title: NullPointer when trying to progmatically capture screen
body: <p>Here is my code</p>
  
  <pre><code>    // create bitmap screen capture
      Bitmap bitmap;
      View v1 = (View)findViewById(R.id.text);
      View rootV = v1.getRootView();
      rootV.setDrawingCacheEnabled(true);
      bitmap = rootV.getDrawingCache();
      rootV.setDrawingCacheEnabled(false);
  </code></pre>
  
  <p>the nullpointer occurs on <code>bitmap = rootV.getDrawingCache();</code>  and <code>R.id.text</code> is a textView in the layout </p>