public Rectangle getSelectionRect() {
if (selectedRows_.size() == 0) return null;
sortSelectedRows();
TableRowElement first = selectedRows_.get(0);
TableRowElement last = selectedRows_.get(selectedRows_.size() - 1);
int top = first.getOffsetTop();
int bottom = last.getOffsetTop() + last.getOffsetHeight();
int left = first.getOffsetLeft();
int width = first.getOffsetWidth();
return new Rectangle(left, top, width, bottom - top);
}