question: @ TargetApi ( VERSION_CODES . LOLLIPOP ) public static void reveal ( final View view , int cx , int cy ) { if ( ! hasLollipop ( ) ) { view . setVisibility ( View . VISIBLE ) ; return ; } int finalRadius = Math . max ( view . getWidth ( ) , view . getHeight ( ) ) ; Animator animator = ViewAnimationUtils . createCircularReveal ( view , cx , cy , 0 , finalRadius ) ; view . setVisibility ( View . VISIBLE ) ; animator . start ( ) ; }
target:  Create the reveal effect animation