finishDragging method
Implementation
void finishDragging(Node<E> node) {
// Do a final overlap check
overlapping = widget.controller.getOverlapping(node);
if (overlapping.isNotEmpty) {
widget.onDrop?.call(node.data, overlapping.first.data);
}
draggedID = null;
overlapping = [];
lastDraggedNode = null;
setState(() {});
}