public void dimAt ( float alpha ) { if ( ! mDimEnabled ) { return ; } if ( mDimView == null ) { mDimView = makeDimView ( ) ; } if ( ! mDimView . isShown ( ) ) { mDimView . setVisibility ( VISIBLE ) ; mDimView . setBackgroundColor ( mDimColor ) ; } mDimView . setAlpha ( alpha ) ; }
Set the dim - behind layer a specific opacity .