title: How to read android:src in my custom component
body: <p>I am trying to create a custom component which inherits from RelativeLayout.</p>
  
  <p>In my xml layout file, I have:</p>
  
  <pre><code>&lt;Mycomponent 
      android:src="@drawable/my_test_image"&gt;
        &lt;TestView&gt;
  &lt;/Mycomponent&gt;
  </code></pre>
  
  <p>My question is how can I create a Drawable class in the constructor of Mycomponent?</p>
  
  <p>I have tried to read the source code of ImageView, but it seems tried to some android Internal.R .</p>
  
  <p>Is there anyway I can do that in my code.</p>
  
  <p>Thank you.</p>