width = width.subtractNotNegative(LayoutUtils.getBorderBegin(orientation, box));
width = width.subtractNotNegative(LayoutUtils.getPaddingBegin(orientation, box));
width = width.subtractNotNegative(LayoutUtils.getPaddingEnd(orientation, box));
width = width.subtractNotNegative(LayoutUtils.getBorderEnd(orientation, box));
final LayoutComponentRenderer renderer = sheet.getLayoutComponentRenderer(facesContext);
width = width.subtractNotNegative(renderer.getCustomMeasure(facesContext, sheet, "columnSeparator"));
LayoutUtils.setCurrentSize(orientation, component, width);
component.setDisplay(Display.BLOCK); // TODO: use CSS via classes and tobago.css
// call sub layout manager
if (component instanceof LayoutContainer) {
((LayoutContainer) component).getLayoutManager().mainProcessing(orientation);