uk.ac.starlink.topcat

Class UserConstant<T>

java.lang.Object

uk.ac.starlink.topcat.UserConstant<T>

All Implemented Interfaces:

uk.ac.starlink.ttools.jel.Constant<T>

public class UserConstant<T>
extends Object
implements uk.ac.starlink.ttools.jel.Constant<T>

Named JEL value that can be set by users for use in expressions. This is constant in the sense that it does not vary with row index, but its value can be changed by the user.

Since:

30 Jun 2025

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
UserConstant(Class<T> clazz, String name, T value) Constructor.

Method Summary

Modifier and Type	Method and Description
Class<T>	getContentClass() Returns the value type for this constant.
String	getName() Returns the name of this constant.
T	getValue() Returns the value of this constant.
boolean	requiresRowIndex()
void	setValue(T value) Sets the value of this constant.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

UserConstant

public UserConstant(Class<T> clazz,
                    String name,
                    T value)

Constructor.

Parameters:

clazz - value type

name - constant name for use in JEL expressions

value - initial value

Method Detail

getContentClass

public Class<T> getContentClass()

Returns the value type for this constant.

Specified by:

getContentClass in interface uk.ac.starlink.ttools.jel.Constant<T>

Returns:

class

getName

public String getName()

Returns the name of this constant.

Returns:

name as used in JEL expressions

setValue

public void setValue(T value)

Sets the value of this constant.

Parameters:

value - new value

getValue

public T getValue()

Returns the value of this constant.

Specified by:

getValue in interface uk.ac.starlink.ttools.jel.Constant<T>

Returns:

current value

requiresRowIndex

public boolean requiresRowIndex()

Specified by:

requiresRowIndex in interface uk.ac.starlink.ttools.jel.Constant<T>

toString

public String toString()

Overrides:

toString in class Object