/**
   * This implementation of <code>javaToNative</code> converts an ImageData object represented by
   * java <code>ImageData</code> to a platform specific representation.
   *
   * @param object a java <code>ImageData</code> containing the ImageData to be converted
   * @param transferData an empty <code>TransferData</code> object that will be filled in on return
   *     with the platform specific format of the data
   * @see Transfer#nativeToJava
   */
  public void javaToNative(Object object, TransferData transferData) {
    if (!checkImage(object) || !isSupportedType(transferData)) {
      DND.error(DND.ERROR_INVALID_DATA);
    }
    if (OS.GTK_VERSION < OS.VERSION(2, 4, 0)) return;

    ImageData imgData = (ImageData) object;
    if (imgData == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
    Image image = new Image(Display.getCurrent(), imgData);
    long /*int*/ pixbuf = ImageList.createPixbuf(image);
    if (pixbuf != 0) {
      String typeStr = "";
      if (transferData.type == JPEG_ID) typeStr = "jpeg";
      else if (transferData.type == PNG_ID) typeStr = "png";
      else if (transferData.type == BMP_ID) typeStr = "bmp";
      else if (transferData.type == EPS_ID) typeStr = "eps";
      else if (transferData.type == PCX_ID) typeStr = "pcx";
      else if (transferData.type == PPM_ID) typeStr = "ppm";
      else if (transferData.type == RGB_ID) typeStr = "rgb";
      else if (transferData.type == TGA_ID) typeStr = "tga";
      else if (transferData.type == XBM_ID) typeStr = "xbm";
      else if (transferData.type == XPM_ID) typeStr = "xpm";
      else if (transferData.type == XV_ID) typeStr = "xv";
      byte[] type = Converter.wcsToMbcs(null, typeStr, true);
      long /*int*/[] buffer = new long /*int*/[1];
      long /*int*/[] len = new long /*int*/[1];
      if (type == null) return;
      OS.gdk_pixbuf_save_to_bufferv(pixbuf, buffer, len, type, null, null, null);
      OS.g_object_unref(pixbuf);
      transferData.pValue = buffer[0];
      transferData.length = (int) (len[0] + 3) / 4 * 4;
      transferData.result = 1;
      transferData.format = 32;
    }
    image.dispose();
  }
  Image getDragSourceImage(DragSourceEvent event) {
    if (dragSourceImage != null) dragSourceImage.dispose();
    dragSourceImage = null;

    Table table = (Table) control;
    if (OS.GTK_VERSION < OS.VERSION(2, 2, 0)) return null;
    // TEMPORARY CODE
    if (table.isListening(SWT.EraseItem) || table.isListening(SWT.PaintItem)) return null;
    /*
     * Bug in GTK.  gtk_tree_selection_get_selected_rows() segmentation faults
     * in versions smaller than 2.2.4 if the model is NULL.  The fix is
     * to give a valid pointer instead.
     */
    long /*int*/ handle = table.handle;
    long /*int*/ selection = OS.gtk_tree_view_get_selection(handle);
    long /*int*/[] model = OS.GTK_VERSION < OS.VERSION(2, 2, 4) ? new long /*int*/[1] : null;
    long /*int*/ list = OS.gtk_tree_selection_get_selected_rows(selection, model);
    if (list == 0) return null;
    int count = Math.min(10, OS.g_list_length(list));

    Display display = table.getDisplay();
    if (count == 1) {
      long /*int*/ path = OS.g_list_nth_data(list, 0);
      long /*int*/ pixmap = OS.gtk_tree_view_create_row_drag_icon(handle, path);
      dragSourceImage = Image.gtk_new(display, SWT.ICON, pixmap, 0);
    } else {
      int width = 0, height = 0;
      int[] w = new int[1], h = new int[1];
      int[] yy = new int[count], hh = new int[count];
      long /*int*/[] pixmaps = new long /*int*/[count];
      GdkRectangle rect = new GdkRectangle();
      for (int i = 0; i < count; i++) {
        long /*int*/ path = OS.g_list_nth_data(list, i);
        OS.gtk_tree_view_get_cell_area(handle, path, 0, rect);
        pixmaps[i] = OS.gtk_tree_view_create_row_drag_icon(handle, path);
        OS.gdk_drawable_get_size(pixmaps[i], w, h);
        width = Math.max(width, w[0]);
        height = rect.y + h[0] - yy[0];
        yy[i] = rect.y;
        hh[i] = h[0];
      }
      long /*int*/ source = OS.gdk_pixmap_new(OS.GDK_ROOT_PARENT(), width, height, -1);
      long /*int*/ gcSource = OS.gdk_gc_new(source);
      long /*int*/ mask = OS.gdk_pixmap_new(OS.GDK_ROOT_PARENT(), width, height, 1);
      long /*int*/ gcMask = OS.gdk_gc_new(mask);
      GdkColor color = new GdkColor();
      color.pixel = 0;
      OS.gdk_gc_set_foreground(gcMask, color);
      OS.gdk_draw_rectangle(mask, gcMask, 1, 0, 0, width, height);
      color.pixel = 1;
      OS.gdk_gc_set_foreground(gcMask, color);
      for (int i = 0; i < count; i++) {
        OS.gdk_draw_drawable(source, gcSource, pixmaps[i], 0, 0, 0, yy[i] - yy[0], -1, -1);
        OS.gdk_draw_rectangle(mask, gcMask, 1, 0, yy[i] - yy[0], width, hh[i]);
        OS.g_object_unref(pixmaps[i]);
      }
      OS.g_object_unref(gcSource);
      OS.g_object_unref(gcMask);
      dragSourceImage = Image.gtk_new(display, SWT.ICON, source, mask);
    }
    OS.g_list_free(list);

    return dragSourceImage;
  }