title: Android Progress Circle With Multiple Colors
body: <p>I'm trying to draw a indeterminate (circular) progress bar that is white and then fades into purple.  </p>
  
  <p>This is my ProgressBar:</p>
  
  <pre><code>&lt;ProgressBar
          android:id="@+id/mainProgressBar"
          style="@style/Widget.AppCompat.ProgressBar"
          android:layout_width="@dimen/progressbar_size"
          android:layout_height="@dimen/progressbar_size"
          android:layout_gravity="center" /&gt;
  </code></pre>
  
  <p>Then I paint it white:</p>
  
  <pre><code>mainProgressBar.getIndeterminateDrawable().setColorFilter(getResources().getColor(R.color.white), PorterDuff.Mode.SRC_ATOP);
  </code></pre>
  
  <p>Do I need add another ColorFilter? Set a style or theme on the progressbar? No idea what to do here.</p>