sclass ImageSurface extends Surface {

  BufferedImage image;

  double zoomX = 1, zoomY = 1, zoomFactor = 1.5;

  private Rectangle selection;

  new L<AutoCloseable> tools;

  // use overlays now

  O overlay; // voidfunc(Graphics2D)

  L<G2Drawable> overlays = syncL();

  Runnable onSelectionChange;

  settable bool verbose;

  bool noMinimumSize = true;

  S titleForUpload;

  O onZoom;

  bool specialPurposed; // true = don't show image changing commands in popup menu

  settable bool allowPaste;

  settable bool zoomable = true;

  bool noAlpha; // set to true to speed up drawing if you don't use alpha

  O interpolationMode = RenderingHints.VALUE_INTERPOLATION_BILINEAR;

  O onNewImage; // use imageChanged event instead

  BufferedImage imageToDraw; // if you want to draw a different image

  File file; // where image was loaded from

  bool autoZoomToDisplay; // only works 100% when not in scrollpane

  settable bool repaintInThread; // after setImage, repaint in same thread

  BoolVar showingVar;

  Pt mousePosition;

  event mousePositionChanged;

  event imageChanged;

  event userModifiedImage(BufferedImage image);

  public ImageSurface() {

    this(dummyImage());

  }

  static BufferedImage dummyImage() {

    ret whiteImage(1);

  }

  *(File file) {

    setImage(file);

  }

  *(MakesBufferedImage image) {

    this(image != null ? image.getBufferedImage() : dummyImage());

  }

  *(BufferedImage image) {

    setImage(image);

    clearSurface = false;

    // perform auto-zoom when shown, resized or when parent resized

    bindToComponent(this, l0 performAutoZoom, null);

    onResize(this, l0 performAutoZoom);

    onEnclosingScrollPaneResize(this, l0 performAutoZoom);

    componentPopupMenu2(this, ImageSurface_popupMenuMaker());

    new ImageSurfaceSelector(this);

    jHandleFileDrop(this, voidfunc(File f) { setImage(loadBufferedImage(f)) });

    imageSurfaceOnHover(this, p -> {

      mousePosition = p;

      mousePositionChanged();

    });

  }

  public ImageSurface(RGBImage image, double zoom) {

    this(image);

    setZoom(zoom);

  }

  // point is already in image coordinates

  protected void fillPopupMenu(JPopupMenu menu, final Point point) {

    if (zoomable) {

      JMenuItem miZoomReset = new JMenuItem("Zoom 100%");

      miZoomReset.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent evt) {

          setZoom(1.0);

          centerPoint(point);

        }

      });

      menu.add(miZoomReset);

      JMenuItem miZoomIn = new JMenuItem("Zoom in");

      miZoomIn.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent evt) {

          zoomIn(zoomFactor);

          centerPoint(point);

        }

      });

      menu.add(miZoomIn);

      JMenuItem miZoomOut = new JMenuItem("Zoom out");

      miZoomOut.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent evt) {

          zoomOut(zoomFactor);

          centerPoint(point);

        }

      });

      menu.add(miZoomOut);

      menu.add(jMenuItemStayCheckedOnClick("Zoom to window",

        -> autoZoomToDisplay,

        -> setAutoZoomToDisplay(true)));

      addMenuItem(menu, "Show full screen", r { showFullScreen() });

      addMenuItem(menu, "Point: " + point.x + "," + point.y + " (image: " + w() + "*" + h() + ")", null);

      menu.addSeparator();

    }

    if (!specialPurposed)

      addMenuItem(menu, "Load image...", r { selectFile("Load image",

        voidfunc(File f) { setImage(loadImage2(f)) }) });

    addMenuItem(menu, "Save image...", r { saveImage() });

    ifdef ImageSurface_AllowUpload

      addMenuItem(menu, "Upload image...", r { uploadTheImage() });

    endifdef

    addMenuItem(menu, "Copy image to clipboard", r { copyImageToClipboard(getImage()) });

    if (!specialPurposed || allowPaste)

      addMenuItem(menu, "Paste image from clipboard", r { loadFromClipboard() });

    if (!specialPurposed)

      addMenuItem(menu, "Load image snippet...", r {

        selectImageSnippet(voidfunc(S imageID) {

          setImage(loadImage2(imageID))

        });

      });

    if (selection != null)

      addMenuItem(menu, "Crop", r { crop() });

    if (!specialPurposed)

      addMenuItem(menu, "No image", r { noImage() });

  }

  void noImage() { setImage((BufferedImage) null); }

  void crop() {

    if (selection == null) ret;

    BufferedImage img = cloneClipBufferedImage(getImage(), selection);

    selection = null;

    setUserModifiedImage(img);

  }

  void setUserModifiedImage(BufferedImage img) {

    setImage(img);

    userModifiedImage(img);

  }

  void loadFromClipboard() {

    BufferedImage img = getImageFromClipboard();

    if (img != null)

      setUserModifiedImage(img);

  }

  swappable File defaultImageDir() { ret getProgramDir(); }

  void saveImage() {

    var image = getImage();

    JFileChooser fileChooser = new JFileChooser(defaultImageDir());

    if (fileChooser.showSaveDialog(this) == JFileChooser.APPROVE_OPTION) {

      try {

        main saveImage(image, file = fileChooser.getSelectedFile());

      } catch e {

        popup(e);

      }

    }

  }

  void drawImageItself(int w, int h, Graphics2D g) {

    int iw = getZoomedWidth(), ih = getZoomedHeight();

    if (interpolationMode == RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR || zoomX >= 1 || zoomY >= 1) {

      // faster

      g.drawImage(image, 0, 0, iw, ih, null);

    } else

      g.drawImage(resizeImage(image, iw, ih), 0, 0, null); // smoother

  }

  swappable void drawBackground(int w, int h, Graphics2D g) {

    g.setColor(or(getBackground(), Color.white));

    g.fillRect(0, 0, w, h);

  }

  public void render(int w, int h, Graphics2D g) {

    if (verbose) _print("render");

    g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, interpolationMode);

    drawBackground(w, h, g);

    BufferedImage image = or(imageToDraw, this.image);

    if (!hasImage())

      drawBackground(w, h, g);

    else {

      bool alpha = !noAlpha && hasTransparency(image);

      if (alpha)

        drawBackground(w, h, g);

      drawImageItself(w, h, g);

      int iw = getZoomedWidth(), ih = getZoomedHeight();

      if (!alpha) {

        g.fillRect(iw, 0, w-iw, h);

        g.fillRect(0, ih, iw, h-ih);

      }

    }

    if (overlay != null) {

      if (verbose) _print("render overlay");

      pcallF(overlay, g);

    }

    for (var overlay : cloneList(overlays)) pcall {

      overlay.drawOn(cloneGraphics(g));

    }

    if (selection != null) {

      if (verbose) _print("render selection");

      // drawRect is inclusive, selection is exclusive, so... whatever, tests show it's cool.

      drawSelectionRect(g, selection, Color.green, Color.white);

    }

  }

  public void drawSelectionRect(Graphics2D g, Rectangle selection, Color green, Color white) {

    drawSelectionRect(g, selection, green, white, zoomX, zoomY);

  }

  public void drawSelectionRect(Graphics2D g, Rectangle selection, Color green, Color white, double zoomX, double zoomY) {

    g.setColor(green);

    int top = (int) (selection.y * zoomY);

    int bottom = (int) ((selection.y+selection.height) * zoomY);

    int left = (int) (selection.x * zoomX);

    int right = (int) ((selection.x+selection.width) * zoomX);

    g.drawRect(left-1, top-1, right-left+1, bottom-top+1);

    g.setColor(white);

    g.drawRect(left - 2, top - 2, right - left + 3, bottom - top + 3);

  }

  public ImageSurface setZoom(double zoom) {

    setZoom(zoom, zoom);

    this;

  }

  public void setZoom(double zoomX, double zoomY) {

    autoZoomToDisplay = false;

    setZoom_dontChangeAutoZoom(zoomX, zoomY);

  }

  public void setZoom_dontChangeAutoZoom(double zoomX, double zoomY default zoomX) {

    if (this.zoomX == zoomX && this.zoomY == zoomY) ret;

    if (verbose) _print("Setting zoom");

    this.zoomX = zoomX;

    this.zoomY = zoomY;

    revalidateMe();

    repaint();

    centerPoint(new Point(getImage().getWidth()/2, getImage().getHeight()/2));

    pcallF(onZoom);

  }

  public scaffolded Dimension getMinimumSize() {

    if (noMinimumSize) ret new Dimension(1, 1);

    int w = getZoomedWidth();

    int h = getZoomedHeight();

    Dimension min = super.getMinimumSize();

    ret printIfScaffoldingEnabled(this, new Dimension(Math.max(w, min.width), Math.max(h, min.height)));

  }

  int getZoomedHeight() {

    return (int) (h() * zoomY);

  }

  int getZoomedWidth() {

    return (int) (w() * zoomX);

  }

  bool isShowing_quick() {

    if (showingVar == null) swing {

      showingVar if null = componentShowingVar(ImageSurface.this);

    }

    ret showingVar!;

  }

  public void setImageIfShowing_thisThread(BufferedImage etc image) {

    if (isShowing_quick())

      setImage_thisThread(image);

  }

  void setImage(File file) {

    setFile(file);

    setImage(loadImage2(file));

  }

  public void setImage(MakesBufferedImage image) swing {

    setImage_thisThread(image);

  }

  public void setImage(BufferedImage img) swing {

    setImage_thisThread(img);

  }

  public void setImage_thisThread(BufferedImage etc img) {

    BufferedImage newImage = img != null ? img : dummyImage();

    BufferedImage oldImage = image;

    image = newImage;

    if (verbose) print("Old image size:" + imageSize(oldImage) + ", new image size: " + imageSize(newImage));

    bool sameSize = imagesHaveSameSize(oldImage, newImage);

    if (!sameSize) {

      if (verbose) _print("New image size");

      revalidateMe();

    }

    quickRepaint();

    pcallF(onNewImage);

    if (!sameSize && autoZoomToDisplay) zoomToDisplaySize();

    imageChanged();

  }

  void setImageAndZoomToDisplay(BufferedImage img) {

    setImage(img);

    zoomToDisplaySize();

  }

  public BufferedImage getImage() {

    return image;

  }

  public double getZoomX() {

    return zoomX;

  }

  public double getZoomY() {

    return zoomY;

  }

  public scaffolded Dimension getPreferredSize() {

    ret printIfScaffoldingEnabled(this, new Dimension(getZoomedWidth(), getZoomedHeight()));

  }

  /** returns a scrollpane with the scroll-mode prevent-garbage-drawing fix applied */

  public JScrollPane makeScrollPane() {

    JScrollPane scrollPane = new JScrollPane(this);

    scrollPane.getViewport().setScrollMode(JViewport.BACKINGSTORE_SCROLL_MODE);

    return scrollPane;

  }

  public void zoomToWindow() { zoomToDisplaySize(); }

  public void zoomToDisplaySize() swing {

    if (!hasImage()) return;

    Dimension display = getDisplaySize();

    if (display.width == 0 || display.height == 0) ret;

    int w = w(), h = h();

    double xRatio = (display.width-5)/(double) w;

    double yRatio = (display.height-5)/(double) h;

    if (scaffoldingEnabled(this))

      printVars zoomToDisplaySize(+display, +w, +h, +xRatio, +yRatio);

    setZoom_dontChangeAutoZoom(min(xRatio, yRatio));

    revalidateMe();

  }

  /** tricky magic to get parent scroll pane */

  private scaffolded Dimension getDisplaySize() {

    Container c = getParent();

    while (c != null) {

      if (c instanceof JScrollPane)

        return c.getSize();

      c = c.getParent();

    }

    return getSize();

  }

  public void setSelection(Rect r) {

    setSelection(toRectangle(r));

  }

  public void setSelection(Rectangle r) {

    if (neq(selection, r)) {

      selection = r;

      pcallF(onSelectionChange);

      quickRepaint();

    }

  }

  public Rectangle getSelection() {

    return selection;

  }

  public RGBImage getRGBImage() {

    return new RGBImage(getImage());

  }

  // p is in image coordinates

  void centerPoint(Point p) {

    JScrollPane sp = enclosingScrollPane(this);

    if (sp == null) ret;

    p = new Point((int) (p.x*getZoomX()), (int) (p.y*getZoomY()));

    final JViewport viewport = sp.getViewport();

    Dimension viewSize = viewport.getExtentSize();

    //_print("centerPoint " + p);

    int x = max(0, p.x-viewSize.width/2);

    int y = max(0, p.y-viewSize.height/2);

    //_print("centerPoint " + p + " => " + x + "/" + y);

    p = new Point(x,y);

    //_print("centerPoint " + p);

    final Point _p = p;

    awtLater(r {

      viewport.setViewPosition(_p);

    });

  }

  Pt pointFromEvent(MouseEvent e) {

    ret pointFromComponentCoordinates(new Pt(e.getX(), e.getY()));

  }

  Pt pointFromComponentCoordinates(Pt p) {

    ret new Pt((int) (p.x/zoomX), (int) (p.y/zoomY));

  }

  Pt pointToComponentCoordinates(double x, double y) {

    ret new Pt((int) (x*zoomX), (int) (y*zoomY));

  }

  void uploadTheImage {

    //call(hotwire(/*#1007313*/#1016427), "go", getImage(), titleForUpload);

    ifdef ImageSurface_AllowUpload

      var img = getImage();

      JTextField tf = jTextField(titleForUpload);

      showFormTitled("Upload Image (PNG)",

        "Image title (optional)", tf, func {

          disableSubmitButton(getFrame(tf));

          thread "Upload Image" {

            try {

              messageBox("Image uploaded as " + uploadPNGToImageServer(img, titleForUpload = getTextTrim(tf)));

              disposeFrame(tf);

            } catch e {

              enableSubmitButton(getFrame(tf));

              messageBox(e);

            }

          }

          false;

        });

    endifdef

  }

  void showFullScreen() {

    showFullScreenImageSurface(getImage());

  }

  void zoomIn(double f) { setZoom(getZoomX()*f, getZoomY()*f); }

  void zoomOut(double f) { setZoom(getZoomX()/f, getZoomY()/f); }

  selfType setFile(File f) { file = f; this; }

  void setOverlay(IVF1<Graphics2D> overlay) {

    this.overlay = overlay;

  }

  bool hasImage() { ret image != null; }

  public int w() { ret image.getWidth(); }

  public int h() { ret image.getHeight(); }

  void setPixelated aka pixelate(bool b) {

    assertTrue(b);

    imageSurface_pixelated(this);

  }

  selfType setAutoZoomToDisplay aka autoZoomToDisplay(bool b) {

    if (autoZoomToDisplay = b)

      zoomToDisplaySize();

    this;

  }

  void quickRepaint() {

    if (repaintInThread)

      paintImmediately(0, 0, getWidth(), getHeight());

    else

      repaint();

  }

  void setTool(ImageSurfaceMouseHandler tool) swing {

    removeAllTools();

    addTool(tool);

  }

  bool hasTool(AutoCloseable tool) {

    ret swing(-> tools.contains(tool));

  }

  void addTool(ImageSurfaceMouseHandler tool) swing {

    if (!tools.contains(tool))

      tool.register(this);

  }

  void removeTool(AutoCloseable tool) swing {

    if (tools.contains(tool)) {

      close(tool);

      tools.remove(tool);

    }

  }

  void removeAllTools aka clearTools() {

    closeAllAndClear(tools);

  }

  void performAutoZoom {

    if (autoZoomToDisplay) zoomToDisplaySize();

  }

  void revalidateMe() {

    revalidateIncludingFullCenterContainer(this);

  }

  void addOverlay(G2Drawable overlay) {

    overlays.add(overlay);

    repaint();

  }

  void clearOverlays() {

    if (nempty(overlays)) {

      overlays.clear();

      repaint();

    }

  }

  void setOverlay(G2Drawable overlay) {

    clearOverlays();

    if (overlay != null) addOverlay(overlay);

  }

  void loadImage(File f) {

    setImage(loadImage2(f));

  }

  JComponent visualize() {

    ret jscroll_center_borderless(this);

  }

  void standardZoom() {

    setZoom(1.0);

  }

  !include #1034645 // print

} // end of ImageSurface

// static function allows garbage collection 

static VF2<ImageSurface, JPopupMenu> ImageSurface_popupMenuMaker() {

  ret voidfunc(ImageSurface is, JPopupMenu menu) {

    Point p = is.pointFromEvent(componentPopupMenu_mouseEvent.get()).getPoint();

    is.fillPopupMenu(menu, p);

  };

}