Android custom material design round button

This is a RelativeLayout wrapping a TextView in it. The RelativeLayout has a selector for stateListAnimator and a selector for the background. It will produce a material design effects, a round button similar to

The selector for the stateListAnimator, info_icon_state_selector.xml

The selector for the background, info_icon_selector.xml

The normal background, info_icon.xml

The background when pressed, info_icon_pressed.xml