!7

sclass ImagePreview extends DynSCP {

  new DynModuleRef mate;

  transient Image shownImage;

  JComponent visualize2() {

    Image image = shownImage;

    if (image == null) ret jcenteredlabel("Need image");

    ret jimage(image);

  }

  Image imageFromMate() {

    ret castCall(mate!, 'getImage);

  }

  void update {

    lock lock;

    // notice mate gone away

    if (mate! != null && !dm_moduleStillThere(mate!)) {

      mate.set(null);

      setField(shownImage := null);

      revisualize2();

    }

    // find new mate

    if (mate! == null)

      if (setField(mate := DynModuleRef(dm_findMateOfType(this, 'ImageInfo))))

        revisualize2();

    if (setField(shownImage := imageFromMate()))

      revisualize2();

  }

}