FadeTransition constructor

const FadeTransition({Key key, @required Animation<double> opacity, bool alwaysIncludeSemantics: false, Widget child })

Creates an opacity transition.

The opacity argument must not be null.

Implementation 

const FadeTransition({
  Key key,
  @required this.opacity,
  this.alwaysIncludeSemantics = false,
  Widget child,
}) : super(key: key, child: child);