Refactored GlobalEventBus

src/main/java/org/toop/eventbus/Events.java

@@ -0,0 +1,23 @@
+package org.toop.eventbus;
+
+import org.toop.server.Server;
+
+/**
+ * Events that are used in the GlobalEventBus class.
+ */
+public class Events {
+
+    public static class ServerEvents {
+        /**
+         * Triggers when a command is sent to a server.
+         */
+        public record OnCommand(Server.Command command, String[] args, Server.Message result) {}
+
+        /**
+         * Triggers on changing the server backend.
+         */
+        public record OnChangingServerBackend(Server.ServerBackend backend) {}
+
+    }
+
+}

src/main/java/org/toop/eventbus/GlobalEventBus.java

@@ -0,0 +1,90 @@
+package org.toop.eventbus;
+
+import com.google.common.eventbus.EventBus;
+import com.google.common.eventbus.Subscribe;
+
+import java.util.function.Consumer;
+
+/**
+ * A singleton Event Bus to be used for creating, triggering and activating events.
+ */
+public enum GlobalEventBus {
+    /**
+     * The instance of the Event Bus.
+     */
+    INSTANCE;
+
+    /**
+     * Singleton event bus.
+     */
+    private final EventBus eventBus = new EventBus("global-bus");
+
+    /**
+     * Wraps a Consumer into a Guava @Subscribe-compatible listener.
+     *
+     * @return Singleton Event Bus
+     */
+    public EventBus get() {
+        return eventBus;
+    }
+
+    /**
+     * Wraps a Consumer into a Guava @Subscribe-compatible listener.
+     *
+     * @param type The event to be used. (e.g. Events.ServerCommand.class)
+     * @param action The function, or lambda to run when fired.
+     * @return Object to be used for registering an event.
+     */
+    public static <T> Object subscribe(Class<T> type, Consumer<T> action) {
+        return new Object() {
+            @Subscribe
+            public void handle(T event) {
+                action.accept(event);
+            }
+        };
+    }
+
+    /**
+     * Wraps a Consumer into a Guava @Subscribe-compatible listener and registers it.
+     *
+     * @param type The event to be used. (e.g. Events.ServerCommand.class)
+     * @param action The function, or lambda to run when fired.
+     * @return Object to be used for registering an event.
+     */
+    public static <T> Object subscribeAndRegister(Class<T> type, Consumer<T> action) {
+        Object listener = new Object() {
+            @Subscribe
+            public void handle(Object event) {
+                if (type.isInstance(event)) {
+                    action.accept(type.cast(event));
+                }
+            }
+        };
+        register(listener);
+        return listener;
+    }
+
+
+    /**
+     * Wrapper for registering a listener.
+     *
+     * @param listener The event listener to register.
+     */
+    public static void register(Object listener) {
+        GlobalEventBus.INSTANCE.get().register(listener);
+    }
+
+    /**
+     * Wrapper for unregistering a listener.
+     *
+     * @param listener The event listener to unregister.
+     */
+    public static void unregister(Object listener) {
+        GlobalEventBus.INSTANCE.get().unregister(listener);
+    }
+
+    public static void post(Object event) {
+        GlobalEventBus.INSTANCE.get().post(event);
+    }
+
+}