toggleExpansion method

void toggleExpansion(
  1. Object key
)

Toggles the expansion state of the node identified by key.

Implementation

void toggleExpansion(Object key) {
  if (_expandedKeys.contains(key)) {
    _expandedKeys.remove(key);
  } else {
    _expandedKeys.add(key);
  }
  notifyListeners();
}