(GraphicsInfo gi)
  {
    Graphics g = gi.g;
    Point sourcePt = null;

    if (source.position() != null)
      {
	// For directional edges, draw a small circle at the
	// exit point.
	sourcePt = exitPoint();
	if (dir != Direction.ANYDIR) {
	  // Draw a small circle at the exit point.
	  drawExitPoint (gi, sourcePt);
	}
	else {
	  sourcePt = source.exitPoint(Direction.SE);
	}
	
	
	g.setColor (color);

	Point destPt = new Point(sourcePt);

	switch (dir) {
 	case Direction.NNW:
	case Direction.N:
	  destPt.x += gi.getTextOffset().width;
	  g.drawArc (sourcePt.x, sourcePt.y-2*gi.getTextOffset().width,
		     gi.getTextOffset().width, 4*gi.getTextOffset().width,
		     0, 180);
	  sourcePt.x = destPt.x;
	  --sourcePt.y;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;
	  
	case Direction.NNE:
	case Direction.NE:
	  destPt.x -= gi.getTextOffset().width;
	  g.drawArc (destPt.x, sourcePt.y-2*gi.getTextOffset().width,
		     gi.getTextOffset().width, 4*gi.getTextOffset().width,
		     0, 180);
	  sourcePt.x = destPt.x;
	  --sourcePt.y;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;
	  
	case Direction.ENE:
	case Direction.E:
	  destPt.y += gi.getTextOffset().width;
	  g.drawArc (sourcePt.x-2*gi.getTextOffset().width, sourcePt.y,
		     4*gi.getTextOffset().width, gi.getTextOffset().width,
		     270, 180);
	  sourcePt.y = destPt.y;
	  ++sourcePt.x;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;

	case Direction.ESE:
	case Direction.SE:
	case Direction.ANYDIR:
	  destPt.y -= gi.getTextOffset().width;
	  g.drawArc (sourcePt.x-2*gi.getTextOffset().width, destPt.y,
		     4*gi.getTextOffset().width, gi.getTextOffset().width,
		     270, 180);
	  sourcePt.y = destPt.y;
	  ++sourcePt.x;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;


	case Direction.SSE:
	case Direction.S:
	  destPt.x -= gi.getTextOffset().width;
	  g.drawArc (destPt.x, sourcePt.y-2*gi.getTextOffset().width,
		     gi.getTextOffset().width, 4*gi.getTextOffset().width,
		     180, 180);
	  sourcePt.x = destPt.x;
	  ++sourcePt.y;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;
	  

	case Direction.SSW:
	case Direction.SW:
	  destPt.x += gi.getTextOffset().width;
	  g.drawArc (sourcePt.x, sourcePt.y-2*gi.getTextOffset().width,
		     gi.getTextOffset().width, 4*gi.getTextOffset().width,
		     180, 180);
	  sourcePt.x = destPt.x;
	  ++sourcePt.y;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;

	case Direction.WSW:
	case Direction.W:
	  destPt.y -= gi.getTextOffset().width;
	  g.drawArc (sourcePt.x-2*gi.getTextOffset().width, destPt.y,
		     4*gi.getTextOffset().width, gi.getTextOffset().width,
		     90, 180);
	  sourcePt.y = destPt.y;
	  --sourcePt.x;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;


	case Direction.WNW:
	case Direction.NW:
	  destPt.y += gi.getTextOffset().width;
	  g.drawArc (sourcePt.x-2*gi.getTextOffset().width, sourcePt.y,
		     4*gi.getTextOffset().width, gi.getTextOffset().width,
		     90, 180);
	  sourcePt.y = destPt.y;
	  --sourcePt.x;
	  drawArrowHead (destPt, sourcePt, gi);
	  break;
	}

	if (label != null && label.length() != 0)
	  {
	    FontMetrics fm = gi.g.getFontMetrics();
	    int labelwidth = fm.stringWidth(label);
	    int labelheight = fm.getAscent();

	    switch (dir) {
	    case Direction.NNW:
	    case Direction.N:
	    case Direction.NNE:
	    case Direction.NE:
	      g.drawString (label,
			    destPt.x - labelwidth/2,
			    destPt.y - gi.getTextOffset().height*5/2);
	      break;


	    case Direction.ENE:
	    case Direction.E:
	    case Direction.ESE:
	    case Direction.SE:
	    case Direction.ANYDIR:
	      g.drawString (label,
			    destPt.x + gi.getTextOffset().width * 5/2,
			    destPt.y);
	      break;
	      
	    case Direction.SSE:
	    case Direction.S:
	    case Direction.SSW:
	    case Direction.SW:
	      g.drawString (label,
			    sourcePt.x - labelwidth/2,
			    sourcePt.y + gi.getTextOffset().height * 2 +
			      labelheight);
	      break;
	  

	    case Direction.WSW:
	    case Direction.W:
	    case Direction.WNW:
	    case Direction.NW:
	      g.drawString (label,
			    sourcePt.x -
			      gi.getTextOffset().width * 5/2 - labelwidth,
			    sourcePt.y);
	      break;
	    }
	  }
      }
  }
  



  double length()
  {
    return 0.0;
  }
  

  double positionScore(double targetLength)
  {
    return 0.0;
  }


}