attach method

  1. @override
void attach (ScrollPosition position)
override

Register the given position with this controller.

After this function returns, the animateTo and jumpTo methods on this controller will manipulate the given position.

Implementation 

@override
void attach(ScrollPosition position) {
  super.attach(position);
  assert(!_positionToListener.containsKey(position));
  _positionToListener[position] = () {
    _lastUpdated = position;
    _lastUpdatedOffset = position.pixels;
  };
  position.addListener(_positionToListener[position]);
}