As of Fzzy Config 0.6.0, create sets of selectable and de-selectable choices with ValidatedChoiceList. This is useful for a feature-flag-style setting, polling for active flags using List#contains.

Like ValidatedChoice, this validation is of the type List<T>, where T is your choice type. Like ValidatedList, this validation implements the List interface, so can be used directly for list operations.

Helper methods toChoiceList in ValidatedList / Set / Choice make creation of a choice list easier

ValidatedChoiceList<String> enabledFeatures = ValidatedList.ofString("dev_mode", "logging", "fail_fast", "compatibility_mode").toChoiceList(listOf("logging"));

The choice list appears in-GUI as a popup with the available choices, each in an enabled or disabled state. Clicking on any choice flip it's state between enabled and disabled.