gdk-pixbuf-Module-Interface {RGtk2} | R Documentation |
Extending
gdkPixbufSetOption(object, key, value)
gdkPixbufGetFormats()
gdkPixbufFormatGetName(object)
gdkPixbufFormatGetDescription(object)
gdkPixbufFormatGetMimeTypes(object)
gdkPixbufFormatGetExtensions(object)
gdkPixbufFormatIsWritable(object)
gdkPixbufFormatIsScalable(object)
gdkPixbufFormatIsDisabled(object)
gdkPixbufFormatSetDisabled(object, disabled)
gdkPixbufFormatGetLicense(object)
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
GdkPixbufModuleFillInfoFuncfunction named
fillInfo
and
a GdkPixbufModuleFillVtableFuncfunction 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 GdkPixbufModulestructure. If a module supports incremental loading (i.e. provides
begin_load,
stop_loadand
load_increment), it doesn't have to implement
load, since
gdk-pixbuf
can
supply a generic loadimplementation wrapping the incremental loading. Installing a module is a two-step process:
copy the module file(s) to the loader directory (normally ‘libdir’, unless overridden by the environment variable GDK_PIXBUF_MODULEDIR)
call gdk-pixbuf-query-loaders
to update the
module file (normally
‘sysconfdir’,
unless overridden by the environment variable
GDK_PIXBUF_MODULE_FILE)
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
.
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.
Derived by RGtkGen from GTK+ documentation
http://library.gnome.org/devel//gdk-pixbuf/gdk-pixbuf-Module-Interface.html