PrintOperation

open class PrintOperation : GLibObject.Object, PrintOperationProtocol

GtkPrintOperation is the high-level, portable printing API. It looks a bit different than other GTK+ dialogs such as the GtkFileChooser, since some platforms don’t expose enough infrastructure to implement a good print dialog. On such platforms, GtkPrintOperation uses the native print dialog. On platforms which do not provide a native print dialog, GTK+ uses its own, see GtkPrintUnixDialog.

The typical way to use the high-level printing API is to create a GtkPrintOperation object with gtk_print_operation_new() when the user selects to print. Then you set some properties on it, e.g. the page size, any GtkPrintSettings from previous print operations, the number of pages, the current page, etc.

Then you start the print operation by calling gtk_print_operation_run(). It will then show a dialog, let the user select a printer and options. When the user finished the dialog various signals will be emitted on the GtkPrintOperation, the main one being GtkPrintOperation::draw-page, which you are supposed to catch and render the page on the provided GtkPrintContext using Cairo.

The high-level printing API

(C Language Example):

static GtkPrintSettings *settings = NULL;

static void
do_print (void)
{
  GtkPrintOperation *print;
  GtkPrintOperationResult res;

  print = gtk_print_operation_new ();

  if (settings != NULL)
    gtk_print_operation_set_print_settings (print, settings);

  g_signal_connect (print, "begin_print", G_CALLBACK (begin_print), NULL);
  g_signal_connect (print, "draw_page", G_CALLBACK (draw_page), NULL);

  res = gtk_print_operation_run (print, GTK_PRINT_OPERATION_ACTION_PRINT_DIALOG,
                                 GTK_WINDOW (main_window), NULL);

  if (res == GTK_PRINT_OPERATION_RESULT_APPLY)
    {
      if (settings != NULL)
        g_object_unref (settings);
      settings = g_object_ref (gtk_print_operation_get_print_settings (print));
    }

  g_object_unref (print);
}

By default GtkPrintOperation uses an external application to do print preview. To implement a custom print preview, an application must connect to the preview signal. The functions gtk_print_operation_preview_render_page(), gtk_print_operation_preview_end_preview() and gtk_print_operation_preview_is_selected() are useful when implementing a print preview.

The PrintOperation type acts as a reference-counted owner of an underlying GtkPrintOperation instance. It provides the methods that can operate on this data type through PrintOperationProtocol conformance. Use PrintOperation as a strong reference or owner of a GtkPrintOperation instance.