Wraith¶

High-performance Java event handling library designed for developers seeking a customizable and efficient event-driven architecture. It provides a straightforward API to define events, listeners, and event buses, facilitating decoupled communication within applications.

Core Components¶

Event¶

An event is a Java class representing a specific occurrence or action within the application. There are no strict requirements for event classes; any object can serve as an event.

public class CustomEvent {

    private final String message;

    public CustomEvent(String message) {
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

Listener¶

Listeners handle events and can be defined by extending EventListener<T> or using LambdaEventListener<T>. They are associated with a Target to specify which events they should respond to.

public class MyListener extends EventListener<MyEvent> {

    public MyListener() {
        super(Target.fine(MyEvent.class));
    }

    @Override
    public void invoke(MyEvent event) {
        // Handle the event
    }
}

Alternatively, using a lambda expression:

new LambdaEventListener<>(
    Target.fine(MyEvent.class),
    event -> {
        // Handle the event
    }
);

Target¶

Targets define the criteria for listener invocation and event dispatching. They provide fine-grained control over which listeners respond to which events.

• Target.all(): Matches all classes.
• Target.fine(Class<?>): Matches the specified class exactly.
• Target.cascade(Class<?>): Matches the specified class and all its subclasses.

Subscriber¶

Subscribers are classes that register one or more listeners with an event bus. They can extend the Subscriber class or implement the ISubscriber interface.

public class CustomSubscriber extends Subscriber {

    public CustomSubscriber() {
        registerListener(new MyListener());
    }
}

EventBus¶

The EventBus manages the registration of subscribers and the dispatching of events. It ensures that events are delivered to all appropriate listeners.

IEventBus eventBus = new EventBus();
eventBus.subscribe(new CustomSubscriber());
eventBus.dispatch(new CustomEvent("Hello, Wraith!"));