title: How to center an entire LinearLayout in xml?
body: <p>I have a few vertically oriented elements in a LinearLayout</p>
  
  <pre><code>&lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_gravity="center_vertical"
          android:orientation="vertical" &gt;
  
      &lt;TextView
              ... /&gt;
  
      &lt;Button
              ... /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>These elements do not take up the entire vertical space of the application, and I want them to be vertically centered. How do I do this?</p>