The anchor point used to pick the closest sub-screen.
If the anchor point sits inside one of these sub-screens, then that sub-screen is picked. If not, then the sub-screen with the closest edge to the point is used.
Offset.zero is the top-left corner of the available screen space. For a vertically split dual-screen device, this is the top-left corner of the left screen.
When this is null, Directionality is used:
- for TextDirection.ltr, anchorPoint is Offset.zero, which will cause the top-left sub-screen to be picked.
- for TextDirection.rtl, anchorPoint is
Offset(double.maxFinite, 0), which will cause the top-right sub-screen to be picked.
final Offset? anchorPoint;