Add extra parameter to EventBus#subscribe which allows a handler to be bound to a plugin

api/src/main/java/me/lucko/luckperms/api/event/EventBus.java

@@ -31,16 +31,20 @@ import java.util.function.Consumer;
 import javax.annotation.Nonnull;
 
 /**
- * The internal LuckPerms event bus.
+ * The LuckPerms event bus.
  *
- * <p>LuckPerms events are posted to any listeners registered with the bus.</p>
+ * <p>Used to subscribe (or "listen") to LuckPerms events.</p>
  *
  * @since 3.0
  */
 public interface EventBus {
 
     /**
-     * Subscribes to an event.
+     * Registers a new subscription to the given event.
+     *
+     * <p>The returned {@link EventHandler} instance encapsulates the subscription state. It has
+     * methods which can be used to terminate the subscription, or view stats about the nature of
+     * the subscription.</p>
      *
      * @param eventClass the event class
      * @param handler    the event handler
@@ -48,7 +52,28 @@ public interface EventBus {
      * @return an event handler instance representing this subscription
      */
     @Nonnull
-    <T extends LuckPermsEvent> EventHandler<T> subscribe(@Nonnull Class<T> eventClass, @Nonnull Consumer<T> handler);
+    <T extends LuckPermsEvent> EventHandler<T> subscribe(@Nonnull Class<T> eventClass, @Nonnull Consumer<? super T> handler);
+
+    /**
+     * Registers a new subscription to the given event.
+     *
+     * <p>The returned {@link EventHandler} instance encapsulates the subscription state. It has
+     * methods which can be used to terminate the subscription, or view stats about the nature of
+     * the subscription.</p>
+     *
+     * <p>Unlike {@link #subscribe(Class, Consumer)}, this method accepts an additional parameter
+     * for {@code plugin}. This object must be a "plugin" instance on the platform, and is used to
+     * automatically {@link EventHandler#unregister() unregister} the subscription when the
+     * corresponding plugin is disabled.</p>
+     *
+     * @param <T>        the event class
+     * @param plugin     a plugin instance to bind the subscription to.
+     * @param eventClass the event class
+     * @param handler    the event handler
+     * @return an event handler instance representing this subscription
+     */
+    @Nonnull
+    <T extends LuckPermsEvent> EventHandler<T> subscribe(Object plugin, @Nonnull Class<T> eventClass, @Nonnull Consumer<? super T> handler);
 
     /**
      * Gets a set of all registered handlers for a given event.

api/src/main/java/me/lucko/luckperms/api/event/EventHandler.java

@@ -30,7 +30,7 @@ import java.util.function.Consumer;
 import javax.annotation.Nonnull;
 
 /**
- * Represents a handler for a LuckPerms event
+ * Represents a subscription to a {@link LuckPermsEvent}.
  *
  * @param <T> the event class
  */
@@ -64,7 +64,7 @@ public interface EventHandler<T extends LuckPermsEvent> extends AutoCloseable {
      * @return the event consumer
      */
     @Nonnull
-    Consumer<T> getConsumer();
+    Consumer<? super T> getConsumer();
 
     /**
      * Gets the number of times this handler has been called

bukkit/src/main/java/me/lucko/luckperms/bukkit/BukkitCommandExecutor.java

@@ -45,7 +45,7 @@ public class BukkitCommandExecutor extends CommandManager implements CommandExec
 
     private final LPBukkitPlugin plugin;
 
-    BukkitCommandExecutor(LPBukkitPlugin plugin) {
+    public BukkitCommandExecutor(LPBukkitPlugin plugin) {
         super(plugin);
         this.plugin = plugin;
     }

bukkit/src/main/java/me/lucko/luckperms/bukkit/BukkitEventBus.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.bukkit;
+
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
+import me.lucko.luckperms.common.event.AbstractEventBus;
+
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.server.PluginDisableEvent;
+import org.bukkit.plugin.Plugin;
+
+public class BukkitEventBus extends AbstractEventBus<Plugin> implements Listener {
+    public BukkitEventBus(LPBukkitPlugin plugin, LuckPermsApiProvider apiProvider) {
+        super(plugin, apiProvider);
+
+        // register listener
+        LPBukkitBootstrap bootstrap = plugin.getBootstrap();
+        bootstrap.getServer().getPluginManager().registerEvents(this, bootstrap);
+    }
+
+    @Override
+    protected Plugin checkPlugin(Object plugin) throws IllegalArgumentException {
+        if (plugin instanceof Plugin) {
+            return (Plugin) plugin;
+        }
+
+        throw new IllegalArgumentException("Object " + plugin + " (" + plugin.getClass().getName() + ") is not a plugin.");
+    }
+
+    @EventHandler
+    public void onPluginDisable(PluginDisableEvent e) {
+        Plugin plugin = e.getPlugin();
+        unregisterHandlers(plugin);
+    }
+
+}

bukkit/src/main/java/me/lucko/luckperms/bukkit/LPBukkitPlugin.java

@@ -43,11 +43,13 @@ import me.lucko.luckperms.bukkit.model.server.LPDefaultsMap;
 import me.lucko.luckperms.bukkit.model.server.LPPermissionMap;
 import me.lucko.luckperms.bukkit.model.server.LPSubscriptionMap;
 import me.lucko.luckperms.bukkit.vault.VaultHookManager;
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
 import me.lucko.luckperms.common.calculators.PlatformCalculatorFactory;
 import me.lucko.luckperms.common.command.access.CommandPermission;
 import me.lucko.luckperms.common.config.ConfigKeys;
 import me.lucko.luckperms.common.config.adapter.ConfigurationAdapter;
 import me.lucko.luckperms.common.contexts.ContextManager;
+import me.lucko.luckperms.common.event.AbstractEventBus;
 import me.lucko.luckperms.common.listener.ConnectionListener;
 import me.lucko.luckperms.common.managers.group.StandardGroupManager;
 import me.lucko.luckperms.common.managers.track.StandardTrackManager;
@@ -171,6 +173,11 @@ public class LPBukkitPlugin extends AbstractLuckPermsPlugin {
         tryVaultHook(false);
     }
 
+    @Override
+    protected AbstractEventBus provideEventBus(LuckPermsApiProvider apiProvider) {
+        return new BukkitEventBus(this, apiProvider);
+    }
+
     public void tryVaultHook(boolean force) {
         if (this.vaultHookManager != null) {
             return; // already hooked

bungee/src/main/java/me/lucko/luckperms/bungee/BungeeCommandExecutor.java

@@ -45,7 +45,7 @@ public class BungeeCommandExecutor extends Command implements TabExecutor {
     private final LPBungeePlugin plugin;
     private final CommandManager manager;
 
-    BungeeCommandExecutor(LPBungeePlugin plugin, CommandManager manager) {
+    public BungeeCommandExecutor(LPBungeePlugin plugin, CommandManager manager) {
         super("luckpermsbungee", null, "lpb", "bperm", "bperms", "bpermission", "bpermissions");
         this.plugin = plugin;
         this.manager = manager;

bungee/src/main/java/me/lucko/luckperms/bungee/BungeeEventBus.java

@@ -0,0 +1,97 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.bungee;
+
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
+import me.lucko.luckperms.common.event.AbstractEventBus;
+
+import net.md_5.bungee.api.plugin.Listener;
+import net.md_5.bungee.api.plugin.Plugin;
+
+import java.util.logging.Handler;
+import java.util.logging.LogRecord;
+
+public class BungeeEventBus extends AbstractEventBus<Plugin> implements Listener {
+    private final LPBungeeBootstrap bootstrap;
+
+    public BungeeEventBus(LPBungeePlugin plugin, LuckPermsApiProvider apiProvider) {
+        super(plugin, apiProvider);
+        this.bootstrap = plugin.getBootstrap();
+    }
+
+    @Override
+    protected Plugin checkPlugin(Object plugin) throws IllegalArgumentException {
+        if (plugin instanceof Plugin) {
+            Plugin bungeePlugin = (Plugin) plugin;
+
+            // add a custom log handler to effectively listen for the plugin being disabled.
+            // BungeeCord doesn't really support enabling/disabling plugins at runtime, and as
+            // such doesn't have a PluginDisableEvent. However, some plugins do exist to reload
+            // plugins at runtime. We rely on these plugins following the BungeeCord behaviour,
+            // and #close ing the plugins logger, so we can unregister the listeners. :)
+            Handler[] handlers = bungeePlugin.getLogger().getHandlers();
+            for (Handler handler : handlers) {
+                if (handler instanceof UnloadHookLoggerHandler) {
+                    return bungeePlugin;
+                }
+            }
+
+            bungeePlugin.getLogger().addHandler(new UnloadHookLoggerHandler(bungeePlugin));
+            return bungeePlugin;
+        }
+
+        throw new IllegalArgumentException("Object " + plugin + " (" + plugin.getClass().getName() + ") is not a plugin.");
+    }
+
+    @Override
+    public void close() {
+        for (Plugin plugin : this.bootstrap.getProxy().getPluginManager().getPlugins()) {
+            for (Handler handler : plugin.getLogger().getHandlers()) {
+                if (handler instanceof UnloadHookLoggerHandler) {
+                    plugin.getLogger().removeHandler(handler);
+                }
+            }
+        }
+
+        super.close();
+    }
+
+    private final class UnloadHookLoggerHandler extends Handler {
+        private final Plugin plugin;
+
+        private UnloadHookLoggerHandler(Plugin plugin) {
+            this.plugin = plugin;
+        }
+
+        @Override
+        public void close() {
+            unregisterHandlers(this.plugin);
+        }
+
+        @Override public void publish(LogRecord record) {}
+        @Override public void flush() {}
+    }
+}

bungee/src/main/java/me/lucko/luckperms/bungee/LPBungeePlugin.java

@@ -34,10 +34,12 @@ import me.lucko.luckperms.bungee.contexts.RedisBungeeCalculator;
 import me.lucko.luckperms.bungee.listeners.BungeeConnectionListener;
 import me.lucko.luckperms.bungee.listeners.BungeePermissionCheckListener;
 import me.lucko.luckperms.bungee.messaging.BungeeMessagingFactory;
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
 import me.lucko.luckperms.common.calculators.PlatformCalculatorFactory;
 import me.lucko.luckperms.common.command.CommandManager;
 import me.lucko.luckperms.common.config.adapter.ConfigurationAdapter;
 import me.lucko.luckperms.common.contexts.ContextManager;
+import me.lucko.luckperms.common.event.AbstractEventBus;
 import me.lucko.luckperms.common.listener.ConnectionListener;
 import me.lucko.luckperms.common.managers.group.StandardGroupManager;
 import me.lucko.luckperms.common.managers.track.StandardTrackManager;
@@ -139,6 +141,11 @@ public class LPBungeePlugin extends AbstractLuckPermsPlugin {
 
     }
 
+    @Override
+    protected AbstractEventBus provideEventBus(LuckPermsApiProvider apiProvider) {
+        return new BungeeEventBus(this, apiProvider);
+    }
+
     @Override
     protected void registerApiOnPlatform(LuckPermsApi api) {
         // BungeeCord doesn't have a services manager

common/src/main/java/me/lucko/luckperms/common/event/AbstractEventBus.java

@@ -39,6 +39,7 @@ import me.lucko.luckperms.api.event.LuckPermsEvent;
 import me.lucko.luckperms.common.api.LuckPermsApiProvider;
 import me.lucko.luckperms.common.plugin.LuckPermsPlugin;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
@@ -51,7 +52,7 @@ import javax.annotation.Nonnull;
 /**
  * Simple implementation of EventBus.
  */
-public class LuckPermsEventBus implements EventBus {
+public abstract class AbstractEventBus<P> implements EventBus, AutoCloseable {
 
     /**
      * The plugin instance
@@ -77,7 +78,7 @@ public class LuckPermsEventBus implements EventBus {
     private final LoadingCache<Class<? extends LuckPermsEvent>, List<LuckPermsEventHandler<?>>> handlerCache = Caffeine.newBuilder()
             .build(eventClass -> {
                 ImmutableList.Builder<LuckPermsEventHandler<?>> matched = ImmutableList.builder();
-                LuckPermsEventBus.this.handlerMap.asMap().forEach((clazz, handlers) -> {
+                AbstractEventBus.this.handlerMap.asMap().forEach((clazz, handlers) -> {
                     if (clazz.isAssignableFrom(eventClass)) {
                         matched.addAll(handlers);
                     }
@@ -85,29 +86,30 @@ public class LuckPermsEventBus implements EventBus {
                 return matched.build();
             });
 
-    public LuckPermsEventBus(LuckPermsPlugin plugin, LuckPermsApiProvider apiProvider) {
+    protected AbstractEventBus(LuckPermsPlugin plugin, LuckPermsApiProvider apiProvider) {
         this.plugin = plugin;
         this.apiProvider = apiProvider;
     }
 
+    public LuckPermsPlugin getPlugin() {
+        return this.plugin;
+    }
+
     @Nonnull
     @Override
-    public <T extends LuckPermsEvent> EventHandler<T> subscribe(@Nonnull Class<T> eventClass, @Nonnull Consumer<T> handler) {
+    public <T extends LuckPermsEvent> EventHandler<T> subscribe(@Nonnull Class<T> eventClass, @Nonnull Consumer<? super T> handler) {
         Objects.requireNonNull(eventClass, "eventClass");
         Objects.requireNonNull(handler, "handler");
+        return registerSubscription(eventClass, handler, null);
+    }
 
-        if (!eventClass.isInterface()) {
-            throw new IllegalArgumentException("class " + eventClass + " is not an interface");
-        }
-        if (!LuckPermsEvent.class.isAssignableFrom(eventClass)) {
-            throw new IllegalArgumentException("class " + eventClass.getName() + " does not implement LuckPermsEvent");
-        }
-
-        LuckPermsEventHandler<T> eventHandler = new LuckPermsEventHandler<>(this, eventClass, handler);
-        this.handlerMap.put(eventClass, eventHandler);
-        this.handlerCache.invalidateAll();
-
-        return eventHandler;
+    @Nonnull
+    @Override
+    public <T extends LuckPermsEvent> EventHandler<T> subscribe(Object plugin, @Nonnull Class<T> eventClass, @Nonnull Consumer<? super T> handler) {
+        Objects.requireNonNull(plugin, "plugin");
+        Objects.requireNonNull(eventClass, "eventClass");
+        Objects.requireNonNull(handler, "handler");
+        return registerSubscription(eventClass, handler, checkPlugin(plugin));
     }
 
     @Nonnull
@@ -122,11 +124,79 @@ public class LuckPermsEventBus implements EventBus {
         return ret.build();
     }
 
+    /**
+     * Checks that the given plugin object is a valid plugin instance for the platform
+     *
+     * @param plugin the object
+     * @return a plugin
+     * @throws IllegalArgumentException if the plugin is invalid
+     */
+    protected abstract P checkPlugin(Object plugin) throws IllegalArgumentException;
+
+    /**
+     * Registers a subscription for the given class, handler and plugin
+     *
+     * @param eventClass the event class
+     * @param handler the handler
+     * @param plugin the plugin, nullable
+     * @param <T> the event type
+     * @return the resultant handler
+     */
+    private <T extends LuckPermsEvent> EventHandler<T> registerSubscription(Class<T> eventClass, Consumer<? super T> handler, Object plugin) {
+        if (!eventClass.isInterface()) {
+            throw new IllegalArgumentException("class " + eventClass + " is not an interface");
+        }
+        if (!LuckPermsEvent.class.isAssignableFrom(eventClass)) {
+            throw new IllegalArgumentException("class " + eventClass.getName() + " does not implement LuckPermsEvent");
+        }
+
+        LuckPermsEventHandler<T> eventHandler = new LuckPermsEventHandler<>(this, eventClass, handler, plugin);
+        this.handlerMap.put(eventClass, eventHandler);
+        this.handlerCache.invalidateAll();
+
+        return eventHandler;
+    }
+
+    /**
+     * Removes a specific handler from the bus
+     *
+     * @param handler the handler to remove
+     */
     public void unregisterHandler(LuckPermsEventHandler<?> handler) {
         this.handlerMap.remove(handler.getEventClass(), handler);
         this.handlerCache.invalidateAll();
     }
 
+    /**
+     * Removes all handlers for a specific plugin
+     *
+     * @param plugin the plugin
+     */
+    protected void unregisterHandlers(P plugin) {
+        List<LuckPermsEventHandler<?>> handlers = new ArrayList<>(this.handlerMap.values());
+        for (LuckPermsEventHandler<?> handler : handlers) {
+            if (handler.getPlugin() == plugin) {
+                handler.unregister();
+            }
+        }
+    }
+
+    /**
+     * Unregisters all handlers in this event bus
+     */
+    @Override
+    public void close() {
+        List<LuckPermsEventHandler<?>> handlers = new ArrayList<>(this.handlerMap.values());
+        for (LuckPermsEventHandler<?> handler : handlers) {
+            handler.unregister();
+        }
+    }
+
+    /**
+     * Fires the given event to all registered handlers in this event bus
+     *
+     * @param event the event to fire
+     */
     public void fireEvent(LuckPermsEvent event) {
         if (event instanceof AbstractEvent) {
             ((AbstractEvent) event).setApi(this.apiProvider);
@@ -142,14 +212,15 @@ public class LuckPermsEventBus implements EventBus {
         }
     }
 
+    /**
+     * Fires the given event asynchronously to all registered handlers in this event bus
+     *
+     * @param event the event to fire
+     */
     public void fireEventAsync(LuckPermsEvent event) {
         if (event instanceof Cancellable) {
             throw new IllegalArgumentException("cannot call Cancellable event async");
         }
         this.plugin.getBootstrap().getScheduler().doAsync(() -> fireEvent(event));
     }
-
-    public LuckPermsPlugin getPlugin() {
-        return this.plugin;
-    }
 }

common/src/main/java/me/lucko/luckperms/common/event/EventFactory.java

@@ -37,7 +37,6 @@ import me.lucko.luckperms.api.event.cause.CreationCause;
 import me.lucko.luckperms.api.event.cause.DeletionCause;
 import me.lucko.luckperms.api.event.log.LogBroadcastEvent;
 import me.lucko.luckperms.api.event.log.LogNotifyEvent;
-import me.lucko.luckperms.common.api.LuckPermsApiProvider;
 import me.lucko.luckperms.common.api.delegates.model.ApiPermissionHolder;
 import me.lucko.luckperms.common.api.delegates.model.ApiUser;
 import me.lucko.luckperms.common.event.impl.EventConfigReload;
@@ -78,7 +77,6 @@ import me.lucko.luckperms.common.model.Group;
 import me.lucko.luckperms.common.model.PermissionHolder;
 import me.lucko.luckperms.common.model.Track;
 import me.lucko.luckperms.common.model.User;
-import me.lucko.luckperms.common.plugin.LuckPermsPlugin;
 import me.lucko.luckperms.common.sender.Sender;
 
 import java.util.Collection;
@@ -87,13 +85,13 @@ import java.util.UUID;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 public final class EventFactory {
-    private final LuckPermsEventBus eventBus;
+    private final AbstractEventBus eventBus;
 
-    public EventFactory(LuckPermsPlugin plugin, LuckPermsApiProvider apiProvider) {
-        this.eventBus = new LuckPermsEventBus(plugin, apiProvider);
+    public EventFactory(AbstractEventBus eventBus) {
+        this.eventBus = eventBus;
     }
 
-    public LuckPermsEventBus getEventBus() {
+    public AbstractEventBus getEventBus() {
         return this.eventBus;
     }
 

common/src/main/java/me/lucko/luckperms/common/event/LuckPermsEventHandler.java

@@ -33,21 +33,51 @@ import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
+/**
+ * Simple implementation of {@link EventHandler}.
+ *
+ * @param <T> the event type
+ */
 public class LuckPermsEventHandler<T extends LuckPermsEvent> implements EventHandler<T> {
-    private final LuckPermsEventBus eventBus;
 
+    /**
+     * The event bus which created this handler
+     */
+    private final AbstractEventBus<?> eventBus;
+
+    /**
+     * The event class
+     */
     private final Class<T> eventClass;
 
-    private final Consumer<T> consumer;
+    /**
+     * The delegate "event handler"
+     */
+    private final Consumer<? super T> consumer;
 
+    /**
+     * The plugin which "owns" this handler
+     */
+    @Nullable
+    private final Object plugin;
+
+    /**
+     * If this handler is active
+     */
     private final AtomicBoolean active = new AtomicBoolean(true);
+
+    /**
+     * How many times this handler has been called
+     */
     private final AtomicInteger callCount = new AtomicInteger(0);
 
-    public LuckPermsEventHandler(LuckPermsEventBus eventBus, Class<T> eventClass, Consumer<T> consumer) {
+    public LuckPermsEventHandler(AbstractEventBus<?> eventBus, Class<T> eventClass, Consumer<? super T> consumer, @Nullable Object plugin) {
         this.eventBus = eventBus;
         this.eventClass = eventClass;
         this.consumer = consumer;
+        this.plugin = plugin;
     }
 
     @Override
@@ -91,7 +121,12 @@ public class LuckPermsEventHandler<T extends LuckPermsEvent> implements EventHan
 
     @Nonnull
     @Override
-    public Consumer<T> getConsumer() {
+    public Consumer<? super T> getConsumer() {
         return this.consumer;
     }
+
+    @Nullable
+    public Object getPlugin() {
+        return this.plugin;
+    }
 }

common/src/main/java/me/lucko/luckperms/common/plugin/AbstractLuckPermsPlugin.java

@@ -41,6 +41,7 @@ import me.lucko.luckperms.common.config.adapter.ConfigurationAdapter;
 import me.lucko.luckperms.common.contexts.LuckPermsCalculator;
 import me.lucko.luckperms.common.dependencies.DependencyManager;
 import me.lucko.luckperms.common.dependencies.DependencyRegistry;
+import me.lucko.luckperms.common.event.AbstractEventBus;
 import me.lucko.luckperms.common.event.EventFactory;
 import me.lucko.luckperms.common.inheritance.InheritanceHandler;
 import me.lucko.luckperms.common.locale.LocaleManager;
@@ -160,7 +161,7 @@ public abstract class AbstractLuckPermsPlugin implements LuckPermsPlugin {
 
         // register with the LP API
         this.apiProvider = new LuckPermsApiProvider(this);
-        this.eventFactory = new EventFactory(this, this.apiProvider);
+        this.eventFactory = new EventFactory(provideEventBus(this.apiProvider));
         ApiRegistrationUtil.registerProvider(this.apiProvider);
         registerApiOnPlatform(this.apiProvider);
 
@@ -234,6 +235,7 @@ public abstract class AbstractLuckPermsPlugin implements LuckPermsPlugin {
     protected abstract PlatformCalculatorFactory provideCalculatorFactory();
     protected abstract void setupContextManager();
     protected abstract void setupPlatformHooks();
+    protected abstract AbstractEventBus provideEventBus(LuckPermsApiProvider apiProvider);
     protected abstract void registerApiOnPlatform(LuckPermsApi api);
     protected abstract void registerHousekeepingTasks();
     protected abstract void performFinalSetup();

nukkit/src/main/java/me/lucko/luckperms/nukkit/LPNukkitPlugin.java

@@ -27,11 +27,13 @@ package me.lucko.luckperms.nukkit;
 
 import me.lucko.luckperms.api.Contexts;
 import me.lucko.luckperms.api.LuckPermsApi;
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
 import me.lucko.luckperms.common.calculators.PlatformCalculatorFactory;
 import me.lucko.luckperms.common.command.access.CommandPermission;
 import me.lucko.luckperms.common.config.ConfigKeys;
 import me.lucko.luckperms.common.config.adapter.ConfigurationAdapter;
 import me.lucko.luckperms.common.contexts.ContextManager;
+import me.lucko.luckperms.common.event.AbstractEventBus;
 import me.lucko.luckperms.common.listener.ConnectionListener;
 import me.lucko.luckperms.common.managers.group.StandardGroupManager;
 import me.lucko.luckperms.common.managers.track.StandardTrackManager;
@@ -162,6 +164,11 @@ public class LPNukkitPlugin extends AbstractLuckPermsPlugin {
         }
     }
 
+    @Override
+    protected AbstractEventBus provideEventBus(LuckPermsApiProvider apiProvider) {
+        return new NukkitEventBus(this, apiProvider);
+    }
+
     @Override
     protected void registerApiOnPlatform(LuckPermsApi api) {
         this.bootstrap.getServer().getServiceManager().register(LuckPermsApi.class, api, this.bootstrap, ServicePriority.NORMAL);

nukkit/src/main/java/me/lucko/luckperms/nukkit/NukkitCommandExecutor.java

@@ -38,7 +38,7 @@ import java.util.Arrays;
 public class NukkitCommandExecutor extends CommandManager implements CommandExecutor {
     private final LPNukkitPlugin plugin;
 
-    NukkitCommandExecutor(LPNukkitPlugin plugin) {
+    public NukkitCommandExecutor(LPNukkitPlugin plugin) {
         super(plugin);
         this.plugin = plugin;
     }

nukkit/src/main/java/me/lucko/luckperms/nukkit/NukkitEventBus.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.nukkit;
+
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
+import me.lucko.luckperms.common.event.AbstractEventBus;
+
+import cn.nukkit.event.EventHandler;
+import cn.nukkit.event.Listener;
+import cn.nukkit.event.plugin.PluginDisableEvent;
+import cn.nukkit.plugin.Plugin;
+
+public class NukkitEventBus extends AbstractEventBus<Plugin> implements Listener {
+    public NukkitEventBus(LPNukkitPlugin plugin, LuckPermsApiProvider apiProvider) {
+        super(plugin, apiProvider);
+
+        // register listener
+        LPNukkitBootstrap bootstrap = plugin.getBootstrap();
+        bootstrap.getServer().getPluginManager().registerEvents(this, bootstrap);
+    }
+
+    @Override
+    protected Plugin checkPlugin(Object plugin) throws IllegalArgumentException {
+        if (plugin instanceof Plugin) {
+            return (Plugin) plugin;
+        }
+
+        throw new IllegalArgumentException("Object " + plugin + " (" + plugin.getClass().getName() + ") is not a plugin.");
+    }
+
+    @EventHandler
+    public void onPluginDisable(PluginDisableEvent e) {
+        Plugin plugin = e.getPlugin();
+        unregisterHandlers(plugin);
+    }
+
+}

sponge/src/main/java/me/lucko/luckperms/sponge/LPSpongePlugin.java

@@ -27,12 +27,14 @@ package me.lucko.luckperms.sponge;
 
 import me.lucko.luckperms.api.Contexts;
 import me.lucko.luckperms.api.LuckPermsApi;
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
 import me.lucko.luckperms.common.calculators.PlatformCalculatorFactory;
 import me.lucko.luckperms.common.command.CommandManager;
 import me.lucko.luckperms.common.command.abstraction.Command;
 import me.lucko.luckperms.common.command.access.CommandPermission;
 import me.lucko.luckperms.common.config.adapter.ConfigurationAdapter;
 import me.lucko.luckperms.common.contexts.ContextManager;
+import me.lucko.luckperms.common.event.AbstractEventBus;
 import me.lucko.luckperms.common.managers.track.StandardTrackManager;
 import me.lucko.luckperms.common.messaging.MessagingFactory;
 import me.lucko.luckperms.common.model.User;
@@ -159,6 +161,11 @@ public class LPSpongePlugin extends AbstractLuckPermsPlugin {
         }
     }
 
+    @Override
+    protected AbstractEventBus provideEventBus(LuckPermsApiProvider apiProvider) {
+        return new SpongeEventBus(this, apiProvider);
+    }
+
     @Override
     protected void registerApiOnPlatform(LuckPermsApi api) {
         this.bootstrap.getGame().getServiceManager().setProvider(this.bootstrap, LuckPermsApi.class, api);

sponge/src/main/java/me/lucko/luckperms/sponge/SpongeCommandExecutor.java

@@ -52,7 +52,7 @@ public class SpongeCommandExecutor extends CommandManager implements CommandCall
 
     private final LPSpongePlugin plugin;
 
-    SpongeCommandExecutor(LPSpongePlugin plugin) {
+    public SpongeCommandExecutor(LPSpongePlugin plugin) {
         super(plugin);
         this.plugin = plugin;
     }

sponge/src/main/java/me/lucko/luckperms/sponge/SpongeEventBus.java

@@ -0,0 +1,71 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.sponge;
+
+import me.lucko.luckperms.common.api.LuckPermsApiProvider;
+import me.lucko.luckperms.common.event.AbstractEventBus;
+
+import org.spongepowered.api.Sponge;
+import org.spongepowered.api.event.Listener;
+import org.spongepowered.api.event.cause.EventContextKeys;
+import org.spongepowered.api.event.game.GameReloadEvent;
+import org.spongepowered.api.plugin.PluginContainer;
+
+public class SpongeEventBus extends AbstractEventBus<PluginContainer> {
+    public SpongeEventBus(LPSpongePlugin plugin, LuckPermsApiProvider apiProvider) {
+        super(plugin, apiProvider);
+
+        // register listener
+        LPSpongeBootstrap bootstrap = plugin.getBootstrap();
+        bootstrap.getGame().getEventManager().registerListeners(bootstrap, this);
+    }
+
+    @Override
+    protected PluginContainer checkPlugin(Object plugin) throws IllegalArgumentException {
+        if (plugin instanceof PluginContainer) {
+            return (PluginContainer) plugin;
+        }
+
+        PluginContainer pluginContainer = Sponge.getPluginManager().fromInstance(plugin).orElse(null);
+        if (pluginContainer != null) {
+            return pluginContainer;
+        }
+
+        throw new IllegalArgumentException("Object " + plugin + " (" + plugin.getClass().getName() + ") is not a plugin.");
+    }
+
+    @Listener
+    public void onReload(GameReloadEvent e) {
+        // sponge doesn't really support unloading of plugins at runtime.
+        // this probably won't ever work/be useful, but I suppose it's worth a try.
+        PluginContainer pluginContainer = e.getContext().get(EventContextKeys.PLUGIN).orElse(null);
+        if (pluginContainer == null) {
+            return;
+        }
+        unregisterHandlers(pluginContainer);
+    }
+
+}