title: How make contents as a grid in a ScrollPanel in GWT project using UIBinder
body: <p>I've my GWT project where I have the following view of a list of movies: 
  <a href="https://i.stack.imgur.com/2MrO8.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2MrO8.jpg" alt="here"></a></p>
  
  <p>Blue boxes are CompositeWidgets inserted in a ScrollPanel.
  I would like to obtain a grid (4 columns) and not a line as view. I'm a beginner in CSS, so I don't know how obtain my purpose. Thanks a lot!</p>