performLayout method

@override Size performLayout(BoxConstraints constraints)

Hook for subclasses to perform layout within the given constraints.

Implementation

@override
Size performLayout(BoxConstraints constraints) {
  final modal = widget as ModalOverlay;
  final width = constraints.hasBoundedWidth
      ? constraints.maxWidth
      : modal.width;
  final height = constraints.hasBoundedHeight
      ? constraints.maxHeight
      : modal.height;

  if (childElement != null) {
    childElement!.relativeOffset = Offset(
      modal.dialogBounds.x + 1,
      modal.dialogBounds.y + 1,
    );
    final childW = max(0, modal.dialogBounds.width - 2);
    final childH = max(0, modal.dialogBounds.height - 2);
    childElement!.layout(BoxConstraints.tight(Size(childW, childH)));
  }

  return constraints.constrain(Size(width, height));
}