function getSVGElemScreenBBox(elem) {
    var svg = SVGTools.findParentSVG(elem);
    var rect = svg.createSVGRect();
    var pt = svg.createSVGPoint();
    var ctm = elem.getScreenCTM();
    var bbox = elem.getBBox();
    pt.x = bbox.x;
    pt.y = bbox.y;
    rect.width = bbox.width;
    rect.height = bbox.height;
    pt = pt.matrixTransform(ctm);
    rect.x = pt.x;
    rect.y = pt.y;
    return rect;
}
Get the bounding box in screen coordinates of an SVG element.

@param {elem} SVG element's node.