/**
* Calculate extra space taken by the popup decorations
*
* @return
*/
protected Size calculatePopupExtra() {
Element pe = popup.getElement();
Element ipe = popup.getContainerElement();
// border + padding
int width = Util.getRequiredWidth(pe) - Util.getRequiredWidth(ipe);
int height = Util.getRequiredHeight(pe) - Util.getRequiredHeight(ipe);
return new Size(width, height);
}
