title: QstackedWidget adding space for arrows when arranged vertically
body: <p>I have a ui file, like this:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;ui version="4.0"&gt;
   &lt;class&gt;MainWindow&lt;/class&gt;
   &lt;widget class="QMainWindow" name="MainWindow"&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;377&lt;/width&gt;
      &lt;height&gt;600&lt;/height&gt;
     &lt;/rect&gt;
    &lt;/property&gt;
    &lt;property name="windowTitle"&gt;
     &lt;string&gt;MainWindow&lt;/string&gt;
    &lt;/property&gt;
    &lt;widget class="QWidget" name="centralwidget"&gt;
     &lt;layout class="QVBoxLayout" name="verticalLayout"&gt;
      &lt;item&gt;
       &lt;widget class="QStackedWidget" name="top_pages"&gt;
        &lt;property name="currentIndex"&gt;
         &lt;number&gt;0&lt;/number&gt;
        &lt;/property&gt;
        &lt;widget class="QFrame" name="page"&gt;
         &lt;layout class="QVBoxLayout" name="verticalLayout_2"&gt;
          &lt;item&gt;
           &lt;widget class="QStackedWidget" name="stackedWidget_2"&gt;
            &lt;property name="currentIndex"&gt;
             &lt;number&gt;1&lt;/number&gt;
            &lt;/property&gt;
            &lt;widget class="QWidget" name="page_3"&gt;
             &lt;layout class="QVBoxLayout" name="verticalLayout_3"&gt;
              &lt;item&gt;
               &lt;widget class="QGroupBox" name="groupBox"&gt;
                &lt;property name="title"&gt;
                 &lt;string&gt;GroupBox&lt;/string&gt;
                &lt;/property&gt;
                &lt;property name="alignment"&gt;
                 &lt;set&gt;Qt::AlignLeading|Qt::AlignLeft|Qt::AlignTop&lt;/set&gt;
                &lt;/property&gt;
                &lt;layout class="QVBoxLayout" name="verticalLayout_4"/&gt;
               &lt;/widget&gt;
              &lt;/item&gt;
             &lt;/layout&gt;
            &lt;/widget&gt;
            &lt;widget class="QWidget" name="page_4"&gt;
             &lt;layout class="QVBoxLayout" name="verticalLayout_5"&gt;
              &lt;item&gt;
               &lt;widget class="QGroupBox" name="groupBox_2"&gt;
                &lt;property name="sizePolicy"&gt;
                 &lt;sizepolicy hsizetype="Preferred" 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="title"&gt;
                 &lt;string&gt;GroupBox&lt;/string&gt;
                &lt;/property&gt;
                &lt;layout class="QVBoxLayout" name="verticalLayout_6"/&gt;
               &lt;/widget&gt;
              &lt;/item&gt;
             &lt;/layout&gt;
            &lt;/widget&gt;
           &lt;/widget&gt;
          &lt;/item&gt;
         &lt;/layout&gt;
        &lt;/widget&gt;
        &lt;widget class="QFrame" name="page_2"/&gt;
       &lt;/widget&gt;
      &lt;/item&gt;
     &lt;/layout&gt;
    &lt;/widget&gt;
    &lt;widget class="QMenuBar" name="menubar"&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;377&lt;/width&gt;
       &lt;height&gt;19&lt;/height&gt;
      &lt;/rect&gt;
     &lt;/property&gt;
    &lt;/widget&gt;
   &lt;/widget&gt;
   &lt;resources/&gt;
   &lt;connections/&gt;
  &lt;/ui&gt;
  </code></pre>
  
  <p>I want the groupboxes to be shown in the whole window( the groupbox text to be just below the menus.  When I build this in an application and look at in the qt designer preview it leaves a space at the top where the arrows of top_pages are located.  How would I make the group box extend into this space?  I can break the layout and extend it into this space but I think this would require doing this for every page of stackedWidget_2.</p>