title: Buttons aren't shown in the LinearLayout
body: <p>I want that it looks so (this is a screenshot from the Graphical Layout editor):</p>
  
  <p><a href="https://i.stack.imgur.com/DjXGY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DjXGY.png" alt="enter image description here"></a></p>
  
  <p>So I created the layout:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical" &gt;
  
      &lt;LinearLayout
          android:id="@+id/controls"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="horizontal" &gt;
  
          &lt;Button
              android:id="@+id/clearButton"
              android:layout_width="wrap_content"
              android:layout_height="match_parent"
              android:text="@string/clearButtonText"
              android:layout_weight="1"
               /&gt;
  
          &lt;EditText
              android:id="@+id/searchText"
              android:layout_width="wrap_content"
              android:layout_height="match_parent"
              android:layout_weight="5"
              android:hint="@string/defaultSearchText"
              &gt;
  
              &lt;requestFocus/&gt;
          &lt;/EditText&gt;
  
          &lt;Button
              android:id="@+id/addButton"
              android:layout_width="wrap_content"
              android:layout_height="match_parent"
              android:text="@string/addButtonText"
              android:layout_weight="1" 
              /&gt;
      &lt;/LinearLayout&gt;
  
      &lt;ListView
          android:id="@+id/list_view"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_weight="1" /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>But when I ran my app on the emulator I saw:</p>
  
  <p><a href="https://i.stack.imgur.com/vI01I.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vI01I.png" alt="enter image description here"></a></p>
  
  <p>When I clicked on the loupe there was still no sign of the buttons.</p>
  
  <p><a href="https://i.stack.imgur.com/roTEj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/roTEj.png" alt="enter image description here"></a></p>