content: /*
   *    This program is free software; you can redistribute it and/or modify
   *    it under the terms of the GNU General Public License as published by
   *    the Free Software Foundation; either version 2 of the License, or
   *    (at your option) any later version.
   *
   *    This program is distributed in the hope that it will be useful,
   *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *    GNU General Public License for more details.
   *
   *    You should have received a copy of the GNU General Public License
   *    along with this program; if not, write to the Free Software
   *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  /*
   *    Filter.java
   *    Copyright (C) 2002 University of Waikato, Hamilton, New Zealand
   *
   */
  
  package weka.gui.beans;
  
  import weka.core.Instance;
  import weka.core.Instances;
  import weka.core.OptionHandler;
  import weka.core.Utils;
  import weka.filters.AllFilter;
  import weka.filters.StreamableFilter;
  import weka.filters.SupervisedFilter;
  import weka.gui.Logger;
  
  import java.awt.BorderLayout;
  import java.beans.EventSetDescriptor;
  import java.io.Serializable;
  import java.util.Enumeration;
  import java.util.EventObject;
  import java.util.Hashtable;
  import java.util.Vector;
  
  import javax.swing.JPanel;
  
  /**
   * A wrapper bean for Weka filters
   *
   * @author <a href="mailto:mhall@cs.waikato.ac.nz">Mark Hall</a>
   * @version $Revision: 6458 $
   */
  public class Filter
    extends JPanel
    implements BeanCommon, Visible, WekaWrapper,
  	     Serializable, UserRequestAcceptor,
  	     TrainingSetListener, TestSetListener,
  	     TrainingSetProducer, TestSetProducer,
  	     DataSource, DataSourceListener, 
  	     InstanceListener, EventConstraints,
  	     ConfigurationProducer {
  
    /** for serialization */
    private static final long serialVersionUID = 8249759470189439321L;
  
    protected BeanVisual m_visual = 
      new BeanVisual("Filter",
  		   BeanVisual.ICON_PATH+"DefaultFilter.gif",
  		   BeanVisual.ICON_PATH+"DefaultFilter_animated.gif");
  
    private static int IDLE = 0;
    private static int FILTERING_TRAINING = 1;
    private static int FILTERING_TEST = 2;
    private int m_state = IDLE;
  
    protected Thread m_filterThread = null;
  
    private transient Instances m_trainingSet;
    private transient Instances m_testingSet;
  
    /**
     * Global info for the wrapped filter (if it exists).
     */
    protected String m_globalInfo;
  
    /**
     * Objects talking to us
     */
    private Hashtable m_listenees = new Hashtable();
  
    /**
     * Objects listening for training set events
     */
    private Vector m_trainingListeners = new Vector();
  
    /**
     * Objects listening for test set events
     */
    private Vector m_testListeners = new Vector();
  
    /**
     * Objects listening for instance events
     */
    private Vector m_instanceListeners = new Vector();
  
    /**
     * Objects listening for data set events
     */
    private Vector m_dataListeners = new Vector();
  
    /**
     * The filter to use.
     */
    private weka.filters.Filter m_Filter = new AllFilter();
  
    /**
     * Instance event object for passing on filtered instance streams
     */
    private InstanceEvent m_ie = new InstanceEvent(this);
  
    /**
     * Logging.
     */
    private transient Logger m_log = null;
    
    /**
     * Counts incoming streamed instances.
     */
    private transient int m_instanceCount;
    
    /**
     * Global info (if it exists) for the wrapped filter
     *
     * @return the global info
     */
    public String globalInfo() {
      return m_globalInfo;
    }
  
    public Filter() {
      setLayout(new BorderLayout());
      add(m_visual, BorderLayout.CENTER);
      setFilter(m_Filter);
    }
  
    /**
     * Set a custom (descriptive) name for this bean
     * 
     * @param name the name to use
     */
    public void setCustomName(String name) {
      m_visual.setText(name);
    }
  
    /**
     * Get the custom (descriptive) name for this bean (if one has been set)
     * 
     * @return the custom name (or the default name)
     */
    public String getCustomName() {
      return m_visual.getText();
    }
  
    /**
     * Set the filter to be wrapped by this bean
     *
     * @param c a <code>weka.filters.Filter</code> value
     */
    public void setFilter(weka.filters.Filter c) {
      boolean loadImages = true;
      if (c.getClass().getName().
  	compareTo(m_Filter.getClass().getName()) == 0) {
        loadImages = false;
      }
      m_Filter = c;
      String filterName = c.getClass().toString();
      filterName = filterName.substring(filterName.
  				      indexOf('.')+1, 
  				      filterName.length());
      if (loadImages) {
        if (m_Filter instanceof Visible) {
          m_visual = ((Visible) m_Filter).getVisual();
        } else {
          if (!m_visual.loadIcons(BeanVisual.ICON_PATH+filterName+".gif",
                                  BeanVisual.ICON_PATH+filterName+"_animated.gif")) {
            useDefaultVisual();
          }
        }
      }
      m_visual.setText(filterName.substring(filterName.lastIndexOf('.')+1,
  					  filterName.length()));
  
      if (m_Filter instanceof LogWriter && m_log != null) {
        ((LogWriter) m_Filter).setLog(m_log);
      }
  
      if (!(m_Filter instanceof StreamableFilter) &&
  	(m_listenees.containsKey("instance"))) {
        if (m_log != null) {
  	m_log.logMessage("[Filter] " + 
  	    statusMessagePrefix() + " WARNING : "
  	    + m_Filter.getClass().getName()
  	    + " is not an incremental filter");
  	m_log.statusMessage(statusMessagePrefix()
  	    + "WARNING: Not an incremental filter.");
        }
      }
      
      // get global info
      m_globalInfo = KnowledgeFlowApp.getGlobalInfo(m_Filter);
    }
  
    public weka.filters.Filter getFilter() {
      return m_Filter;
    }
  
    /**
     * Set the filter to be wrapped by this bean
     *
     * @param algorithm a weka.filters.Filter
     * @exception IllegalArgumentException if an error occurs
     */
    public void setWrappedAlgorithm(Object algorithm) {
      
      if (!(algorithm instanceof weka.filters.Filter)) { 
        throw new IllegalArgumentException(algorithm.getClass()+" : incorrect "
  					 +"type of algorithm (Filter)");
      }
      setFilter((weka.filters.Filter)algorithm);
    }
  
    /**
     * Get the filter wrapped by this bean
     *
     * @return an <code>Object</code> value
     */
    public Object getWrappedAlgorithm() {
      return getFilter();
    }
  
    /**
     * Accept a training set
     *
     * @param e a <code>TrainingSetEvent</code> value
     */
    public void acceptTrainingSet(TrainingSetEvent e) {
      processTrainingOrDataSourceEvents(e);
    }
  
    private boolean m_structurePassedOn = false;
    /**
     * Accept an instance for processing by StreamableFilters only
     *
     * @param e an <code>InstanceEvent</code> value
     */
    public void acceptInstance(InstanceEvent e) {
      // to do!
      if (m_filterThread != null) {
        String messg = "[Filter] " + statusMessagePrefix() 
          + " is currently batch processing!";
        if (m_log != null) {
  	m_log.logMessage(messg);
  	m_log.statusMessage(statusMessagePrefix()
  	    + "WARNING: Filter is currently batch processing.");
        } else {
  	System.err.println(messg);
        }
        return;
      }
      if (!(m_Filter instanceof StreamableFilter)) {
        stop(); // stop all processing
        if (m_log != null) {
  	m_log.logMessage("[Filter] " + statusMessagePrefix() 
  	    + " ERROR : "+m_Filter.getClass().getName()
  	    +"can't process streamed instances; can't continue");
  	m_log.statusMessage(statusMessagePrefix()
  	    + "ERROR: Can't process streamed instances; can't continue.");
        }
        return;
      }
      if (e.getStatus() == InstanceEvent.FORMAT_AVAILABLE) {
        try {
          m_instanceCount = 0;
          //notifyInstanceListeners(e);
  	//	Instances dataset = e.getInstance().dataset();
  	Instances dataset = e.getStructure();
  	if (m_Filter instanceof SupervisedFilter) {
  	  // defualt to last column if no class is set
  	  if (dataset.classIndex() < 0) {
  	    dataset.setClassIndex(dataset.numAttributes()-1);
  	  }
  	}
  	// initialize filter
  	m_Filter.setInputFormat(dataset);
  	// attempt to determine post-filtering
  	// structure. If successful this can be passed on to instance
  	// listeners as a new FORMAT_AVAILABLE event.
  	m_structurePassedOn = false;
  	try {
  	  if (m_Filter.isOutputFormatDefined()) {
  //	    System.err.println("Filter - passing on output format...");
  	    //	    System.err.println(m_Filter.getOutputFormat());
  	    m_ie.setStructure(m_Filter.getOutputFormat());
  	    notifyInstanceListeners(m_ie);
  	    m_structurePassedOn = true;
  	  }
  	} catch (Exception ex) {
  	  stop(); // stop all processing
  	  if (m_log != null) {
  	    m_log.logMessage("[Filter] " + statusMessagePrefix() 
                  + " Error in obtaining post-filter structure. " 
                  + ex.getMessage());
  	    m_log.statusMessage(statusMessagePrefix()
  	        +"ERROR (See log for details).");
  	  } else {
  	    System.err.println("[Filter] " + statusMessagePrefix() 
  	        + " Error in obtaining post-filter structure");
  	  }
  	}
        } catch (Exception ex) {
  	ex.printStackTrace();
        }
        return;
      }
     
      if (e.getStatus() == InstanceEvent.BATCH_FINISHED) {
        // get the last instance (if available)
        try {
          if (m_log != null) {
            m_log.statusMessage(statusMessagePrefix() 
                + "Stream finished.");
          }
          if (m_Filter.input(e.getInstance())) {
            Instance filteredInstance = m_Filter.output();
            if (filteredInstance != null) {
              if (!m_structurePassedOn) {
                // pass on the new structure first
                m_ie.setStructure(new Instances(filteredInstance.dataset(), 0));
                notifyInstanceListeners(m_ie);
                m_structurePassedOn = true;
              }
  
              m_ie.setInstance(filteredInstance);
              
              // if there are instances pending for output don't want to send
              // a batch finisehd at this point...
              //System.err.println("Filter - in batch finisehd...");
              if (m_Filter.batchFinished() && m_Filter.numPendingOutput() > 0) {
                m_ie.setStatus(InstanceEvent.INSTANCE_AVAILABLE);
              } else {
                m_ie.setStatus(e.getStatus());
              }
              notifyInstanceListeners(m_ie);
            }
          }
          if (m_log != null) {
            m_log.statusMessage(statusMessagePrefix() + "Done.");
          }
        } catch (Exception ex) {
          stop(); // stop all processing
          if (m_log != null) {
            m_log.logMessage("[Filter] " 
                + statusMessagePrefix() + ex.getMessage());
            m_log.statusMessage(statusMessagePrefix()
                + "ERROR (See log for details).");
          }
          ex.printStackTrace();
        }
        
        // check for any pending instances that we might need to pass on
        try {
          if (m_Filter.batchFinished() && m_Filter.numPendingOutput() > 0) {
            if (m_log != null) {
              m_log.statusMessage(statusMessagePrefix() 
                  + "Passing on pending instances...");
            }
            Instance filteredInstance = m_Filter.output();
            if (filteredInstance != null) {
              if (!m_structurePassedOn) {
                // pass on the new structure first
                m_ie.setStructure(new Instances(filteredInstance.dataset(), 0));
                notifyInstanceListeners(m_ie);
                m_structurePassedOn = true;
              }
  
              m_ie.setInstance(filteredInstance);
              
              //TODO here is the problem I think
              m_ie.setStatus(InstanceEvent.INSTANCE_AVAILABLE);
              notifyInstanceListeners(m_ie);
            }
            while (m_Filter.numPendingOutput() > 0) {
              filteredInstance = m_Filter.output();
              m_ie.setInstance(filteredInstance);
  //            System.err.println("Filter - sending pending...");
              if (m_Filter.numPendingOutput() == 0) {
                m_ie.setStatus(InstanceEvent.BATCH_FINISHED);
              } else {
                m_ie.setStatus(InstanceEvent.INSTANCE_AVAILABLE);
              }
              notifyInstanceListeners(m_ie);
            }
            if (m_log != null) {
              m_log.statusMessage(statusMessagePrefix() + "Finished.");
            }
          }
        } catch (Exception ex) {
          stop(); // stop all processing
          if (m_log != null) {
            m_log.logMessage("[Filter] " 
                + statusMessagePrefix() 
                + ex.toString());
            m_log.statusMessage(statusMessagePrefix()
                + "ERROR (See log for details.");
          }
          ex.printStackTrace();
        }
      } else {
        // pass instance through the filter
        try {
          if (!m_Filter.input(e.getInstance())) {
  //          System.err.println("Filter - inputing instance into filter...");
            /* if (m_log != null) {
              m_log.logMessage("ERROR : filter not ready to output instance");
            } */
            
            // quietly return. Filter might be able to output some instances
            // once the batch is finished.
            return;
          }
  
          // collect output instance.
          Instance filteredInstance = m_Filter.output();
          if (filteredInstance == null) {
            return;
          }
          m_instanceCount++;
          
          if (!m_structurePassedOn) {
            // pass on the new structure first
            m_ie.setStructure(new Instances(filteredInstance.dataset(), 0));
            notifyInstanceListeners(m_ie);
            m_structurePassedOn = true;
          }
  
          m_ie.setInstance(filteredInstance);
          m_ie.setStatus(e.getStatus());
          
          if (m_log != null && (m_instanceCount % 10000 == 0)) {
            m_log.statusMessage(statusMessagePrefix()
                + "Received " + m_instanceCount + " instances.");
          }
          notifyInstanceListeners(m_ie);
        } catch (Exception ex) {
          stop(); // stop all processing
          if (m_log != null) {
            m_log.logMessage("[Filter] " + statusMessagePrefix() 
                + ex.toString());
            m_log.statusMessage(statusMessagePrefix()
                + "ERROR (See log for details).");
          }
          ex.printStackTrace();
        }
      }
    }
  
    private void processTrainingOrDataSourceEvents(final EventObject e) {
      boolean structureOnly = false;
      if (e instanceof DataSetEvent) {
        structureOnly = ((DataSetEvent)e).isStructureOnly();
        if(structureOnly){
         notifyDataOrTrainingListeners(e);  
        }
      }
      if (e instanceof TrainingSetEvent) {
        structureOnly = ((TrainingSetEvent)e).isStructureOnly();
        if(structureOnly){
         notifyDataOrTrainingListeners(e);  
        }
      }
      if (structureOnly && !(m_Filter instanceof StreamableFilter)) {
        return; // nothing can be done
      }
      
      if (m_filterThread == null) {
        try {
  	if (m_state == IDLE) {
  	  synchronized (this) {
  	    m_state = FILTERING_TRAINING;
  	  }
  	  m_trainingSet = (e instanceof TrainingSetEvent) 
  	    ? ((TrainingSetEvent)e).getTrainingSet()
  	    : ((DataSetEvent)e).getDataSet();
  
  //	  final String oldText = m_visual.getText();
  	  m_filterThread = new Thread() {
  	      public void run() {
  		try {
  		  if (m_trainingSet != null) {
  		    m_visual.setAnimated();
  //		    m_visual.setText("Filtering training data...");
  		    if (m_log != null) {
  		      m_log.statusMessage(statusMessagePrefix() 
  		          + "Filtering training data ("
  		          + m_trainingSet.relationName() + ")");
  		    }
  		    m_Filter.setInputFormat(m_trainingSet);
  		    Instances filteredData = 
  		      weka.filters.Filter.useFilter(m_trainingSet, m_Filter);
  //		    m_visual.setText(oldText);
  		    m_visual.setStatic();
  		    EventObject ne;
  		    if (e instanceof TrainingSetEvent) {
  		      ne = new TrainingSetEvent(weka.gui.beans.Filter.this, 
  						filteredData);
  		      ((TrainingSetEvent)ne).m_setNumber =
  			((TrainingSetEvent)e).m_setNumber;
  		      ((TrainingSetEvent)ne).m_maxSetNumber = 
  			((TrainingSetEvent)e).m_maxSetNumber;
  		    } else {
  		      ne = new DataSetEvent(weka.gui.beans.Filter.this,
  					    filteredData);
  		    }
  
  		    notifyDataOrTrainingListeners(ne);
  		  }
  		} catch (Exception ex) {
  		  ex.printStackTrace();
                    if (m_log != null) {
                      m_log.logMessage("[Filter] " + statusMessagePrefix() 
                          + ex.getMessage());
                      m_log.statusMessage(statusMessagePrefix()
                          + "ERROR (See log for details).");
  //                    m_log.statusMessage("Problem filtering: see log for details.");
                    }
                    Filter.this.stop(); // stop all processing
  		} finally {
  //		  m_visual.setText(oldText);
  		  m_visual.setStatic();
  		  m_state = IDLE;
  		  if (isInterrupted()) {
  		    m_trainingSet = null;
  		    if (m_log != null) {
  		      m_log.logMessage("[Filter] " + statusMessagePrefix()
                                         + " training set interrupted!");
  		      m_log.statusMessage(statusMessagePrefix()
  		          + "INTERRUPTED");
  		    }		    
  		  } else {
  		    if (m_log != null) {
  		      m_log.statusMessage(statusMessagePrefix() + "Finished.");
  		    }
  		  }
  		  block(false);
  		}
  	      }
  	    };
  	  m_filterThread.setPriority(Thread.MIN_PRIORITY);
  	  m_filterThread.start();
  	  block(true);
  	  m_filterThread = null;
  	  m_state = IDLE;
  	}
        } catch (Exception ex) {
  	ex.printStackTrace();
        }
      }
    }
  
    /**
     * Accept a test set
     *
     * @param e a <code>TestSetEvent</code> value
     */
    public void acceptTestSet(final TestSetEvent e) {
        if(e.isStructureOnly())
              notifyTestListeners(e);
        if (m_trainingSet != null && 
  	m_trainingSet.equalHeaders(e.getTestSet()) && 
  	m_filterThread == null) {
        try {
  	if (m_state == IDLE) {
  	  m_state = FILTERING_TEST;
  	}
  	m_testingSet = e.getTestSet();
          //	final String oldText = m_visual.getText();
  	m_filterThread = new Thread() {
  	    public void run() {
  	      try {
  		if (m_testingSet != null) {
  		  m_visual.setAnimated();
                    //		  m_visual.setText("Filtering test data...");
  		  if (m_log != null) {
  		    m_log.statusMessage(statusMessagePrefix() 
  		        + "Filtering test data ("
  			+ m_testingSet.relationName() + ")");
  		  }
  		  Instances filteredTest = 
  		    weka.filters.Filter.useFilter(m_testingSet, m_Filter);
                    //		  m_visual.setText(oldText);
  		  m_visual.setStatic();
  		  TestSetEvent ne =
  		    new TestSetEvent(weka.gui.beans.Filter.this,
  				     filteredTest);
  		  ne.m_setNumber = e.m_setNumber;
  		  ne.m_maxSetNumber = e.m_maxSetNumber;
  		  notifyTestListeners(ne);
  		}
  	      } catch (Exception ex) {
  		ex.printStackTrace();
                  if (m_log != null) {
                    m_log.logMessage("[Filter] " + statusMessagePrefix() 
                        + ex.getMessage());
                    m_log.statusMessage(statusMessagePrefix() 
                        + "ERROR (See log for details).");
                  }
                  Filter.this.stop();
  	      } finally {
                  //		m_visual.setText(oldText);
  		m_visual.setStatic();
  		m_state = IDLE;
  		if (isInterrupted()) {
  		  m_trainingSet = null;
  		  if (m_log != null) {
  		      m_log.logMessage("[Filter] " + statusMessagePrefix()
                                         + " test set interrupted!");
  		      m_log.statusMessage(statusMessagePrefix()
  		          + "INTERRUPTED");
  //		    m_log.statusMessage("OK");
  		  }
  		} else {
  		  if (m_log != null) {
  		    m_log.statusMessage(statusMessagePrefix() + "Finished.");
  		  }
  		}
  		block(false);
  	      }
  	    }
  	  };
  	m_filterThread.setPriority(Thread.MIN_PRIORITY);
  	m_filterThread.start();
  	block(true);
  	m_filterThread = null;
  	m_state = IDLE;
        } catch (Exception ex) {
  	ex.printStackTrace();
        }
      }
    }
  
    /**
     * Accept a data set
     *
     * @param e a <code>DataSetEvent</code> value
     */
    public void acceptDataSet(DataSetEvent e) {
      processTrainingOrDataSourceEvents(e);
    }
  
    /**
     * Set the visual appearance of this bean
     *
     * @param newVisual a <code>BeanVisual</code> value
     */
    public void setVisual(BeanVisual newVisual) {
      m_visual = newVisual;
    }
  
    /**
     * Get the visual appearance of this bean
     *
     * @return a <code>BeanVisual</code> value
     */
    public BeanVisual getVisual() {
      return m_visual;
    }
  
    /**
     * Use the default visual appearance
     */
    public void useDefaultVisual() {
      m_visual.loadIcons(BeanVisual.ICON_PATH+"DefaultFilter.gif",
  		       BeanVisual.ICON_PATH+"DefaultFilter_animated.gif");
    }
  
    /**
     * Add a training set listener
     *
     * @param tsl a <code>TrainingSetListener</code> value
     */
    public synchronized void addTrainingSetListener(TrainingSetListener tsl) {
      m_trainingListeners.addElement(tsl);
    }
    
    /**
     * Remove a training set listener
     *
     * @param tsl a <code>TrainingSetListener</code> value
     */
    public synchronized void removeTrainingSetListener(TrainingSetListener tsl) {
       m_trainingListeners.removeElement(tsl);
    }
  
    /**
     * Add a test set listener
     *
     * @param tsl a <code>TestSetListener</code> value
     */
    public synchronized void addTestSetListener(TestSetListener tsl) {
      m_testListeners.addElement(tsl);
    }
    
    /**
     * Remove a test set listener
     *
     * @param tsl a <code>TestSetListener</code> value
     */
    public synchronized void removeTestSetListener(TestSetListener tsl) {
      m_testListeners.removeElement(tsl);
    }
  
    /**
     * Add a data source listener
     *
     * @param dsl a <code>DataSourceListener</code> value
     */
    public synchronized void addDataSourceListener(DataSourceListener dsl) {
      m_dataListeners.addElement(dsl);
    }
  
    /**
     * Remove a data source listener
     *
     * @param dsl a <code>DataSourceListener</code> value
     */
    public synchronized void removeDataSourceListener(DataSourceListener dsl) {
      m_dataListeners.remove(dsl);
    }
  
    /**
     * Add an instance listener
     *
     * @param tsl an <code>InstanceListener</code> value
     */
    public synchronized void addInstanceListener(InstanceListener tsl) {
      m_instanceListeners.addElement(tsl);
    }
  
    /**
     * Remove an instance listener
     *
     * @param tsl an <code>InstanceListener</code> value
     */
    public synchronized void removeInstanceListener(InstanceListener tsl) {
      m_instanceListeners.removeElement(tsl);
    }
    
    /**
     * We don't have to keep track of configuration listeners (see the
     * documentation for ConfigurationListener/ConfigurationEvent).
     * 
     * @param cl a ConfigurationListener.
     */
    public synchronized void addConfigurationListener(ConfigurationListener cl) {
      
    }
    
    /**
     * We don't have to keep track of configuration listeners (see the
     * documentation for ConfigurationListener/ConfigurationEvent).
     * 
     * @param cl a ConfigurationListener.
     */
    public synchronized void removeConfigurationListener(ConfigurationListener cl) {
      
    }
  
    private void notifyDataOrTrainingListeners(EventObject ce) {
      Vector l;
      synchronized (this) {
        l = (ce instanceof TrainingSetEvent)
  	? (Vector)m_trainingListeners.clone()
  	: (Vector)m_dataListeners.clone();
      }
      if (l.size() > 0) {
        for(int i = 0; i < l.size(); i++) {
  	if (ce instanceof TrainingSetEvent) {
  	  ((TrainingSetListener)l.elementAt(i)).
  	    acceptTrainingSet((TrainingSetEvent)ce);
  	} else {
  	  ((DataSourceListener)l.elementAt(i)).acceptDataSet((DataSetEvent)ce);
  	}
        }
      }
    }
  
    private void notifyTestListeners(TestSetEvent ce) {
      Vector l;
      synchronized (this) {
        l = (Vector)m_testListeners.clone();
      }
      if (l.size() > 0) {
        for(int i = 0; i < l.size(); i++) {
  	((TestSetListener)l.elementAt(i)).acceptTestSet(ce);
        }
      }
    }
  
    protected void notifyInstanceListeners(InstanceEvent tse) {
      Vector l;
      synchronized (this) {
        l = (Vector)m_instanceListeners.clone();
      }
      if (l.size() > 0) {
        for(int i = 0; i < l.size(); i++) {
  	//	System.err.println("Notifying instance listeners "
  	//			   +"(Filter)");
  	((InstanceListener)l.elementAt(i)).acceptInstance(tse);
        }
      }
    }
    
    /**
     * Returns true if, at this time, 
     * the object will accept a connection with respect to the supplied
     * event name
     *
     * @param eventName the event
     * @return true if the object will accept a connection
     */
    public boolean connectionAllowed(String eventName) {
  
      if (m_listenees.containsKey(eventName)) {
        return false;
      }
  
      /* reject a test event if we don't have a training or data set event
      if (eventName.compareTo("testSet") == 0) {
        if (!m_listenees.containsKey("trainingSet") &&
  	  !m_listenees.containsKey("dataSet")) {
  	return false;
        }
        } */
      
      // will need to reject train/test listener if we have a
      // data source listener and vis versa
      if (m_listenees.containsKey("dataSet") &&
  	(eventName.compareTo("trainingSet") == 0 ||
  	 eventName.compareTo("testSet") == 0 ||
  	eventName.compareTo("instance") == 0)) {
        return false;
      }
  
      if ((m_listenees.containsKey("trainingSet") ||
  	 m_listenees.containsKey("testSet")) &&
  	(eventName.compareTo("dataSet") == 0 || 
  	eventName.compareTo("instance") == 0)) {
        return false;
      }
  
      if (m_listenees.containsKey("instance") &&
  	(eventName.compareTo("trainingSet") == 0 ||
  	 eventName.compareTo("testSet") == 0 ||
  	 eventName.compareTo("dataSet") == 0)) {
        return false;
      }
  
      // reject an instance event connection if our filter isn't
      // streamable
      if (eventName.compareTo("instance") == 0 &&
  	!(m_Filter instanceof StreamableFilter)) {
        return false;
      }
      return true;
    }
  
    /**
     * Returns true if, at this time, 
     * the object will accept a connection according to the supplied
     * EventSetDescriptor
     *
     * @param esd the EventSetDescriptor
     * @return true if the object will accept a connection
     */
    public boolean connectionAllowed(EventSetDescriptor esd) {
      return connectionAllowed(esd.getName());
    }
  
    /**
     * Notify this object that it has been registered as a listener with
     * a source with respect to the supplied event name
     *
     * @param eventName
     * @param source the source with which this object has been registered as
     * a listener
     */
    public synchronized void connectionNotification(String eventName,
  						  Object source) {
      if (connectionAllowed(eventName)) {
        m_listenees.put(eventName, source);
        if (m_Filter instanceof ConnectionNotificationConsumer) {
          ((ConnectionNotificationConsumer) m_Filter).
            connectionNotification(eventName, source);
        }
      }
    }
  
    /**
     * Notify this object that it has been deregistered as a listener with
     * a source with respect to the supplied event name
     *
     * @param eventName the event
     * @param source the source with which this object has been registered as
     * a listener
     */
    public synchronized void disconnectionNotification(String eventName,
  						     Object source) {
      if (m_Filter instanceof ConnectionNotificationConsumer) {
        ((ConnectionNotificationConsumer) m_Filter).
          disconnectionNotification(eventName, source);
      }
      m_listenees.remove(eventName);
    }
  
    /**
     * Function used to stop code that calls acceptTrainingSet, acceptTestSet,
     * or acceptDataSet. This is 
     * needed as filtering is performed inside a separate
     * thread of execution.
     *
     * @param tf a <code>boolean</code> value
     */
    private synchronized void block(boolean tf) {
      if (tf) {
        try {
  	// only block if thread is still doing something useful!
  	if (m_filterThread.isAlive() && m_state != IDLE) {
  	  wait();
  	}
        } catch (InterruptedException ex) {
        }
      } else {
        notifyAll();
      }
    }
  
    /**
     * Stop all action if possible
     */
    public void stop() {
      // tell all listenees (upstream beans) to stop
      Enumeration en = m_listenees.keys();
      while (en.hasMoreElements()) {
        Object tempO = m_listenees.get(en.nextElement());
        if (tempO instanceof BeanCommon) {
  	((BeanCommon)tempO).stop();
        }
      }
      
      // stop the filter thread
      if (m_filterThread != null) {
        m_filterThread.interrupt();
        m_filterThread.stop();
        m_filterThread = null;
        m_visual.setStatic();
      }
    }
    
    /**
     * Returns true if. at this time, the bean is busy with some
     * (i.e. perhaps a worker thread is performing some calculation).
     * 
     * @return true if the bean is busy.
     */
    public boolean isBusy() {
      return (m_filterThread != null);
    }
    
    /**
     * Set a logger
     *
     * @param logger a <code>Logger</code> value
     */
    public void setLog(Logger logger) {
      m_log = logger;
  
      if (m_Filter != null && m_Filter instanceof LogWriter) {
        ((LogWriter) m_Filter).setLog(m_log);
      }
    }
  
    /**
     * Return an enumeration of user requests
     *
     * @return an <code>Enumeration</code> value
     */
    public Enumeration enumerateRequests() {
      Vector newVector = new Vector(0);
      if (m_filterThread != null) {
        newVector.addElement("Stop");
      }
      return newVector.elements();
    }
  
    /**
     * Perform the named request
     *
     * @param request a <code>String</code> value
     * @exception IllegalArgumentException if an error occurs
     */
    public void performRequest(String request) {
      if (request.compareTo("Stop") == 0) {
        stop();
      } else {
        throw new IllegalArgumentException(request
  					 + " not supported (Filter)");
      }
    }
  
    /**
     * Returns true, if at the current time, the named event could
     * be generated. Assumes that supplied event names are names of
     * events that could be generated by this bean.
     *
     * @param eventName the name of the event in question
     * @return true if the named event could be generated at this point in
     * time
     */
    public boolean eventGeneratable(String eventName) {
      
      if (eventName.equals("configuration") && m_Filter != null) {
        return true;
      }
      
      // can't generate the named even if we are not receiving it as an
      // input!
      if (!m_listenees.containsKey(eventName)) {
        return false;
      }
      Object source = m_listenees.get(eventName);
      if (source instanceof EventConstraints) {
        if (!((EventConstraints)source).eventGeneratable(eventName)) {
  	return false;
        }
      }
      if (eventName.compareTo("instance") == 0) {
        if (!(m_Filter instanceof StreamableFilter)) {
  	return false;
        }
      }
      return true;
    }
    
    private String statusMessagePrefix() {
      return getCustomName() + "$" + hashCode() + "|"
      + ((m_Filter instanceof OptionHandler &&
          Utils.joinOptions(((OptionHandler)m_Filter).getOptions()).length() > 0) 
          ? Utils.joinOptions(((OptionHandler)m_Filter).getOptions()) + "|"
              : "");
    }
  }
  