title: Layout : How to make one widget 3x the rest in a vertical layout
body: <p>I have 3 tables (A,B and C) in a vertical layout.The size policy (Horizontal and vertical) of these 3 are set to expanding. How can I make table-A  3 times the size of B and C and always have that ratio maintained. I am doing this through QT Designer. </p>
  
  <p>Update:</p>
  
  <p>In order to test the layout stretch method. I added four QlistWidgets inside a vertical layout to a form having a horizontal layout. Here is the XML for the form</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;ui version="4.0"&gt;
   &lt;class&gt;formPracticeClass&lt;/class&gt;
   &lt;widget class="QMainWindow" name="formPracticeClass"&gt;
    &lt;property name="geometry"&gt;
     &lt;rect&gt;
      &lt;x&gt;0&lt;/x&gt;
      &lt;y&gt;0&lt;/y&gt;
      &lt;width&gt;847&lt;/width&gt;
      &lt;height&gt;661&lt;/height&gt;
     &lt;/rect&gt;
    &lt;/property&gt;
    &lt;property name="sizePolicy"&gt;
     &lt;sizepolicy hsizetype="Expanding" vsizetype="Expanding"&gt;
      &lt;horstretch&gt;0&lt;/horstretch&gt;
      &lt;verstretch&gt;0&lt;/verstretch&gt;
     &lt;/sizepolicy&gt;
    &lt;/property&gt;
    &lt;property name="windowTitle"&gt;
     &lt;string&gt;formPractice&lt;/string&gt;
    &lt;/property&gt;
    &lt;widget class="QWidget" name="centralWidget"&gt;
     &lt;layout class="QHBoxLayout" name="horizontalLayout"&gt;
      &lt;item&gt;
       &lt;layout class="QVBoxLayout" name="verticalLayout_2" stretch="1,0,0,0"&gt;
        &lt;item&gt;
         &lt;widget class="QListWidget" name="listWidget"/&gt;
        &lt;/item&gt;
        &lt;item&gt;
         &lt;widget class="QListWidget" name="listWidget_3"/&gt;
        &lt;/item&gt;
        &lt;item&gt;
         &lt;widget class="QListWidget" name="listWidget_2"/&gt;
        &lt;/item&gt;
        &lt;item&gt;
         &lt;widget class="QListWidget" name="listWidget_4"/&gt;
        &lt;/item&gt;
       &lt;/layout&gt;
      &lt;/item&gt;
     &lt;/layout&gt;
    &lt;/widget&gt;
   &lt;/widget&gt;
   &lt;layoutdefault spacing="6" margin="11"/&gt;
   &lt;resources&gt;
    &lt;include location="formpractice.qrc"/&gt;
   &lt;/resources&gt;
   &lt;connections/&gt;
  &lt;/ui&gt;
  </code></pre>
  
  <p>The vertical layout with the 4 widgets has a stretch layout of 1,0,0,0. The height of the topmost widget looks smaller to the others. I want the topmost widget to be 2 times  bigger than the others</p>