prefuse.data.expression
Class Literal

java.lang.Object
  prefuse.data.expression.AbstractExpression
      prefuse.data.expression.Literal

All Implemented Interfaces:

java.util.EventListener, ExpressionListener, Expression

Direct Known Subclasses:

BooleanLiteral, NumericLiteral, ObjectLiteral

public abstract class Literal
extends AbstractExpression

Abstarct base class for a Literal Expression that evaluates to a constant value.

Author:

jeffrey heer

Constructor Summary

Literal()

Method Summary

static Literal	getLiteral(java.lang.Object val) Return the given object as a new Literal instance.
static Literal	getLiteral(java.lang.Object val, java.lang.Class type) Return the given object as a new Literal instance.
static Literal	getLiteral(Tuple t, java.lang.String field) Evaluate the given tuple and data field and return the result as a new Literal instance.

Methods inherited from class prefuse.data.expression.AbstractExpression

addChildListeners, addExpressionListener, expressionChanged, fireExpressionChange, get, getBoolean, getDouble, getFloat, getInt, getLong, hasListeners, removeChildListeners, removeExpressionListener, visit

Methods inherited from class java.lang.Object

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

Methods inherited from interface prefuse.data.expression.Expression

getType

Constructor Detail

Literal

public Literal()

Method Detail

getLiteral

public static Literal getLiteral(Tuple t,
                                 java.lang.String field)

Evaluate the given tuple and data field and return the result as a new Literal instance.

Parameters:

t - the Tuple

field - the data field to lookup

Returns:

a new Literal expression containing the value of the Tuple's data field

getLiteral

public static Literal getLiteral(java.lang.Object val)

Return the given object as a new Literal instance.

Parameters:

val - the object value

Returns:

a new Literal expression containing the object value. The type is assumed to be the value's concrete runtime type.

getLiteral

public static Literal getLiteral(java.lang.Object val,
                                 java.lang.Class type)

Return the given object as a new Literal instance.

Parameters:

val - the object value

type - the type the literal should take

Returns:

a new Literal expression containing the object value