!7

sclass DynSCP extends DynModule {
  SingleComponentPanel scp;
  
  final JComponent visualize() { ret scp = singleComponentPanel(visualize2()); }
  void unvisualize2() { scp = null; }
  JComponent visualize2() { null; }
  
  void revisualize2() {
    lock lock;
    if (scp != null) scp.setComponent(visualize2());
  }
}

sclass LastImagesInDirectory extends DynSCP {
  /*DirectoryInfo*/O mate;
  S dir;
  L<S> allFiles, imageFiles;
  
  transient DynamicHStack stack;
  transient ButtonImageLoader imageLoader;

  File dirObject() { ret newFile(dir); }
  
  JComponent visualize2() {
    if (stack == null) stack = makeNiceButtons();
    if (imageLoader == null) imageLoader = new ButtonImageLoader(buttons);
    if (mate == null) ret jcenteredlabel("Need directory");
    ret jHigherScrollPane(jfullcenter(stack));
  }
  
  void update {
    lock lock;
    int oldChangeCount = changeCount;
    try {
      if (mate == null)
        if (setField(mate := dm_findMateOfType(this, 'DirectoryInfo)))
          revisualize2();
      if (mate == null) ret;
      setField(dir := (S) call(mate, 'getDir));
      L<S> allFiles = castCall(mate, 'getFiles);
      if (this.allFiles != allFiles) {
        setField(+allFiles);
        setField(imageFiles := filterOrNull(allFiles, f isImageFileName));
      }
    } finally {
      if (changeCount != oldChangeCount) updateButtons();
    }
  }
  
  void updateButtons {
    replaceNiceButtons(buttons,
      filesForNiceButtons(sortFilesByDate(
        fileNamesInDirToFile(dir, imageFiles)), f showImage));
    imageLoader.update();
  }
}