firstWalk method

void firstWalk(Graph graph, Node node, int depth, int number,)

Implementation

void firstWalk(Graph graph, Node node, int depth, int number) {
  final nodeData = getNodeData(node)!;
  nodeData.depth = depth;
  nodeData.number = number;
  minNodeHeight = min(minNodeHeight, node.height);
  minNodeWidth = min(minNodeWidth, node.width);
  maxNodeWidth = max(maxNodeWidth, node.width);
  maxNodeHeight = max(maxNodeHeight, node.height);

  if (isLeaf(graph, node)) {
    // if the node has no left sibling, prelim(node) should be set to 0, but we don't have to set it
    // here, because it's already initialized with 0
    if (hasLeftSibling(graph, node)) {
      final leftSibling = getLeftSibling(graph, node);
      nodeData.prelim = getPrelim(leftSibling) + getSpacing(graph, leftSibling, node);
    }
  } else {
    final leftMost = getLeftMostChild(graph, node);
    final rightMost = getRightMostChild(graph, node);
    var defaultAncestor = leftMost;

    Node? next = leftMost;
    var i = 1;
    while (next != null) {
      firstWalk(graph, next, depth + 1, i++);
      defaultAncestor = apportion(graph, next, defaultAncestor);

      next = getRightSibling(graph, next);
    }

    executeShifts(graph, node);

    var vertical = isVertical();
    var midPoint = 0.5 *
        ((getPrelim(leftMost) + getPrelim(rightMost) + (vertical ? rightMost!.width : rightMost!.height)) -
            (vertical ? node.width : node.height));

    if (hasLeftSibling(graph, node)) {
      final leftSibling = getLeftSibling(graph, node);
      nodeData.prelim = getPrelim(leftSibling) + getSpacing(graph, leftSibling, node);
      nodeData.modifier = nodeData.prelim - midPoint;
    } else {
      nodeData.prelim = midPoint;
    }
  }
}