title: Angular 2: check if shift key is down when an element is clicked
body: <p>In an Angular 2 app, i want the click event to trigger something different when <em>the shift key is being held down</em>. how to achieve this?</p>
  
  <p>html is below:</p>
  
  <pre><code>&lt;div class="item" *ngFor="#obj of available" (click)="toggleSelected(obj)"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>and i want to do something like this:</p>
  
  <pre><code>  toggleSelected(obj) {
      if(shift is pressed) {
        do this
      } else {
        do that
      }
    }
  </code></pre>
  
  <p>so how can i detect if shift key is pressed? thanks!</p>