GuavaEvent.cs

using System;
using Bolt;
using Ludiq;
using UnityEngine;

public class TestComponent : MonoBehaviour
{
	public event Action<TestArgs> testEvent;

	private void Update()
	{
		if (Input.GetKeyDown(KeyCode.Alpha1))
		{
			Debug.Log("Triggering Test.SuperEvent");

			if (testEvent != null)
			{
				testEvent(new TestArgs { testArg = true });
			}
		}
	}
}

public class TestArgs
{
	public bool testArg;
}

[UnitCategory("Events")]
public sealed class TestEventUnit : EventUnit<TestArgs>
{
	public new class Data : EventUnit<TestArgs>.Data
	{
		public TestComponent testComponent;
	}

	[DoNotSerialize]
	public ValueInput testComponent { get; private set; }

	[DoNotSerialize]
	public ValueOutput testArg { get; private set; }

	protected override bool register => false;

	protected override void Definition()
	{
		base.Definition();
		testComponent = ValueInput<TestComponent>(nameof(testComponent));
		testArg = ValueOutput<bool>(nameof(testArg));
	}

	public override void StartListening(GraphStack stack)
	{
		var data = stack.GetElementData<Data>(this);

		if (data.isListening)
		{
			return;
		}

		var reference = stack.ToReference();

		var testComponent = Flow.FetchValue<TestComponent>(this.testComponent, reference);

		if (testComponent == null)
		{
			return;
		}
		
		Action<TestArgs> handler = args => Trigger(reference, args);
		testComponent.testEvent += handler;
		data.testComponent = testComponent;
		data.handler = handler;
		data.isListening = true;
	}

	public override void StopListening(GraphStack stack)
	{
		var data = stack.GetElementData<Data>(this);

		if (!data.isListening)
		{
			return;
		}

		if (data.testComponent != null)
		{
			data.testComponent.testEvent -= (Action<TestArgs>)data.handler;
		}

		data.isListening = false;
	}

	protected override void AssignArguments(Flow flow, TestArgs args)
	{
		base.AssignArguments(flow, args);

		flow.SetValue(testArg, args.testArg);
	}
}