casa.event

Class EventDescriptor

java.lang.Object

casa.event.EventDescriptor

All Implemented Interfaces:

Descriptor<Event>

Direct Known Subclasses:

MessageEventDescriptor

public class EventDescriptor
extends Object
implements Descriptor<Event>

Top-level event descriptor for the lisp interpreter POLICY function.

Author:

Rob Kremer

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	EventDescriptor.EventDescriptorLispOperator a class representation of Event Descriptor Lisp Operator

Field Summary

Fields

Modifier and Type	Field and Description
protected PolicyAgentInterface	agent An agent used for type checking of type against the event type
private static CasaLispOperator	EVENT_DESCRIPTOR Lisp operator: (EVENT-DESCRIPTOR performative act) Create a EventDescriptor object.
private String	name
private EventPattern	pattern
private String	type Describes the type of the event descriptor.

Constructor Summary

Constructors

Constructor and Description
EventDescriptor(PolicyAgentInterface agent, String type, Object... pairs)
EventDescriptor(PolicyAgentInterface agent, String type, Pair<String,? extends Object>[] pairs) Simple constructor

Method Summary

Modifier and Type	Method and Description
int	compareTo(PolicyAgentInterface agent, EventDescriptor o)
Act	getAct()
protected String	getLispFunctionName()
String	getName()
EventPattern	getPattern()
String	getPerformative()
String	getType()
Status	isApplicable(PolicyAgentInterface agent, Event event) Returns true if event descriptor matches the event in the context of the agent.
protected static <T extends Comparable<T>> Pair<String,? extends T>[]	makePairs(Object... pairs)
boolean	overrides(EventDescriptor other) Determines if this EventDescriptor should override (replace, takes precidence over) the other one such that the other one's associated policy doesn't get executed at all.
void	setPattern(EventPattern p)
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

agent

protected PolicyAgentInterface agent

An agent used for type checking of type against the event type

type

private String type

Describes the type of the event descriptor.

name

private String name

pattern

private EventPattern pattern

EVENT_DESCRIPTOR

private static final CasaLispOperator EVENT_DESCRIPTOR

Lisp operator: (EVENT-DESCRIPTOR performative act)
Create a EventDescriptor object.

Constructor Detail

EventDescriptor

public EventDescriptor(PolicyAgentInterface agent,
                       String type,
                       Pair<String,? extends Object>[] pairs)

Simple constructor

Parameters:

type - initialized the type attribute.

EventDescriptor

public EventDescriptor(PolicyAgentInterface agent,
                       String type,
                       Object... pairs)

Method Detail

makePairs

protected static <T extends Comparable<T>> Pair<String,? extends T>[] makePairs(Object... pairs)

getType

public String getType()

Returns:

returns value of the type attribute.

isApplicable

public Status isApplicable(PolicyAgentInterface agent,
                           Event event)

Returns true if event descriptor matches the event in the context of the agent. The eventInstanceInfo is used to pass any additional info (such as a message object) for additional context.

Specified by:

isApplicable in interface Descriptor<Event>

Parameters:

agent - the agent that forms the context of evaluation.

event - the event to match against.

eventInstanceInfo - additional context that may be used to determine the match.

Returns:

true if this event descriptor matches the event in the context of the agent and eventInstanceInfo.

compareTo

public int compareTo(PolicyAgentInterface agent,
                     EventDescriptor o)

overrides

public boolean overrides(EventDescriptor other)

Determines if this EventDescriptor should override (replace, takes precidence over) the other one such that the other one's associated policy doesn't get executed at all. This is not the same as being more general or specific: two EventDescriptors may be in a sub/super type relationship and both be executable.
Subclasses may override this behaviour.

Parameters:

other - The EventDescriptor to compare to

Returns:

Returns true iff both have identical performatives, and the act of this one is more specialized than the act of the other one..

getPerformative

public String getPerformative()

Returns:

getAct

public Act getAct()

Returns:

getPattern

public EventPattern getPattern()

setPattern

public void setPattern(EventPattern p)

getLispFunctionName

protected String getLispFunctionName()

Returns:

The name of the lisp function that will create an instance of this type

toString

public String toString()

Overrides:

toString in class Object

getName

public String getName()