beanconnection.java

代码是一个分类器的实现,其中使用了部分weka的源代码。可以将项目导入eclipse运行

            angle = Math.atan(a);
          } catch(Exception ex) {
            angle = Math.PI / 2;
          }
          //	Point arrowstart = new Point((p1.x + p2.x) / 2, (p1.y + p2.y) / 2);
          Point arrowstart = new Point(bestTargetPt.x,
                                       bestTargetPt.y);
          Point arrowoffset = new Point((int)(7 * Math.cos(angle)), 
                                        (int)(7 * Math.sin(angle)));
          Point arrowend;
          if (bestSourcePt.getX() >= bestTargetPt.getX()) {
	  
            arrowend = new Point(arrowstart.x + arrowoffset.x, 
                                 arrowstart.y + arrowoffset.y);
          } else {
            arrowend = new Point(arrowstart.x - arrowoffset.x, 
                                 arrowstart.y - arrowoffset.y);
          }
          int xs[] = { arrowstart.x,
                       arrowend.x + (int)(7 * Math.cos(angle + (Math.PI / 2))),
                       arrowend.x + (int)(7 * Math.cos(angle - (Math.PI / 2)))};
          int ys[] = { arrowstart.y,
                       arrowend.y + (int)(7 * Math.sin(angle + (Math.PI / 2))),
                       arrowend.y + (int)(7 * Math.sin(angle - (Math.PI / 2)))};
          gx.fillPolygon(xs, ys, 3);
          // ----

          // paint the connection name
          int midx = (int)bestSourcePt.getX();
          midx += (int)((bestTargetPt.getX() - bestSourcePt.getX()) / 2);
          int midy = (int)bestSourcePt.getY();
          midy += (int)((bestTargetPt.getY() - bestSourcePt.getY()) / 2) - 2 ;
          gx.setColor((active) ? Color.blue : Color.gray);
          if (previousLink(source, target, i)) {
            midy -= 15;
          }
          gx.drawString(srcEsd.getName(), midx, midy);
        }
      }
    }
  }

  /**
   * Return a list of connections within some delta of a point
   *
   * @param pt the point at which to look for connections
   * @param delta connections have to be within this delta of the point
   * @return a list of connections
   */
  public static Vector getClosestConnections(Point pt, int delta) {
    Vector closestConnections = new Vector();
    
    for (int i = 0; i < CONNECTIONS.size(); i++) {
      BeanConnection bc = (BeanConnection)CONNECTIONS.elementAt(i);
      BeanInstance source = bc.getSource();
      BeanInstance target = bc.getTarget();
      EventSetDescriptor srcEsd = bc.getSourceEventSetDescriptor();
      BeanVisual sourceVisual = (source.getBean() instanceof Visible) ?
	((Visible)source.getBean()).getVisual() :
	null;
      BeanVisual targetVisual = (target.getBean() instanceof Visible) ?
	((Visible)target.getBean()).getVisual() :
	null;
      if (sourceVisual != null && targetVisual != null) {
	Point bestSourcePt = 
	  sourceVisual.getClosestConnectorPoint(
		       new Point((target.getX()+(target.getWidth()/2)), 
				 (target.getY() + (target.getHeight() / 2))));
	Point bestTargetPt = 
	  targetVisual.getClosestConnectorPoint(
		       new Point((source.getX()+(source.getWidth()/2)), 
				 (source.getY() + (source.getHeight() / 2))));

	int minx = (int) Math.min(bestSourcePt.getX(), bestTargetPt.getX());
	int maxx = (int) Math.max(bestSourcePt.getX(), bestTargetPt.getX());
	int miny = (int) Math.min(bestSourcePt.getY(), bestTargetPt.getY());
	int maxy = (int) Math.max(bestSourcePt.getY(), bestTargetPt.getY());
	// check to see if supplied pt is inside bounding box
	if (pt.getX() >= minx-delta && pt.getX() <= maxx+delta && 
	    pt.getY() >= miny-delta && pt.getY() <= maxy+delta) {
	  // now see if the point is within delta of the line
	  // formulate ax + by + c = 0
	  double a = bestSourcePt.getY() - bestTargetPt.getY();
	  double b = bestTargetPt.getX() - bestSourcePt.getX();
	  double c = (bestSourcePt.getX() * bestTargetPt.getY()) -
	    (bestTargetPt.getX() * bestSourcePt.getY());
	  
	  double distance = Math.abs((a * pt.getX()) + (b * pt.getY()) + c);
	  distance /= Math.abs(Math.sqrt((a*a) + (b*b)));

	  if (distance <= delta) {
	    closestConnections.addElement(bc);
	  }
	}
      }
    }
    return closestConnections;
  }

  /**
   * Remove all connections for a bean. If the bean is a target for
   * receiving events then it gets deregistered from the corresonding
   * source bean. If the bean is a source of events then all targets 
   * implementing BeanCommon are notified via their
   * disconnectionNotification methods that the source (and hence the
   * connection) is going away.
   *
   * @param instance the bean to remove connections to/from
   */
  public static void removeConnections(BeanInstance instance) {
    
    Vector instancesToRemoveFor = new Vector();
    if (instance.getBean() instanceof MetaBean) {
      instancesToRemoveFor = 
        ((MetaBean)instance.getBean()).getBeansInSubFlow();
    } else {
      instancesToRemoveFor.add(instance);
    }
    Vector removeVector = new Vector();
    for (int j = 0; j < instancesToRemoveFor.size(); j++) {
      BeanInstance tempInstance = 
        (BeanInstance)instancesToRemoveFor.elementAt(j);
      for (int i = 0; i < CONNECTIONS.size(); i++) {
        // In cases where this instance is the target, deregister it
        // as a listener for the source
        BeanConnection bc = (BeanConnection)CONNECTIONS.elementAt(i);
        BeanInstance tempTarget = bc.getTarget();
        BeanInstance tempSource = bc.getSource();

        EventSetDescriptor tempEsd = bc.getSourceEventSetDescriptor();
        if (tempInstance == tempTarget) {
          // try to deregister the target as a listener for the source
          try {
            Method deregisterMethod = tempEsd.getRemoveListenerMethod();
            Object targetBean = tempTarget.getBean();
            Object [] args = new Object[1];
            args[0] = targetBean;
            deregisterMethod.invoke(tempSource.getBean(), args);
            System.err.println("Deregistering listener");
            removeVector.addElement(bc);
          } catch (Exception ex) {
            ex.printStackTrace();
          }
        } else if (tempInstance == tempSource) {
          removeVector.addElement(bc);
          if (tempTarget.getBean() instanceof BeanCommon) {
            // tell the target that the source is going away, therefore
            // this type of connection is as well
            ((BeanCommon)tempTarget.getBean()).
              disconnectionNotification(tempEsd.getName(),
                                        tempSource.getBean());
          }
        }
      }
    }
    for (int i = 0; i < removeVector.size(); i++) {
      System.err.println("removing connection");
      CONNECTIONS.removeElement((BeanConnection)removeVector.elementAt(i));
    }
  }

  public static void doMetaConnection(BeanInstance source, BeanInstance target,
                                      final EventSetDescriptor esd,
                                      final JComponent displayComponent) {

    Object targetBean = target.getBean();
    BeanInstance realTarget = null;
    final BeanInstance realSource = source;
    if (targetBean instanceof MetaBean) {
      Vector receivers = ((MetaBean)targetBean).getSuitableTargets(esd);
      if (receivers.size() == 1) {
        realTarget = (BeanInstance)receivers.elementAt(0);
        BeanConnection bc = new BeanConnection(realSource, realTarget,
                                               esd);
        //        m_target = (BeanInstance)receivers.elementAt(0);
      } else {
        // have to do the popup thing here
        int menuItemCount = 0;
        JPopupMenu targetConnectionMenu = new JPopupMenu();
        targetConnectionMenu.insert(new JLabel("Select target",
                                               SwingConstants.CENTER),
                                    menuItemCount++);
        for (int i = 0; i < receivers.size(); i++) {
          final BeanInstance tempTarget = 
            (BeanInstance)receivers.elementAt(i);
          String tName = ""+(i+1)+": " 
            + tempTarget.getBean().getClass().getName();
          JMenuItem targetItem = new JMenuItem(tName);
          targetItem.addActionListener(new ActionListener() {
              public void actionPerformed(ActionEvent e) {
                //    finalTarget.add(tempTarget);
                BeanConnection bc = 
                  new BeanConnection(realSource, tempTarget,
                                     esd);
                displayComponent.repaint();
              }
            });
          targetConnectionMenu.add(targetItem);
          menuItemCount++;
        }
        targetConnectionMenu.show(displayComponent, target.getX(),
                                  target.getY());
        //        m_target = (BeanInstance)finalTarget.elementAt(0);
      }
    }
  }

  /**
   * Creates a new <code>BeanConnection</code> instance.
   *
   * @param source the source bean
   * @param target the target bean
   * @param esd the EventSetDescriptor for the connection
   * be displayed
   */
  public BeanConnection(BeanInstance source, BeanInstance target,
			EventSetDescriptor esd) {
    m_source = source;
    m_target = target;
    //    m_sourceEsd = sourceEsd;
    m_eventName = esd.getName();
    System.err.println(m_eventName);

    // attempt to connect source and target beans
    Method registrationMethod = 
      //      m_sourceEsd.getAddListenerMethod();
      //      getSourceEventSetDescriptor().getAddListenerMethod();
      esd.getAddListenerMethod();
    Object targetBean = m_target.getBean();

    Object [] args = new Object[1];
    args[0] = targetBean;
    Class listenerClass = esd.getListenerType();
    if (listenerClass.isInstance(targetBean)) {
      try {
	registrationMethod.invoke(m_source.getBean(), args);
	// if the target implements BeanCommon, then inform
	// it that it has been registered as a listener with a source via
	// the named listener interface
	if (targetBean instanceof BeanCommon) {
	  ((BeanCommon)targetBean).
	    connectionNotification(esd.getName(), m_source.getBean());
	}
	CONNECTIONS.addElement(this);
      } catch (Exception ex) {
	System.err.println("Unable to connect beans (BeanConnection)");
	ex.printStackTrace();
      }
    } else {
      System.err.println("Unable to connect beans (BeanConnection)");
    }
  }

  /**
   * Make this connection invisible on the display
   *
   * @param hidden true to make the connection invisible
   */
  public void setHidden(boolean hidden) {
    m_hidden = hidden;
  }

  /**
   * Returns true if this connection is invisible
   *
   * @return true if connection is invisible
   */
  public boolean isHidden() {
    return m_hidden;
  }

  /**
   * Remove this connection
   */
  public void remove() {
    EventSetDescriptor tempEsd = getSourceEventSetDescriptor();
    // try to deregister the target as a listener for the source
    try {
      Method deregisterMethod = tempEsd.getRemoveListenerMethod();
      Object targetBean = getTarget().getBean();
      Object [] args = new Object[1];
      args[0] = targetBean;
      deregisterMethod.invoke(getSource().getBean(), args);
      System.err.println("Deregistering listener");
    } catch (Exception ex) {
      ex.printStackTrace();
    }

    if (getTarget().getBean() instanceof BeanCommon) {
      // tell the target that this connection is going away
      ((BeanCommon)getTarget().getBean()).
	disconnectionNotification(tempEsd.getName(),
				  getSource().getBean());
    }

    CONNECTIONS.remove(this);
  }

  /**
   * returns the source BeanInstance for this connection
   *
   * @return a <code>BeanInstance</code> value
   */
  public BeanInstance getSource() {
    return m_source;
  }

  /**
   * Returns the target BeanInstance for this connection
   *
   * @return a <code>BeanInstance</code> value
   */
  public BeanInstance getTarget() {
    return m_target;
  }
  
  /**
   * Returns the name of the event for this conncetion
   * 
   * @return the name of the event for this connection
   */
  public String getEventName() {
    return m_eventName;
  }

  /**
   * Returns the event set descriptor for the event generated by the source
   * for this connection
   *
   * @return an <code>EventSetDescriptor</code> value
   */
  protected EventSetDescriptor getSourceEventSetDescriptor() {
    JComponent bc = (JComponent)m_source.getBean();
     try {
       BeanInfo sourceInfo = Introspector.getBeanInfo(bc.getClass());
       if (sourceInfo == null) {
       System.err.println("Error");
       } else {
	 EventSetDescriptor [] esds = sourceInfo.getEventSetDescriptors();
	 for (int i = 0; i < esds.length; i++) {
	   if (esds[i].getName().compareTo(m_eventName) == 0) {
	     return esds[i];
	   }
	 }
       }
     } catch (Exception ex) {
       System.err.println("Problem retrieving event set descriptor (BeanConnection)");
     }
     return null;
     
     //    return m_sourceEsd;
  }
}