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 Details

    • 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 Details

    • 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(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

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