/** Checks to see if the font metrics and longest line are up-to-date. */
 private void updateMetrics() {
   host = (RSyntaxTextArea) getContainer();
   Font f = host.getFont();
   if (font != f) {
     // The font changed, we need to recalculate the longest line!
     // This also updates cached font and tab size.
     calculateLongestLine();
   }
 }