title: Refer to both bitmap and state list drawables
body: <p>I'm setting up an xml layout that has a button on it, the button has both text and an image on it. To get the image to appear unstretched I refer to a bitmap xml file and adjust the gravity of the image. I also want to change the image on the button when the user clicks it. To do this I have a state list xml file. Both of these components work correctly individually when referred to but I can only seem to be able to do this one at a time. Is there a way to refer multiple drawable files, or a way to combine them into one?</p>
  
  <p>homescreen.xml</p>
  
  <pre><code>&lt;Button
  android:id="@+id/bHome"
  android:layout_width="fill_parent"
  android:layout_height="60dp"
  android:layout_weight="2"
  android:background="@drawable/homebutton"
  android:text="Home"
  android:textColor="#FFFFFF"
  android:gravity="bottom|center"&gt;
  &lt;/Button&gt;    
  </code></pre>
  
  <p>homebutton.xml</p>
  
  <pre><code>&lt;bitmap xmlns:android="http://schemas.android.com/apk/res/android"
  android:src="@drawable/homeimage"
  android:gravity="center"/&gt;
  </code></pre>
  
  <p>homebuttonclicked.xml</p>
  
  <pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android" &gt;
  &lt;item android:drawable="@drawable/homeclicked" android:state_pressed="true" &gt;&lt;/item&gt;
  &lt;item android:drawable="@drawable/homeclicked" android:state_focused="true"&gt;&lt;/item&gt;
  &lt;item android:drawable="@drawable/home"&gt;&lt;/item&gt;
  &lt;/selector&gt;
  </code></pre>