From 210a04650e6b7f1d718240195a78c66e1783a1c3 Mon Sep 17 00:00:00 2001
From: LordMidas <55047920+LordMidas@users.noreply.github.com>
Date: Fri, 6 Oct 2023 22:17:22 -0400
Subject: [PATCH] feat: add MSU.Class.Event class

This emulates event listeners. Now someone can raise an event without having to know who is listening to the event.
---
 msu/classes/event.nut | 72 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 msu/classes/event.nut

diff --git a/msu/classes/event.nut b/msu/classes/event.nut
new file mode 100644
index 000000000..f241afbeb
--- /dev/null
+++ b/msu/classes/event.nut
@@ -0,0 +1,72 @@
+::MSU.Class.Event <- class
+{
+	__Functions = null;
+
+	constructor()
+	{
+		this.__Functions = [];
+	}
+
+	function register( _env, _function )
+	{
+		// ::MSU.requireFunction(_function);
+		foreach (i, funcInfo in this.__Functions)
+		{
+			if (funcInfo[1] == _function)
+			{
+				return;
+			}
+		}
+
+		this.__Functions.push([_env, _function]);
+	}
+
+	function unregister( _function )
+	{
+		// ::MSU.requireFunction(_function);
+		foreach (i, funcInfo in this.__Functions)
+		{
+			if (funcInfo[1] == _function)
+			{
+				this.__Functions.remove[i];
+				return;
+			}
+		}
+
+		throw ::MSU.Exception.KeyNotFound(_function);
+	}
+
+	function invoke( _argsArray = null )
+	{
+		if (_argsArray == null) _argsArray = [null];
+		else _argsArray.insert(0, null);
+
+		foreach (funcInfo in this.__Functions)
+		{
+			_argsArray[0] = funcInfo[0];
+			funcInfo[1].acall(_argsArray);
+		}
+	}
+
+	// Will iterate over every registered function and check _conditionFunction
+	// if _conditionFunction returns false, stops iteration immediately
+	function conditionalInvoke( _conditionFunction, _argsArray = null )
+	{
+		if (_argsArray == null) _argsArray = [null];
+		else _argsArray.insert(0, null);
+
+		foreach (funcInfo in this.__Functions)
+		{
+			if (_conditionFunction() == false)
+				return;
+
+			_argsArray[0] = funcInfo[0];
+			funcInfo[1].acall(_argsArray);
+		}
+	}
+
+	function clear()
+	{
+		this.__Functions.clear();
+	}
+}