selectRoot method

@override IGraphEditable<T> selectRoot(String key)

Implementation

@override
IGraphEditable<T> selectRoot(String key) {
  _guardGraphContainsNode(Node(key));
  final root = getNodeByKey(key)!;
  final tree = Graph<T>(root: root);

  final currentPath = [root];
  _visitDepthBacktrack(
    root,
    (path) {
      if (path.length < 2) {
        return VisitResult.continueVisit;
      }

      final parent = path[path.length - 2];
      if (!tree.containsNode(parent.key)) {
        tree.addNode(parent);
      }

      final child = path[path.length - 1];
      if (!tree.containsNode(child.key)) {
        tree.addNode(child);
      }

      tree.addEdge(parent, child);

      return VisitResult.continueVisit;
    },
    currentPath,
  );

  return tree;
}