feat: foundations of an event system

Author: Jamalam360

common/src/client/java/io/github/jamalam360/jamlib/api/events/client/ClientPlayLifecycleEvents.java

@@ -1,7 +1,6 @@
 package io.github.jamalam360.jamlib.api.events.client;
 
-import dev.architectury.event.Event;
-import dev.architectury.event.EventFactory;
+import io.github.jamalam360.jamlib.events.Event;
 import net.minecraft.client.Minecraft;
 
 /**
@@ -11,11 +10,11 @@ public class ClientPlayLifecycleEvents {
 	/**
 	 * Called when the local player has joined a logical server.
 	 */
-	public static final Event<Join> JOIN = EventFactory.createLoop(Join.class);
+	public static final Event<Join> JOIN = new Event<>();
 	/**
 	 * Called when the local player leaves a logical server.
 	 */
-	public static final Event<Leave> DISCONNECT = EventFactory.createLoop(Leave.class);
+	public static final Event<Leave> DISCONNECT = new Event<>();
 
 	@FunctionalInterface
 	public interface Join {

common/src/client/java/io/github/jamalam360/jamlib/client/mixin/event/ClientPacketListenerMixin.java

@@ -19,6 +19,6 @@ public class ClientPacketListenerMixin {
 			at = @At("RETURN")
 	)
 	private void jamlib$joinServer(ClientboundLoginPacket packet, CallbackInfo ci) {
-		ClientPlayLifecycleEvents.JOIN.invoker().onJoin(Minecraft.getInstance());
+		ClientPlayLifecycleEvents.JOIN.invoke((listener) -> listener.onJoin(Minecraft.getInstance()));
 	}
 }

common/src/client/java/io/github/jamalam360/jamlib/client/mixin/event/ConnectionMixin.java

@@ -16,7 +16,7 @@ public class ConnectionMixin {
 			at = @At("HEAD")
 	)
 	private void jamlib$callDisconnectEvent(ChannelHandlerContext channelHandlerContext, CallbackInfo ci) {
-		ClientPlayLifecycleEvents.DISCONNECT.invoker().onLeave(Minecraft.getInstance());
+		ClientPlayLifecycleEvents.DISCONNECT.invoke((listener) -> listener.onLeave(Minecraft.getInstance()));
 	}
 
 	@Inject(
@@ -27,6 +27,6 @@ public class ConnectionMixin {
 			)
 	)
 	private void jamlib$callDisconnectEvent(CallbackInfo ci) {
-		ClientPlayLifecycleEvents.DISCONNECT.invoker().onLeave(Minecraft.getInstance());
+		ClientPlayLifecycleEvents.DISCONNECT.invoke((listener) -> listener.onLeave(Minecraft.getInstance()));
 	}
 }

common/src/client/java/io/github/jamalam360/jamlib/impl/JamLibClient.java

@@ -12,7 +12,7 @@
 public class JamLibClient {
     @ApiStatus.Internal
     public static void init() {
-        ClientPlayLifecycleEvents.JOIN.register(JamLibClient::onPlayerJoin);
+        ClientPlayLifecycleEvents.JOIN.listen(JamLibClient::onPlayerJoin);
     }
 
     private static void onPlayerJoin(Minecraft minecraft) {

common/src/main/java/io/github/jamalam360/jamlib/events/CancellableEvent.java

@@ -0,0 +1,19 @@
+package io.github.jamalam360.jamlib.events;
+
+import java.util.function.Function;
+
+public class CancellableEvent<L, R> extends Event<L> {
+	public EventResult<R> invokeCancellable(Function<L, EventResult<R>> invoker)  {
+		for (int priority : this.getListeners().keySet()) {
+			for (L listener : this.getListeners().get(priority)) {
+				EventResult<R> result = invoker.apply(listener);
+
+				if (result.wasCancelled()) {
+					return result;
+				}
+			}
+		}
+
+		return EventResult.pass();
+	}
+}

common/src/main/java/io/github/jamalam360/jamlib/events/Event.java

@@ -0,0 +1,35 @@
+package io.github.jamalam360.jamlib.events;
+
+import com.google.common.collect.Ordering;
+import com.google.common.collect.TreeMultimap;
+
+import java.util.function.Consumer;
+
+public class Event<L> {
+	public static final int DEFAULT_PRIORITY = 1000;
+	private final TreeMultimap<Integer, L> listeners;
+
+	public Event() {
+		this.listeners = TreeMultimap.create(Ordering.natural().reverse(), Ordering.arbitrary());
+	}
+
+	public void listen(L listener) {
+		this.listen(DEFAULT_PRIORITY, listener);
+	}
+
+	public void listen(int priority, L listener) {
+		this.listeners.put(priority, listener);
+	}
+
+	public void invoke(Consumer<L> invoker) {
+		for (int priority : this.listeners.keySet()) {
+			for (L listener : this.listeners.get(priority)) {
+				invoker.accept(listener);
+			}
+		}
+	}
+
+	protected TreeMultimap<Integer, L> getListeners() {
+		return this.listeners;
+	}
+}

common/src/main/java/io/github/jamalam360/jamlib/events/EventResult.java

@@ -0,0 +1,31 @@
+package io.github.jamalam360.jamlib.events;
+
+import org.jetbrains.annotations.Nullable;
+
+public class EventResult<T> {
+	private final boolean cancelled;
+	@Nullable
+	private final T result;
+
+	private EventResult(boolean cancelled, @Nullable T result) {
+		this.cancelled = cancelled;
+		this.result = result;
+	}
+
+	public static <T> EventResult<T> pass() {
+		return new EventResult<>(false, null);
+	}
+
+	public static <T> EventResult<T> cancel(T result) {
+		return new EventResult<>(true, result);
+	}
+
+	public boolean wasCancelled() {
+		return this.cancelled;
+	}
+
+	@Nullable
+	public T getResult() {
+		return this.result;
+	}
+}

testmod-common/src/main/java/io/github/jamalam360/testmod/TestMod.java

@@ -33,8 +33,8 @@ public static void init() {
         System.out.println(CONFIG_MANAGER.get());
         System.out.println(QCB_CONFIG.get());
 
-        ClientPlayLifecycleEvents.JOIN.register(client -> LOGGER.info("Joined server!"));
-        ClientPlayLifecycleEvents.DISCONNECT.register(client -> LOGGER.info("Left server!"));
+        ClientPlayLifecycleEvents.JOIN.listen(client -> LOGGER.info("Joined server!"));
+        ClientPlayLifecycleEvents.DISCONNECT.listen(client -> LOGGER.info("Left server!"));
 
         Network.registerPayloadType(PotatoPacket.TYPE, PotatoPacket.INSTANCE);