visualedge.java

OpenJGraph是一个开源的Java库

package salvo.jesus.graph.visual;

import java.awt.*;
import java.awt.geom.*;
import java.awt.geom.Point2D.*;
import salvo.jesus.graph.java.awt.geom.Point2DDouble;
import salvo.jesus.geom.*;
import salvo.jesus.graph.*;
import salvo.jesus.graph.visual.layout.*;
import salvo.jesus.graph.visual.drawing.*;

/**
 * The VisualEdge class encapsulates an <tt>Edge</tt> with attributes
 * used for visual rendering of the vertex. Visual attributes in
 * addition to those already defined in <tt>AbstractVisualGraphComponent</tt>
 * are the <tt>Point2D</tt>s where the <tt>VisualEdge</tt> should
 * start and finish. The actual direction and path taken from the two
 * <tt>Point2D</tt>s is defined by the <tt>GeneralPath</tt> in
 * <tt>AbstractVisualGraphComponent</tt>.
 *
 * @author		Jesus M. Salvo Jr.
 */
public	class VisualEdge extends AbstractVisualGraphComponent {

  /**
    * The VisualVertex object of the edge's tail.
    */
  private VisualVertex	  visualVertexA;

  /**
    * The VisualVertex object of the edge's head.
    */
  private VisualVertex	  visualVertexB;

  int               linetype = STRAIGHT_LINE;
  static final int  STRAIGHT_LINE = 1;
  static final int  ORTHOGONAL_LINE = 2;

  private Point2DDouble     fromPortAssignment = new Point2DDouble( -1, -1 );
  private Point2DDouble     toPortAssignment = new Point2DDouble( -1, -1 );

  /**
    * Creates a new VisualEdge object that encapsulates the given Edge object.
    * Because an Edge object does not have any knowledge of the VisualVertex
    * in its endpoints, the parameter visualgraph is required for this class
    * to determine the VisualVertex objects at its endpoints.
    *
    * @param	edge	    The Edge object that the VisualEdge will encapsulate.
    * @param  visualgraph   The VisualGraph object where the VisualEdge will be drawn.
    */
  public VisualEdge( Edge edge, VisualGraph vGraph ){
    this.component = edge;
    this.painter = vGraph.getVisualEdgePainterFactory().getPainter( this );

    visualVertexA = vGraph.getVisualVertex( edge.getVertexA( ));
    visualVertexB = vGraph.getVisualVertex( edge.getVertexB( ));
    drawpath = new GeneralPath();
    this.setOutlinecolor( Color.blue );
    this.setFillcolor( Color.blue );
    this.visualGraph = vGraph;
  }

  /**
   * Returns the Edge object that VisualEdge encapsulates.
   *
   * @return	The Edge object that the VisualEdge encapsulates.
   */
  public Edge getEdge( ){
    return (Edge) this.component;
  }

  /**
   * Returns the VisualVertex object at the tail of the edge.
   * For directed graphs, this is the VisualVertex at the opposite end
   * of where the arrowhead is drawn.
   *
   * @return	The VisualVertex object at the tail of the edge.
   */
  public VisualVertex getVisualVertexA( ){
    return visualVertexA;
  }

  /**
   * Returns the VisualVertex object at the head of the edge.
   * For directed graphs, this is the VisualVertex at the end
   * where the arrowhead is drawn.
   *
   * @return	The VisualVertex object at the head of the edge.
   */
  public VisualVertex getVisualVertexB( ){
    return visualVertexB;
  }

  protected void setLinetype( int linetype ){
    this.linetype = linetype;
  }

  public void setOrthogonalLine() {
    this.setLinetype( ORTHOGONAL_LINE );
  }

  public void setStraightLine() {
    this.setLinetype( STRAIGHT_LINE );
  }

  public void setFromPortAssignment( Point2D newport ) {
    this.fromPortAssignment.setLocation( newport );
  }

  public void setToPortAssignment( Point2D newport ) {
    this.toPortAssignment.setLocation( newport );
  }

  public Point2D.Double getFromPortAssignment() {
    return this.fromPortAssignment;
  }

  public Point2D.Double getToPortAssignment() {
    return this.toPortAssignment;
  }

  public String toString() {
    return this.getLabel();
  }

  /**
    * Returns the distance between a point and the edge's path.
    * All segments of the edge's GeneralPath is iterated to determine
    * which segment has the shortest distance with the point, and that
    * distance is returned.
    *
    * @param	x   x coordinate of the point
    * @param    y   y coordinate of the points
    * @return     The distance between the point and the edge's path.
    */
  public double ptSegDist( int x, int y ){
    PathIterator  edgepathiterator;
    double        edgesegment[] = new double[6];
    double        previouspoint[] = new double[2];
    double        currentpoint[] = new double[2];
    int           segmenttype;
    Line2D.Double edgecurrsegment;
    double        distance = 0.0;
    double        currdistance;
    boolean       firstSegment = true;

    // Iterater through all the segments of the edge until we find the edge
    // that is nearest to the point
    edgepathiterator = drawpath.getPathIterator( null );
    while( !edgepathiterator.isDone() ){
      previouspoint[0] = currentpoint[0];
      previouspoint[1] = currentpoint[1];

      segmenttype = edgepathiterator.currentSegment( edgesegment );
      switch( segmenttype ){
      case PathIterator.SEG_LINETO:
      case PathIterator.SEG_MOVETO:
        currentpoint[0] = edgesegment[0];
        currentpoint[1] = edgesegment[1];
        break;
      case PathIterator.SEG_QUADTO:
        currentpoint[0] = edgesegment[2];
        currentpoint[1] = edgesegment[3];
        break;
      case PathIterator.SEG_CUBICTO:
        currentpoint[0] = edgesegment[4];
        currentpoint[1] = edgesegment[5];
      }

      if( segmenttype == PathIterator.SEG_LINETO ||
          segmenttype == PathIterator.SEG_QUADTO ||
          segmenttype == PathIterator.SEG_CUBICTO ){
        currdistance =
            Line2D.ptSegDist(  previouspoint[0], previouspoint[1],
                                currentpoint[0], currentpoint[1], x, y );
        if( currdistance < distance || firstSegment ) {
            firstSegment = false;
            distance = currdistance;
        }
      }
      edgepathiterator.next();
    }
    return distance;
  }

  /**
   * Draw the VisualEdge with the specified 2D graphics context.
   * The endpoints of the line is always determined at every call to this method
   * by the center coordinates of the bounding rectangle of
   * both visualVertexA and visualVertexB.
   *
   * @param	g2d		The Graphics2D graphics context object used to draw
   * the VisualEdge object.
   */
  public void paint( Graphics2D g2d, GraphLayoutManager layoutmanager ){
    this.painter.paint( this, g2d );
  }

  /**
   * Do nothing.
   */
  public void rescale(){}

    /**
     * Returns the length of the <tt>VisualEdge</tt> as dictated by its <tt>GeneralPath</tt>
     */
    public float getEdgeLength( VisualEdge vEdge, Point fromPoint, Point toPoint ) {
        GeneralPath gPath = vEdge.getGeneralPath();
        PathIterator iterator = gPath.getPathIterator( null );
        float  edgeSegment[] = new float[6];
        float  edgeLength = 0;
        float  x1 = 0, y1 = 0, x2 = 0, y2 = 0;
        int     segmentType;
        boolean firstPointInitialized = false;

        while( !iterator.isDone() ){
            segmentType = iterator.currentSegment( edgeSegment );

            switch( segmentType ){
            case PathIterator.SEG_LINETO:
            case PathIterator.SEG_MOVETO:
                x2 = edgeSegment[0];
                y2 = edgeSegment[1];
                break;
            case PathIterator.SEG_QUADTO:
                x2 = edgeSegment[2];
                y2 = edgeSegment[3];
                break;
            case PathIterator.SEG_CUBICTO:
                x2 = edgeSegment[4];
                y2 = edgeSegment[5];
            }

            if( firstPointInitialized ) {
                edgeLength += Point2D.distance( x1, y1, x2, y2 );
            }

            iterator.next();

            x1 = x2;
            y1 = y2;

            if( !firstPointInitialized ) {
                firstPointInitialized = true;
                fromPoint.setLocation( x1, y1 );
            }
        }
        toPoint.setLocation( x2, y2 );

        return edgeLength;
    }
}