Animation

<?xml version="1.0" encoding="UTF-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android">
   <item android:drawable="@drawable/one" android:duration="500" />
   <item android:drawable="@drawable/two" android:duration="500" />
   <item android:drawable="@drawable/three" android:duration="500" />
   <item android:drawable="@drawable/four" android:duration="500" />
</animation-list>