title: Eclipse TreeViewer/ViewPart background click
body: <p>I am developing a flashcard application using eclipse. I have a TreeViewer in a ViewPart, and I use it to display various categories. However, I cannot find a way to process a background click event. I do not have much experience with eclipse development, so maybe background is the wrong word.</p>
  
  <p>I need something like this:</p>
  
  <pre><code>TreeViewer.setOnBackGroundClickListener(new ClickListener() {});
  </code></pre>
  
  <p><strong>Screenshot</strong></p>
  
  <p><img src="https://i.stack.imgur.com/WaJ0h.png" alt="enter image description here"></p>