/* An attribute that extends its container's scope.
Copyright (c) 2001-2007 The Regents of the University of California.
All rights reserved.
Permission is hereby granted, without written agreement and without
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software and its documentation for any purpose, provided that the above
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of this software.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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@ProposedRating Red (liuxj)
@AcceptedRating Red (liuxj)
*/
package ptolemy.data.expr;
import java.util.Iterator;
import ptolemy.kernel.util.Attribute;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
import ptolemy.kernel.util.Nameable;
import ptolemy.kernel.util.NamedObj;
//////////////////////////////////////////////////////////////////////////
//// ScopeExtendingAttribute
/**
An attribute that extends its container's scope. Any
parameter contained by such an attribute has the same
visibility as parameters of the container of the attribute.
They are shadowed, however, by parameters of the container.
That is, if the container has a parameter with the same name
as one in the parameter set, the one in the container provides
the value to any observer.
@author Xiaojun Liu
@version $Id$
@see ptolemy.data.expr.Variable
*/
public class ScopeExtendingAttribute extends Attribute implements ScopeExtender {
/** Construct an attribute with the given name contained by the specified
* entity. The container argument must not be null, or a
* NullPointerException will be thrown. This attribute will use the
* workspace of the container for synchronization and version counts.
* If the name argument is null, then the name is set to the empty string.
* Increment the version of the workspace.
* @param container The container.
* @param name The name of this attribute.
* @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 ScopeExtendingAttribute(NamedObj container, String name)
throws IllegalActionException, NameDuplicationException {
super(container, name);
}
///////////////////////////////////////////////////////////////////
//// public methods ////
/** Specify the container NamedObj, adding this attribute to the
* list of attributes in the container. Notify parameters that
* depends on any parameter of this attribute about the change in
* scope. If the container already
* contains an attribute with the same name, then throw an exception
* and do not make any changes. Similarly, if the container is
* not in the same workspace as this attribute, throw an exception.
* If this attribute is already contained by the NamedObj, do nothing.
* This method is write-synchronized on the workspace and increments
* its version number.
* @param container The container to attach this attribute to..
* @exception IllegalActionException If this attribute is not of the
* expected class for the container, or it has no name,
* or the attribute and container are not in the same workspace, or
* the proposed container would result in recursive containment.
* @exception NameDuplicationException If the container already has
* an attribute with the name of this attribute.
*/
public void setContainer(NamedObj container) throws IllegalActionException,
NameDuplicationException {
Nameable oldContainer = getContainer();
super.setContainer(container);
if (oldContainer != container) {
// Every variable in the new scope that may be shadowed by
// a variable inside this attribute must be invalidated.
// This does not include variables inside the container itself,
// which take precedence.
if (container != null) {
_invalidateShadowedSettables(container.getContainer());
}
// Every variable inside this attribute, and anything that
// had been depending on them, must still be valid.
Iterator vars = attributeList(Variable.class).iterator();
while (vars.hasNext()) {
Variable var = (Variable) vars.next();
var.validate();
}
}
}
///////////////////////////////////////////////////////////////////
//// private methods ////
private void _invalidateShadowedSettables(NamedObj object)
throws IllegalActionException {
if (object == null) {
// Nothing to do.
return;
}
for (Iterator variables = object.attributeList(Variable.class)
.iterator(); variables.hasNext();) {
Variable variable = (Variable) variables.next();
if (getAttribute(variable.getName()) != null) {
variable.invalidate();
}
}
// Also invalidate the variables inside any
// scopeExtendingAttributes.
Iterator scopeAttributes = object.attributeList(
ScopeExtendingAttribute.class).iterator();
while (scopeAttributes.hasNext()) {
ScopeExtendingAttribute attribute = (ScopeExtendingAttribute) scopeAttributes
.next();
Iterator variables = attribute.attributeList(Variable.class)
.iterator();
while (variables.hasNext()) {
Variable variable = (Variable) variables.next();
if (getAttribute(variable.getName()) != null) {
variable.invalidate();
}
}
}
NamedObj container = object.getContainer();
if (container != null) {
_invalidateShadowedSettables(container);
}
}
}