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src/events/Events.ts

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+/**
+ * @class Events
+ * @description A basic event handling system that supports adding events, listeners, and emitting events.
+ */
+export default class Events
+{
+    /** Stores events and associated data. */
+    private _events: Record<string, Array<any>>;
+
+    /** Stores listeners for specific events. */
+    private _listeners: Record<string, Array<{ event: string; fn: (data?: any) => void; context: any }>>;
+
+    /** Initializes an empty events storage and listeners storage. */
+    constructor()
+    {
+        this._events = {};
+        this._listeners = {};
+    }
+
+    /**
+     * Adds an event with associated data to be emitted later.
+     * @param event
+     * @param data
+     */
+    addEvent(event: string, data?: any): void
+    {
+        if (!this._events[event])
+        {
+            this._events[event] = [];
+        }
+        this._events[event].push(data);
+    }
+
+    /**
+     * Registers a listener for a specific event.
+     * @param event
+     * @param fn
+     * @param context
+     */
+    addListener(event: string, fn: (data?: any) => void, context: any): void
+    {
+        if (!this._listeners[event])
+        {
+            this._listeners[event] = [];
+        }
+        this._listeners[event].push({ event, fn, context });
+    }
+
+    /**
+     * Removes a specific listener for an event.
+     * @param event
+     * @param fn
+     * @param context
+     */
+    removeEventListener(event: string, fn: (data?: any) => void, context: any): void
+    {
+        if (!this._listeners[event]) return;
+        this._listeners[event] = this._listeners[event].filter(
+            (listener) => listener.fn !== fn || listener.context !== context
+        );
+    }
+
+    /** Clears all stored events. */
+    clearEvents(): void
+    {
+        this._events = {};
+    }
+
+    /**
+     * Emits all stored events, invoking associated listeners with the event data.
+     * The listeners for each event receive each piece of data associated with that event.
+     */
+    emitEvents(): void
+    {
+        for (const eventName in this._events)
+        {
+            const dataObjects = this._events[eventName];
+            const listeners = this._listeners[eventName];
+
+            if (!listeners) continue;
+
+            dataObjects.forEach((data) =>
+            {
+                listeners.forEach((listener) =>
+                {
+                    listener.fn.call(listener.context, data);
+                });
+            });
+            delete this._events[eventName];
+        }
+    }
+}