ListWheelScrollView.useDelegate constructor

const ListWheelScrollView.useDelegate({Key key, ScrollController controller, ScrollPhysics physics, double diameterRatio: RenderListWheelViewport.defaultDiameterRatio, double perspective: RenderListWheelViewport.defaultPerspective, double offAxisFraction: 0.0, bool useMagnifier: false, double magnification: 1.0, @required double itemExtent, ValueChanged<int> onSelectedItemChanged, bool clipToSize: true, bool renderChildrenOutsideViewport: false, @required ListWheelChildDelegate childDelegate })

Constructs a list in which children are scrolled a wheel. Its children are managed by a delegate and are lazily built during layout.

Implementation 

const ListWheelScrollView.useDelegate({
  Key key,
  this.controller,
  this.physics,
  this.diameterRatio = RenderListWheelViewport.defaultDiameterRatio,
  this.perspective = RenderListWheelViewport.defaultPerspective,
  this.offAxisFraction = 0.0,
  this.useMagnifier = false,
  this.magnification = 1.0,
  @required this.itemExtent,
  this.onSelectedItemChanged,
  this.clipToSize = true,
  this.renderChildrenOutsideViewport = false,
  @required this.childDelegate,
}) : assert(childDelegate != null),
     assert(diameterRatio != null),
     assert(diameterRatio > 0.0, RenderListWheelViewport.diameterRatioZeroMessage),
     assert(perspective != null),
     assert(perspective > 0),
     assert(perspective <= 0.01, RenderListWheelViewport.perspectiveTooHighMessage),
     assert(magnification > 0),
     assert(itemExtent != null),
     assert(itemExtent > 0),
     assert(clipToSize != null),
     assert(renderChildrenOutsideViewport != null),
     assert(
       !renderChildrenOutsideViewport || !clipToSize,
       RenderListWheelViewport.clipToSizeAndRenderChildrenOutsideViewportConflict,
     ),
     super(key: key);