+ struct xr_rendering *r = NULL;
+
+ if (is_text_item (item))
+ r = xr_rendering_create_text (xr, text_item_get_text (to_text_item (item)),
+ cr);
+ else if (is_message_item (item))
+ {
+ const struct message_item *message_item = to_message_item (item);
+ const struct msg *msg = message_item_get_msg (message_item);
+ char *s = msg_to_string (msg, NULL);
+ r = xr_rendering_create_text (xr, s, cr);
+ free (s);
+ }
+ else if (is_table_item (item))
+ {
+ r = xzalloc (sizeof *r);
+ r->xr = xr;
+ xr_set_cairo (xr, cr);
+ r->page = xr_render_table_item (xr, to_table_item (item),
+ &r->title_height);
+ }
+ else if (is_chart_item (item))
+ {
+ r = xzalloc (sizeof *r);
+ r->chart = to_chart_item (output_item_ref (item));
+ }
+
+ return r;
+}
+
+void
+xr_rendering_measure (struct xr_rendering *r, int *w, int *h)
+{
+ if (r->chart == NULL)
+ {
+ *w = render_page_get_size (r->page, H) / 1024;
+ *h = (render_page_get_size (r->page, V) + r->title_height) / 1024;
+ }
+ else
+ {
+ *w = CHART_WIDTH;
+ *h = CHART_HEIGHT;
+ }
+}
+
+/* Draws onto CR at least the region of R that is enclosed in (X,Y)-(X+W,Y+H),
+ and possibly some additional parts. */
+void
+xr_rendering_draw (struct xr_rendering *r, cairo_t *cr,
+ int x, int y, int w, int h)
+{
+ if (r->chart == NULL)
+ {
+ struct xr_driver *xr = r->xr;
+
+ xr_set_cairo (xr, cr);
+ xr->y = 0;
+ render_page_draw_region (r->page,
+ x * 1024, y * 1024, w * 1024, h * 1024);
+ }
+ else
+ xr_draw_chart (r->chart, cr, 0, 0, CHART_WIDTH, CHART_HEIGHT);
+}
+
+void
+xr_draw_chart (const struct chart_item *chart_item, cairo_t *cr,
+ double x, double y, double width, double height)
+{
+ struct xrchart_geometry geom;
+
+ cairo_save (cr);
+ cairo_translate (cr, x, y + height);
+ cairo_scale (cr, 1.0, -1.0);
+ xrchart_geometry_init (cr, &geom, width, height);
+ if (is_boxplot (chart_item))
+ xrchart_draw_boxplot (chart_item, cr, &geom);
+ else if (is_histogram_chart (chart_item))
+ xrchart_draw_histogram (chart_item, cr, &geom);
+ else if (is_np_plot_chart (chart_item))
+ xrchart_draw_np_plot (chart_item, cr, &geom);
+ else if (is_piechart (chart_item))
+ xrchart_draw_piechart (chart_item, cr, &geom);
+ else if (is_roc_chart (chart_item))
+ xrchart_draw_roc (chart_item, cr, &geom);
+ else if (is_scree (chart_item))
+ xrchart_draw_scree (chart_item, cr, &geom);
+ else
+ NOT_REACHED ();
+ xrchart_geometry_free (cr, &geom);
+
+ cairo_restore (cr);
+}
+
+char *
+xr_draw_png_chart (const struct chart_item *item,
+ const char *file_name_template, int number)
+{
+ const int width = 640;
+ const int length = 480;
+
+ cairo_surface_t *surface;
+ cairo_status_t status;
+ const char *number_pos;
+ char *file_name;
+ cairo_t *cr;
+
+ number_pos = strchr (file_name_template, '#');
+ if (number_pos != NULL)
+ file_name = xasprintf ("%.*s%d%s", (int) (number_pos - file_name_template),
+ file_name_template, number, number_pos + 1);
+ else
+ file_name = xstrdup (file_name_template);
+
+ surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, width, length);
+ cr = cairo_create (surface);
+
+ cairo_save (cr);
+ cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+ cairo_rectangle (cr, 0, 0, width, length);
+ cairo_fill (cr);
+ cairo_restore (cr);
+
+ cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
+
+ xr_draw_chart (item, cr, 0.0, 0.0, width, length);
+
+ status = cairo_surface_write_to_png (surface, file_name);
+ if (status != CAIRO_STATUS_SUCCESS)
+ error (0, 0, _("error writing output file `%s': %s"),
+ file_name, cairo_status_to_string (status));
+
+ cairo_destroy (cr);
+ cairo_surface_destroy (surface);
+
+ return file_name;