实现Notification上的跑马灯效果

<TextView
android:id="@+id/txt_trackinfo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toRightOf="@+id/iv_cover"
android:gravity="center"
android:paddingLeft="10dip"
android:paddingRight="10dip"
android:paddingTop="25dip"
android:textColor="#ffffff"
android:textSize="15sp"
android:ellipsize="marquee"
android:fadingEdge="horizontal"
android:marqueeRepeatLimit="marquee_forever"
android:scrollHorizontally="false"
android:focusable="true"
android:focusableInTouchMode="true"
android:singleLine="true">
<requestFocus/>
</TextView>