!7

sclass DirectoryInfo extends DynModule {
  S dir;
  bool allowedToLook;
  Bool exists, isFile;
  L<S> filesContained;
  
  File dirObject() { ret newFile(dir); }
  
  void start {
    ownTimer(doEvery(10.0, r fullUpdate));
  }
  
  JComponent visualize() {
    if (dir == null)
      ret jcenteredbutton("Select directory...", r {
        selectFile("Select directory to show", voidfunc(File dir) {
          setField(dir := f2s(dir));
          revisualize();
        });
      });
      
    ret makeForm(
      +dir,
      allowedToLook := yesNoComboBox(allowedToLook, voidfunc(bool b) {
        setField(allowedToLook := b) }),
      +exists,
      +isFile,
      "Files contained", filesContained == null ? "Unknown" : l(filesContained));
  }
  
  void fullUpdate {
    lock lock;
    filesContained = null;
    update();
  }
  
  void update {
    lock lock;
    if (dir != null && allowedToLook) {
      File dirObject = dirObject();
      setField(exists := dirObject.isDirectory());
      setField(isFile := dirObject.isFile());
      if (filesContained == null
        && setField(filesContained := listFileNames(dirObject)))
          revisualize();
    } else
      if (setFields(exists := null, isFile := null, filesContained := null)) revisualize();
  }
}