getChildScrollOffset method
Implementation
Offset getChildScrollOffset(RenderObject child, Offset offset) {
final RenderLayoutParentData? childParentData =
child.parentData as RenderLayoutParentData?;
bool isChildFixed = child is RenderBoxModel
? child.renderStyle.position == CSSPositionType.fixed
: false;
// Fixed elements always paint original offset
Offset scrollOffset = isChildFixed
? childParentData!.offset
: childParentData!.offset + offset;
return scrollOffset;
}