attachChild method

Implementation

void attachChild(DomRenderObject child, DomRenderObject? after, {web.Node? startNode}) {
  child.parent = this;

  final targetNode = attachTargetNode;
  final afterNode = getRealNodeOf(after) ?? startNode;

  if (child case DomRenderFragment(isAttached: true)) {
    child.move(this, targetNode, afterNode);
    return;
  }

  try {
    final childNode = child.node;
    if (childNode.previousSibling == afterNode && childNode.parentNode == targetNode) {
      return;
    }

    if (kVerboseMode) {
      print("Attach node $childNode to $targetNode after $afterNode ($after)");
    }

    if (afterNode == null) {
      targetNode.insertBefore(childNode, targetNode.childNodes.item(0));
    } else {
      targetNode.insertBefore(childNode, afterNode.nextSibling);
    }

    if (child is! DomRenderFragment) {
      assert(childNode.previousSibling == afterNode, 'Child node should have been placed after the specified node.');
    } else if (child.firstChildNode != null) {
      assert(
        child.firstChildNode?.previousSibling == afterNode,
        'Fragment first child should have been placed after the specified node.',
      );
    }

    final next = after?.nextSibling;
    child.previousSibling = after;
    after?.nextSibling = child;
    child.nextSibling = next;
    next?.previousSibling = child;
  } finally {
    child.finalize();
  }
}