sclass JGallery_v2 {
  JPanel panel = jpanel(new VScrollingWrapLayout);
  
  settable ThumbnailCache thumbnailCache;
  
  void add(File imageFile) {
    if (imageFile == null) ret;
    addComponent(panel, new JThumbnailButton(thumbnailCache, imageFile));
  }
  
  cachedVisual
    jscroll_vertical(panel);
}