gdk-pixbuf-Module-Interface {RGtk2}R Documentation

Module Interface

Description

Extending

Methods and Functions

gdkPixbufSetOption(object, key, value)
gdkPixbufGetFormats()
gdkPixbufFormatGetName(object)
gdkPixbufFormatGetDescription(object)
gdkPixbufFormatGetMimeTypes(object)
gdkPixbufFormatGetExtensions(object)
gdkPixbufFormatIsWritable(object)
gdkPixbufFormatIsScalable(object)
gdkPixbufFormatIsDisabled(object)
gdkPixbufFormatSetDisabled(object, disabled)
gdkPixbufFormatGetLicense(object)

Detailed Description

If gdk-pixbuf has been compiled with GModule support, it can be extended by modules which can load (and perhaps also save) new image and animation formats. Each loadable module must export a

GdkPixbufModuleFillInfoFunc
function named fillInfo and a
GdkPixbufModuleFillVtableFunc
function named fillVtable. In order to make format-checking work before actually loading the modules (which may require dlopening image libraries), modules export their signatures (and other information) via the fillInfo function. An external utility, gdk-pixbuf-query-loaders, uses this to create a text file containing a list of all available loaders and their signatures. This file is then read at runtime by gdk-pixbuf to obtain the list of available loaders and their signatures. Modules may only implement a subset of the functionality available via
GdkPixbufModule
. If a particular functionality is not implemented, the fillVtable function will simply not set the corresponding function pointers of the
GdkPixbufModule
structure. If a module supports incremental loading (i.e. provides
begin_load
,
stop_load
and
load_increment
), it doesn't have to implement
load
, since gdk-pixbuf can supply a generic
load
implementation wrapping the incremental loading. Installing a module is a two-step process:

The gdk-pixbuf interfaces needed for implementing modules are contained in ‘gdk-pixbuf-io.h’ (and ‘gdk-pixbuf-animation.h’ if the module supports animations). They are not covered by the same stability guarantees as the regular gdk-pixbuf API. To underline this fact, they are protected by #ifdef GDK_PIXBUF_ENABLE_BACKEND.

Structures

GdkPixbufFormat

A GdkPixbufFormat contains information about the image format accepted by a module. Only modules should access the fields directly, applications should use the gdkPixbufFormat* functions. Since 2.2

name

the name of the image format.

signature

the signature of the module.

domain

the message domain for the description.

description

a description of the image format.

mime_types

a list of MIME types for the image format.

extensions

a list of typical filename extensions for the image format.

flags

a combination of

GdkPixbufFormatFlags
.
disabled

a boolean determining whether the loader is disabled.

license

a string containing license information, typically set to shorthands like "GPL", "LGPL", etc.

User Functions

Author(s)

Derived by RGtkGen from GTK+ documentation

References

http://library.gnome.org/devel//gdk-pixbuf/gdk-pixbuf-Module-Interface.html


[Package RGtk2 version 2.20.21 Index]