Add support for generic events in Java client

src/games/stendhal/client/events/EventFactory.java

@@ -1,6 +1,6 @@
 /* $Id$ */
 /***************************************************************************
- *                   (C) Copyright 2003-2010 - Stendhal                    *
+ *                   (C) Copyright 2003-2024 - Stendhal                    *
  ***************************************************************************
  ***************************************************************************
  *                                                                         *
@@ -123,6 +123,8 @@ private static Event<Entity> createEventsForEntity(Entity entity, RPEvent rpeven
 			event = new EntityMessageEvent();
 		}  else if (name.equals(Events.GLOBAL_VISUAL)) {
 			event = new GlobalVisualEffectEvent();
+		} else if (name.equals(Events.GENERIC)) {
+			event = new GenericEvent();
 		}
 
 		if (event != null) {

src/games/stendhal/client/events/GenericEvent.java

@@ -0,0 +1,54 @@
+/***************************************************************************
+ *                    Copyright © 2024 - Faiumoni e. V.                    *
+ ***************************************************************************
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+package games.stendhal.client.events;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.log4j.Logger;
+
+import games.stendhal.client.entity.Entity;
+import games.stendhal.client.events.generic.SubEvent;
+
+
+/**
+ * A generic event that will execute a registered sub-event.
+ *
+ * TODO: allow execution without an associated entity
+ */
+public class GenericEvent extends Event<Entity> {
+
+	/** Registered sub-events. */
+	private static Map<String, Class<? extends SubEvent>> registry = new HashMap<String,
+			Class<? extends SubEvent>>();
+
+
+	@Override
+	public void execute() {
+		final String subevent = event.get("subevent");
+		if (subevent == null || !registry.containsKey(subevent)) {
+			Logger.getLogger(GenericEvent.class).warn("Unknown generic event: " + subevent);
+			return;
+		}
+		final String[] flags = event.has("flags") ? event.get("flags").split(",") : new String[] {};
+		try {
+			final Constructor<? extends SubEvent> constructor = registry.get(subevent)
+					.getConstructor(String[].class);
+			constructor.newInstance((Object) flags).execute(entity);
+		} catch (NoSuchMethodException|SecurityException|InstantiationException|IllegalAccessException
+				|IllegalArgumentException|InvocationTargetException e) {
+			Logger.getLogger(GenericEvent.class).error("Failed to create sub-event instance", e);
+		}
+	}
+}

src/games/stendhal/client/events/generic/SubEvent.java

@@ -0,0 +1,64 @@
+/***************************************************************************
+ *                    Copyright © 2024 - Faiumoni e. V.                    *
+ ***************************************************************************
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+package games.stendhal.client.events.generic;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import games.stendhal.client.entity.Entity;
+
+
+/**
+ * Sub-event for generic events.
+ */
+public abstract class SubEvent {
+
+	/** List of enabled flags. */
+	private final List<String> flags;
+
+
+	/**
+	 * Creates a new event.
+	 *
+	 * @param flags
+	 *   List of enabled flags.
+	 */
+	public SubEvent(final String[] flags) {
+		this.flags = Collections.unmodifiableList(Arrays.asList(flags));
+	}
+
+	/**
+	 * Called when the event occurs.
+	 *
+	 * @param entity
+	 *   Entity associated with event.
+	 */
+	public abstract void execute(Entity entity);
+
+	/**
+	 * Checks if a flag has been specified.
+	 *
+	 * @param flag
+	 *   Name of flag checking for.
+	 * @return
+	 *   {@code true} if {@code flag} found in list of enabled flags.
+	 */
+	protected boolean flagEnabled(final String flag) {
+		for (final String f: flags) {
+			if (f.equals(flag)) {
+				return true;
+			}
+		}
+		return false;
+	}
+}

src/games/stendhal/client/events/generic/package-info.java

@@ -0,0 +1,12 @@
+/***************************************************************************
+ *                    Copyright © 2024 - Faiumoni e. V.                    *
+ ***************************************************************************
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+package games.stendhal.client.events.generic;