[1.21.X] Improved Event System

core-api/src/main/java/dev/compactmods/machines/api/event/IEventListenerList.java

@@ -0,0 +1,19 @@
+package dev.compactmods.machines.api.event;
+
+import java.util.stream.Stream;
+
+/**
+ * Used to gather a list of listeners.
+ *
+ * @param <B> Base Class used for the event listeners
+ */
+public interface IEventListenerList<B> {
+    void addListener(B listener);
+
+    default <E extends B> void addListener(Class<E> eClass, E listener) {
+        addListener(listener);
+    }
+
+    Stream<B> getListeners();
+
+}

core-api/src/main/java/dev/compactmods/machines/api/room/upgrade/RoomUpgrade.java

@@ -1,5 +1,6 @@
 package dev.compactmods.machines.api.room.upgrade;
 
+import dev.compactmods.machines.api.event.IEventListenerList;
 import dev.compactmods.machines.api.room.upgrade.events.RoomUpgradeEvent;
 import net.minecraft.world.flag.FeatureElement;
 import net.minecraft.world.item.ItemStack;
@@ -11,7 +12,5 @@ public interface RoomUpgrade extends TooltipProvider {
 
     RoomUpgradeType<?> getType();
 
-    default Stream<RoomUpgradeEvent> gatherEvents() {
-        return Stream.empty();
-    }
+    default void gatherEvents(IEventListenerList<RoomUpgradeEvent> listenerList) {}
 }

neoforge-main/src/main/java/dev/compactmods/machines/event/EventListenerList.java

@@ -0,0 +1,31 @@
+package dev.compactmods.machines.event;
+
+import dev.compactmods.machines.api.event.IEventListenerList;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Stream;
+
+/**
+ * Used to gather a list of listeners.
+ * An implementation of {@link IEventListenerList}
+ *
+ * @param <B> Base Class used for the event listeners
+ */
+public final class EventListenerList<B> implements IEventListenerList<B> {
+    public static <B> EventListenerList<B> createList() {
+        return new EventListenerList<>();
+    }
+
+    private final List<B> listeners = new ArrayList<>();
+
+    private EventListenerList() {}
+
+    public void addListener(B listener) {
+        this.listeners.add(listener);
+    }
+
+    public Stream<B> getListeners() {
+        return listeners.stream();
+    }
+}

neoforge-main/src/main/java/dev/compactmods/machines/room/upgrade/RoomUpgradeEventHandlers.java

@@ -3,7 +3,10 @@
 import dev.compactmods.machines.CompactMachinesCommon;
 import dev.compactmods.machines.api.CompactMachines;
 import dev.compactmods.machines.api.dimension.CompactDimension;
+import dev.compactmods.machines.api.event.IEventListenerList;
+import dev.compactmods.machines.api.room.upgrade.events.RoomUpgradeEvent;
 import dev.compactmods.machines.api.room.upgrade.events.lifecycle.UpgradeTickedEventListener;
+import dev.compactmods.machines.event.EventListenerList;
 import dev.compactmods.machines.feature.CMFeatureFlags;
 import dev.compactmods.machines.room.Rooms;
 import net.minecraft.network.chat.Component;
@@ -38,13 +41,15 @@ public static void onLevelTick(LevelTickEvent.Post postTick) {
 
 				   for (final var upgradeStack : upgradeStacks) {
 					  final var upgrades = upgradeStack.get(RoomUpgrades.UPGRADE_LIST_COMPONENT);
+					  final IEventListenerList<RoomUpgradeEvent> listenerList = EventListenerList.createList();
 					  upgrades.upgrades()
-						  .stream()
-						  .flatMap(ru -> ru.gatherEvents().filter(UpgradeTickedEventListener.class::isInstance))
-						  .map(UpgradeTickedEventListener.class::cast)
-						  .forEach(ticker -> {
-							 ticker.handle(serverLevel, room, upgradeStack);
-						  });
+							  .forEach(upgrade -> upgrade.gatherEvents(listenerList));
+					  listenerList.getListeners()
+							  .filter(UpgradeTickedEventListener.class::isInstance)
+							  .map(UpgradeTickedEventListener.class::cast)
+							  .forEach(ticker -> {
+								  ticker.handle(serverLevel, room, upgradeStack);
+							  });
 				   }
 				});
 		 }

neoforge-main/src/main/java/dev/compactmods/machines/room/upgrade/example/TreeCutterUpgrade.java

@@ -1,6 +1,7 @@
 package dev.compactmods.machines.room.upgrade.example;
 
 import com.mojang.serialization.MapCodec;
+import dev.compactmods.machines.api.event.IEventListenerList;
 import dev.compactmods.machines.api.room.RoomInstance;
 import dev.compactmods.machines.api.room.upgrade.RoomUpgrade;
 import dev.compactmods.machines.api.room.upgrade.RoomUpgradeType;
@@ -48,9 +49,8 @@ public void addToTooltip(@NotNull Item.TooltipContext ctx, Consumer<Component> t
     }
 
     @Override
-    public Stream<RoomUpgradeEvent> gatherEvents() {
-        final UpgradeTickedEventListener ticker = TreeCutterUpgrade::onTick;
-        return Stream.of(ticker);
+    public void gatherEvents(IEventListenerList<RoomUpgradeEvent> listenerList) {
+        listenerList.addListener(UpgradeTickedEventListener.class, TreeCutterUpgrade::onTick);
     }
 
     @Override