Struct IOExtensionPoint

pub struct IOExtensionPoint(/* private fields */);

An extension point provides a mechanism to extend the functionality of a library or application. Each extension point is identified by a name, and it may optionally require that any implementation must be of a certain type. 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()][Self::register()] to register an extension point, and [set_required_type()][Self::set_required_type()] to set a required type.

A module can implement an extension point by specifying the [type@GObject.Type] that implements the functionality. Additionally, each implementation of an extension point has a name, and a priority. Use implement() to implement an extension point.

⚠️ The following code is in c ⚠️

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);

⚠️ The following code is in c ⚠️

// 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.

Implementations

impl IOExtensionPoint

pub fn builder(name: impl Into<GString>) -> IOExtensionPointBuilder

Create a new builder for an extension point.

pub fn lookup(name: impl IntoGStr) -> Option<Self>

Looks up an existing extension point.

name

the name of the extension point

Returns

the #GIOExtensionPoint, or None if there is no registered extension point with the given name.

pub fn extensions(&self) -> Vec<IOExtension>

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.

pub fn extension_by_name(&self, name: impl IntoGStr) -> Option<IOExtension>

Finds a #GIOExtension for an extension point by name.

name

the name of the extension to get

Returns

the #GIOExtension for @self that has the given name, or None if there is no extension with that name

pub fn required_type(&self) -> Type

Gets the required type for @self.

Returns

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

pub fn implement( extension_point_name: impl IntoGStr, type_: Type, extension_name: impl IntoGStr, priority: i32, ) -> Option<IOExtension>

Registers @type_ as extension for the extension point with name @extension_point_name.

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

extension_point_name

the name of the extension point

type_

the #GType to register as extension

extension_name

the name for the extension

priority

the priority for the extension

Returns

a #GIOExtension object for #GType

Trait Implementations

impl Clone for IOExtensionPoint

fn clone(&self) -> IOExtensionPoint

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for IOExtensionPoint

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl FromGlibPtrNone<*mut _GIOExtensionPoint> for IOExtensionPoint

unsafe fn from_glib_none(ptr: *mut GIOExtensionPoint) -> Self

Safety

impl PartialEq for IOExtensionPoint

fn eq(&self, other: &IOExtensionPoint) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> ToGlibPtr<'a, *mut _GIOExtensionPoint> for &'a IOExtensionPoint

type Storage = PhantomData<&'a IOExtensionPoint>

fn to_glib_none( &self, ) -> Stash<'a, *mut GIOExtensionPoint, &'a IOExtensionPoint>

Transfer: none.

fn to_glib_container(&'a self) -> Stash<'a, P, Self>

Transfer: container.

fn to_glib_full(&self) -> P

Transfer: full.

impl Copy for IOExtensionPoint

impl Eq for IOExtensionPoint

impl StructuralPartialEq for IOExtensionPoint