title: Setting contentDescription from label for android accessibility
body: <p>While a constant <code>contentDescription</code> is appropriate for some widgets, other cases such as an image gallery with captions already have appropriate accessibility labels in the UI. Is there any way to link an <code>ImageView</code>'s <code>contentDescription</code> with its labelling <code>Textview</code> in XML?</p>
  
  <p>For example, is there a real equivalent for the last (fictional) line of this <code>ImageView</code> definition:</p>
  
  <pre><code>&lt;LinearLayout&gt;
      &lt;ImageView
          android:id="@+id/image"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:contentDescription="@+id/label" /&gt;
      &lt;TextView
          android:id="@+id/label"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content" /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>