Improve and fix events

base/src/main/java/de/staropensource/sosengine/base/Engine.java

@@ -91,9 +91,6 @@ public final class Engine {
         // Initialize classes
         initializeClasses();
 
-        // Initialize events
-        initializeEvents();
-
         // Populate crash content
         populateCrashContent();
 
@@ -119,14 +116,6 @@ public final class Engine {
         new ShortcodeConverter();
     }
 
-    /**
-     * Initializes all events.
-     *
-     * @since 1-alpha0
-     */
-    private void initializeEvents() {
-    }
-
     /**
      * This method populates the Crash Handler's content with the default set of content.
      *

base/src/main/java/de/staropensource/sosengine/base/annotations/EventListener.java

@@ -20,15 +20,29 @@
 package de.staropensource.sosengine.base.annotations;
 
 import de.staropensource.sosengine.base.classes.Event;
+import de.staropensource.sosengine.base.classes.EventPriority;
 
 import java.lang.annotation.*;
 
 /**
  * Annotation for registering events on methods.
  */
+@SuppressWarnings("unused")
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.METHOD)
 @Documented
 public @interface EventListener {
+    /**
+     * The event to listen for.
+     *
+     * @return the event the method listens for
+     */
     Class<? extends Event> event();
+
+    /**
+     * The priority of the event.
+     *
+     * @return the event priority
+     */
+    EventPriority priority();
 }

base/src/main/java/de/staropensource/sosengine/base/classes/Event.java

@@ -1,131 +1,14 @@
-/*
-    STAROPENSOURCE ENGINE SOURCE FILE
-    Copyright (c) 2024 The StarOpenSource Engine Contributors
-    Licensed under the GNU Affero General Public License v3
-
-    This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as
-    published by the Free Software Foundation, either version 3 of the
-    License, or (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU Affero General Public License for more details.
-
-    You should have received a copy of the GNU Affero General Public License
-    along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
 package de.staropensource.sosengine.base.classes;
 
-import de.staropensource.sosengine.base.annotations.EventListener;
-import de.staropensource.sosengine.base.logging.Logger;
-import de.staropensource.sosengine.base.types.CodePart;
-import de.staropensource.sosengine.base.types.LogIssuer;
-import lombok.Getter;
-import org.jetbrains.annotations.NotNull;
-import org.reflections.Reflections;
-import org.reflections.scanners.Scanners;
-import org.reflections.util.ClasspathHelper;
-import org.reflections.util.ConfigurationBuilder;
-
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Set;
-
 /**
  * Represents an event.
  *
  * @since 1-alpha0
  */
-@Getter
-@SuppressWarnings({ "unused", "JavadocDeclaration", "JavadocBlankLines" })
-public abstract class Event {
+@SuppressWarnings({ "unused" })
+public interface Event {
     /**
-     * Instance.
-     *
-     * @since 1-alpha0
-     *
-     * -- GETTER --
-     * Returns the extending {@link Event} instance.
-     *
-     * @return extending {@link Event} instance
-     * @since 1-alpha0
+     * Calls the event.
      */
-    @Getter()
-    protected static Event instance;
-
-    /**
-     * The name of the event.
-     *
-     * @since 1-alpha0
-     *
-     * -- GETTER --
-     * Returns the name of the event.
-     *
-     * @return the event name
-     * @since 1-alpha0
-     */
-    @NotNull
-    private final String eventName;
-
-    /**
-     * Constructor.
-     *
-     * @since 1-alpha0
-     */
-    public Event() {
-        this.eventName = this.getClass().getName().replace(this.getClass().getPackage() + ".", "");
-
-        // Only allow one instance
-        if (instance == null)
-            instance = this;
-        else
-            Logger.crash(new LogIssuer(getClass(), CodePart.ENGINE), "Tried reinitializing " + getClass().getName() + " twice");
-    }
-
-    /**
-     * Returns all annotated methods.
-     *
-     * @return list of annotated methods
-     * @since 1-alpha0
-     */
-    @NotNull
-    protected List<Method> getAnnotatedMethods() {
-        List<Method> methods = new ArrayList<>();
-
-        Reflections reflections = new Reflections(
-                new ConfigurationBuilder()
-                .setUrls(ClasspathHelper.forJavaClassPath())
-                .setScanners(Scanners.MethodsAnnotated)
-        );
-        Set<Method> annotatedMethods = reflections.getMethodsAnnotatedWith(EventListener.class);
-
-        for (Method method : annotatedMethods)
-            if (method.getAnnotation(EventListener.class).event() == this.getClass())
-                methods.add(method);
-
-        return methods;
-    }
-
-    /**
-     * Invokes all annotated methods without any arguments.
-     */
-    protected void invokeAnnotatedMethods() {
-        for (Method method : getAnnotatedMethods()) {
-            try {
-                method.invoke(null);
-            } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException | NullPointerException | ExceptionInInitializerError ignored) {}
-        }
-    }
-
-    /**
-     * Calls the event and notifies all annotated methods about it.
-     *
-     * @since 1-alpha0
-     */
-    public abstract void callEvent();
+    void callEvent();
 }

base/src/main/java/de/staropensource/sosengine/base/classes/EventPriority.java

@@ -0,0 +1,39 @@
+package de.staropensource.sosengine.base.classes;
+
+/**
+ * Determines in which order events are processed.
+ */
+@SuppressWarnings("unused")
+public enum EventPriority {
+    /**
+     * Events with this priority are processed first.
+     * This event is exclusive to subsystems and should not be used by applications.
+     */
+    EXTREMELY_IMPORTANT,
+
+    /**
+     * Events with this priority are processed after {@code EXTREMELY_IMPORTANT}.
+     */
+    VERY_IMPORTANT,
+
+    /**
+     * Events with this priority are processed after {@code VERY_IMPORTANT}.
+     */
+    IMPORTANT,
+
+    /**
+     * Events with this priority are processed after {@code IMPORTANT}.
+     */
+    UNIMPORTANT,
+
+    /**
+     * Events with this priority are processed after {@code UNIMPORTANT}.
+     */
+    VERY_UNIMPORTANT,
+
+    /**
+     * Events with this priority are processed last.
+     * This event is exclusive to subsystems and should not be used by applications.
+     */
+    EXTREMELY_UNIMPORTANT,
+}

base/src/main/java/de/staropensource/sosengine/base/events/EngineCrashEvent.java

@@ -20,6 +20,7 @@
 package de.staropensource.sosengine.base.events;
 
 import de.staropensource.sosengine.base.classes.Event;
+import de.staropensource.sosengine.base.utility.EventHelper;
 
 /**
  * Called in the event of an engine crash, just before the JVM exists.
@@ -27,10 +28,10 @@ import de.staropensource.sosengine.base.classes.Event;
  * @since 1-alpha0
  */
 @SuppressWarnings({ "unused" })
-public final class EngineCrashEvent extends Event {
+public final class EngineCrashEvent implements Event {
     /** {@inheritDoc} */
     @Override
     public void callEvent() {
-        invokeAnnotatedMethods();
+        EventHelper.invokeAnnotatedMethods(getClass());
     }
 }

base/src/main/java/de/staropensource/sosengine/base/events/LogEvent.java

@@ -22,6 +22,7 @@ package de.staropensource.sosengine.base.events;
 import de.staropensource.sosengine.base.classes.Event;
 import de.staropensource.sosengine.base.types.LogIssuer;
 import de.staropensource.sosengine.base.types.LogLevel;
+import de.staropensource.sosengine.base.utility.EventHelper;
 import org.jetbrains.annotations.NotNull;
 
 import java.lang.reflect.InvocationTargetException;
@@ -33,16 +34,16 @@ import java.lang.reflect.Method;
  * @since 1-alpha0
  */
 @SuppressWarnings({ "unused" })
-public final class LogEvent extends Event {
+public final class LogEvent implements Event {
     /**
      * {@inheritDoc}
      * @deprecated use the {@code callEvent} method with arguments
-     * @see LogEvent#callEventNew(LogLevel, LogIssuer, String)
+     * @see LogEvent#callEvent(LogLevel, LogIssuer, String)
      */
     @Deprecated
     @Override
     public void callEvent() {
-        invokeAnnotatedMethods();
+        EventHelper.invokeAnnotatedMethods(getClass());
     }
 
     /**
@@ -50,8 +51,8 @@ public final class LogEvent extends Event {
      *
      * @since 1-alpha0
      */
-    public void callEventNew(@NotNull LogLevel level, @NotNull LogIssuer logIssuer, @NotNull String message) {
-        for (Method method : getAnnotatedMethods()) {
+    public void callEvent(@NotNull LogLevel level, @NotNull LogIssuer logIssuer, @NotNull String message) {
+        for (Method method : EventHelper.getAnnotatedMethods(getClass())) {
             try {
                 method.invoke(null, level, logIssuer, message);
             } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException | NullPointerException | ExceptionInInitializerError ignored) {}

base/src/main/java/de/staropensource/sosengine/base/logging/CrashHandler.java

@@ -144,7 +144,7 @@ public final class CrashHandler {
         Logger.getLoggerImplementation().print(LogLevel.CRASH, logIssuer, base);
 
         // Send EngineCrash event
-        EngineCrashEvent.getInstance().callEvent();
+        new EngineCrashEvent().callEvent();
 
         // Shutdown JVM
         if (EngineConfiguration.getInstance().isLoggerImmediateShutdown())

base/src/main/java/de/staropensource/sosengine/base/logging/Logger.java

@@ -115,7 +115,7 @@ public final class Logger {
         base = loggerImplementation.postPlaceholder(level, logIssuer, base);
 
         // Call event
-        ((LogEvent) LogEvent.getInstance()).callEventNew(level, logIssuer, message);
+        new LogEvent().callEvent(level, logIssuer, message);
 
         // Print log message
         loggerImplementation.print(level, logIssuer, base);

base/src/main/java/de/staropensource/sosengine/base/utility/EventHelper.java

@@ -0,0 +1,82 @@
+/*
+    STAROPENSOURCE ENGINE SOURCE FILE
+    Copyright (c) 2024 The StarOpenSource Engine Contributors
+    Licensed under the GNU Affero General Public License v3
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation, either version 3 of the
+    License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.sosengine.base.utility;
+
+import de.staropensource.sosengine.base.annotations.EventListener;
+import de.staropensource.sosengine.base.classes.Event;
+import lombok.Getter;
+import org.jetbrains.annotations.NotNull;
+import org.reflections.Reflections;
+import org.reflections.scanners.Scanners;
+import org.reflections.util.ClasspathHelper;
+import org.reflections.util.ConfigurationBuilder;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.*;
+
+/**
+ * Represents an event.
+ *
+ * @since 1-alpha0
+ */
+@Getter
+@SuppressWarnings({ "unused" })
+public class EventHelper {
+    /**
+     * Returns all annotated methods.
+     *
+     * @return list of annotated methods
+     * @since 1-alpha0
+     */
+    @NotNull
+    public static LinkedList<Method> getAnnotatedMethods(Class<? extends Event> clazz) {
+        LinkedList<Method> methods = new LinkedList<>();
+
+        Reflections reflections = new Reflections(
+                new ConfigurationBuilder()
+                .setUrls(ClasspathHelper.forJavaClassPath())
+                .setScanners(Scanners.MethodsAnnotated)
+        );
+        Set<Method> annotatedMethods = reflections.getMethodsAnnotatedWith(EventListener.class);
+
+        for (Method method : annotatedMethods)
+            if (method.getAnnotation(EventListener.class).event() == clazz)
+                methods.add(method);
+
+        // Sort 'methods' linked list
+        methods.sort(Comparator.comparing(method0 -> method0.getAnnotation(EventListener.class).priority()));
+
+        return methods;
+    }
+
+    /**
+     * Invokes all annotated methods without any arguments.
+     *
+     * @since 1-alpha0
+     */
+    public static void invokeAnnotatedMethods(Class<? extends Event> clazz) {
+        for (Method method : getAnnotatedMethods(clazz)) {
+            try {
+                method.invoke(null);
+            } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException | NullPointerException | ExceptionInInitializerError ignored) {}
+        }
+    }
+}