Package ch.bailu.gtk.gdkpixbuf

Class PixbufModule

java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.type.Record
ch.bailu.gtk.gdkpixbuf.PixbufModule
All Implemented Interfaces:
PointerInterface
public class PixbufModule extends Record
A `GdkPixbufModule` contains the necessary functions to load and save
images in a certain file format.

If `GdkPixbuf` has been compiled with `GModule` support, it can be extended
by modules which can load (and perhaps also save) new image and animation
formats.

## Implementing modules

The `GdkPixbuf` 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 GdkPixbuf API. To underline this fact, they are protected by the
`GDK_PIXBUF_ENABLE_BACKEND` pre-processor symbol.

Each loadable module must contain a `GdkPixbufModuleFillVtableFunc` function
named `fill_vtable`, which will get called when the module
is loaded and must set the function pointers of the `GdkPixbufModule`.

In order to make format-checking work before actually loading the modules
(which may require calling `dlopen` to load image libraries), modules export
their signatures (and other information) via the `fill_info` 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 `GdkPixbuf` 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
`fill_vtable` 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 `GdkPixbuf`
can supply a generic `load` implementation wrapping the incremental loading.

## Installing modules

Installing a module is a two-step process:

- copy the module file(s) to the loader directory (normally
`$libdir/gdk-pixbuf-2.0/$version/loaders`, unless overridden by the
environment variable `GDK_PIXBUF_MODULEDIR`)
- call `gdk-pixbuf-query-loaders` to update the module file (normally
`$libdir/gdk-pixbuf-2.0/$version/loaders.cache`, unless overridden
by the environment variable `GDK_PIXBUF_MODULE_FILE`)

https://docs.gtk.org/gdk-pixbuf/struct.PixbufModule.html

  • Field Details

    • MODULE_NAME

      public static final String MODULE_NAME
      the name of the module, usually the same as the
      usual file extension for images of this type, eg. "xpm", "jpeg" or "png".
      See Also:

    • MODULE_PATH

      public static final String MODULE_PATH
      the path from which the module is loaded.
      See Also:

  • Constructor Details

  • Method Details

    • getClassHandler

      public static ClassHandler getClassHandler()

    • setFieldModuleName

      public void setFieldModuleName(Str module_name)
      the name of the module, usually the same as the
      usual file extension for images of this type, eg. "xpm", "jpeg" or "png".

    • getFieldModuleName

      public Str getFieldModuleName()
      the name of the module, usually the same as the
      usual file extension for images of this type, eg. "xpm", "jpeg" or "png".

    • setFieldModulePath

      public void setFieldModulePath(Str module_path)
      the path from which the module is loaded.

    • getFieldModulePath

      public Str getFieldModulePath()
      the path from which the module is loaded.