cancelReorder method Null safety
Cancel any item drag in progress.
This should be called before any major changes to the item list occur so that any item drags will not get confused by changes to the underlying list.
If a drag operation is in progress, this will immediately reset the list to back to its pre-drag state.
If no drag is active, this will do nothing.
Implementation
void cancelReorder() {
setState(() {
_dragReset();
});
}