## GtkPrintOperation GtkPrintOperation — High-level Printing API |

## Synopsis

    #include <gtk/gtk.h>

                        GtkPrintOperation;
    enum                GtkPrintStatus;
    enum                GtkPrintOperationAction;
    enum                GtkPrintOperationResult;
    enum                GtkPrintError;
    #define             GTK_PRINT_ERROR
    GtkPrintOperation*  gtk_print_operation_new             (void);
    void                gtk_print_operation_set_allow_async (GtkPrintOperation *op,
                                                             gboolean allow_async);
    void                gtk_print_operation_get_error       (GtkPrintOperation *op,
                                                             GError **error);
    void                gtk_print_operation_set_default_page_setup
                                                            (GtkPrintOperation *op,
                                                             GtkPageSetup *default_page_setup);
    GtkPageSetup*       gtk_print_operation_get_default_page_setup
                                                            (GtkPrintOperation *op);
    void                gtk_print_operation_set_print_settings
                                                            (GtkPrintOperation *op,
                                                             GtkPrintSettings *print_settings);
    GtkPrintSettings*   gtk_print_operation_get_print_settings
                                                            (GtkPrintOperation *op);
    void                gtk_print_operation_set_job_name    (GtkPrintOperation *op,
                                                             const gchar *job_name);
    void                gtk_print_operation_set_n_pages     (GtkPrintOperation *op,
                                                             gint n_pages);
    void                gtk_print_operation_set_current_page
                                                            (GtkPrintOperation *op,
                                                             gint current_page);
    void                gtk_print_operation_set_use_full_page
                                                            (GtkPrintOperation *op,
                                                             gboolean full_page);
    void                gtk_print_operation_set_unit        (GtkPrintOperation *op,
                                                             GtkUnit unit);
    void                gtk_print_operation_set_export_filename
                                                            (GtkPrintOperation *op,
                                                             const gchar *filename);
    void                gtk_print_operation_set_show_progress
                                                            (GtkPrintOperation *op,
                                                             gboolean show_progress);
    void                gtk_print_operation_set_track_print_status
                                                            (GtkPrintOperation *op,
                                                             gboolean track_status);
    void                gtk_print_operation_set_custom_tab_label
                                                            (GtkPrintOperation *op,
                                                             const gchar *label);
    GtkPrintOperationResult gtk_print_operation_run         (GtkPrintOperation *op,
                                                             GtkPrintOperationAction action,
                                                             GtkWindow *parent,
                                                             GError **error);
    void                gtk_print_operation_cancel          (GtkPrintOperation *op);
    GtkPrintStatus      gtk_print_operation_get_status      (GtkPrintOperation *op);
    const gchar*        gtk_print_operation_get_status_string
                                                            (GtkPrintOperation *op);
    gboolean            gtk_print_operation_is_finished     (GtkPrintOperation *op);
    void                gtk_print_operation_get_error       (GtkPrintOperation *op,
                                                             GError **error);
    GtkPageSetup*       gtk_print_run_page_setup_dialog     (GtkWindow *parent,
                                                             GtkPageSetup *page_setup,
                                                             GtkPrintSettings *settings);
    void                (*GtkPageSetupDoneFunc)             (GtkPageSetup *page_setup,
                                                             gpointer data);
    void                gtk_print_run_page_setup_dialog_async
                                                            (GtkWindow *parent,
                                                             GtkPageSetup *page_setup,
                                                             GtkPrintSettings *settings,
                                                             GtkPageSetupDoneFunc done_cb,
                                                             gpointer data);

                        GtkPrintOperationPreview;
    void                gtk_print_operation_preview_end_preview
                                                            (GtkPrintOperationPreview *preview);
    gboolean            gtk_print_operation_preview_is_selected
                                                            (GtkPrintOperationPreview *preview,
                                                             gint page_nr);
    void                gtk_print_operation_preview_render_page
                                                            (GtkPrintOperationPreview *preview,
                                                             gint page_nr);

## Object Hierarchy

      GObject
       +----GtkPrintOperation

      GInterface
       +----GtkPrintOperationPreview

## Prerequisites

GtkPrintOperationPreview requires GObject.

## Implemented Interfaces

GtkPrintOperation implements GtkPrintOperationPreview.

## Known Implementations

GtkPrintOperationPreview is implemented by GtkPrintOperation.

## Properties

      allow-async              gboolean              : Read / Write
      current-page             gint                  : Read / Write
      custom-tab-label         gchararray            : Read / Write
      default-page-setup       GtkPageSetup          : Read / Write
      export-filename          gchararray            : Read / Write
      job-name                 gchararray            : Read / Write
      n-pages                  gint                  : Read / Write
      print-settings           GtkPrintSettings      : Read / Write
      show-progress            gboolean              : Read / Write
      status                   GtkPrintStatus        : Read
      status-string            gchararray            : Read
      track-print-status       gboolean              : Read / Write
      unit                     GtkUnit               : Read / Write
      use-full-page            gboolean              : Read / Write

## Signals

      begin-print                                    : Run Last
      create-custom-widget                           : Run Last
      custom-widget-apply                            : Run Last
      done                                           : Run Last
      draw-page                                      : Run Last
      end-print                                      : Run Last
      paginate                                       : Run Last
      preview                                        : Run Last
      request-page-setup                             : Run Last
      status-changed                                 : Run Last

## Description

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 ::draw-page, which you are supposed to catch and render the page on the provided GtkPrintContext using Cairo.

Example 30. The high-level printing API

    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_print_preview_render_page()`, `gtk_print_operation_preview_end_preview()` and `gtk_print_operation_preview_is_selected()` are useful when implementing a print preview.

Printing support was added in GTK+ 2.10.

## Details

### GtkPrintOperation

    typedef struct _GtkPrintOperation GtkPrintOperation;

### enum GtkPrintStatus

    typedef enum {
      GTK_PRINT_STATUS_INITIAL,
      GTK_PRINT_STATUS_PREPARING,
      GTK_PRINT_STATUS_GENERATING_DATA,
      GTK_PRINT_STATUS_SENDING_DATA,
      GTK_PRINT_STATUS_PENDING,
      GTK_PRINT_STATUS_PENDING_ISSUE,
      GTK_PRINT_STATUS_PRINTING,
      GTK_PRINT_STATUS_FINISHED,
      GTK_PRINT_STATUS_FINISHED_ABORTED
    } GtkPrintStatus;

The status gives a rough indication of the completion of a running print operation.

`GTK_PRINT_STATUS_INITIAL` | The printing has not started yet; this status is set initially, and while the print dialog is shown.
`GTK_PRINT_STATUS_PREPARING` | This status is set while the begin-print signal is emitted and during pagination.
`GTK_PRINT_STATUS_GENERATING_DATA` | This status is set while the pages are being rendered.
`GTK_PRINT_STATUS_SENDING_DATA` | The print job is being sent off to the printer.
`GTK_PRINT_STATUS_PENDING` | The print job has been sent to the printer, but is not printed for some reason, e.g. the printer may be stopped.
`GTK_PRINT_STATUS_PENDING_ISSUE` | Some problem has occurred during printing, e.g. a paper jam.
`GTK_PRINT_STATUS_PRINTING` | The printer is processing the print job.
`GTK_PRINT_STATUS_FINISHED` | The printing has been completed successfully.
`GTK_PRINT_STATUS_FINISHED_ABORTED` | The printing has been aborted.

### enum GtkPrintOperationAction

    typedef enum {
      GTK_PRINT_OPERATION_ACTION_PRINT_DIALOG,
      GTK_PRINT_OPERATION_ACTION_PRINT,
      GTK_PRINT_OPERATION_ACTION_PREVIEW,
      GTK_PRINT_OPERATION_ACTION_EXPORT
    } GtkPrintOperationAction;

The `action` parameter to `gtk_print_operation_run()` determines what action the print operation should perform.

`GTK_PRINT_OPERATION_ACTION_PRINT_DIALOG` | Show the print dialog.
`GTK_PRINT_OPERATION_ACTION_PRINT` | Start to print without showing the print dialog, based on the current print settings.
`GTK_PRINT_OPERATION_ACTION_PREVIEW` | Show the print preview.
`GTK_PRINT_OPERATION_ACTION_EXPORT` | Export to a file. This requires the export-filename property to be set.

### enum GtkPrintOperationResult

    typedef enum {
      GTK_PRINT_OPERATION_RESULT_ERROR,
      GTK_PRINT_OPERATION_RESULT_APPLY,
      GTK_PRINT_OPERATION_RESULT_CANCEL,
      GTK_PRINT_OPERATION_RESULT_IN_PROGRESS
    } GtkPrintOperationResult;

A value of this type is returned by `gtk_print_operation_run()`.

`GTK_PRINT_OPERATION_RESULT_ERROR` | An error has occured.
`GTK_PRINT_OPERATION_RESULT_APPLY` | The print settings should be stored.
`GTK_PRINT_OPERATION_RESULT_CANCEL` | The print operation has been canceled, the print settings should not be stored.
`GTK_PRINT_OPERATION_RESULT_IN_PROGRESS` | The print operation is complete yet. This value will only be returned when running asynchronously.

### enum GtkPrintError

    typedef enum
    {
      GTK_PRINT_ERROR_GENERAL,
      GTK_PRINT_ERROR_INTERNAL_ERROR,
      GTK_PRINT_ERROR_NOMEM
    } GtkPrintError;

### GTK_PRINT_ERROR

    #define GTK_PRINT_ERROR gtk_print_error_quark ()

The GQuark used for GtkPrintError errors.

### gtk_print_operation_new ()

    GtkPrintOperation*  gtk_print_operation_new             (void);

Creates a new GtkPrintOperation.

Returns : | a new GtkPrintOperation

Since 2.10

### gtk_print_operation_set_allow_async ()

    void                gtk_print_operation_set_allow_async (GtkPrintOperation *op,
                                                             gboolean allow_async);

Sets whether the `gtk_print_operation_run()` may return before the print operation is completed. Note that some platforms may not allow asynchronous operation.

`op` : | a GtkPrintOperation
`allow_async` : | `TRUE` to allow asynchronous operation

Since 2.10

### gtk_print_operation_get_error ()

    void                gtk_print_operation_get_error       (GtkPrintOperation *op,
                                                             GError **error);

Call this when the result of a print operation is `GTK_PRINT_OPERATION_RESULT_ERROR`, either as returned by `gtk_print_operation_run()`, or in the ::done signal handler. The returned GError will contain more details on what went wrong.

`op` : | a GtkPrintOperation
`error` : | return location for the error

Since 2.10

### gtk_print_operation_set_default_page_setup ()

    void                gtk_print_operation_set_default_page_setup
                                                            (GtkPrintOperation *op,
                                                             GtkPageSetup *default_page_setup);

Makes `default_page_setup` the default page setup for `op`.

This page setup will be used by `gtk_print_operation_run()`, but it can be overridden on a per-page basis by connecting to the ::request-page-setup signal.

`op` : | a GtkPrintOperation
`default_page_setup` : | a GtkPageSetup, or `NULL`

Since 2.10

### gtk_print_operation_get_default_page_setup ()

    GtkPageSetup*       gtk_print_operation_get_default_page_setup
                                                            (GtkPrintOperation *op);

Returns the default page setup, see `gtk_print_operation_set_default_page_setup()`.

`op` : | a GtkPrintOperation
Returns : | the default page setup

Since 2.10

### gtk_print_operation_set_print_settings ()

    void                gtk_print_operation_set_print_settings
                                                            (GtkPrintOperation *op,
                                                             GtkPrintSettings *print_settings);

Sets the print settings for `op`. This is typically used to re-establish print settings from a previous print operation, see `gtk_print_operation_run()`.

`op` : | a GtkPrintOperation
`print_settings` : | GtkPrintSettings, or `NULL`

Since 2.10

### gtk_print_operation_get_print_settings ()

    GtkPrintSettings*   gtk_print_operation_get_print_settings
                                                            (GtkPrintOperation *op);

Returns the current print settings.

Note that the return value is `NULL` until either `gtk_print_operation_set_print_settings()` or `gtk_print_operation_run()` have been called.

`op` : | a GtkPrintOperation
Returns : | the current print settings of `op`.

Since 2.10

### gtk_print_operation_set_job_name ()

    void                gtk_print_operation_set_job_name    (GtkPrintOperation *op,
                                                             const gchar *job_name);

Sets the name of the print job. The name is used to identify the job (e.g. in monitoring applications like eggcups).

If you don't set a job name, GTK+ picks a default one by numbering successive print jobs.

`op` : | a GtkPrintOperation
`job_name` : | a string that identifies the print job

Since 2.10

### gtk_print_operation_set_n_pages ()

    void                gtk_print_operation_set_n_pages     (GtkPrintOperation *op,
                                                             gint n_pages);

Sets the number of pages in the document.

This must be set to a positive number before the rendering starts. It may be set in a ::begin-print signal hander.

Note that the page numbers passed to the ::request-page-setup and ::draw-page signals are 0-based, i.e. if the user chooses to print all pages, the last ::draw-page signal will be for page `n_pages` - 1.

`op` : | a GtkPrintOperation
`n_pages` : | the number of pages

Since 2.10

### gtk_print_operation_set_current_page ()

    void                gtk_print_operation_set_current_page
                                                            (GtkPrintOperation *op,
                                                             gint current_page);

Sets the current page.

If this is called before `gtk_print_operation_run()`, the user will be able to select to print only the current page.

Note that this only makes sense for pre-paginated documents.

`op` : | a GtkPrintOperation
`current_page` : | the current page, 0-based

Since 2.10

### gtk_print_operation_set_use_full_page ()

    void                gtk_print_operation_set_use_full_page
                                                            (GtkPrintOperation *op,
                                                             gboolean full_page);

If `full_page` is `TRUE`, the transformation for the cairo context obtained from GtkPrintContext puts the origin at the top left corner of the page (which may not be the top left corner of the sheet, depending on page orientation and the number of pages per sheet). Otherwise, the origin is at the top left corner of the imageable area (i.e. inside the margins).

`op` : | a GtkPrintOperation
`full_page` : | `TRUE` to set up the GtkPrintContext for the full page

Since 2.10

### gtk_print_operation_set_unit ()

    void                gtk_print_operation_set_unit        (GtkPrintOperation *op,
                                                             GtkUnit unit);

Sets up the transformation for the cairo context obtained from GtkPrintContext in such a way that distances are measured in units of `unit`.

`op` : | a GtkPrintOperation
`unit` : | the unit to use

Since 2.10

### gtk_print_operation_set_export_filename ()

    void                gtk_print_operation_set_export_filename
                                                            (GtkPrintOperation *op,
                                                             const gchar *filename);

Sets up the GtkPrintOperation to generate a file instead of showing the print dialog. The indended use of this function is for implementing "Export to PDF" actions. Currently, PDF is the only supported format.

"Print to PDF" support is independent of this and is done by letting the user pick the "Print to PDF" item from the list of printers in the print dialog.

`op` : | a GtkPrintOperation
`filename` : | the filename for the exported file

Since 2.10

### gtk_print_operation_set_show_progress ()

    void                gtk_print_operation_set_show_progress
                                                            (GtkPrintOperation *op,
                                                             gboolean show_progress);

If `show_progress` is `TRUE`, the print operation will show a progress dialog during the print operation.

`op` : | a GtkPrintOperation
`show_progress` : | `TRUE` to show a progress dialog

Since 2.10

### gtk_print_operation_set_track_print_status ()

    void                gtk_print_operation_set_track_print_status
                                                            (GtkPrintOperation *op,
                                                             gboolean track_status);

If track_status is `TRUE`, the print operation will try to continue report on the status of the print job in the printer queues and printer. This can allow your application to show things like "out of paper" issues, and when the print job actually reaches the printer.

This function is often implemented using some form of polling, so it should not be enabled unless needed.

`op` : | a GtkPrintOperation
`track_status` : | `TRUE` to track status after printing

Since 2.10

### gtk_print_operation_set_custom_tab_label ()

    void                gtk_print_operation_set_custom_tab_label
                                                            (GtkPrintOperation *op,
                                                             const gchar *label);

Sets the label for the tab holding custom widgets.

`op` : | a GtkPrintOperation
`label` : | the label to use, or `NULL` to use the default label

Since 2.10

### gtk_print_operation_run ()

    GtkPrintOperationResult gtk_print_operation_run         (GtkPrintOperation *op,
                                                             GtkPrintOperationAction action,
                                                             GtkWindow *parent,
                                                             GError **error);

Runs the print operation, by first letting the user modify print settings in the print dialog, and then print the document.

Normally that this function does not return until the rendering of all pages is complete. You can connect to the ::status-changed signal on `op` to obtain some information about the progress of the print operation. Furthermore, it may use a recursive mainloop to show the print dialog.

If you call `gtk_print_operation_set_allow_async()` or set the allow-async property the operation will run asyncronously if this is supported on the platform. The ::done signal will be emitted with the operation results when the operation is done (i.e. when the dialog is canceled, or when the print succeeds or fails).

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

    if (page_setup != NULL)
      gtk_print_operation_set_default_page_setup (print, page_setup);

    g_signal_connect (print, "begin-print",
                      G_CALLBACK (begin_print), &data);
    g_signal_connect (print, "draw-page",
                      G_CALLBACK (draw_page), &data);

    res = gtk_print_operation_run (print, GTK_PRINT_OPERATION_ACTION_PRINT_DIALOG, parent, &error);

    if (res == GTK_PRINT_OPERATION_RESULT_ERROR)
     {
       error_dialog = gtk_message_dialog_new (GTK_WINDOW (parent),
      			                     GTK_DIALOG_DESTROY_WITH_PARENT,
    					     GTK_MESSAGE_ERROR,
    					     GTK_BUTTONS_CLOSE,
    					     "Error printing file:\n%s",
    					     error->message);
       g_signal_connect (error_dialog, "response",
                         G_CALLBACK (gtk_widget_destroy), NULL);
       gtk_widget_show (error_dialog);
       g_error_free (error);
     }
    else 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));
     }

Note that `gtk_print_operation_run()` can only be called once on a given GtkPrintOperation.

`op` : | a GtkPrintOperation
`action` : | the action to start
`parent` : | Transient parent of the dialog, or `NULL`
`error` : | Return location for errors, or `NULL`
Returns : | the result of the print operation. A return value of `GTK_PRINT_OPERATION_RESULT_APPLY` indicates that the printing was completed successfully. In this case, it is a good idea to obtain the used print settings with `gtk_print_operation_get_print_settings()` and store them for reuse with the next print operation. A value of `GTK_PRINT_OPERATION_RESULT_IN_PROGRESS` means the operation is running asynchronously, and will emit the ::done signal when done.

Since 2.10

### gtk_print_operation_cancel ()

    void                gtk_print_operation_cancel          (GtkPrintOperation *op);

Cancels a running print operation. This function may be called from a begin-print, paginate or draw-page signal handler to stop the currently running print operation.

`op` : | a GtkPrintOperation

Since 2.10

### gtk_print_operation_get_status ()

    GtkPrintStatus      gtk_print_operation_get_status      (GtkPrintOperation *op);

Returns the status of the print operation. Also see `gtk_print_operation_get_status_string()`.

`op` : | a GtkPrintOperation
Returns : | the status of the print operation

Since 2.10

### gtk_print_operation_get_status_string ()

    const gchar*        gtk_print_operation_get_status_string
                                                            (GtkPrintOperation *op);

Returns a string representation of the status of the print operation. The string is translated and suitable for displaying the print status e.g. in a GtkStatusbar.

Use `gtk_print_operation_get_status()` to obtain a status value that is suitable for programmatic use.

`op` : | a GtkPrintOperation
Returns : | a string representation of the status of the print operation

Since 2.10

### gtk_print_operation_is_finished ()

    gboolean            gtk_print_operation_is_finished     (GtkPrintOperation *op);

A convenience function to find out if the print operation is finished, either successfully (`GTK_PRINT_STATUS_FINISHED`) or unsuccessfully (`GTK_PRINT_STATUS_FINISHED_ABORTED`).

Note: when you enable print status tracking the print operation can be in a non-finished state even after done has been called, as the operation status then tracks the print job status on the printer.

`op` : | a GtkPrintOperation
Returns : | `TRUE`, if the print operation is finished.

Since 2.10

### gtk_print_operation_get_error ()

    void                gtk_print_operation_get_error       (GtkPrintOperation *op,
                                                             GError **error);

Call this when the result of a print operation is `GTK_PRINT_OPERATION_RESULT_ERROR`, either as returned by `gtk_print_operation_run()`, or in the ::done signal handler. The returned GError will contain more details on what went wrong.

`op` : | a GtkPrintOperation
`error` : | return location for the error

Since 2.10

### gtk_print_run_page_setup_dialog ()

    GtkPageSetup*       gtk_print_run_page_setup_dialog     (GtkWindow *parent,
                                                             GtkPageSetup *page_setup,
                                                             GtkPrintSettings *settings);

Runs a page setup dialog, letting the user modify the values from `page_setup`. If the user cancels the dialog, the returned GtkPageSetup is identical to the passed in `page_setup`, otherwise it contains the modifications done in the dialog.

Note that this function may use a recursive mainloop to show the page setup dialog. See `gtk_print_run_page_setup_dialog_async()` if this is a problem.

`parent` : | transient parent, or `NULL`
`page_setup` : | an existing GtkPageSetup, or `NULL`
`settings` : | a GtkPrintSettings
Returns : | a new GtkPageSetup

Since 2.10

### GtkPageSetupDoneFunc ()

    void                (*GtkPageSetupDoneFunc)             (GtkPageSetup *page_setup,
                                                             gpointer data);

The type of function that is passed to `gtk_print_run_page_setup_dialog_async()`. This function will be called when the page setup dialog is dismissed, and also serves as destroy notify for `data`.

`page_setup` : | the GtkPageSetup that has been
`data` : | user data that has been passed to `gtk_print_run_page_setup_dialog_async()`.

### gtk_print_run_page_setup_dialog_async ()

    void                gtk_print_run_page_setup_dialog_async
                                                            (GtkWindow *parent,
                                                             GtkPageSetup *page_setup,
                                                             GtkPrintSettings *settings,
                                                             GtkPageSetupDoneFunc done_cb,
                                                             gpointer data);

Runs a page setup dialog, letting the user modify the values from `page_setup`.

In contrast to `gtk_print_run_page_setup_dialog()`, this function returns after showing the page setup dialog on platforms that support this, and calls `done_cb` from a signal handler for the ::response signal of the dialog.

`parent` : | transient parent, or `NULL`
`page_setup` : | an existing GtkPageSetup, or `NULL`
`settings` : | a GtkPrintSettings
`done_cb` : | a function to call when the user saves the modified page setup
`data` : | user data to pass to `done_cb`

Since 2.10

### GtkPrintOperationPreview

    typedef struct _GtkPrintOperationPreview GtkPrintOperationPreview;

### gtk_print_operation_preview_end_preview ()

    void                gtk_print_operation_preview_end_preview
                                                            (GtkPrintOperationPreview *preview);

Ends a preview.

This function must be called to finish a custom print preview.

`preview` : | a GtkPrintOperationPreview

Since 2.10

### gtk_print_operation_preview_is_selected ()

    gboolean            gtk_print_operation_preview_is_selected
                                                            (GtkPrintOperationPreview *preview,
                                                             gint page_nr);

Returns whether the given page is included in the set of pages that have been selected for printing.

`preview` : | a GtkPrintOperationPreview
`page_nr` : | a page number
Returns : | `TRUE` if the page has been selected for printing

Since 2.10

### gtk_print_operation_preview_render_page ()

    void                gtk_print_operation_preview_render_page
                                                            (GtkPrintOperationPreview *preview,
                                                             gint page_nr);

Renders a page to the preview, using the print context that was passed to the GtkPrintOperation::preview handler together with `preview`.

Note that this function requires a suitable cairo context to be associated with the print context.

`preview` : | a GtkPrintOperationPreview
`page_nr` : | the page to render

Since 2.10

## Property Details

### The :`allow-async` property

      allow-async              gboolean              : Read / Write

Determines whether the print operation may run asynchronously or not.

Some systems don't support asynchronous printing, but those that do will return `GTK_PRINT_OPERATION_RESULT_IN_PROGRESS` as the status, and emit the done signal when the operation is actually done.

The Windows port does not support asynchronous operation at all (this is unlikely to change). On other platforms, all actions except for `GTK_PRINT_OPERATION_ACTION_EXPORT` support asynchronous operation.

Default value: FALSE

Since 2.10

### The :`current-page` property

      current-page             gint                  : Read / Write

The current page in the document.

If this is set before `gtk_print_operation_run()`, the user will be able to select to print only the current page.

Note that this only makes sense for pre-paginated documents.

Allowed values: >= -1

Default value: -1

Since 2.10

### The :`custom-tab-label` property

      custom-tab-label         gchararray            : Read / Write

Used as the label of the tab containing custom widgets. Note that this property may be ignored on some platforms.

If this is `NULL`, GTK+ uses a default label.

Default value: NULL

Since 2.10

### The :`default-page-setup` property

      default-page-setup       GtkPageSetup          : Read / Write

The GtkPageSetup used by default.

This page setup will be used by `gtk_print_operation_run()`, but it can be overridden on a per-page basis by connecting to the ::request-page-setup signal.

Since 2.10

### The :`export-filename` property

      export-filename          gchararray            : Read / Write

The name of a file file to generate instead of showing the print dialog. Currently, PDF is the only supported format.

The intended use of this property is for implementing "Export to PDF" actions.

"Print to PDF" support is independent of this and is done by letting the user pick the "Print to PDF" item from the list of printers in the print dialog.

Default value: NULL

Since 2.10

### The :`job-name` property

      job-name                 gchararray            : Read / Write

A string used to identify the job (e.g. in monitoring applications like eggcups).

If you don't set a job name, GTK+ picks a default one by numbering successive print jobs.

Default value: ""

Since 2.10

### The :`n-pages` property

      n-pages                  gint                  : Read / Write

The number of pages in the document.

This must be set to a positive number before the rendering starts. It may be set in a ::begin-print signal hander.

Note that the page numbers passed to the ::request-page-setup and ::draw-page signals are 0-based, i.e. if the user chooses to print all pages, the last ::draw-page signal will be for page `n_pages` - 1.

Allowed values: >= -1

Default value: -1

Since 2.10

### The :`print-settings` property

      print-settings           GtkPrintSettings      : Read / Write

The GtkPrintSettings used for initializing the dialog.

Setting this property is typically used to re-establish print settings from a previous print operation, see `gtk_print_operation_run()`.

Since 2.10

### The :`show-progress` property

      show-progress            gboolean              : Read / Write

Determines whether to show a progress dialog during the print operation.

Default value: FALSE

Since 2.10

### The :`status` property

      status                   GtkPrintStatus        : Read

The status of the print operation.

Default value: GTK_PRINT_STATUS_INITIAL

Since 2.10

### The :`status-string` property

      status-string            gchararray            : Read

A string representation of the status of the print operation. The string is translated and suitable for displaying the print status e.g. in a GtkStatusbar.

See the ::status property for a status value that is suitable for programmatic use.

Default value: ""

Since 2.10

### The :`track-print-status` property

      track-print-status       gboolean              : Read / Write

If `TRUE`, the print operation will try to continue report on the status of the print job in the printer queues and printer. This can allow your application to show things like "out of paper" issues, and when the print job actually reaches the printer. However, this is often implemented using polling, and should not be enabled unless needed.

Default value: FALSE

Since 2.10

### The :`unit` property

      unit                     GtkUnit               : Read / Write

The transformation for the cairo context obtained from GtkPrintContext is set up in such a way that distances are measured in units of `unit`.

Default value: GTK_UNIT_PIXEL

Since 2.10

### The :`use-full-page` property

      use-full-page            gboolean              : Read / Write

If `TRUE`, the transformation for the cairo context obtained from GtkPrintContext puts the origin at the top left corner of the page (which may not be the top left corner of the sheet, depending on page orientation and the number of pages per sheet). Otherwise, the origin is at the top left corner of the imageable area (i.e. inside the margins).

Default value: FALSE

Since 2.10

## Signal Details

### The `::begin-print` signal

    void                user_function                      (GtkPrintOperation *operation,
                                                            GtkPrintContext   *context,
                                                            gpointer           user_data)      : Run Last

Emitted after the user has finished changing print settings in the dialog, before the actual rendering starts.

A typical use for this signal is to use the parameters from the GtkPrintContext and paginate the document accordingly, and then set the number of pages with `gtk_print_operation_set_n_pages()`.

`operation` : | the GtkPrintOperation on which the signal was emitted
`context` : | the GtkPrintContext for the current operation
`user_data` : | user data set when the signal handler was connected.

Since 2.10

### The `::create-custom-widget` signal

    GObject*            user_function                      (GtkPrintOperation *operation,
                                                            gpointer           user_data)      : Run Last

Emitted when displaying the print dialog. If you return a widget in a handler for this signal it will be added to a custom tab in the print dialog. You typically return a container widget with multiple widgets in it.

The print dialog owns the returned widget, and its lifetime isn't controlled by the app. However, the widget is guaranteed to stay around until the custom-widget-apply signal is emitted on the operation. Then you can read out any information you need from the widgets.

`operation` : | the GtkPrintOperation on which the signal was emitted
`user_data` : | user data set when the signal handler was connected.
Returns : | A custom widget that gets embedded in the print dialog, or `NULL`

Since 2.10

### The `::custom-widget-apply` signal

    void                user_function                      (GtkPrintOperation *operation,
                                                            GtkWidget         *widget,
                                                            gpointer           user_data)      : Run Last

Emitted right before begin-print if you added a custom widget in the create-custom-widget handler. When you get this signal you should read the information from the custom widgets, as the widgets are not guaraneed to be around at a later time.

`operation` : | the GtkPrintOperation on which the signal was emitted
`widget` : | the custom widget added in create-custom-widget
`user_data` : | user data set when the signal handler was connected.

Since 2.10

### The `::done` signal

    void                user_function                      (GtkPrintOperation      *operation,
                                                            GtkPrintOperationResult result,
                                                            gpointer                user_data)      : Run Last

Emitted when the print operation run has finished doing everything required for printing. `result` gives you information about what happened during the run. If `result` is `GTK_PRINT_OPERATION_RESULT_ERROR` then you can call `gtk_print_operation_get_error()` for more information.

If you enabled print status tracking then `gtk_print_operation_is_finished()` may still return `FALSE` after this was emitted.

`operation` : | the GtkPrintOperation on which the signal was emitted
`result` : | the result of the print operation
`user_data` : | user data set when the signal handler was connected.

Since 2.10

### The `::draw-page` signal

    void                user_function                      (GtkPrintOperation *operation,
                                                            GtkPrintContext   *context,
                                                            gint               page_nr,
                                                            gpointer           user_data)      : Run Last

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 `gtk_print_context_get_cairo_context()`.

    static void
    draw_page (GtkPrintOperation *operation,
               GtkPrintContext   *context,
               gint               page_nr,
               gpointer           user_data)
    {
      cairo_t *cr;
      PangoLayout *layout;
      gdouble width, text_height;
      gint 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_layout_set_alignment (layout, PANGO_ALIGN_CENTER);

      pango_layout_get_size (layout, NULL, &layout_height);
      text_height = (gdouble)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 `gtk_print_operation_set_use_full_page()` and `gtk_print_operation_set_unit()` before starting the print operation to set up the transformation of the cairo context according to your needs.

`operation` : | the GtkPrintOperation on which the signal was emitted
`context` : | the GtkPrintContext for the current operation
`page_nr` : | the number of the currently printed page
`user_data` : | user data set when the signal handler was connected.

Since 2.10

### The `::end-print` signal

    void                user_function                      (GtkPrintOperation *operation,
                                                            GtkPrintContext   *context,
                                                            gpointer           user_data)      : Run Last

Emitted after all pages have been rendered. A handler for this signal can clean up any resources that have been allocated in the ::begin-print handler.

`operation` : | the GtkPrintOperation on which the signal was emitted
`context` : | the GtkPrintContext for the current operation
`user_data` : | user data set when the signal handler was connected.

Since 2.10

### The `::paginate` signal

    gboolean            user_function                      (GtkPrintOperation *operation,
                                                            GtkPrintContext   *context,
                                                            gpointer           user_data)      : Run Last

Emitted after the begin-print signal, but before the actual rendering starts. It keeps getting emitted until it returns `FALSE`.

This signal is intended to be used for paginating the document in small chunks, to avoid blocking the user interface for a long time. The signal handler should update the number of pages using `gtk_print_operation_set_n_pages()`, and return `TRUE` if the document has been completely paginated.

If you don't need to do pagination in chunks, you can simply do it all in the begin-print handler, and set the number of pages from there.

`operation` : | the GtkPrintOperation on which the signal was emitted
`context` : | the GtkPrintContext for the current operation
`user_data` : | user data set when the signal handler was connected.
Returns : | `TRUE` if pagination is complete

Since 2.10

### The `::preview` signal

    gboolean            user_function                      (GtkPrintOperation        *operation,
                                                            GtkPrintOperationPreview *preview,
                                                            GtkPrintContext          *context,
                                                            GtkWindow                *parent,
                                                            gpointer                  user_data)      : Run Last

Gets emitted when a preview is requested from the native dialog.

The default handler for this signal uses an external viewer application to preview.

To implement a custom print preview, an application must return `TRUE` from its handler for this signal. In order to use the provided `context` for the preview implementation, it must be given a suitable cairo context with `gtk_print_context_set_cairo_context()`.

The custom preview implementation can use `gtk_print_operation_preview_is_selected()` and `gtk_print_operation_preview_render_page()` to find pages which are selected for print and render them. The preview must be finished by calling `gtk_print_operation_preview_end_preview()` (typically in response to the user clicking a close button).

`operation` : | the GtkPrintOperation on which the signal was emitted
`preview` : | the GtkPrintPreviewOperation for the current operation
`context` : | the GtkPrintContext that will be used
`parent` : | the GtkWindow to use as window parent, or `NULL`
`user_data` : | user data set when the signal handler was connected.
Returns : | `TRUE` if the listener wants to take over control of the preview

Since 2.10

### The `::request-page-setup` signal

    void                user_function                      (GtkPrintOperation *operation,
                                                            GtkPrintContext   *context,
                                                            gint               page_nr,
                                                            GtkPageSetup      *setup,
                                                            gpointer           user_data)      : Run Last

Emitted once for every page that is printed, to give the application a chance to modify the page setup. Any changes done to `setup` will be in force only for printing this page.

`operation` : | the GtkPrintOperation on which the signal was emitted
`context` : | the GtkPrintContext for the current operation
`page_nr` : | the number of the currently printed page
`setup` : | the GtkPageSetup
`user_data` : | user data set when the signal handler was connected.

Since 2.10

### The `::status-changed` signal

    void                user_function                      (GtkPrintOperation *operation,
                                                            gpointer           user_data)      : Run Last

Emitted at between the various phases of the print operation. See GtkPrintStatus for the phases that are being discriminated. Use `gtk_print_operation_get_status()` to find out the current status.

`operation` : | the GtkPrintOperation on which the signal was emitted
`user_data` : | user data set when the signal handler was connected.

Since 2.10

## See Also

GtkPrintContext, GtkPrintUnixDialog