Class
GdkPixbufPixbufLoader
Description [src]
class GdkPixbuf.PixbufLoader : GObject.Object
{
/* No available fields */
}Incremental image loader.
GdkPixbufLoader provides a way for applications to drive the
process of loading an image, by letting them send the image data
directly to the loader instead of having the loader read the data
from a file. Applications can use this functionality instead of
gdk_pixbuf_new_from_file() or gdk_pixbuf_animation_new_from_file()
when they need to parse image data in small chunks. For example,
it should be used when reading an image from a (potentially) slow
network connection, or when loading an extremely large file.
To use GdkPixbufLoader to load an image, create a new instance,
and call gdk_pixbuf_loader_write() to send the data
to it. When done, gdk_pixbuf_loader_close() should be
called to end the stream and finalize everything.
The loader will emit three important signals throughout the process:
GdkPixbufLoader::size-preparedwill be emitted as soon as the image has enough information to determine the size of the image to be used. If you want to scale the image while loading it, you can callgdk_pixbuf_loader_set_size()in response to this signal.GdkPixbufLoader::area-preparedwill be emitted as soon as the pixbuf of the desired has been allocated. You can obtain theGdkPixbufinstance by callinggdk_pixbuf_loader_get_pixbuf(). If you want to use it, simply acquire a reference to it. You can also callgdk_pixbuf_loader_get_pixbuf()later to get the same pixbuf.GdkPixbufLoader::area-updatedwill be emitted every time a region is updated. This way you can update a partially completed image. Note that you do not know anything about the completeness of an image from the updated area. For example, in an interlaced image you will need to make several passes before the image is done loading.
Loading an animation
Loading an animation is almost as easy as loading an image. Once the
first GdkPixbufLoader::area-prepared signal has been
emitted, you can call gdk_pixbuf_loader_get_animation() to
get the GdkPixbufAnimation instance, and then call
and gdk_pixbuf_animation_get_iter() to get a
GdkPixbufAnimationIter to retrieve the pixbuf for the
desired time stamp.
Constructors
gdk_pixbuf_loader_new_with_mime_type
Creates a new pixbuf loader object that always attempts to parse
image data as if it were an image of MIME type mime_type, instead of
identifying the type automatically.
since: 2.4
gdk_pixbuf_loader_new_with_type
Creates a new pixbuf loader object that always attempts to parse
image data as if it were an image of type image_type, instead of
identifying the type automatically.
Instance methods
gdk_pixbuf_loader_close
Informs a pixbuf loader that no further writes with
gdk_pixbuf_loader_write() will occur, so that it can free its
internal loading structures.
gdk_pixbuf_loader_get_animation
Queries the GdkPixbufAnimation that a pixbuf loader is currently creating.
gdk_pixbuf_loader_get_format
Obtains the available information about the format of the currently loading image file.
since: 2.2
Signals
GdkPixbuf.PixbufLoader::area-prepared
This signal is emitted when the pixbuf loader has allocated the pixbuf in the desired size.
GdkPixbuf.PixbufLoader::area-updated
This signal is emitted when a significant area of the image being loaded has been updated.
GdkPixbuf.PixbufLoader::size-prepared
This signal is emitted when the pixbuf loader has been fed the initial amount of data that is required to figure out the size of the image that it will create.
Signals inherited from GObject (1)
GObject::notify
The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.
Class structure
struct GdkPixbufPixbufLoaderClass {
GObjectClass parent_class;
void (* size_prepared) (
GdkPixbufLoader* loader,
int width,
int height
);
void (* area_prepared) (
GdkPixbufLoader* loader
);
void (* area_updated) (
GdkPixbufLoader* loader,
int x,
int y,
int width,
int height
);
void (* closed) (
GdkPixbufLoader* loader
);
}No description available.
Class members
parent_class: GObjectClassNo description available.
size_prepared: void (* size_prepared) ( GdkPixbufLoader* loader, int width, int height )No description available.
area_prepared: void (* area_prepared) ( GdkPixbufLoader* loader )No description available.
area_updated: void (* area_updated) ( GdkPixbufLoader* loader, int x, int y, int width, int height )No description available.
closed: void (* closed) ( GdkPixbufLoader* loader )No description available.