GdkPixbufLoader: GdkPixbufLoader
Description
Application-driven progressive image loading.Hierarchy
\link{GObject}
+----GdkPixbufLoaderDetailed Description
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
gdkPixbufNewFromFile or gdkPixbufAnimationNewFromFile
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, just create a new one,
and call gdkPixbufLoaderWrite to send the data to it. When
done, gdkPixbufLoaderClose should be called to end the stream
and finalize everything. The loader will emit three important
signals throughout the process. The first, "size_prepared",
will be called 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 gdkPixbufLoaderSetSize
in response to this signal.
The second signal, "area_prepared",
will be called as soon as the pixbuf of the desired has been
allocated. You can obtain it by calling gdkPixbufLoaderGetPixbuf.
If you want to use it, simply ref it.
In addition, no actual information will be passed in yet, so the
pixbuf can be safely filled with any temporary graphics (or an
initial color) as needed. You can also call
gdkPixbufLoaderGetPixbuf later and get the same pixbuf.
The last signal, "area_updated" gets
called 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 area updated. For
example, in an interlaced image, you need to make several passes
before the image is done loading.References
http://developer.gnome.org/doc/API/2.0/gdk-pixbuf/GdkPixbufLoader.html