popupMenu function
Implementation
Future<void> popupMenu(BuildContext context, List<PopupMenuItem> items) async {
final RenderBox button = context.findRenderObject()! as RenderBox;
final RenderBox overlay =
Navigator.of(context).overlay!.context.findRenderObject()! as RenderBox;
const Offset offset = Offset(0.0, 30.0);
await showMenu(
context: context,
position: RelativeRect.fromRect(
Rect.fromPoints(
button.localToGlobal(offset, ancestor: overlay),
button.localToGlobal(button.size.bottomRight(Offset.zero) + offset,
ancestor: overlay),
),
Offset.zero & overlay.size,
),
items: items,
elevation: 8.0,
);
}