Allow arbitrary post orders

api/src/main/java/com/velocitypowered/api/event/EventManager.java

@@ -46,7 +46,7 @@ public interface EventManager {
    * @param handler the handler to register
    * @param <E> the event type to handle
    */
-  <E> void register(Object plugin, Class<E> eventClass, PostOrder postOrder,
+  <E> void register(Object plugin, Class<E> eventClass, short postOrder,
       EventHandler<E> handler);
 
   /**

api/src/main/java/com/velocitypowered/api/event/PostOrder.java

@@ -10,8 +10,12 @@ package com.velocitypowered.api.event;
 /**
  * Represents the order an event will be posted to a listener method, relative to other listeners.
  */
-public enum PostOrder {
+public class PostOrder {
 
-  FIRST, EARLY, NORMAL, LATE, LAST
+  public static final short FIRST = -32768;
+  public static final short EARLY = -16384;
+  public static final short NORMAL = 0;
+  public static final short LATE = 16834;
+  public static final short LAST = 32767;
 
 }

api/src/main/java/com/velocitypowered/api/event/Subscribe.java

@@ -24,7 +24,7 @@ public @interface Subscribe {
    *
    * @return the order
    */
-  PostOrder order() default PostOrder.NORMAL;
+  short order() default PostOrder.NORMAL;
 
   /**
    * Whether the handler must be called asynchronously.

proxy/src/main/java/com/velocitypowered/proxy/event/VelocityEventManager.java

@@ -29,7 +29,6 @@ import com.velocitypowered.api.event.Continuation;
 import com.velocitypowered.api.event.EventHandler;
 import com.velocitypowered.api.event.EventManager;
 import com.velocitypowered.api.event.EventTask;
-import com.velocitypowered.api.event.PostOrder;
 import com.velocitypowered.api.event.Subscribe;
 import com.velocitypowered.api.plugin.PluginContainer;
 import com.velocitypowered.api.plugin.PluginManager;
@@ -330,7 +329,7 @@ public class VelocityEventManager implements EventManager {
       if (subscribe.async()) {
         asyncType = AsyncType.ALWAYS;
       }
-      final short order = (short) subscribe.order().ordinal();
+      final short order = subscribe.order();
       final String errorsJoined = errors.isEmpty() ? null : String.join(",", errors);
       collected.put(key, new MethodHandlerInfo(method, asyncType, eventType, order, errorsJoined,
           continuationType));
@@ -370,13 +369,13 @@ public class VelocityEventManager implements EventManager {
   @Override
   @SuppressWarnings("unchecked")
   public <E> void register(final Object plugin, final Class<E> eventClass,
-      final PostOrder order, final EventHandler<E> handler) {
+      final short order, final EventHandler<E> handler) {
     final PluginContainer pluginContainer = pluginManager.ensurePluginContainer(plugin);
     requireNonNull(eventClass, "eventClass");
     requireNonNull(handler, "handler");
 
     final HandlerRegistration registration = new HandlerRegistration(pluginContainer,
-        (short) order.ordinal(), eventClass, handler, (EventHandler<Object>) handler,
+        order, eventClass, handler, (EventHandler<Object>) handler,
         AsyncType.SOMETIMES);
     register(Collections.singletonList(registration));
   }