Package org.gnome.gio

Class IOExtensionPoint

java.lang.Object

org.javagi.base.ProxyInstance

org.gnome.gio.IOExtensionPoint

All Implemented Interfaces:

Proxy

@Generated("io.github.jwharm.JavaGI")
public class IOExtensionPoint
extends ProxyInstance

GIOExtensionPoint provides a mechanism for modules to extend the functionality of the library or application that loaded it in an organized fashion.

An extension point is identified by a name, and it may optionally require that any implementation must be of a certain type (or derived thereof). Use register(java.lang.String) to register an extension point, and setRequiredType(org.gnome.glib.Type) to set a required type.

A module can implement an extension point by specifying the GObject.Type that implements the functionality. Additionally, each implementation of an extension point has a name, and a priority. Use implement(java.lang.String, org.gnome.glib.Type, java.lang.String, int) to implement an extension point.

GIOExtensionPoint *ep;

 // Register an extension point
 ep = g_io_extension_point_register ("my-extension-point");
 g_io_extension_point_set_required_type (ep, MY_TYPE_EXAMPLE);
 

// Implement an extension point
 G_DEFINE_TYPE (MyExampleImpl, my_example_impl, MY_TYPE_EXAMPLE)
 g_io_extension_point_implement ("my-extension-point",
                                 my_example_impl_get_type (),
                                 "my-example",
                                 10);
 

It is up to the code that registered the extension point how it uses the implementations that have been associated with it. Depending on the use case, it may use all implementations, or only the one with the highest priority, or pick a specific one by name.

To avoid opening all modules just to find out what extension points they implement, GIO makes use of a caching mechanism, see gio-querymodules. You are expected to run this command after installing a GIO module.

The GIO_EXTRA_MODULES environment variable can be used to specify additional directories to automatically load modules from. This environment variable has the same syntax as the PATH. If two modules have the same base name in different directories, then the latter one will be ignored. If additional directories are specified GIO will load modules from the built-in directory last.

Constructor Summary

Constructors

Constructor	Description
IOExtensionPoint(MemorySegment address)	Create a IOExtensionPoint proxy instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
IOExtension	getExtensionByName(String name)	Finds a GIOExtension for an extension point by name.
List<IOExtension>	getExtensions()	Gets a list of all extensions that implement this extension point.
Type	getRequiredType()	Gets the required type for extensionPoint.
static IOExtension	implement(String extensionPointName, Type type, String extensionName, int priority)	Registers type as extension for the extension point with name extensionPointName.
static IOExtensionPoint	lookup(String name)	Looks up an existing extension point.
static IOExtensionPoint	register(String name)	Registers an extension point.
void	setRequiredType(Type type)	Sets the required type for this IOExtensionPoint to type. All implementations must henceforth have this type.

Methods inherited from class org.javagi.base.ProxyInstance

equals, handle, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

IOExtensionPoint

public IOExtensionPoint(MemorySegment address)

Create a IOExtensionPoint proxy instance for the provided memory address.

Parameters:

address - the memory address of the native object

Method Details

implement

public static IOExtension implement(String extensionPointName,
 Type type,
 String extensionName,
 int priority)

Registers type as extension for the extension point with name extensionPointName.

If type has already been registered as an extension for this extension point, the existing GIOExtension object is returned.

Parameters:

extensionPointName - the name of the extension point

type - the GType to register as extension

extensionName - the name for the extension

priority - the priority for the extension

Returns:

a GIOExtension object for GType

lookup

public static IOExtensionPoint lookup(String name)

Looks up an existing extension point.

Parameters:

name - the name of the extension point

Returns:

the GIOExtensionPoint, or null if there is no registered extension point with the given name.

register

public static IOExtensionPoint register(String name)

Registers an extension point.

Parameters:

name - The name of the extension point

Returns:

the new GIOExtensionPoint. This object is owned by GIO and should not be freed.

getExtensionByName

public IOExtension getExtensionByName(String name)

Finds a GIOExtension for an extension point by name.

Parameters:

name - the name of the extension to get

Returns:

the GIOExtension for this IOExtensionPoint that has the given name, or null if there is no extension with that name

getExtensions

public List<IOExtension> getExtensions()

Gets a list of all extensions that implement this extension point. The list is sorted by priority, beginning with the highest priority.

Returns:

a GList of GIOExtensions. The list is owned by GIO and should not be modified.

getRequiredType

public Type getRequiredType()

Gets the required type for extensionPoint.

Returns:

the GType that all implementations must have, or G_TYPE_INVALID if the extension point has no required type

setRequiredType

public void setRequiredType(Type type)

Sets the required type for this IOExtensionPoint to type. All implementations must henceforth have this type.

Parameters:

type - the GType to require