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File Loading

File Loading — Loading a pixbuf from a file.

Includes

#include <gdk-pixbuf/gdk-pixbuf.h>

Description

The GdkPixBuf library provides a simple mechanism for loading an image from a file in synchronous fashion. This means that the library takes control of the application while the file is being loaded; from the user's point of view, the application will block until the image is done loading.

This interface can be used by applications in which blocking is acceptable while an image is being loaded. It can also be used to load small images in general. Applications that need progressive loading can use the GdkPixbufLoader functionality instead.

Functions

gdk_pixbuf_new_from_file ()

GdkPixbuf *
gdk_pixbuf_new_from_file (const char *filename,
                          GError **error);

Creates a new pixbuf by loading an image from a file. The file format is detected automatically. If NULL is returned, then error will be set. Possible errors are in the GDK_PIXBUF_ERROR and G_FILE_ERROR domains.

Parameters

filename

Name of file to load, in the GLib file name encoding

 

error

Return location for an error

 

Returns

A newly-created pixbuf with a reference count of 1, or NULL if any of several error conditions occurred: the file could not be opened, there was no loader for the file's format, there was not enough memory to allocate the image buffer, or the image file contained invalid data.


gdk_pixbuf_new_from_file_at_size ()

GdkPixbuf *
gdk_pixbuf_new_from_file_at_size (const char *filename,
                                  int width,
                                  int height,
                                  GError **error);

Creates a new pixbuf by loading an image from a file. The file format is detected automatically. If NULL is returned, then error will be set. Possible errors are in the GDK_PIXBUF_ERROR and G_FILE_ERROR domains.

The image will be scaled to fit in the requested size, preserving the image's aspect ratio. Note that the returned pixbuf may be smaller than width x height , if the aspect ratio requires it. To load and image at the requested size, regardless of aspect ratio, use gdk_pixbuf_new_from_file_at_scale().

Parameters

filename

Name of file to load, in the GLib file name encoding

 

width

The width the image should have or -1 to not constrain the width

 

height

The height the image should have or -1 to not constrain the height

 

error

Return location for an error

 

Returns

A newly-created pixbuf with a reference count of 1, or NULL if any of several error conditions occurred: the file could not be opened, there was no loader for the file's format, there was not enough memory to allocate the image buffer, or the image file contained invalid data.

Since: 2.4


gdk_pixbuf_new_from_file_at_scale ()

GdkPixbuf *
gdk_pixbuf_new_from_file_at_scale (const char *filename,
                                   int width,
                                   int height,
                                   gboolean preserve_aspect_ratio,
                                   GError **error);

Creates a new pixbuf by loading an image from a file. The file format is detected automatically. If NULL is returned, then error will be set. Possible errors are in the GDK_PIXBUF_ERROR and G_FILE_ERROR domains. The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio.

When preserving the aspect ratio, a width of -1 will cause the image to be scaled to the exact given height, and a height of -1 will cause the image to be scaled to the exact given width. When not preserving aspect ratio, a width or height of -1 means to not scale the image at all in that dimension. Negative values for width and height are allowed since 2.8.

Parameters

filename

Name of file to load, in the GLib file name encoding

 

width

The width the image should have or -1 to not constrain the width

 

height

The height the image should have or -1 to not constrain the height

 

preserve_aspect_ratio

TRUE to preserve the image's aspect ratio

 

error

Return location for an error

 

Returns

A newly-created pixbuf with a reference count of 1, or NULL if any of several error conditions occurred: the file could not be opened, there was no loader for the file's format, there was not enough memory to allocate the image buffer, or the image file contained invalid data.

Since: 2.6


gdk_pixbuf_get_file_info ()

GdkPixbufFormat *
gdk_pixbuf_get_file_info (const gchar *filename,
                          gint *width,
                          gint *height);

Parses an image file far enough to determine its format and size.

Parameters

filename

The name of the file to identify.

 

width

Return location for the width of the image, or NULL.

[optional][out]

height

Return location for the height of the image, or NULL.

[optional][out]

Returns

A GdkPixbufFormat describing the image format of the file or NULL if the image format wasn't recognized. The return value is owned by GdkPixbuf and should not be freed.

[nullable][transfer none]

Since: 2.4


gdk_pixbuf_get_file_info_async ()

void
gdk_pixbuf_get_file_info_async (const gchar *filename,
                                GCancellable *cancellable,
                                GAsyncReadyCallback callback,
                                gpointer user_data);

Asynchronously parses an image file far enough to determine its format and size.

For more details see gdk_pixbuf_get_file_info(), which is the synchronous version of this function.

When the operation is finished, callback will be called in the main thread. You can then call gdk_pixbuf_get_file_info_finish() to get the result of the operation.

Parameters

filename

The name of the file to identify

 

cancellable

optional GCancellable object, NULL to ignore.

[allow-none]

callback

a GAsyncReadyCallback to call when the file info is available

 

user_data

the data to pass to the callback function

 

Since: 2.32


gdk_pixbuf_get_file_info_finish ()

GdkPixbufFormat *
gdk_pixbuf_get_file_info_finish (GAsyncResult *async_result,
                                 gint *width,
                                 gint *height,
                                 GError **error);

Finishes an asynchronous pixbuf parsing operation started with gdk_pixbuf_get_file_info_async().

Parameters

async_result

a GAsyncResult

 

width

Return location for the width of the image, or NULL.

[out]

height

Return location for the height of the image, or NULL.

[out]

error

a GError, or NULL

 

Returns

A GdkPixbufFormat describing the image format of the file or NULL if the image format wasn't recognized. The return value is owned by GdkPixbuf and should not be freed.

[transfer none]

Since: 2.32


gdk_pixbuf_new_from_resource ()

GdkPixbuf *
gdk_pixbuf_new_from_resource (const char *resource_path,
                              GError **error);

Creates a new pixbuf by loading an image from an resource.

The file format is detected automatically. If NULL is returned, then error will be set.

Parameters

resource_path

the path of the resource file

 

error

Return location for an error

 

Returns

A newly-created pixbuf, or NULL if any of several error conditions occurred: the file could not be opened, the image format is not supported, there was not enough memory to allocate the image buffer, the stream contained invalid data, or the operation was cancelled.

Since: 2.26


gdk_pixbuf_new_from_resource_at_scale ()

GdkPixbuf *
gdk_pixbuf_new_from_resource_at_scale (const char *resource_path,
                                       int width,
                                       int height,
                                       gboolean preserve_aspect_ratio,
                                       GError **error);

Creates a new pixbuf by loading an image from an resource.

The file format is detected automatically. If NULL is returned, then error will be set.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio. When preserving the aspect ratio, a width of -1 will cause the image to be scaled to the exact given height, and a height of -1 will cause the image to be scaled to the exact given width. When not preserving aspect ratio, a width or height of -1 means to not scale the image at all in that dimension.

The stream is not closed.

Parameters

resource_path

the path of the resource file

 

width

The width the image should have or -1 to not constrain the width

 

height

The height the image should have or -1 to not constrain the height

 

preserve_aspect_ratio

TRUE to preserve the image's aspect ratio

 

error

Return location for an error

 

Returns

A newly-created pixbuf, or NULL if any of several error conditions occurred: the file could not be opened, the image format is not supported, there was not enough memory to allocate the image buffer, the stream contained invalid data, or the operation was cancelled.

Since: 2.26


gdk_pixbuf_new_from_stream ()

GdkPixbuf *
gdk_pixbuf_new_from_stream (GInputStream *stream,
                            GCancellable *cancellable,
                            GError **error);

Creates a new pixbuf by loading an image from an input stream.

The file format is detected automatically. If NULL is returned, then error will be set. The cancellable can be used to abort the operation from another thread. If the operation was cancelled, the error G_IO_ERROR_CANCELLED will be returned. Other possible errors are in the GDK_PIXBUF_ERROR and G_IO_ERROR domains.

The stream is not closed.

Parameters

stream

a GInputStream to load the pixbuf from

 

cancellable

optional GCancellable object, NULL to ignore.

[allow-none]

error

Return location for an error

 

Returns

A newly-created pixbuf, or NULL if any of several error conditions occurred: the file could not be opened, the image format is not supported, there was not enough memory to allocate the image buffer, the stream contained invalid data, or the operation was cancelled.

Since: 2.14


gdk_pixbuf_new_from_stream_async ()

void
gdk_pixbuf_new_from_stream_async (GInputStream *stream,
                                  GCancellable *cancellable,
                                  GAsyncReadyCallback callback,
                                  gpointer user_data);

Creates a new pixbuf by asynchronously loading an image from an input stream.

For more details see gdk_pixbuf_new_from_stream(), which is the synchronous version of this function.

When the operation is finished, callback will be called in the main thread. You can then call gdk_pixbuf_new_from_stream_finish() to get the result of the operation.

Parameters

stream

a GInputStream from which to load the pixbuf

 

cancellable

optional GCancellable object, NULL to ignore.

[allow-none]

callback

a GAsyncReadyCallback to call when the pixbuf is loaded

 

user_data

the data to pass to the callback function

 

Since: 2.24


gdk_pixbuf_new_from_stream_finish ()

GdkPixbuf *
gdk_pixbuf_new_from_stream_finish (GAsyncResult *async_result,
                                   GError **error);

Finishes an asynchronous pixbuf creation operation started with gdk_pixbuf_new_from_stream_async().

Parameters

async_result

a GAsyncResult

 

error

a GError, or NULL

 

Returns

a GdkPixbuf or NULL on error. Free the returned object with g_object_unref().

Since: 2.24


gdk_pixbuf_new_from_stream_at_scale ()

GdkPixbuf *
gdk_pixbuf_new_from_stream_at_scale (GInputStream *stream,
                                     gint width,
                                     gint height,
                                     gboolean preserve_aspect_ratio,
                                     GCancellable *cancellable,
                                     GError **error);

Creates a new pixbuf by loading an image from an input stream.

The file format is detected automatically. If NULL is returned, then error will be set. The cancellable can be used to abort the operation from another thread. If the operation was cancelled, the error G_IO_ERROR_CANCELLED will be returned. Other possible errors are in the GDK_PIXBUF_ERROR and G_IO_ERROR domains.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio.

When preserving the aspect ratio, a width of -1 will cause the image to be scaled to the exact given height, and a height of -1 will cause the image to be scaled to the exact given width. If both width and height are given, this function will behave as if the smaller of the two values is passed as -1.

When not preserving aspect ratio, a width or height of -1 means to not scale the image at all in that dimension.

The stream is not closed.

Parameters

stream

a GInputStream to load the pixbuf from

 

width

The width the image should have or -1 to not constrain the width

 

height

The height the image should have or -1 to not constrain the height

 

preserve_aspect_ratio

TRUE to preserve the image's aspect ratio

 

cancellable

optional GCancellable object, NULL to ignore.

[allow-none]

error

Return location for an error

 

Returns

A newly-created pixbuf, or NULL if any of several error conditions occurred: the file could not be opened, the image format is not supported, there was not enough memory to allocate the image buffer, the stream contained invalid data, or the operation was cancelled.

Since: 2.14


gdk_pixbuf_new_from_stream_at_scale_async ()

void
gdk_pixbuf_new_from_stream_at_scale_async
                               (GInputStream *stream,
                                gint width,
                                gint height,
                                gboolean preserve_aspect_ratio,
                                GCancellable *cancellable,
                                GAsyncReadyCallback callback,
                                gpointer user_data);

Creates a new pixbuf by asynchronously loading an image from an input stream.

For more details see gdk_pixbuf_new_from_stream_at_scale(), which is the synchronous version of this function.

When the operation is finished, callback will be called in the main thread. You can then call gdk_pixbuf_new_from_stream_finish() to get the result of the operation.

Parameters

stream

a GInputStream from which to load the pixbuf

 

width

the width the image should have or -1 to not constrain the width

 

height

the height the image should have or -1 to not constrain the height

 

preserve_aspect_ratio

TRUE to preserve the image's aspect ratio

 

cancellable

optional GCancellable object, NULL to ignore.

[allow-none]

callback

a GAsyncReadyCallback to call when the pixbuf is loaded

 

user_data

the data to pass to the callback function

 

Since: 2.24

Types and Values

See Also

GdkPixbufLoader.

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