/* A clock source where the period is given as an input.
Copyright (c) 1998-2007 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.actor.lib;
import ptolemy.actor.TypedIOPort;
import ptolemy.data.DoubleToken;
import ptolemy.data.Token;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
//////////////////////////////////////////////////////////////////////////
//// VariableClock
/**
This actor is identical to Clock except that it has an additional
input port, <i>periodControl</i>. If this port has a token when the actor
fires, then the value read from that port is used to set the parameter
value. The initial value of the <i>period</i> parameter is used before
any input is observed on <i>periodControl</i>.
<p>
This actor can be fairly tricky to use with multiple values and
offsets because of the constraint that all offsets must be less
than the period. Thus, the default values and offsets are different
from those of the base class. The output value, by default, is
just the constant integer 1, and the offset is 0.0. The default
value of <i>period</i> is changed to 1.0. This gives
a very simply behavior, where the output is always the same, but
the time between outputs is controlled by the <i>periodControl</i>
input.
@author Edward A. Lee
@version $Id$
@since Ptolemy II 0.4
@Pt.ProposedRating Yellow (eal)
@Pt.AcceptedRating Yellow (yuhong)
@deprecated Use Clock instead.
*/
public class VariableClock extends Clock {
/** Construct an actor with the specified container and name.
* @param container The container.
* @param name The name of this actor.
* @exception IllegalActionException If the entity cannot be contained
* by the proposed container.
* @exception NameDuplicationException If the container already has an
* actor with this name.
*/
public VariableClock(CompositeEntity container, String name)
throws NameDuplicationException, IllegalActionException {
super(container, name);
periodControl = new TypedIOPort(this, "periodControl", true, false);
periodControl.setTypeEquals(BaseType.DOUBLE);
// Change default values from the base class.
offsets.setExpression("{0.0}");
values.setExpression("{1}");
period.setToken(new DoubleToken(1.0));
}
///////////////////////////////////////////////////////////////////
//// ports and parameters ////
/** The port that controls the value of the <i>period</i> parameter.
*/
public TypedIOPort periodControl;
///////////////////////////////////////////////////////////////////
//// public methods ////
/** If there is an input on the <i>periodControl</i> port, read it
* and set the value of the <i>period</i> parameter.
* Then call the base class fire() method.
* @exception IllegalActionException If the input is not positive,
* or if the base class throws it.
*/
public void fire() throws IllegalActionException {
// FIXME
//double time = getDirector().getModelTime().getDoubleValue();
if ((periodControl.isOutsideConnected()) && periodControl.hasToken(0)) {
Token in = periodControl.get(0);
period.setToken(in);
}
super.fire();
}
}