popoverAnchor property
The point on the popover (floating content) that connects with the child at the child's anchor.
For example, Alignment.topCenter means the top-center point of the popover will connect with the child. See childAnchor for changing the child's anchor.
Defaults to Alignment.bottomCenter on Android and iOS, and Alignment.topCenter on all other platforms.
Implementation
final AlignmentGeometry popoverAnchor;