scrollController property
External scroll controller for the scrollable variant. Scrollable mode only.
Lets the host read and position the viewport — for example, keeping the selected segment at an exact screen position while the segment list is reconfigured around it (a picker changing its granularity). When null the control manages its own. Provide it from the first build; swapping between external and internal after mount is not supported.
Implementation
final ScrollController? scrollController;