*[<Null safety>](https://dart.dev/null-safety)*
dynamic viewport
Returns the viewport rect of the child view in parent's coordinates.
This only works if there is one and only one widget that has the Key
set to GlobalObjectKey using this constroller's instance. FuchsiaView
set's its key to the controller instance passed to it.
Returns null if the child view has not been rendered.
Implementation
Rect? get viewport {
final key = GlobalObjectKey(this);
RenderBox? box = key.currentContext?.findRenderObject() as RenderBox?;
if (box?.hasSize == true) {
final offset = box!.localToGlobal(Offset.zero);
return offset & box.size;
}
return null;
}