title: Widget or layout to fill parent
body: <p>What I'm trying to accomplish is a very simple and straight forward need, or I thought, but for the life of me, I can't seem to find a way to do it.</p>
  
  <p>In my qt application I want to be able to make a widget or a layout fill the entire space of the parent widget.</p>
  
  <p>For example, let's say I want to have a label with a fixed height and beneath it a stacked widget which occupies the rest of the height of the window.
  Here's what I do in the qt-creator designer:</p>
  
  <ol>
  <li>drag a label to the form</li>
  <li>drag a stacked widget to the form</li>
  <li>select both of them and then right click > lay out > lay out vertically</li>
  <li>select the <code>verticalLayout</code> object and in the <code>layoutStretch</code> property have <code>0,1</code></li>
  </ol>
  
  <p>Now, how do I make the <code>verticalLayout</code> occupy all of the width/height of the <code>centralWidget</code>?
  Nothing seems to work for me.</p>
  
  <p>Thanks.</p>