crossAxisPadding property

double crossAxisPadding

The total padding in the cross-axis direction. (In other words, for a vertical downwards-growing list, the sum of the padding on the left and right.)

Only valid after layout has started, since before layout the render object doesn't know what direction it will be laid out in.

Implementation 

double get crossAxisPadding {
  assert(constraints != null);
  assert(constraints.axis != null);
  assert(_resolvedPadding != null);
  switch (constraints.axis) {
    case Axis.horizontal:
      return _resolvedPadding.vertical;
    case Axis.vertical:
      return _resolvedPadding.horizontal;
  }
  return null;
}