Enums and android annotation intDef

The main idea of IntDef annotation is to use set of int constants like an enum, but without enum. In this case you have to declare all constants manually.

@IntDef({Status.IDLE, Status.PROCESSING, Status.DONE, Status.CANCELLED})
@Retention(RetentionPolicy.SOURCE)
@interface Status {
    int IDLE = 0;
    int PROCESSING = 1;
    int DONE = 2;
    int CANCELLED = 3;
}

You can see detailed example here.