uk.ac.starlink.topcat

Class ColumnConverter

java.lang.Object

uk.ac.starlink.topcat.ColumnConverter

Direct Known Subclasses:

AngleColumnConverter

public abstract class ColumnConverter
extends Object

Performs unit conversions on data values based on a given ValueInfo.

Since:

17 Sep 2004

Author:

Mark Taylor (Starlink)

Constructor Summary

Constructors

Constructor and Description
ColumnConverter()

Method Summary

Modifier and Type	Method and Description
abstract String	convertExpression(String inExpr) Returns a JEL expression for the converted value of a supplied unconverted input expression.
abstract Object	convertValue(Object value) Converts a value from its raw value to the value required for a particular purpose.
static ColumnConverter[]	getConverters(uk.ac.starlink.table.ValueInfo info) Returns a set of converters appropriate for a given ValueInfo.
abstract String	toString() Provides a user-understandable description of what this converter does.

Methods inherited from class java.lang.Object

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

Constructor Detail

ColumnConverter

public ColumnConverter()

Method Detail

convertValue

public abstract Object convertValue(Object value)

Converts a value from its raw value to the value required for a particular purpose.

Parameters:

value - raw value

Returns:

converted value

convertExpression

public abstract String convertExpression(String inExpr)

Returns a JEL expression for the converted value of a supplied unconverted input expression.

Parameters:

inExpr - input unconverted expression, assumed JEL-friendly

Returns:

JEL expression for converted value

toString

public abstract String toString()

Provides a user-understandable description of what this converter does. Must be enough to distinguish it from distinct converters which might do the same sort of thing.

Overrides:

toString in class Object

getConverters

public static ColumnConverter[] getConverters(uk.ac.starlink.table.ValueInfo info)

Returns a set of converters appropriate for a given ValueInfo. If only one converter is returned, it's a unit converter (equivalent to a no-op).

Parameters:

info - object describing the data which is required

Returns:

a set of alternative converters which could be used to modify the values in a given column