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