renderChildrenOutsideViewport property
final
Whether to paint children inside the viewport only.
If false, every child will be painted. However the Scrollable is still the size of the viewport and detects gestures inside only.
Defaults to false. Cannot be true if clipBehavior is not Clip.none since children outside the viewport will be clipped, and therefore cannot render children outside the viewport.
Implementation
final bool renderChildrenOutsideViewport;