static class ShowBigText {
  S fontID = "#1000993";  // Brother Deluxe Font
  Color background = Color.white;
  Color foreground = Color.black;
  S text = "test";
  ImageSurface is;
  Font font;
  S title = "JavaX";

  // thread-safe
  void showText(final S text) {
    swing {
      ShowBigText.this.text = text;
      if (is == null) {
        font = loadFont(fontID);
        
        BufferedImage img = makeImage();
        is = showImage_centered(img, title);
        moveToTopRightCorner(getFrame(is));
      }
  
      getFrame(is).setTitle(title);
      is.setImage(makeImage());
    }
  }

  BufferedImage makeImage() {  
    // TODO: dispose old image?
    BufferedImage img = new BufferedImage(200, 60, BufferedImage.TYPE_INT_RGB);
    
    Graphics g = img.getGraphics();
    int w = img.getWidth(), h = img.getHeight();
    g.setColor(background);
    g.fillRect(0, 0, w, h);
    g.setColor(foreground);
    g.setFont(font.deriveFont(30f));
    FontMetrics fm = g.getFontMetrics();
    int y = fm.getAscent() + (h-fm.getHeight())/2;
    int x = (w-fm.stringWidth(text))/2;
    g.drawString(text, x, y);
    g.dispose();
    
    return img;
  }
  
  void setToolTip(S text) {
    if (is != null) is.setToolTipText(text);
  }
}

Began life as a copy of #1001424