Swing/BorderHighlightPainter のバックアップ(No.1)

Highlighter.Highlight hh = highlighter.getHighlights()[idx];
highlighter.removeHighlight(hh);
HighlightPainter currentPainter = new DefaultHighlightPainter(Color.ORANGE) {
  @Override public Shape paintLayer(
        Graphics g, int offs0, int offs1,
        Shape bounds, JTextComponent c, View view) {
    Shape s = super.paintLayer(g, offs0, offs1, bounds, c, view);
    if (s instanceof Rectangle) {
      Graphics2D g2 = (Graphics2D) g.create();
      g2.setPaint(Color.RED);
      Rectangle r = s.getBounds();
      // g2.draw(r);
      g2.drawRect(r.x, r.y, r.width - 1, r.height - 1);
      g2.dispose();
    }
    return s;
  }
};
try {
  highlighter.addHighlight(
      hh.getStartOffset(), hh.getEndOffset(), currentPainter);
  scrollToCenter(textArea, hh.getStartOffset());
} catch (BadLocationException ex) {
  // should never happen
  RuntimeException wrap = new StringIndexOutOfBoundsException(
      ex.offsetRequested());
  wrap.initCause(ex);
  throw wrap;
}