From ae6a6abcd1ca0588bfcb6b493eec349b114ca5b1 Mon Sep 17 00:00:00 2001
From: KingRainbow44 <kobedo11@gmail.com>
Date: Tue, 26 Apr 2022 20:47:45 -0400
Subject: [PATCH] woo back to generics

---
 .../emu/grasscutter/plugin/PluginManager.java |  9 +++--
 .../server/event/EventHandler.java            | 37 ++++++++-----------
 .../emu/grasscutter/utils/EventConsumer.java  |  4 +-
 3 files changed, 22 insertions(+), 28 deletions(-)

diff --git a/src/main/java/emu/grasscutter/plugin/PluginManager.java b/src/main/java/emu/grasscutter/plugin/PluginManager.java
index 53ac467f3..d436b54d7 100644
--- a/src/main/java/emu/grasscutter/plugin/PluginManager.java
+++ b/src/main/java/emu/grasscutter/plugin/PluginManager.java
@@ -21,7 +21,7 @@ import java.util.jar.JarFile;
  */
 public final class PluginManager {
     private final Map<String, Plugin> plugins = new HashMap<>();
-    private final List<EventHandler> listeners = new LinkedList<>();
+    private final List<EventHandler<? extends Event>> listeners = new LinkedList<>();
     
     public PluginManager() {
         this.loadPlugins(); // Load all plugins from the plugins directory.
@@ -131,7 +131,7 @@ public final class PluginManager {
      * Registers a plugin's event listener.
      * @param listener The event listener.
      */
-    public void registerListener(EventHandler listener) {
+    public void registerListener(EventHandler<? extends Event> listener) {
         this.listeners.add(listener);
     }
     
@@ -161,9 +161,10 @@ public final class PluginManager {
      * @param event The event passed through to the handler.
      * @param handler The handler to invoke.
      */
-    private void invokeHandler(Event event, EventHandler handler) {
+    @SuppressWarnings("unchecked")
+    private <T extends Event> void invokeHandler(Event event, EventHandler<T> handler) {
         if(!event.isCanceled() ||
                 (event.isCanceled() && handler.ignoresCanceled())
-        ) handler.getCallback().consume(event);
+        ) handler.getCallback().consume((T) event);
     }
 }
\ No newline at end of file
diff --git a/src/main/java/emu/grasscutter/server/event/EventHandler.java b/src/main/java/emu/grasscutter/server/event/EventHandler.java
index 14da6f6a1..be6b1c452 100644
--- a/src/main/java/emu/grasscutter/server/event/EventHandler.java
+++ b/src/main/java/emu/grasscutter/server/event/EventHandler.java
@@ -3,39 +3,32 @@ package emu.grasscutter.server.event;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.utils.EventConsumer;
 
-public final class EventHandler {
-    private final Class<? extends Event> event;
+import java.lang.reflect.ParameterizedType;
 
-    /**
-     * Creates an instance of {@link EventHandler} for the specified event.
-     * @param event The event to handle.
-     * @return An instance of {@link EventHandler}.
-     */
-    public static EventHandler forEvent(Class<? extends Event> event) {
-        return new EventHandler(event);
-    }
-    
-    private EventHandler(Class<? extends Event> event) {
-        this.event = event;
-    }
-    
-    private EventConsumer listener;
+public final class EventHandler<T extends Event> {
+    private final Class<T> eventClass;
+    private EventConsumer<T> listener;
     private HandlerPriority priority;
     private boolean handleCanceled;
+    
+    @SuppressWarnings("unchecked")
+    public EventHandler() {
+        this.eventClass = (Class<T>) ((ParameterizedType) (getClass().getGenericSuperclass())).getActualTypeArguments()[0];
+    }
 
     /**
      * Gets which event this handler is handling.
      * @return An event class.
      */
-    public Class<? extends Event> handles() {
-        return this.event;
+    public Class<T> handles() {
+        return this.eventClass;
     }
 
     /**
      * Returns the callback for the handler.
      * @return A consumer callback.
      */
-    public EventConsumer getCallback() {
+    public EventConsumer<T> getCallback() {
         return this.listener;
     }
 
@@ -60,7 +53,7 @@ public final class EventHandler {
      * @param listener An event handler method.
      * @return Method chaining.
      */
-    public EventHandler listener(EventConsumer listener) {
+    public EventHandler<T> listener(EventConsumer<T> listener) {
         this.listener = listener; return this;
     }
 
@@ -69,7 +62,7 @@ public final class EventHandler {
      * @param priority The priority of the handler.
      * @return Method chaining.
      */
-    public EventHandler priority(HandlerPriority priority) {
+    public EventHandler<T> priority(HandlerPriority priority) {
         this.priority = priority; return this;
     }
 
@@ -78,7 +71,7 @@ public final class EventHandler {
      * @param ignore If the handler should ignore cancelled events.
      * @return Method chaining.
      */
-    public EventHandler ignore(boolean ignore) {
+    public EventHandler<T> ignore(boolean ignore) {
         this.handleCanceled = ignore; return this;
     }
 
diff --git a/src/main/java/emu/grasscutter/utils/EventConsumer.java b/src/main/java/emu/grasscutter/utils/EventConsumer.java
index ae8bb5a9b..baa531944 100644
--- a/src/main/java/emu/grasscutter/utils/EventConsumer.java
+++ b/src/main/java/emu/grasscutter/utils/EventConsumer.java
@@ -2,6 +2,6 @@ package emu.grasscutter.utils;
 
 import emu.grasscutter.server.event.Event;
 
-public interface EventConsumer {
-    <T extends Event> void consume(T event);
+public interface EventConsumer<T extends Event> {
+    void consume(T event);
 }