setExpansionState method

void setExpansionState(
  1. T node,
  2. bool expanded
)

Updates the expansion state of node to the value of expanded.

When overriding this method, do not call notifyListeners as this may be called many times recursively in cascading operations.

Implementation

void setExpansionState(T node, bool expanded) {
  expanded ^ defaultExpansionState
      ? toggledNodes.add(node)
      : toggledNodes.remove(node);
}