expandNode method

void expandNode(
  1. TreeNode<D> node
)

Implementation

void expandNode(TreeNode<D> node) {
  if (node.hasChildren) {
  // Collapse rings up to the clicked expanded node.
  if (node.children.any((e) => _nodeToExpand.contains(e))) {
    node.visit((e) {
      if (node != e) {
        _nodeToExpand.remove(e);
      }
    });
  } else {
    // Expand clicked node by one level.
    _nodeToExpand.add(node);
    _nodeToExpand.addAll(node.children);
  }
}
}