eventlistener.ts

class EventListener<T> {
    private callbacks:{(user : T) : void}[] = [];

    addEventListener(callback:{(user : T) : void}):void {
        this.callbacks.push(callback);
    }

    removeEventListener(callback:{(user: T) : void}):void {
        this.callbacks.splice(this.callbacks.lastIndexOf(callback));
    }

    fireEventListener(user:T) {
        this.callbacks.forEach(_ => _(user));
    }
}
var event = new EventListener<number>();