glib/subclass/mod.rs
1// Take a look at the license at the top of the repository in the LICENSE file.
2
3#![allow(clippy::needless_doctest_main)]
4// rustdoc-stripper-ignore-next
5//! Module containing infrastructure for subclassing `GObject`s and registering boxed types.
6//!
7//! # Example for registering a `glib::Object` subclass
8//!
9//! The following code implements a subclass of `glib::Object` with a
10//! string-typed "name" property.
11//!
12//! ```rust
13//! use glib::prelude::*;
14//! use glib::subclass;
15//! use glib::subclass::prelude::*;
16//! use glib::{Variant, VariantType};
17//!
18//! use std::cell::{Cell, RefCell};
19//!
20//! #[derive(Debug, Eq, PartialEq, Clone, Copy, glib::Enum)]
21//! #[repr(u32)]
22//! // type_name: GType name of the enum (mandatory)
23//! #[enum_type(name = "SimpleObjectAnimal")]
24//! enum Animal {
25//! Goat = 0,
26//! #[enum_value(name = "The Dog")]
27//! Dog = 1,
28//! // name: the name of the GEnumValue (optional), default to the enum name in CamelCase
29//! // nick: the nick of the GEnumValue (optional), default to the enum name in kebab-case
30//! #[enum_value(name = "The Cat", nick = "chat")]
31//! Cat = 2,
32//! }
33//!
34//! impl Default for Animal {
35//! fn default() -> Self {
36//! Animal::Goat
37//! }
38//! }
39//!
40//! #[glib::flags(name = "MyFlags")]
41//! enum MyFlags {
42//! #[flags_value(name = "Flag A", nick = "nick-a")]
43//! A = 0b00000001,
44//! #[flags_value(name = "Flag B")]
45//! B = 0b00000010,
46//! #[flags_value(skip)]
47//! AB = Self::A.bits() | Self::B.bits(),
48//! C = 0b00000100,
49//! }
50//!
51//! impl Default for MyFlags {
52//! fn default() -> Self {
53//! MyFlags::A
54//! }
55//! }
56//!
57//! mod imp {
58//! use super::*;
59//!
60//! // This is the struct containing all state carried with
61//! // the new type. Generally this has to make use of
62//! // interior mutability.
63//! // If it implements the `Default` trait, then `Self::default()`
64//! // will be called every time a new instance is created.
65//! #[derive(Default)]
66//! pub struct SimpleObject {
67//! name: RefCell<Option<String>>,
68//! animal: Cell<Animal>,
69//! flags: Cell<MyFlags>,
70//! variant: RefCell<Option<Variant>>,
71//! }
72//!
73//! // ObjectSubclass is the trait that defines the new type and
74//! // contains all information needed by the GObject type system,
75//! // including the new type's name, parent type, etc.
76//! // If you do not want to implement `Default`, you can provide
77//! // a `new()` method.
78//! #[glib::object_subclass]
79//! impl ObjectSubclass for SimpleObject {
80//! // This type name must be unique per process.
81//! const NAME: &'static str = "SimpleObject";
82//!
83//! type Type = super::SimpleObject;
84//!
85//! // The parent type this one is inheriting from.
86//! // Optional, if not specified it defaults to `glib::Object`
87//! type ParentType = glib::Object;
88//!
89//! // Interfaces this type implements.
90//! // Optional, if not specified it defaults to `()`
91//! type Interfaces = ();
92//! }
93//!
94//! // Trait that is used to override virtual methods of glib::Object.
95//! impl ObjectImpl for SimpleObject {
96//! // Called once in the very beginning to list all properties of this class.
97//! fn properties() -> &'static [glib::ParamSpec] {
98//! use std::sync::OnceLock;
99//! static PROPERTIES: OnceLock<Vec<glib::ParamSpec>> = OnceLock::new();
100//! PROPERTIES.get_or_init(|| {
101//! vec![
102//! glib::ParamSpecString::builder("name")
103//! .build(),
104//! glib::ParamSpecEnum::builder::<Animal>("animal")
105//! .build(),
106//! glib::ParamSpecFlags::builder::<MyFlags>("flags")
107//! .build(),
108//! glib::ParamSpecVariant::builder("variant", glib::VariantTy::ANY)
109//! .build(),
110//! ]
111//! })
112//! }
113//!
114//! // Called whenever a property is set on this instance. The id
115//! // is the same as the index of the property in the PROPERTIES array.
116//! fn set_property(&self, _id: usize, value: &glib::Value, pspec: &glib::ParamSpec) {
117//! match pspec.name() {
118//! "name" => {
119//! let name = value
120//! .get()
121//! .expect("type conformity checked by `Object::set_property`");
122//! self.name.replace(name);
123//! },
124//! "animal" => {
125//! let animal = value
126//! .get()
127//! .expect("type conformity checked by `Object::set_property`");
128//! self.animal.replace(animal);
129//! },
130//! "flags" => {
131//! let flags = value
132//! .get()
133//! .expect("type conformity checked by `Object::set_property`");
134//! self.flags.replace(flags);
135//! },
136//! "variant" => {
137//! let variant = value
138//! .get()
139//! .expect("type conformity checked by `Object::set_property`");
140//! self.variant.replace(variant);
141//! },
142//! _ => unimplemented!(),
143//! }
144//! }
145//!
146//! // Called whenever a property is retrieved from this instance. The id
147//! // is the same as the index of the property in the PROPERTIES array.
148//! fn property(&self, _id: usize, pspec: &glib::ParamSpec) -> glib::Value {
149//! match pspec.name() {
150//! "name" => self.name.borrow().to_value(),
151//! "animal" => self.animal.get().to_value(),
152//! "flags" => self.flags.get().to_value(),
153//! "variant" => self.variant.borrow().to_value(),
154//! _ => unimplemented!(),
155//! }
156//! }
157//!
158//! // Called right after construction of the instance.
159//! fn constructed(&self) {
160//! // Chain up to the parent type's implementation of this virtual
161//! // method.
162//! self.parent_constructed();
163//!
164//! // And here we could do our own initialization.
165//! }
166//! }
167//! }
168//!
169//! // Optionally, define a wrapper type to make it more ergonomic to use from Rust
170//! glib::wrapper! {
171//! pub struct SimpleObject(ObjectSubclass<imp::SimpleObject>);
172//! }
173//!
174//! impl SimpleObject {
175//! // Create an object instance of the new type.
176//! pub fn new() -> Self {
177//! glib::Object::new()
178//! }
179//! }
180//!
181//! pub fn main() {
182//! let obj = SimpleObject::new();
183//!
184//! // Get the name property and change its value.
185//! assert_eq!(obj.property::<Option<String>>("name"), None);
186//! obj.set_property("name", "test");
187//! assert_eq!(&obj.property::<String>("name"), "test");
188//!
189//! assert_eq!(obj.property::<Animal>("animal"), Animal::Goat);
190//! obj.set_property("animal", Animal::Cat);
191//! assert_eq!(obj.property::<Animal>("animal"), Animal::Cat);
192//!
193//! assert_eq!(obj.property::<MyFlags>("flags"), MyFlags::A);
194//! obj.set_property("flags", MyFlags::B);
195//! assert_eq!(obj.property::<MyFlags>("flags"), MyFlags::B);
196//! }
197//! ```
198//!
199//! # Example for registering a `glib::Object` subclass within a module
200//!
201//! The following code implements a subclass of `glib::Object` and registers it as
202//! a dynamic type.
203//!
204//! ```rust
205//! use glib::prelude::*;
206//! use glib::subclass::prelude::*;
207//!
208//! pub mod imp {
209//! use super::*;
210//!
211//! // SimpleModuleObject is a dynamic type.
212//! #[derive(Default)]
213//! pub struct SimpleModuleObject;
214//!
215//! #[glib::object_subclass]
216//! #[object_subclass_dynamic]
217//! impl ObjectSubclass for SimpleModuleObject {
218//! const NAME: &'static str = "SimpleModuleObject";
219//! type Type = super::SimpleModuleObject;
220//! }
221//!
222//! impl ObjectImpl for SimpleModuleObject {}
223//!
224//! // SimpleTypeModule is the type module within the object subclass is registered as a dynamic type.
225//! #[derive(Default)]
226//! pub struct SimpleTypeModule;
227//!
228//! #[glib::object_subclass]
229//! impl ObjectSubclass for SimpleTypeModule {
230//! const NAME: &'static str = "SimpleTypeModule";
231//! type Type = super::SimpleTypeModule;
232//! type ParentType = glib::TypeModule;
233//! type Interfaces = (glib::TypePlugin,);
234//! }
235//!
236//! impl ObjectImpl for SimpleTypeModule {}
237//!
238//! impl TypeModuleImpl for SimpleTypeModule {
239//! /// Loads the module and registers the object subclass as a dynamic type.
240//! fn load(&self) -> bool {
241//! SimpleModuleObject::on_implementation_load(self.obj().upcast_ref::<glib::TypeModule>())
242//! }
243//!
244//! /// Unloads the module.
245//! fn unload(&self) {
246//! SimpleModuleObject::on_implementation_unload(self.obj().upcast_ref::<glib::TypeModule>());
247//! }
248//! }
249//!
250//! impl TypePluginImpl for SimpleTypeModule {}
251//! }
252//!
253//! // Optionally, defines a wrapper type to make SimpleModuleObject more ergonomic to use from Rust.
254//! glib::wrapper! {
255//! pub struct SimpleModuleObject(ObjectSubclass<imp::SimpleModuleObject>);
256//! }
257//!
258//! // Optionally, defines a wrapper type to make SimpleTypeModule more ergonomic to use from Rust.
259//! glib::wrapper! {
260//! pub struct SimpleTypeModule(ObjectSubclass<imp::SimpleTypeModule>)
261//! @extends glib::TypeModule, @implements glib::TypePlugin;
262//! }
263//!
264//! impl SimpleTypeModule {
265//! // Creates an object instance of the new type.
266//! pub fn new() -> Self {
267//! glib::Object::new()
268//! }
269//! }
270//!
271//! pub fn main() {
272//! let simple_type_module = SimpleTypeModule::new();
273//! // at this step, SimpleTypeModule has not been loaded therefore
274//! // SimpleModuleObject must not be registered yet.
275//! let simple_module_object_type = imp::SimpleModuleObject::type_();
276//! assert!(!simple_module_object_type.is_valid());
277//!
278//! // simulates the GLib type system to load the module.
279//! TypeModuleExt::use_(&simple_type_module);
280//!
281//! // at this step, SimpleModuleObject must have been registered.
282//! let simple_module_object_type = imp::SimpleModuleObject::type_();
283//! assert!(simple_module_object_type.is_valid());
284//! }
285//! ```
286//!
287//! # Example for registering a `glib::Object` subclass within a plugin
288//!
289//! The following code implements a subclass of `glib::Object` and registers it as
290//! a dynamic type.
291//!
292//! ```rust
293//! use glib::prelude::*;
294//! use glib::subclass::prelude::*;
295//!
296//! pub mod imp {
297//! use super::*;
298//!
299//! // SimplePluginObject is a dynamic type.
300//! #[derive(Default)]
301//! pub struct SimplePluginObject;
302//!
303//! #[glib::object_subclass]
304//! #[object_subclass_dynamic(plugin_type = super::SimpleTypePlugin)]
305//! impl ObjectSubclass for SimplePluginObject {
306//! const NAME: &'static str = "SimplePluginObject";
307//! type Type = super::SimplePluginObject;
308//! }
309//!
310//! impl ObjectImpl for SimplePluginObject {}
311//!
312//! // SimpleTypePlugin is the type plugin within the object subclass is registered as a dynamic type.
313//! #[derive(Default)]
314//! pub struct SimpleTypePlugin {
315//! type_info: std::cell::Cell<Option<glib::TypeInfo>>
316//! }
317//!
318//! #[glib::object_subclass]
319//! impl ObjectSubclass for SimpleTypePlugin {
320//! const NAME: &'static str = "SimpleTypePlugin";
321//! type Type = super::SimpleTypePlugin;
322//! type Interfaces = (glib::TypePlugin,);
323//! }
324//!
325//! impl ObjectImpl for SimpleTypePlugin {}
326//!
327//! impl TypePluginImpl for SimpleTypePlugin {
328//! /// Uses the plugin and registers the object subclass as a dynamic type.
329//! fn use_plugin(&self) {
330//! SimplePluginObject::on_implementation_load(self.obj().as_ref());
331//! }
332//!
333//! /// Unuses the plugin.
334//! fn unuse_plugin(&self) {
335//! SimplePluginObject::on_implementation_unload(self.obj().as_ref());
336//! }
337//!
338//! /// Returns type information about the object subclass registered as a dynamic type.
339//! fn complete_type_info(&self, _type_: glib::Type) -> (glib::TypeInfo, glib::TypeValueTable) {
340//! assert!(self.type_info.get().is_some());
341//! // returns type info.
342//! (self.type_info.get().unwrap(), glib::TypeValueTable::default())
343//! }
344//! }
345//!
346//! impl TypePluginRegisterImpl for SimpleTypePlugin {
347//! fn register_dynamic_type(&self, parent_type: glib::Type, type_name: &str, type_info: &glib::TypeInfo, flags: glib::TypeFlags) -> glib::Type {
348//! let type_ = glib::Type::from_name(type_name).unwrap_or_else(|| {
349//! glib::Type::register_dynamic(parent_type, type_name, self.obj().upcast_ref::<glib::TypePlugin>(), flags)
350//! });
351//! if type_.is_valid() {
352//! // saves type info.
353//! self.type_info.set(Some(*type_info));
354//! }
355//! type_
356//! }
357//! }
358//! }
359//!
360//! // Optionally, defines a wrapper type to make SimplePluginObject more ergonomic to use from Rust.
361//! glib::wrapper! {
362//! pub struct SimplePluginObject(ObjectSubclass<imp::SimplePluginObject>);
363//! }
364//!
365//! // Optionally, defines a wrapper type to make SimpleTypePlugin more ergonomic to use from Rust.
366//! glib::wrapper! {
367//! pub struct SimpleTypePlugin(ObjectSubclass<imp::SimpleTypePlugin>)
368//! @implements glib::TypePlugin;
369//! }
370//!
371//! impl SimpleTypePlugin {
372//! // Creates an object instance of the new type.
373//! pub fn new() -> Self {
374//! glib::Object::new()
375//! }
376//! }
377//!
378//! pub fn main() {
379//! let simple_type_plugin = SimpleTypePlugin::new();
380//! // at this step, SimpleTypePlugin has not been used therefore
381//! // SimplePluginObject must not be registered yet.
382//! let simple_plugin_object_type = imp::SimplePluginObject::type_();
383//! assert!(!simple_plugin_object_type.is_valid());
384//!
385//! // simulates the GLib type system to use the plugin.
386//! TypePluginExt::use_(&simple_type_plugin);
387//!
388//! // at this step, SimplePluginObject must have been registered.
389//! let simple_plugin_object_type = imp::SimplePluginObject::type_();
390//! assert!(simple_plugin_object_type.is_valid());
391//! }
392//! ```
393//!
394//!//! # Example for registering a boxed type for a Rust struct
395//!
396//! The following code boxed type for a tuple struct around `String` and uses it in combination
397//! with `glib::Value`.
398//!
399//! ```rust
400//! use glib::prelude::*;
401//! use glib::subclass;
402//! use glib::subclass::prelude::*;
403//!
404//! #[derive(Clone, Debug, PartialEq, Eq, glib::Boxed)]
405//! #[boxed_type(name = "MyBoxed")]
406//! struct MyBoxed(String);
407//!
408//! pub fn main() {
409//! assert!(MyBoxed::static_type().is_valid());
410//!
411//! let b = MyBoxed(String::from("abc"));
412//! let v = b.to_value();
413//! let b2 = v.get::<&MyBoxed>().unwrap();
414//! assert_eq!(&b, b2);
415//! }
416//! ```
417
418pub mod basic;
419#[macro_use]
420pub mod types;
421
422#[macro_use]
423pub mod interface;
424
425#[macro_use]
426pub mod object;
427
428#[macro_use]
429pub mod boxed;
430
431pub mod shared;
432
433pub mod signal;
434
435mod object_impl_ref;
436pub use object_impl_ref::{ObjectImplRef, ObjectImplWeakRef};
437
438pub mod type_module;
439
440pub mod type_plugin;
441
442pub mod prelude {
443 // rustdoc-stripper-ignore-next
444 //! Prelude that re-exports all important traits from this crate.
445 pub use super::{
446 boxed::BoxedType,
447 interface::{ObjectInterface, ObjectInterfaceExt, ObjectInterfaceType},
448 object::{DerivedObjectProperties, ObjectClassSubclassExt, ObjectImpl, ObjectImplExt},
449 shared::{RefCounted, SharedType},
450 type_module::{TypeModuleImpl, TypeModuleImplExt},
451 type_plugin::{TypePluginImpl, TypePluginImplExt, TypePluginRegisterImpl},
452 types::{
453 ClassStruct, InstanceStruct, InstanceStructExt, InterfaceStruct, IsImplementable,
454 IsSubclassable, IsSubclassableExt, ObjectSubclass, ObjectSubclassExt,
455 ObjectSubclassIsExt, ObjectSubclassType,
456 },
457 };
458}
459
460pub use self::{
461 boxed::register_boxed_type,
462 interface::{register_dynamic_interface, register_interface},
463 signal::{
464 Signal, SignalClassHandlerToken, SignalId, SignalInvocationHint, SignalQuery, SignalType,
465 },
466 types::{register_dynamic_type, register_type, InitializingObject, InitializingType, TypeData},
467};