uk.ac.starlink.ttools.plot2.config

Class ToggleNullConfigKey<T>

java.lang.Object

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

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

public class ToggleNullConfigKey<T>
extends ConfigKey<T>

Wraps a supplied ConfigKey to provide one that will also allow selection of the null value. In the GUI, this is represented with a toggle button that when selected indicates null, and when not defers to the usual specifier GUI.

This is intended for use with config keys that do not normally accept null values. If used with config keys that do permit null values, confusion may result.

Since:

29 Jun 2016

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
ToggleNullConfigKey(ConfigKey<T> baseKey, String toggleLabel, boolean toggleDflt) Constructor.

Method Summary

Modifier and Type	Method and Description
Specifier<T>	createSpecifier() Constructs a graphical control with which the user can specify a suitable value for association with this key.
T	stringToValue(String txt) 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, getDefaultValue, getMeta, getValueClass, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ToggleNullConfigKey

public ToggleNullConfigKey(ConfigKey<T> baseKey,
                           String toggleLabel,
                           boolean toggleDflt)

Constructor.

Parameters:

baseKey - config key providing non-null-valued behaviour

toggleLabel - GUI label for the toggle button selecting null

toggleDflt - true if the default is null, false if the default is that of the base key

Method Detail

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

stringToValue

public T stringToValue(String txt)
                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:

txt - string representation of value

Returns:

value

Throws:

ConfigException

createSpecifier

public Specifier<T> createSpecifier()

Description copied from class: ConfigKey

Constructs a graphical control with which the user can specify a suitable value for association with this key.

Specified by:

createSpecifier in class ConfigKey<T>

Returns:

new specifier