title: SWT TreeViewer is slow when filling with many elements
body: <p>I'm new in the java world, so I'm sorry if my question is trivial.</p>
  
  <p>I'm developing a Eclipse view part, and I'm filling a SWT tree view with the following data structure. All data is in memory:</p>
  
  <pre><code>Node1
     Child1
     Child2
  Node2
     Child1
     ...
     Child2915
  </code></pre>
  
  <p>I think that is not a very big tree, but it is slow being drawn (10 seconds). I have manage trees in .NET with more than 10.000 elements and it loaded smoothly. I don't know if I've implemented the code, but the same problem appeared in .NET if I did not call <code>BeginUpdate() - EndUpdate()</code>.</p>
  
  <p>Must I call something similar in Java/SWT? Any other tips about why the tree is so slow?</p>