Package ch.bailu.gtk.gtk

Interface PrintOperation.OnDrawPage

Enclosing class:
PrintOperation
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public static interface PrintOperation.OnDrawPage

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    onDrawPage(PrintContext context, int page_nr)
    Emitted for every page that is printed.

  • Method Details

    • onDrawPage

      void onDrawPage(@Nonnull PrintContext context, int page_nr)
      Emitted for every page that is printed.

      The signal handler must render the @page_nr's page onto the cairo
      context obtained from @context using
      [method@Gtk.PrintContext.get_cairo_context].

      ```c
      static void
      draw_page (GtkPrintOperation *operation,
      GtkPrintContext *context,
      int page_nr,
      gpointer user_data)
      {
      cairo_t *cr;
      PangoLayout *layout;
      double width, text_height;
      int layout_height;
      PangoFontDescription *desc;

      cr = gtk_print_context_get_cairo_context (context);
      width = gtk_print_context_get_width (context);

      cairo_rectangle (cr, 0, 0, width, HEADER_HEIGHT);

      cairo_set_source_rgb (cr, 0.8, 0.8, 0.8);
      cairo_fill (cr);

      layout = gtk_print_context_create_pango_layout (context);

      desc = pango_font_description_from_string ("sans 14");
      pango_layout_set_font_description (layout, desc);
      pango_font_description_free (desc);

      pango_layout_set_text (layout, "some text", -1);
      pango_layout_set_width (layout, width * PANGO_SCALE);
      pango_layout_set_alignment (layout, PANGO_ALIGN_CENTER);

      pango_layout_get_size (layout, NULL, &layout_height);
      text_height = (double)layout_height / PANGO_SCALE;

      cairo_move_to (cr, width / 2, (HEADER_HEIGHT - text_height) / 2);
      pango_cairo_show_layout (cr, layout);

      g_object_unref (layout);
      }
      ```

      Use [method@Gtk.PrintOperation.set_use_full_page] and
      [method@Gtk.PrintOperation.set_unit] before starting the print
      operation to set up the transformation of the cairo context
      according to your needs.
      Parameters:
      context - the `GtkPrintContext` for the current operation
      page_nr - the number of the currently printed page (0-based)