PixbufLoader
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 method@GdkPixbuf.PixbufLoader.write to send the data to it. When done, method@GdkPixbuf.PixbufLoader.close should be called to end the stream and finalize everything.
The loader will emit three important signals throughout the process:
signal@GdkPixbuf.PixbufLoader::size-prepared will 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 call method@GdkPixbuf.PixbufLoader.set_size in response to this signal.
signal@GdkPixbuf.PixbufLoader::area-prepared will be emitted as soon as the pixbuf of the desired has been allocated. You can obtain the
GdkPixbuf
instance by calling method@GdkPixbuf.PixbufLoader.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.signal@GdkPixbuf.PixbufLoader::area-updated will 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 signal@GdkPixbuf.PixbufLoader::area-prepared signal has been emitted, you can call method@GdkPixbuf.PixbufLoader.get_animation to get the class@GdkPixbuf.PixbufAnimation instance, and then call and method@GdkPixbuf.PixbufAnimation.get_iter to get a class@GdkPixbuf.PixbufAnimationIter to retrieve the pixbuf for the desired time stamp.
Skipped during bindings generation
parameter
buf
: Array parameter of type guint8 is not supported
Constructors
Creates a new pixbuf loader object.
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.
Functions
This signal is emitted when the pixbuf loader has allocated the pixbuf in the desired size.
This signal is emitted when a significant area of the image being loaded has been updated.
This signal is emitted when gdk_pixbuf_loader_close() is called.
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.
Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.
Obtains the available information about the format of the currently loading image file.
Parses the next contents of the given image buffer.