remove method

void remove({ required TKey key, bool animate = true, })

Removes a node and all its descendants from the tree.

If animate is true, the nodes will animate out.

Implementation

void remove({required TKey key, bool animate = true}) {
  if (animationDuration == Duration.zero) animate = false;
  if (!_hasKey(key)) {
    return;
  }
  final descendants = _getDescendants(key);
  final nodesToRemove = [key, ...descendants];
  // Capture the parent BEFORE mutation; _removeNodesImmediate purges the
  // node and releases its nid, after which _parentKeyOfKey returns null.
  final parentKey = _parentKeyOfKey(key);
  final affected = <TKey>{};
  if (animate && _order.contains(key)) {
    // Mark nodes as pending deletion so _finalizeAnimation knows to
    // fully remove them (vs just hiding due to parent collapse)
    for (final nodeId in nodesToRemove) {
      _markPendingDeletion(nodeId);
    }
    // Mark all visible nodes as exiting
    for (final nodeId in nodesToRemove) {
      if (_order.contains(nodeId)) {
        _startStandaloneExitAnimation(nodeId);
      }
    }
    // Animated path: parent's child list is not mutated until exit
    // animations complete; the hasChildren-flip refresh is fired from
    // the standalone-tick / group-dismissed sites at completion time.
  } else {
    _removeNodesImmediate(nodesToRemove);
    _structureGeneration++;
    // Immediate path: if [key] was the last child under its parent, the
    // parent's hasChildren just flipped true → false.
    if (parentKey != null) {
      final siblings = _childListOf(parentKey);
      if (siblings == null || siblings.isEmpty) {
        affected.add(parentKey);
      }
    }
  }
  _notifyStructural(affectedKeys: affected);
}