android:requiresFadingEdge

added in API Level 14

Defines which edges should be faded on scrolling.

Ensure to change the minSDKVersion to 14, or greater.

android:requiresFadingEdge = "none"
android:requiresFadingEdge = "horizontal"
android:requires:FadingEdge = "vertical"

non - No edge is faded
horizontal - Fades horizontal edges only.
vertical - Fades vertical edges only.

Related Articles:

Resources:
http://developer.android.com/reference/android/view/View.html#attr_android:requiresFadingEdge
http://developer.android.com/reference/android/R.attr.html#requiresFadingEdge