TreeViewport constructor

const TreeViewport({
  1. Key? key,
  2. required ViewportOffset verticalOffset,
  3. required AxisDirection verticalAxisDirection,
  4. required ViewportOffset horizontalOffset,
  5. required AxisDirection horizontalAxisDirection,
  6. required TreeRowDelegateMixin delegate,
  7. double? cacheExtent,
  8. Clip clipBehavior = Clip.hardEdge,
  9. required Map<UniqueKey, TreeViewNodesAnimation> activeAnimations,
  10. required Map<int, int> rowDepths,
  11. required double indentation,
})

Creates a viewport for Widgets that extend and scroll in both horizontal and vertical dimensions.

Implementation

const TreeViewport({
  super.key,
  required super.verticalOffset,
  required super.verticalAxisDirection,
  required super.horizontalOffset,
  required super.horizontalAxisDirection,
  required TreeRowDelegateMixin super.delegate,
  super.cacheExtent,
  super.clipBehavior,
  required this.activeAnimations,
  required this.rowDepths,
  required this.indentation,
})  : assert(verticalAxisDirection == AxisDirection.down &&
          horizontalAxisDirection == AxisDirection.right),
      // This is fixed as there is currently only one traversal pattern, https://github.com/flutter/flutter/issues/148357
      super(mainAxis: Axis.vertical);