Decorator.java

/** An interface for decorators.

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 Permission is hereby granted, without written agreement and without
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 PT_COPYRIGHT_VERSION_2
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 */
package ptolemy.kernel.util;

//////////////////////////////////////////////////////////////////////////
////Decorator


/**
A decorator is a class that decorates other NamedObj
with extra attributes that are specific to both the decorator
and the NamedObj.

<p>A NamedObj can contain DecoratedAttributes. These are attributes that are
added by another NamedObj, called a decorator to this NamedObj.
An example is for example a code generator. This one has specific attributes
for for example the generated code of the director in a model. These attributes
are added by the Decorator (the code generator), to the director ("this" object).
These attributes are stored seperately and can be retrieved by using
{@link NamedObj#getDecoratorAttributes(Decorator)} or
{@link NamedObj#getDecoratorAttributes(Decorator)}.

<p>For a description of a decorator pattern, see
<a href="http://en.wikipedia.org/wiki/Decorator_pattern">http://en.wikipedia.org/wiki/Decorator_pattern</a>.

@author Bert Rodiers
@version $Id$
@since Ptolemy II 8.0
@Pt.ProposedRating Red (rodiers)
@Pt.AcceptedRating Red (rodiers)
*/

public interface Decorator extends Nameable{

    /** Return the decorated attributes for the target NamedObj.
     *  @param target The NamedObj that will be decorated.
     *  @return The decorated attributes for the target NamedObj. 
     *  @exception IllegalActionException If the attribute is not of an
     *   acceptable class for the container, or if the name contains a period.
     *  @exception NameDuplicationException If the name coincides with
     *   an attribute already in the container.
     */
    public DecoratedAttributes createDecoratedAttributes(NamedObj target) throws IllegalActionException, NameDuplicationException;
    
    /** Set the current type of the decorated attributes.
     *  The type information of the parameters are not saved in the
     *  model hand hence this has to be reset when reading the model
     *  again.
     *  @param decoratedAttributes The decorated attributes.
     *  @exception IllegalActionException If the attribute is not of an
     *   acceptable class for the container, or if the name contains a period.
     */
    public void setTypesOfDecoratedVariables(
            DecoratedAttributes decoratedAttributes) throws IllegalActionException;
}