PTOLEMY II - CiteSeerX

Designing Actors
alComm actor. Because these process hardware events, which can occur at any time, they instead use
the fireAtCurrentTime() method. The fireAt() is incorrect because model time may advance between
the call to getCurrentTime() and the call to fireAt(), which could result in fireAt() requesting a firing in
the past. This will trigger an exception.
5.7 Icons
An actor designer can specify a custom icon when defining the actor. A (very primitive) icon editor
is supplied with Ptolemy II version 4.0 and higher. To create an icon, in the File menu, select New
and then Icon Editor. An editor opens that contains a gray box for reference that is the size of the
default icon that will be supplied if you do not create a custom icon. To create a custom icon, drag in
the visual elements from the library, set their parameters, and then save the icon in an XML file in the
same directory with the actor definition. If the name of the actor class is Foo, then the name of the file
should be FooIcon.xml. That is, simply append “Icon” to the class name and complete the file name
with the extension “.xml”.
One useful feature that is not immediately evident in the user interface is that when you specify a
color to fill a geometric shape or to serve as the outline for the shape, you can make the color translus-
public class Ramp extends SequenceSource {
public Ramp(CompositeEntity container, String name)
throws NameDuplicationException, IllegalActionException {
super(container, name);
...
_resultArray = new Token[1];
}
}
...
public Object clone(Workspace workspace) throws CloneNotSupportedException {
...
_resultArray = new Token[1];
return newObject;
}
public int iterate(int count) throws IllegalActionException {
// Check whether we need to reallocate the output token array.
if (count > _resultArray.length) {
_resultArray = new Token[count];
}
for (int i = 0; i < count; i++) {
_resultArray[i] = _stateToken;
step.update();
_stateToken = _stateToken.add(step.getToken());
}
output.send(0, _resultArray, count);
if (_firingCountLimit != 0) {
_iterationCount += count;
if (_iterationCount >= _firingCountLimit) {
return STOP_ITERATING;
}
}
return COMPLETED;
}
...
private Token[] _resultArray;
FIGURE 5.11. More code segments from the Ramp actor of figure 5.10, showing the iterate() method.
Heterogeneous Concurrent Modeling and Design 171