 
     private static function constraintsDetermineWidth(layoutItem:ILayoutItem):Boolean
     {
-        return !isNaN(layoutItem.percentSize.x) ||
-               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "left")) &&
-               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "right"));
+        return !isNaN(layoutItem.percentWidth) ||
+               !isNaN(LayoutItemHelper.parseConstraintValue(layoutItem.left)) &&
+               !isNaN(LayoutItemHelper.parseConstraintValue(layoutItem.right));
     }
 
     private static function constraintsDetermineHeight(layoutItem:ILayoutItem):Boolean
     {
-        return !isNaN(layoutItem.percentSize.y) ||
-               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "top")) &&
-               !isNaN(LayoutItemHelper.getConstraint(layoutItem, "bottom"));
+        return !isNaN(layoutItem.percentHeight) ||
+               !isNaN(LayoutItemHelper.parseConstraintValue(layoutItem.top)) &&
+               !isNaN(LayoutItemHelper.parseConstraintValue(layoutItem.bottom));
     }
 
     //--------------------------------------------------------------------------

            {
                childWidth = unscaledWidth - right - left;
            }
            else if (!isNaN(layoutItem.percentSize.x))
            {
                childWidth = unscaledWidth * Math.min(layoutItem.percentSize.x * 0.01, 1);
                itemMaxSize.x = Math.min(itemMaxSize.x,
                    maxSizeToFitIn(unscaledWidth, hCenter, left, right, childX));
            }

            if (!layoutItem || !layoutItem.includeInLayout)
                continue;

            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 extX:Number = 0;
            var extY:Number = 0;

            if (isNaN(left) && isNaN(right) &&
                isNaN(LayoutItemHelper.parseConstraintValue(layoutItem.horizontalCenter)))
            {
                extX += layoutItem.actualPosition.x;
            }
