PTOLEMY II - CiteSeerX

Custom Applets
public class TutorialApplet1 extends TypedCompositeActor {...}
defines a class called TutorialApplet1 that extends TypedCompositeActor. The new class provides a
constructor that takes one argument, the Workspace into which to place the model:
public TutorialApplet1(Workspace workspace)
throws IllegalActionException, NameDuplicationException {...}
The body of the constructor first invokes the constructor in the base class with:
super(workspace);
It then creates a DE director.
DEDirector director = new DEDirector(this, "director");
The director implements the discrete-event model of computation, which controls when the component
actors are invoked and how they communicate. The next line tells the model to use the director:
setDirector(director);
The next line sets a director parameter that controls the duration of an execution of the model:
director.stopTime.setExpression("10.0");
If we don’t set the stop time, then the model will run forever, or until the user hits the stop button. The
next few lines create an instance of Clock and an instance of TimedPlotter, and connect them together:
// Create two actors.
Clock clock = new Clock(this,"clock");
TimedPlotter plotter = new TimedPlotter(this,"plotter");
// Connect them.
connect(clock.output, plotter.input);
The constructors for Clock and TimedPlotter take two arguments, the container (a composite actor),
and an arbitrary name (which must be unique within the container). This example uses the variable
this, which refers to the class we are creating, a TypedCompositeActor, as a container. The connection
is accomplished by the connect() method of the composite actor, which takes two ports as arguments.
Instances of Clock have one output port, output, which is a public member, and instances of
TimedPlotter have one input port, input, which is also a public member.
8.3.2 Compiling
To compile this class definition, you must tell the Java compiler where to find the Ptolemy classes
by using the -classpath command line argument. For example, in bash or a similar shell, assuming the
environment variable PTII is set to the location of the Ptolemy II installation:
Heterogeneous Concurrent Modeling and Design 8-237