getNearestDatumDetailPerSeries method

@override List<DatumDetails<D>> getNearestDatumDetailPerSeries(Point<double> chartPoint, bool byDomain, Rectangle<int>? boundsOverride, { bool selectOverlappingPoints = false, bool selectExactEventLocation = false, })

Datum details of nearest rectangles in the treemap.

Implementation

@override
List<DatumDetails<D>> getNearestDatumDetailPerSeries(
  Point<double> chartPoint,
  bool byDomain,
  Rectangle<int>? boundsOverride, {
  bool selectOverlappingPoints = false,
  bool selectExactEventLocation = false,
}) {
  final nearest = <DatumDetails<D>>[];

  // Checks if the [chartPoint] is within bounds.
  if (!isPointWithinBounds(chartPoint, boundsOverride)) return nearest;

  final root = _treeNodeToRendererElement.entries.first.key;
  final queue = Queue<TreeNode<Object>>()..add(root);

  while (queue.isNotEmpty) {
    final node = queue.removeFirst();
    final element = _getRendererElement(node);

    if (element.boundingRect.containsPoint(chartPoint)) {
      nearest.add(DatumDetails<D>(
        index: element.index,
        series: element.series,
        datum: node,
        domain: element.domain,
        measure: element.measure,
        domainDistance: 0.0,
        measureDistance: 0.0,
      ));
      // No need to verify remaining siblings.
      queue.clear();

      // Only processes nodes whose parents contain the [chartPoint].
      // This reduces the number of nodes to verify.
      queue.addAll(node.children);
    }
  }

  // Prioritizes nodes with larger depth;
  nearest.sort((a, b) {
    final nodeA = a.datum as TreeNode<Object>;
    final nodeB = b.datum as TreeNode<Object>;
    return nodeB.depth.compareTo(nodeA.depth);
  });
  return nearest;
}