void redrawFrom(int lno) {
if (lno < 0 || lno >= text.getLineCount()) return;
int y = text.getLocationAtOffset(text.getOffsetAtLine(lno)).y;
int height = text.getClientArea().height - y;
int width = text.getClientArea().width + text.getHorizontalPixel();
text.redraw(0, y, width, height, false);
}
void drawLine(int lno) {
if (lno < 0 || lno >= text.getLineCount()) return;
int y = text.getLocationAtOffset(text.getOffsetAtLine(lno)).y;
int height = 0;
if (text.getLineCount() > lno + 1)
height = text.getLocationAtOffset(text.getOffsetAtLine(lno + 1)).y - y;
else height = text.getLocationAtOffset(text.getCharCount()).y + text.getLineHeight();
int width = text.getClientArea().width + text.getHorizontalPixel();
text.redraw(0, y, width, height, false);
}