title: How can you get current positional information about an element in Angular2
body: <p>I have the <code>ElementRef</code> of my navbar and I'm trying to find out how close it is to the top of my window so I can make it sticky</p>
  
  <pre><code>&lt;div class="nav-bar" #navBar&gt;
  
  &lt;/div&gt;
  
  @ViewChild("navBar")
    navBarElement;
  </code></pre>
  
  <p>I'm printing out the positions of it's nativeElement in a scroll event but the values seem to be static</p>
  
  <pre><code>@HostListener('window:scroll', ['$event'])
  onScroll(event) {
     console.log("offset top", this.navBarElement.nativeElement.offsetTop);
  }
  </code></pre>
  
  <p>How can I track the current position of my element?</p>