GTK+ 3 Reference Manual: GtkOffscreenWindow

## GtkOffscreenWindow GtkOffscreenWindow — A toplevel to manage offscreen rendering of child widgets |

## Functions

GtkWidget * | gtk_offscreen_window_new ()
cairo_surface_t * | gtk_offscreen_window_get_surface ()
GdkPixbuf * | gtk_offscreen_window_get_pixbuf ()

## Types and Values

struct | GtkOffscreenWindow
struct | GtkOffscreenWindowClass

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── GtkWidget
                ╰── GtkContainer
                    ╰── GtkBin
                        ╰── GtkWindow
                            ╰── GtkOffscreenWindow

## Implemented Interfaces

GtkOffscreenWindow implements AtkImplementorIface and GtkBuildable.

## Includes

    #include <gtk/gtk.h>

## Description

GtkOffscreenWindow is strictly intended to be used for obtaining snapshots of widgets that are not part of a normal widget hierarchy. Since GtkOffscreenWindow is a toplevel widget you cannot obtain snapshots of a full window with it since you cannot pack a toplevel widget in another toplevel.

The idea is to take a widget and manually set the state of it, add it to a GtkOffscreenWindow and then retrieve the snapshot as a cairo_surface_t or GdkPixbuf.

GtkOffscreenWindow derives from GtkWindow only as an implementation detail. Applications should not use any API specific to GtkWindow to operate on this object. It should be treated as a GtkBin that has no parent widget.

When contained offscreen widgets are redrawn, GtkOffscreenWindow will emit a “damage-event” signal.

## Functions

### gtk_offscreen_window_new ()

    GtkWidget *
    gtk_offscreen_window_new (void);

Creates a toplevel container widget that is used to retrieve snapshots of widgets without showing them on the screen.

#### Returns

A pointer to a GtkWidget

Since 2.20

### gtk_offscreen_window_get_surface ()

    cairo_surface_t *
    gtk_offscreen_window_get_surface (GtkOffscreenWindow *offscreen);

Retrieves a snapshot of the contained widget in the form of a cairo_surface_t. If you need to keep this around over window resizes then you should add a reference to it.

#### Parameters

offscreen | the GtkOffscreenWindow contained widget. |

#### Returns

A cairo_surface_t pointer to the offscreen surface, or `NULL`.

[transfer none]

Since 2.20

### gtk_offscreen_window_get_pixbuf ()

    GdkPixbuf *
    gtk_offscreen_window_get_pixbuf (GtkOffscreenWindow *offscreen);

Retrieves a snapshot of the contained widget in the form of a GdkPixbuf. This is a new pixbuf with a reference count of 1, and the application should unreference it once it is no longer needed.

#### Parameters

offscreen | the GtkOffscreenWindow contained widget. |

#### Returns

A GdkPixbuf pointer, or `NULL`.

[transfer full]

Since 2.20

## Types and Values

### struct GtkOffscreenWindow

    struct GtkOffscreenWindow;

### struct GtkOffscreenWindowClass

    struct GtkOffscreenWindowClass {
      GtkWindowClass parent_class;
    };

#### Members

GtkWindowClass `parent_class`; | The parent class. |