beforePadding property

double beforePadding

The padding in the scroll direction on the side nearest the 0.0 scroll direction.

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 beforePadding {
  assert(constraints != null);
  assert(constraints.axisDirection != null);
  assert(constraints.growthDirection != null);
  assert(_resolvedPadding != null);
  switch (applyGrowthDirectionToAxisDirection(constraints.axisDirection, constraints.growthDirection)) {
    case AxisDirection.up:
      return _resolvedPadding.bottom;
    case AxisDirection.right:
      return _resolvedPadding.left;
    case AxisDirection.down:
      return _resolvedPadding.top;
    case AxisDirection.left:
      return _resolvedPadding.right;
  }
  return null;
}