title: Vertical Alignment gravity not responding
body: <p>Why won't this center the contents in the view?</p>
  
  <pre><code>&lt;LinearLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="horizontal"
      android:layout_gravity="center_vertical"
      tools:context=".MainActivity"&gt;
  
      &lt;EditText 
          android:id="@+id/messageTextField"
          android:layout_weight="1"
          android:inputType="number"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:hint="@string/messageTextFieldPlaceholder"
      /&gt;
      &lt;Button
          android:id="@+id/sendButton"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/sendButtonTitle"
          android:onClick="sendMessage"
      /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>I saw a few SO threads about vertical alignment and I have also seen <a href="http://thinkandroid.wordpress.com/2010/01/14/how-to-position-views-properly-in-layouts/" rel="nofollow">this</a>, but I only have a horizontal LinearLayout, so setting the gravity will adjust the views from side to side.</p>
  
  <p>Since the LinearLayout has the parent's dimensions, does it not fill the whole screen?</p>
  
  <p>Shouldn't <code>android:layout_gravity="center_vertical"</code> align it's subviews in the center (vertically) of it's dimensions?</p>
  
  <p>This is what makes sense to me across the coding that I've done, so why is android not making sense?</p>
  
  <p>Do I need another LinearLayout that is vertical that holds everything else inside of it and have that with <code>android:layout_gravity="center_vertical"</code>?</p>