Class EventEmitter

src/utils/EventEmitter.ts:4–59

 * A simple event emitter class for communication between views
 */
export class EventEmitter {
	private events: { [key: string]: Array<(...args: unknown[]) => void> } = {};

	/**
	 * Subscribe to an event
	 * @param event The event name to listen for
	 * @param listener The callback function to execute when the event is triggered
	 * @returns An unsubscribe function
	 */
	on(event: string, listener: (...args: unknown[]) => void): () => void {
		if (!this.events[event]) {
			this.events[event] = [];
		}
		this.events[event].push(listener);

		// Return unsubscribe function
		return () => {
			const listeners = this.events[event];
			if (!listeners) {
				return;
			}

			const remainingListeners = listeners.filter((l) => l !== listener);
			if (remainingListeners.length > 0) {
				this.events[event] = remainingListeners;
			} else {
				delete this.events[event];
			}
		};
	}

	/**
	 * Emit an event with data
	 * @param event The event name to emit
	 * @param args The data to pass to the event listeners
	 */
	emit(event: string, ...args: unknown[]): void {
		if (this.events[event]) {
			this.events[event].forEach((listener) => {
				listener(...args);
			});
		}
	}

	/**
	 * Remove all listeners for a specific event
	 * @param event The event name to clear listeners for
	 */
	removeAllListeners(event?: string): void {
		if (event) {
			delete this.events[event];
		} else {
			this.events = {};
		}
	}
}