feat(EventBus): add event priority

src/main/java/me/alpha432/oyvey/event/system/EventBus.java

@@ -13,14 +13,18 @@ public class EventBus {
 
     public void register(Object host) {
         for (Method method : host.getClass().getDeclaredMethods()) {
-            if (method.isAnnotationPresent(Subscribe.class)) {
+            Subscribe subscribe = method.getAnnotation(Subscribe.class);
+            if (subscribe == null) continue;
+
             Class<?>[] params = method.getParameterTypes();
             if (params.length == 1) {
                 Class<?> eventType = params[0];
 
-                    listeners.computeIfAbsent(eventType, k -> new CopyOnWriteArrayList<>())
-                            .add(Listener.of(host, method));
-                }
+                Listener listener = Listener.of(host, subscribe.priority(), method);
+                List<Listener> registry = listeners.computeIfAbsent(eventType,
+                        k -> new CopyOnWriteArrayList<>());
+
+                register(registry, listener);
             }
         }
     }
@@ -40,4 +44,13 @@ public class EventBus {
             listener.invoke(event);
         }
     }
+
+    private void register(List<Listener> registry, Listener target) {
+        int i = 0;
+        for (Listener listener : registry) {
+            i++;
+            if (target.priority() > listener.priority()) break;
+        }
+        registry.add(i, target);
+    }
 }

src/main/java/me/alpha432/oyvey/event/system/Listener.java

@@ -4,9 +4,9 @@ import java.lang.invoke.*;
 import java.lang.reflect.Method;
 import java.util.function.Consumer;
 
-public record Listener(Object host, Consumer<Object> consumer) {
-    public static Listener of(Object host, Method method) {
-        return new Listener(host, buildLambdaMetafactory(host, method));
+public record Listener(Object host, int priority, Consumer<Object> consumer) {
+    public static Listener of(Object host, int priority, Method method) {
+        return new Listener(host, priority, buildLambdaMetafactory(host, method));
     }
 
     public void invoke(Object event) {

src/main/java/me/alpha432/oyvey/event/system/Subscribe.java

@@ -8,5 +8,6 @@ import java.lang.annotation.Target;
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.METHOD)
 public @interface Subscribe {
+    int priority() default 0;
 }