uk.ac.starlink.ttools.plot2.config

Class ChoiceConfigKey<T>

java.lang.Object

uk.ac.starlink.ttools.plot2.config.ConfigKey<T>

uk.ac.starlink.ttools.plot2.config.ChoiceConfigKey<T>

Direct Known Subclasses:

ColorConfigKey, DashConfigKey, ShaderConfigKey

public abstract class ChoiceConfigKey<T>
extends ConfigKey<T>

ConfigKey that allows named choices from a given list, and optionally provides other ways of specifying values from string descriptions.

Since:

10 Sep 2014

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
ChoiceConfigKey(ConfigMeta meta, Class<T> clazz, T dflt, boolean nullPermitted) Constructor.

Method Summary

Modifier and Type	Method and Description
void	addOption(T option) Adds an option to the permitted list.
abstract T	decodeString(String sval) Takes a string, and attempts to turn it into an object which may be a value for this key.
Map<String,T>	getOptionMap() Returns a mutable map giving the currently available known options and their string values.
abstract String	stringifyValue(T value) Takes an object which may be a value of this key, and attempts to turn it into a string for reporting purposes.
T	stringToValue(String sval) Decodes a string value to the value type of this key.
String	valueToString(T value) Reports a value as a string.

Methods inherited from class uk.ac.starlink.ttools.plot2.config.ConfigKey

cast, createSpecifier, getDefaultValue, getMeta, getValueClass, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ChoiceConfigKey

public ChoiceConfigKey(ConfigMeta meta,
                       Class<T> clazz,
                       T dflt,
                       boolean nullPermitted)

Constructor.

Parameters:

meta - metadata

clazz - value class

dflt - default value

nullPermitted - true iff null is a permitted value

Method Detail

addOption

public void addOption(T option)

Adds an option to the permitted list. Its name is obtained using the stringifyValue(T) method, which must return a non-null value.

For more flexibility, you can manipulate the return value of getOptionMap() directly.

Parameters:

option - option to add

getOptionMap

public Map<String,T> getOptionMap()

Returns a mutable map giving the currently available known options and their string values.

Returns:

current name->value map of known options

decodeString

public abstract T decodeString(String sval)

Takes a string, and attempts to turn it into an object which may be a value for this key. If the string is not of a recognised form, null is returned.

This method should be the opposite of stringifyValue(T), but does not need to be consistent with stringToValue or valueToString.

Parameters:

sval - string representation

Returns:

typed object represented by sval, or null

stringifyValue

public abstract String stringifyValue(T value)

Takes an object which may be a value of this key, and attempts to turn it into a string for reporting purposes.

This method should if possible be the opposite of decodeString(java.lang.String), but does not need to be consistent with stringToValue or valueToString. If no round-trippable value is available, null should be returned.

Parameters:

value - typed object

Returns:

string representing object, or null

stringToValue

public T stringToValue(String sval)
                throws ConfigException

Description copied from class: ConfigKey

Decodes a string value to the value type of this key. An empty string should be interpreted as a null value, but this may cause an exception if null is not a permissible value for this key.

Specified by:

stringToValue in class ConfigKey<T>

Parameters:

sval - string representation of value

Returns:

value

Throws:

ConfigException

valueToString

public String valueToString(T value)

Description copied from class: ConfigKey

Reports a value as a string. If at all possible the roundtripping should be possible, so stringToValue(valueToString(v)).equals(v). A null value, if permitted, should be represented as an empty string.

Specified by:

valueToString in class ConfigKey<T>

Parameters:

value - possible value associated with this key

Returns:

string representation