/**
* Converts a y co-ordinate to a line index.
*
* @param y The y co-ordinate
*/
public int yToLine(int y) {
FontMetrics fm = painter.getFontMetrics();
int height = fm.getHeight();
return Math.max(0, Math.min(getLineCount() - 1, y / height + firstLine));
}
/**
* Converts a line index to a y co-ordinate.
*
* @param line The line
*/
public int lineToY(int line) {
FontMetrics fm = painter.getFontMetrics();
return (line - firstLine) * fm.getHeight() - (fm.getLeading() + fm.getMaxDescent());
}