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javawrapperabstractionenumset

Enumset wrapper for AbstractActions


I'd like to load a series of Swing Actions into a container at runtime and access them by a constant name as is possible with an Enum. The purpose of this would be to both restrict the Actions possible and also improve readability.

Initially, I was considering a sort of dynamic enum (see http://blog.xebia.com/2009/04/02/dynamic-enums-in-java/) but as Java Drinker points out below this is unnecessary since the actions remain unchanged.

Ideally, what I'd like to do is a sort of wrapper that contains AbstractAction instances which could be enabled/disabled and be able to refer to each action through a symbolic name.

Edit: Question has been reformulated.


Solution

  • You can do something like this:

    public enum Actions {
        COPY( new AbstractAction() {
            public void actionPerformed(ActionEvent e) {
                //do something
            }
        }),
        PASTE( new PasteAction() );
    
        public final AbstractAction action;
        private Actions(AbstractAction action) {
            this.action = action;
        }
    
    }
    
    //...
    Actions.COPY.action...;
    

    And then as others have said, use the enum in conjunction with an EnumSet or EnumMap. Personally, I don't see a huge value in it over just having a few named fields without an enum.

    I think what you really want is some kind of Action registry like this:

    public class ActionsManager {
        private final Map<String, Action> actions;
        private final Map<User, Set<String>> enabledActions;
        public Action get(String id);
        public void register(String id, Action action);
        public void deregister(String id);
        public boolean isEnabled(User user, Action action);
    }
    

    Implementation left as an exercise.