sclass JFFMPEGVideoPlayer extends JSelfSwingable {

  //SurfaceShowingAutoZoomedImage imageSurface;

  ImageSurface imageSurface;

  JPanel buttons = rightAlignedLine();

  JButton btnPlayPause = jDisabledButton("Pause", r playPause);

  ImageStreamFromVideoFile stream;

  long playStartTime;

  new BoolVar paused;

  RSTVar<BufferedImage> imageToDisplay = new(image -> imageSurface.setImage(image));

  gettable File videoFile;

  event videoStarted(File videoFile);

  event userSelectedVideo(File videoFile);

  void init {

    //imageSurface = swing(-> new SurfaceShowingAutoZoomedImage);

    imageSurface = doubleBufferedImageSurface();

    imageSurface.setAutoZoomToDisplay(true);

    buttons.add(btnPlayPause);

    buttons.add(jbutton("Open video...", rThread openDialog));

    bindToComponent(imageSurface, null, rThread closeStream);

    setComponent(

      centerAndSouth(

        jscroll_center_borderless(imageSurface),

        withMargin(buttons)

      ));

  }

  selfType standardZoom() { imageSurface.standardZoom(); this; }

  *() { init(); }

  *(File videoFile) {

    init();

    if (videoFile != null)

      onFirstShow(imageSurface, -> play(videoFile));

  }

  void openDialog swing {

    new JFileChooser fc;

    fc.setDialogTitle("Open video");

    fc.setCurrentDirectory(dirToOpen());

    File videoFile = execFileChooser(fc);

    if (videoFile == null) ret;

    print("openDialog " + nListeners(onUserSelectedVideo));

    userSelectedVideo(videoFile);

    play(videoFile);

  }

  File dirToOpen() {

    if (videoFile != null) ret dirOfFile(videoFile);

    ret videosDir();

  }

  void play(File videoFile) {

    printCommaCombine("JFFMPEGVideoPlayer.play " + videoFile,

      nListeners(onVideoStarted));

    if (!isFile(videoFile))

      ret with print("Not a file");

    thread { // TODO: use something better than just a new thread

      if (videoFile == null) ret;

      JFFMPEGVideoPlayer.this.videoFile = videoFile;

      pcall-infobox {

        closeStream();

        stream = new ImageStreamFromVideoFile;

        stream.open(videoFile);

        stream.onHaveImage((image, pos) -> {

          waitWhileTrue(paused);

          if (playStartTime == 0 || playStartTime+pos.toMillis() < sysNow())

            playStartTime = sysNow()-pos.toMillis();

          else

            sleepUntilSysTime(playStartTime+pos.toMillis());

          possiblyDisplay(image);

        });

        paused.set(false);

        enableButton(btnPlayPause);

        stream.startDecodeThread();

        videoStarted(videoFile);

      }

    }

  }

  void possiblyDisplay(BufferedImage image) {

    imageToDisplay.set(cloneBufferedImage(image));

  }

  void closeStream {

    disableButton(btnPlayPause);

    possiblyDisplay(whiteImage(10));

    dispose stream;

    playStartTime = 0;

  }

  void playPause() swing {

    paused.set(!paused!);

    setText(btnPlayPause, paused! ? "Play" : "Pause");

  }

}