It is very strange feeling to write xml files for android like this in emacs.

shadow.xml

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"
    >

  (truncate  (* 255 0.2))51 (#o63, #x33, ?3)

  <gradient
      android:startColor="#4C000000"
      android:endColor="#33000000"
      android:type="radial"
      />

</shape>