             if (!layoutItem || !layoutItem.includeInLayout)
                 continue;
 
-            var hCenter:Number = LayoutItemHelper.getConstraint(layoutItem, "horizontalCenter");
-            var vCenter:Number = LayoutItemHelper.getConstraint(layoutItem, "verticalCenter");
-            var left:Number    = LayoutItemHelper.getConstraint(layoutItem, "left");
-            var right:Number   = LayoutItemHelper.getConstraint(layoutItem, "right");
-            var top:Number     = LayoutItemHelper.getConstraint(layoutItem, "top");
-            var bottom:Number  = LayoutItemHelper.getConstraint(layoutItem, "bottom");
+            var hCenter:Number = LayoutItemHelper.parseConstraintValue(layoutItem.horizontalCenter);
+            var vCenter:Number = LayoutItemHelper.parseConstraintValue(layoutItem.verticalCenter);
+            var left:Number    = LayoutItemHelper.parseConstraintValue(layoutItem.left);
+            var right:Number   = LayoutItemHelper.parseConstraintValue(layoutItem.right);
+            var top:Number     = LayoutItemHelper.parseConstraintValue(layoutItem.top);
+            var bottom:Number  = LayoutItemHelper.parseConstraintValue(layoutItem.bottom);
             var itemMinSize:Point = layoutItem.minSize;
             var itemMaxSize:Point = layoutItem.maxSize.clone(); // Since we may update it below
 


    private static function constraintsDetermineWidth(layoutItem:ILayoutItem):Boolean
    {
        return !isNaN(layoutItem.percentSize.x) ||
               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "left")) &&
               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "right"));
    }

    private static function constraintsDetermineHeight(layoutItem:ILayoutItem):Boolean
    {
        return !isNaN(layoutItem.percentSize.y) ||
               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "top")) &&
               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "bottom"));
    }

    //--------------------------------------------------------------------------

            {
                childHeight = unscaledHeight - bottom - top;
            }
            else if (!isNaN(layoutItem.percentHeight))
            {
                childHeight = unscaledHeight * Math.min(layoutItem.percentHeight * 0.01, 1);
                itemMaxSize.y = Math.min(itemMaxSize.y,
                    maxSizeToFitIn(unscaledHeight, vCenter, top, bottom, childY));
            }
