marquee in android

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

   <TextView
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:singleLine="true"
       android:ellipsize="marquee"
       android:marqueeRepeatLimit="marquee_forever"
       android:focusable="true"
       android:id="@+id/fd"
       android:focusableInTouchMode="true"
       android:text="http://androidresearch.wordpress.com/2012/03/17/understanding-asynctask-once-and-forever/"
       />

</LinearLayout>