FlexibleSpaceBarSettings constructor

const FlexibleSpaceBarSettings({Key key, double toolbarOpacity, double minExtent, double maxExtent, @required double currentExtent, @required Widget child })

Creates a Flexible Space Bar Settings widget.

Used by Scaffold and SliverAppBar. child must have a FlexibleSpaceBar widget in its tree for the settings to take affect.

Implementation 

const FlexibleSpaceBarSettings({
  Key key,
  this.toolbarOpacity,
  this.minExtent,
  this.maxExtent,
  @required this.currentExtent,
  @required Widget child,
}) :  assert(currentExtent != null),
      super(key: key, child: child);