RelativePositionedTransition constructor

const RelativePositionedTransition({Key key, @required Animation<Rect> rect, @required Size size, @required Widget child })

Create an animated version of Positioned.

Each frame, the Positioned widget will be configured to represent the current value of the rect argument assuming that the stack has the given size. Both rect and size must not be null.

Implementation 

const RelativePositionedTransition({
  Key key,
  @required Animation<Rect> rect,
  @required this.size,
  @required this.child,
}) : super(key: key, listenable: rect);