buildStackChild static method

Widget buildStackChild(BaseNode node, BaseNode parent, BuildContext context, { WidgetNodeTransformerManager? manager, Widget? childWidget, required BaseNode? widestChild, required BaseNode? tallestChild, required AlignmentModel commonAlignment, required WidgetBuildSettings settings, })

Implementation

static Widget buildStackChild(
  BaseNode node,
  BaseNode parent,
  BuildContext context, {
  WidgetNodeTransformerManager? manager,
  Widget? childWidget,
  required BaseNode? widestChild,
  required BaseNode? tallestChild,
  required AlignmentModel commonAlignment,
  required WidgetBuildSettings settings,
}) {
  assert(childWidget != null || manager != null,
      'Either childWidget or manager must be provided.');

  Widget child = childWidget ??
      manager!.buildWidgetFromNode(node, context, settings: settings);

  final bool potentiallyPositionable =
      node.alignment == AlignmentModel.none ||
          (parent.isOneOrBothWrap && node.alignment != commonAlignment);

  if (potentiallyPositionable) {
    // You cannot use the Align widget when inside a shrink-wrapping Stack.
    // The Align RenderBox will force the Stack to grow as much as possible.
    // Positioned widgets are only laid out after the Stack lays out its
    // concrete children and figures out its own size. So for wrapping stacks,
    // we need to use Positioned instead of Align.
    //
    // The behavior is absolutely different, but it's the best compromise we
    // can do.
    if (node.alignment != AlignmentModel.none &&
        parent.childrenOrEmpty.length > 1) {
      final align = node.alignment.data!;

      child = Positioned(
        left: align.x <= 0
            ? node.outerBoxLocal.left - parent.innerBoxLocal.edgeLeft
            : null,
        right: align.x >= 0
            ? (parent.innerBoxLocal.width - node.outerBoxLocal.right) +
                parent.innerBoxLocal.edgeRight
            : null,
        top: align.y <= 0
            ? node.outerBoxLocal.top - parent.innerBoxLocal.edgeTop
            : null,
        bottom: align.y >= 0
            ? (parent.innerBoxLocal.height - node.outerBoxLocal.bottom) +
                parent.innerBoxLocal.edgeBottom
            : null,
        child: child,
      );
    } else {
      child = wrapWithPositioned(
        node,
        parent,
        child,
        isWidest: widestChild?.id == node.id,
        isTallest: tallestChild?.id == node.id,
      );
    }
  } else {
    if (node.alignment != commonAlignment) {
      child = Align(
        alignment: node.alignment.flutterAlignment!,
        child: child,
      );
    }
  }

  return KeyedSubtree(
    key: ValueKey(
      'Static Stack child [${node.id}](${node.name})<${node.type}> on parent [${parent.id}](${parent.name})<${parent.type}>',
    ),
    child: child,
  );
}