/*
* Get the line number to be drawn. The empty string will be returned
* when a line of text has wrapped.
*/
protected String getTextLineNumber(int rowStartOffset) {
Element root = component.getDocument().getDefaultRootElement();
int index = root.getElementIndex(rowStartOffset);
Element line = root.getElement(index);
if (line.getStartOffset() == rowStartOffset) return String.valueOf(index + 1);
else return "";
}
