<alpha xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="@android:anim/accelerate_decelerate_interpolator"
android:fromAlpha="1.0"
android:toAlpha="0.0"
android:duration="1000"
android:repeatCount="-1"
android:repeatMode="reverse"
android:fillAfter="true"/>