PixbufLoader

Object Hierarchy:

Description:

[ CCode ( type_id = "gdk_pixbuf_loader_get_type ()" ) ]
public class PixbufLoader : Object

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 [methodGdkPixbuf.PixbufLoader.write] to send the data to it. When done, [methodGdkPixbuf.PixbufLoader.close] should be called to end the stream and finalize everything.

The loader will emit three important signals throughout the process:

- [signalGdkPixbuf.PixbufLoadersize_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 [methodGdkPixbuf.PixbufLoader.set_size] in response to this signal. - [signalGdkPixbuf.PixbufLoaderarea_prepared] will be emitted as soon as the pixbuf of the desired has been allocated. You can obtain the `GdkPixbuf` instance by calling [methodGdkPixbuf.PixbufLoader.get_pixbuf]. If you want to use it, simply acquire a reference to it. You can also call `gdk_pixbuf_loader_get_pixbuf()` later to get the same pixbuf. - [signal GdkPixbuf.PixbufLoaderarea_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.

typeof (unichar2)typeof (unichar2) Loading an animation

Loading an animation is almost as easy as loading an image. Once the first [signalGdkPixbuf.PixbufLoader area_prepared] signal has been emitted, you can call [method GdkPixbuf.PixbufLoader.get_animation] to get the [classGdkPixbuf.PixbufAnimation] instance, and then call and [method GdkPixbuf.PixbufAnimation.get_iter] to get a [classGdkPixbuf.PixbufAnimationIter] to retrieve the pixbuf for the desired time stamp.

Namespace: Gdk

Package: gdk-pixbuf-2.0

Content:

Creation methods:

public PixbufLoader ()
Creates a new pixbuf loader object.
public PixbufLoader.with_mime_type (string mime_type) throws Error
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.
public PixbufLoader.with_type (string image_type) throws Error
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.

Methods:

public bool close () throws Error
Informs a pixbuf loader that no further writes with write will occur, so that it can free its internal loading structures.
public unowned PixbufAnimation? get_animation ()
Queries the PixbufAnimation that a pixbuf loader is currently creating.
public unowned PixbufFormat? get_format ()
Obtains the available information about the format of the currently loading image file.
public unowned Pixbuf? get_pixbuf ()
Queries the Pixbuf that a pixbuf loader is currently creating.
public void set_size (int width, int height)
Causes the image to be scaled while it is loaded.
public bool write (uint8[] buf) throws Error
Parses the next `count` bytes in the given image buffer.
public bool write_bytes (Bytes buffer) throws Error
Parses the next contents of the given image buffer.

Signals:

public virtual signal void area_prepared ()
This signal is emitted when the pixbuf loader has allocated the pixbuf in the desired size.
public virtual signal void area_updated (int x, int y, int width, int height)
This signal is emitted when a significant area of the image being loaded has been updated.
public virtual signal void closed ()
This signal is emitted when close is called.
public virtual signal void size_prepared (int width, int height)
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.

Inherited Members:

All known members inherited from class GLib.Object