/* An actor that filters false boolean tokens.
Copyright (c) 2001-2005 The Regents of the University of California.
All rights reserved.
Permission is hereby granted, without written agreement and without
license or royalty fees, to use, copy, modify, and distribute this
software and its documentation for any purpose, provided that the above
copyright notice and the following two paragraphs appear in all copies
of this software.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
ENHANCEMENTS, OR MODIFICATIONS.
PT_COPYRIGHT_VERSION_2
COPYRIGHTENDKEY
*/
package ptolemy.domains.de.lib;
import ptolemy.data.BooleanToken;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
//////////////////////////////////////////////////////////////////////////
//// EventFilter
/**
An actor that filters a stream of Boolean Tokens. Every true input token
that it receives is reproduced on the output port.
False tokens are discarded.
This is usually used to properly trigger other discrete event actors
(such as inhibit and select) based on boolean values.
<p>
@author Steve Neuendorffer and Sonia Sachs
@version $Id$
@since Ptolemy II 2.0
@Pt.ProposedRating Yellow (neuendor)
@Pt.AcceptedRating Yellow (neuendor)
*/
public class EventFilter extends DETransformer {
/** Construct an actor with the given container and name.
* @param container The container.
* @param name The name of this actor.
* @exception IllegalActionException If the actor cannot be contained
* by the proposed container.
* @exception NameDuplicationException If the container already has an
* actor with this name.
*/
public EventFilter(CompositeEntity container, String name)
throws NameDuplicationException, IllegalActionException {
super(container, name);
input.setMultiport(true);
output.setMultiport(true);
input.setTypeEquals(BaseType.BOOLEAN);
output.setTypeEquals(BaseType.BOOLEAN);
}
///////////////////////////////////////////////////////////////////
//// public methods ////
/** Consume at most one token from each channel of the
* <i>input</i> port. If any token is true, then output it on the
* corresponding channel of the output port. No false tokens
* are ever output.
* @exception IllegalActionException If there is no director.
*/
public void fire() throws IllegalActionException {
super.fire();
for (int i = 0; i < input.getWidth(); i++) {
if (input.hasToken(i)) {
BooleanToken token = (BooleanToken) input.get(i);
if (token.booleanValue()) {
output.send(i, token);
}
}
}
}
}