title: Auto-expanding layout with Qt-Designer
body: <p>I'm using the Qt Designer.</p>
  
  <p>I want to create a <code>QVBoxLayout</code> which will automatically expand to fill the whole window.</p>
  
  <p>The layout of the <code>QVBoxLayout</code> remains fixed.</p>
  
  <p>How can I cause the <code>QVBoxLayout</code> to expand and fill the entire window through the designer?</p>