TreeReorderController<TKey> constructor

TreeReorderController<TKey>({ required TreeController<TKey, Object?> treeController, required TickerProvider vsync, bool canReorder(TKey key)?, bool canAcceptDrop({ int? index, required TKey movingKey, TKey? newParent, })?, void onReorder(TKey key, TKey? newParent, int index)?, double autoScrollEdgeZone = 48.0, double autoScrollMaxVelocity = 1200.0, Duration? autoExpandDelay = const Duration(milliseconds: 700), })

Implementation

TreeReorderController({
  required this.treeController,
  required TickerProvider vsync,
  this.canReorder,
  this.canAcceptDrop,
  this.onReorder,
  this.autoScrollEdgeZone = 48.0,
  this.autoScrollMaxVelocity = 1200.0,
  this.autoExpandDelay = const Duration(milliseconds: 700),
}) {
  // Runtime check in all build modes: asserts disappear in release.
  // hasComparator, not comparator: reading the comparator getter through
  // this class's covariant `TreeController<TKey, Object?>` view throws a
  // TypeError (TData appears contravariantly in its function type).
  if (treeController.hasComparator) {
    throw ArgumentError.value(
      treeController,
      "treeController",
      "TreeReorderController is incompatible with a comparator-based "
          "TreeController: comparator auto-sort would override drag order. "
          "Pass a controller with comparator: null, or remove the comparator.",
    );
  }
  _vsync = vsync;
}