Class Emitter

jsonrpc/src/events.ts:118–179

}

export class Emitter<T> {

	private static _noop = function () { };

	private _event: Event<T>;
	private _callbacks: CallbackList | undefined;

	constructor(private _options?: EmitterOptions) {
	}

	/**
	 * For the public to allow to subscribe
	 * to events from this Emitter
	 */
	get event(): Event<T> {
		if (!this._event) {
			this._event = (listener: (e: T) => any, thisArgs?: any, disposables?: Disposable[]) => {
				if (!this._callbacks) {
					this._callbacks = new CallbackList();
				}
				if (this._options && this._options.onFirstListenerAdd && this._callbacks.isEmpty()) {
					this._options.onFirstListenerAdd(this);
				}
				this._callbacks.add(listener, thisArgs);

				let result: Disposable;
				result = {
					dispose: () => {
						this._callbacks!.remove(listener, thisArgs);
						result.dispose = Emitter._noop;
						if (this._options && this._options.onLastListenerRemove && this._callbacks!.isEmpty()) {
							this._options.onLastListenerRemove(this);
						}
					}
				};
				if (Array.isArray(disposables)) {
					disposables.push(result);
				}

				return result;
			};
		}
		return this._event;
	}

	/**
	 * To be kept private to fire an event to
	 * subscribers
	 */
	fire(event: T): any {
		if (this._callbacks) {
			this._callbacks.invoke.call(this._callbacks, event);
		}
	}

	dispose() {
		if (this._callbacks) {
			this._callbacks.dispose();