private void highlightItem(int pos) {
if (pos == -1) return;
String text = textField.getText();
String[] parts = text.split(",");
int start = 0;
for (int i = 0; i < pos; i++) start += parts[i].length() + 1;
if (pos >= parts.length) return;
int end = start + parts[pos].length();
textField.highlight(start, end);
int width = textField.getFontMetrics(textField.getFont()).stringWidth(text.substring(0, start));
textField.getHorizontalVisibility().setValue(width);
} // highlightItem
