/* ClassOnlyFilter.java -- filter on specific class
   Copyright (C) 2005 Free Software Foundation

This file is part of GNU Classpath.

GNU Classpath 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, or (at your option)
any later version.

GNU Classpath 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 GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package gnu.classpath.jdwp.event.filters;

import gnu.classpath.jdwp.event.Event;
import gnu.classpath.jdwp.exception.InvalidClassException;
import gnu.classpath.jdwp.id.ReferenceTypeId;

/**
 * An event filter which filters out events in uninteresting
 * classes.
 *
 * @author Keith Seitz  (keiths@redhat.com)
 */
public class ClassOnlyFilter
  implements IEventFilter
{
  // Class ID for which to filter
  private ReferenceTypeId _id;

  /**
   * Constructs a new <code>ClassOnlyFilter</code>
   *
   * @param refId  the reference type id for a class for which events
   *               will be reported
   * @throws InvalidClassException if the ID is no longer valid
   */
  public ClassOnlyFilter (ReferenceTypeId refId)
    throws InvalidClassException
  {
    // validity check
    refId.getType ();
    _id = refId;
  }

  /**
   * Returns the class to which to restrict events
   *
   * @return the class's ID
   */
  public ReferenceTypeId getType ()
  {
    return _id;
  }

  /**
   * Does the given event match the filter?
   *
   * @param event  the <code>Event</code> to scrutinize
   */
  public boolean matches (Event event)
  {
    Object type = event.getParameter (Event.EVENT_CLASS);
    if (type != null)
      {
	try
	  {
	    Class clazz = _id.getType ();
	    Class eventClass = (Class) type;
	    if (clazz.isAssignableFrom (eventClass))
	      return true;
	  }
	catch (InvalidClassException ice)
	  {
	    // class is no longer valid
	    return false;
	  }
      }

    return false;
  }
}