Reading the scroll position of an html element in Angular 2.0 Typescript

I've seen some implement a component, which you can can do but this expects (to my knowledge) an html template.  I've used instead directive (which a component is but without the requirement of having an associated html template).

Here is my directive:
import { HostListener, Component, OnChanges, Directive, Input, Output, EventEmitter, SimpleChange, ElementRef} from '@angular/core';

@Directive({
    selector: '[track-scroll]',
    //host: {'(window:scroll)': 'track($event)'},
 
})

export class TrackScrollComponent {
  @HostListener('scroll', [''])
    track() {
        console.debug("Scroll Event");
        console.debug(this._elementRef.nativeElement.scrollTop);
    }
   constructor(private _elementRef: ElementRef) {}
}

I did use injection of the Element Ref, or as it is instanced from the 'div' tag the div ElementRef.

All directives in RC 6.0 (?) + go to the ngModule, or otherwise assigned in parent component.

Thus in my app.module.ts

@NgModule({
  imports: [ BrowserModule, AppRouting ],
  declarations: [TrackScrollComponent],
  bootstrap: [ App ]
})

Implementing in your component then goes to yourcomponent.html or template as follows:

<div track-scroll> </div>

 Sorry for some of the imports I hadn't tested which one were exclusively needed for this howTo.

There is mentions about not working directly with ElementRef, but at the moment I wanted to provide clarity for solution as opposed to creating added confusion for something that really should be simple.