1// Take a look at the license at the top of the repository in the LICENSE file.
2
3// rustdoc-stripper-ignore-next
4//! `IMPL` The `wrapper!` macro and miscellaneous wrapper traits.
5
6// rustdoc-stripper-ignore-next
7/// Defines a wrapper type and implements the appropriate traits.
8///
9/// The basic syntax is
10///
11/// ```ignore
12/// wrapper! {
13/// /// Your documentation goes here
14/// pub struct $name($kind<$foreign>);
15///
16/// match fn {
17/// $fn_name => /* a closure-like expression */,
18/// ...
19/// }
20/// }
21/// ```
22///
23/// This creates a wrapper named `$name` around the foreign type
24/// `$foreign` of `$kind` — one of [`Boxed`][#boxed],
25/// [`Shared`][#shared], or [`Object`][#object].
26///
27/// Inside the `match fn` block there are closure-like expressions to
28/// provide ways of copying/freeing, or referencing/unreferencing the
29/// value that you are wrapping. These expressions will be evaluated
30/// in an `unsafe` context, since they frequently invoke `extern`
31/// functions from an FFI crate.
32///
33/// What follows is a description of each of the possible `$kind`:
34/// [`Boxed`][#boxed], [`Shared`][#shared], and [`Object`][#object];
35/// note that each supports different sets of `$fn_name` inside the
36/// `match fn` block. Also, `Object` may require you to specify
37/// things like the class struct to wrap, plus any interfaces that the
38/// class implements.
39///
40/// ### Boxed (heap allocated)
41///
42/// Boxed records with single ownership allocated on the heap.
43///
44/// With no registered `glib_ffi::GType`:
45///
46/// ```ignore
47/// wrapper! {
48/// /// Text buffer iterator
49/// pub struct TextIter(Boxed<ffi::GtkTextIter>);
50///
51/// match fn {
52/// copy => |ptr| ffi::gtk_text_iter_copy(ptr),
53/// free => |ptr| ffi::gtk_text_iter_free(ptr),
54/// }
55/// }
56/// ```
57///
58/// `copy`: `|*const $foreign| -> *mut $foreign` creates a copy of the value.
59///
60/// `free`: `|*mut $foreign|` frees the value.
61///
62/// With a registered `glib_ffi::GType`:
63///
64/// ```ignore
65/// wrapper! {
66/// /// Text buffer iterator
67/// pub struct TextIter(Boxed<ffi::GtkTextIter>);
68///
69/// match fn {
70/// copy => |ptr| ffi::gtk_text_iter_copy(ptr),
71/// free => |ptr| ffi::gtk_text_iter_free(ptr),
72/// type_ => || ffi::gtk_text_iter_get_type(),
73/// }
74/// }
75/// ```
76///
77/// `type_`: `|| -> glib_ffi::GType` (optional) returns the
78/// `glib_ffi::GType` that corresponds to the foreign struct.
79///
80/// ### BoxedInline (inline, stack allocated)
81///
82/// Boxed records with single ownership allocated on the stack or otherwise inline.
83/// With no registered `glib_ffi::GType`:
84///
85/// ```ignore
86/// wrapper! {
87/// /// Text buffer iterator
88/// pub struct TextIter(BoxedInline<ffi::GtkTextIter>);
89///
90/// match fn {
91/// copy => |ptr| ffi::gtk_text_iter_copy(ptr),
92/// free => |ptr| ffi::gtk_text_iter_free(ptr),
93/// }
94/// }
95/// ```
96///
97/// `copy`: `|*const $foreign| -> *mut $foreign` (optional) creates a heap allocated copy of the value.
98///
99/// `free`: `|*mut $foreign|` (optional) frees the value.
100///
101/// With a registered `glib_ffi::GType`:
102///
103/// ```ignore
104/// wrapper! {
105/// /// Text buffer iterator
106/// pub struct TextIter(BoxedInline<ffi::GtkTextIter>);
107///
108/// match fn {
109/// copy => |ptr| ffi::gtk_text_iter_copy(ptr),
110/// free => |ptr| ffi::gtk_text_iter_free(ptr),
111/// type_ => || ffi::gtk_text_iter_get_type(),
112/// }
113/// }
114/// ```
115///
116/// `type_`: `|| -> glib_ffi::GType` (optional) returns the
117/// `glib_ffi::GType` that corresponds to the foreign struct.
118///
119/// ### Shared
120///
121/// Records with reference-counted, shared ownership.
122///
123/// With no registered `glib_ffi::GType`:
124///
125/// ```ignore
126/// wrapper! {
127/// /// Object holding timing information for a single frame.
128/// pub struct FrameTimings(Shared<ffi::GdkFrameTimings>);
129///
130/// match fn {
131/// ref => |ptr| ffi::gdk_frame_timings_ref(ptr),
132/// unref => |ptr| ffi::gdk_frame_timings_unref(ptr),
133/// }
134/// }
135/// ```
136///
137/// `ref`: `|*mut $foreign|` increases the refcount.
138///
139/// `unref`: `|*mut $foreign|` decreases the refcount.
140///
141/// With a registered `glib_ffi::GType`:
142///
143/// ```ignore
144/// wrapper! {
145/// /// Object holding timing information for a single frame.
146/// pub struct FrameTimings(Shared<ffi::GdkFrameTimings>);
147///
148/// match fn {
149/// ref => |ptr| ffi::gdk_frame_timings_ref(ptr),
150/// unref => |ptr| ffi::gdk_frame_timings_unref(ptr),
151/// type_ => || ffi::gdk_frame_timings_get_type(),
152/// }
153/// }
154/// ```
155///
156/// `type_`: `|| -> glib_ffi::GType` (optional) returns the
157/// `glib_ffi::GType` that corresponds to the foreign struct.
158///
159/// ### Object
160///
161/// Objects -- classes. Note that the class name, if available, must be specified after the
162/// $foreign type; see below for [non-derivable classes][#non-derivable-classes].
163///
164/// The basic syntax is this:
165///
166/// ```ignore
167/// wrapper! {
168/// /// Your documentation goes here
169/// pub struct InstanceName(Object<ffi::InstanceStruct, ffi::ClassStruct>)
170/// @extends ParentClass, GrandparentClass, ...,
171/// @implements Interface1, Interface2, ...;
172///
173/// match fn {
174/// type_ => || ffi::instance_get_type(),
175/// }
176/// }
177/// ```
178///
179/// `type_`: `|| -> glib_ffi::GType` returns the `glib_ffi::GType`
180/// that corresponds to the foreign class.
181///
182/// #### All parent classes must be specified
183///
184/// In the example above, "`@extends ParentClass, GrandparentClass, ...,`" is where you must
185/// specify all the parent classes of the one you are wrapping. The uppermost parent class,
186/// `glib::Object`, must not be specified.
187///
188/// For example, `ffi::GtkWindowGroup` derives directly from
189/// `GObject`, so it can be simply wrapped as follows:
190///
191/// ```ignore
192/// wrapper! {
193/// pub struct WindowGroup(Object<ffi::GtkWindowGroup, ffi::GtkWindowGroupClass>);
194///
195/// match fn {
196/// type_ => || ffi::gtk_window_group_get_type(),
197/// }
198/// }
199/// ```
200///
201/// In contrast, `ffi::GtkButton` has a parent, grandparent, etc. classes, which must be specified:
202///
203/// ```ignore
204/// wrapper! {
205/// pub struct Button(Object<ffi::GtkButton>) @extends Bin, Container, Widget;
206/// // see note on interfaces in the example below
207///
208/// match fn {
209/// type_ => || ffi::gtk_button_get_type(),
210/// }
211/// }
212/// ```
213///
214/// #### Objects which implement interfaces
215///
216/// The example above is incomplete, since `ffi::GtkButton` actually implements two interfaces,
217/// `Buildable` and `Actionable`. In this case, they must be specified after all the parent classes
218/// behind the `@implements` keyword:
219///
220/// ```ignore
221/// wrapper! {
222/// pub struct Button(Object<ffi::GtkButton>)
223/// @extends Bin, Container, Widget, // parent classes
224/// @implements Buildable, Actionable; // interfaces
225///
226/// match fn {
227/// type_ => || ffi::gtk_button_get_type(),
228/// }
229/// }
230/// ```
231///
232/// #### Non-derivable classes
233///
234/// By convention, GObject implements "final" classes, i.e. those who
235/// cannot be subclassed, by *not* exposing a public Class struct.
236/// This way it is not possible to override any methods, as there are
237/// no `klass.method_name` fields to overwrite. In this case, don't
238/// specify a FFI class name at all in the `Object<>` part:
239///
240/// ```ignore
241/// wrapper! {
242/// pub struct Clipboard(Object<ffi::GtkClipboard>);
243/// ...
244/// }
245/// ```
246///
247/// #### Interfaces
248///
249/// Interfaces are passed in the same way to the macro but instead of specifying
250/// `Object`, `Interface` has to be specified:
251///
252/// ```ignore
253/// wrapper! {
254/// pub struct TreeModel(Interface<ffi::GtkTreeModel, ffi::GtkTreeModelIface>);
255/// ...
256/// }
257/// ```
258///
259/// #### Interfaces with prerequisites
260///
261/// Interfaces can declare prerequisites, i.e. the classes from which types that implement the
262/// interface have to inherit or interfaces that have to be implemented:
263///
264/// ```ignore
265/// wrapper! {
266/// pub struct TreeSortable(Interface<ffi::GtkTreeSortable, ffi::GtkTreeSortable>) @requires TreeModel;
267/// ...
268/// }
269/// ```
270///
271/// [#boxed]: #boxed
272/// [#shared]: #shared
273/// [#object]: #object
274/// [#non-derivable-classes]: #non-derivable-classes
275#[macro_export]
276macro_rules! wrapper {
277 // Boxed
278 (
279 $(#[$attr:meta])*
280 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (Boxed<$ffi_name:ty>);
281
282 match fn {
283 copy => |$copy_arg:ident| $copy_expr:expr,
284 free => |$free_arg:ident| $free_expr:expr,
285 $(
286 type_ => || $get_type_expr:expr,
287 )?
288 }
289 ) => {
290 $crate::glib_boxed_wrapper!(
291 [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, $ffi_name,
292 @copy $copy_arg $copy_expr, @free $free_arg $free_expr
293 $(, @type_ $get_type_expr)?
294 );
295 };
296
297 // BoxedInline
298 (
299 $(#[$attr:meta])*
300 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (BoxedInline<$ffi_name:ty>);
301
302 match fn {
303 $(
304 copy => |$copy_arg:ident| $copy_expr:expr,
305 free => |$free_arg:ident| $free_expr:expr,
306 )?
307 $(
308 init => |$init_arg:ident| $init_expr:expr,
309 copy_into => |$copy_into_arg_dest:ident, $copy_into_arg_src:ident| $copy_into_expr:expr,
310 clear => |$clear_arg:ident| $clear_expr:expr,
311 )?
312 $(
313 type_ => || $get_type_expr:expr,
314 )?
315 }
316 ) => {
317 $crate::glib_boxed_inline_wrapper!(
318 [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, $ffi_name
319 $(, @copy $copy_arg $copy_expr, @free $free_arg $free_expr)?
320 $(, @init $init_arg $init_expr, @copy_into $copy_into_arg_dest $copy_into_arg_src $copy_into_expr, @clear $clear_arg $clear_expr)?
321 $(, @type_ $get_type_expr)?
322 );
323 };
324
325 // BoxedInline
326 (
327 $(#[$attr:meta])*
328 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (BoxedInline<$ffi_name:ty>);
329 ) => {
330 $crate::glib_boxed_inline_wrapper!(
331 [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, $ffi_name
332 );
333 };
334
335 // Shared
336 (
337 $(#[$attr:meta])*
338 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (Shared<$ffi_name:ty>);
339
340 match fn {
341 ref => |$ref_arg:ident| $ref_expr:expr,
342 unref => |$unref_arg:ident| $unref_expr:expr,
343 $(
344 type_ => || $get_type_expr:expr,
345 )?
346 }
347 ) => {
348 $crate::glib_shared_wrapper!(
349 [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, $ffi_name,
350 @ref $ref_arg $ref_expr, @unref $unref_arg $unref_expr
351 $(, @type_ $get_type_expr)?
352 );
353 };
354
355 // Object, no parents
356 (
357 $(#[$attr:meta])*
358 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (Object<$ffi_name:ty $(, $ffi_class_name:ty)?>) $(@implements $($implements:path),+)?;
359
360 match fn {
361 type_ => || $get_type_expr:expr,
362 }
363 ) => {
364 $crate::glib_object_wrapper!(
365 @object [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, *mut std::os::raw::c_void, (), $ffi_name,
366 $( @ffi_class $ffi_class_name ,)?
367 @type_ $get_type_expr,
368 @extends [],
369 @implements [$($($implements),+)?]
370 );
371 };
372
373 // Object, parents
374 (
375 $(#[$attr:meta])*
376 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (Object<$ffi_name:ty $(, $ffi_class_name:ty)?>) @extends $($extends:path),+ $(, @implements $($implements:path),+)?;
377
378 match fn {
379 type_ => || $get_type_expr:expr,
380 }
381 ) => {
382 $crate::glib_object_wrapper!(
383 @object [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, *mut std::os::raw::c_void, (), $ffi_name,
384 $( @ffi_class $ffi_class_name ,)?
385 @type_ $get_type_expr,
386 @extends [$($extends),+],
387 @implements [$($($implements),+)?]
388 );
389 };
390
391 // ObjectSubclass, no parents
392 (
393 $(#[$attr:meta])*
394 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (ObjectSubclass<$subclass:ty>) $(@implements $($implements:path),+)?;
395 ) => {
396 $crate::glib_object_wrapper!(
397 @object_subclass [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, $subclass,
398 @extends [],
399 @implements [$($($implements),+)?]
400 );
401 };
402
403 // ObjectSubclass, parents
404 (
405 $(#[$attr:meta])*
406 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (ObjectSubclass<$subclass:ty>) @extends $($extends:path),+ $(, @implements $($implements:path),+)?;
407 ) => {
408 $crate::glib_object_wrapper!(
409 @object_subclass [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, $subclass,
410 @extends [$($extends),+],
411 @implements [$($($implements),+)?]
412 );
413 };
414
415 // Interface
416 (
417 $(#[$attr:meta])*
418 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (Interface<$ffi_name:ty $(, $ffi_class_name:ty)?>) $(@requires $($requires:path),+)?;
419
420 match fn {
421 type_ => || $get_type_expr:expr,
422 }
423 ) => {
424 $crate::glib_object_wrapper!(
425 @interface [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, *mut std::os::raw::c_void, $ffi_name,
426 $( @ffi_class $ffi_class_name ,)?
427 @type_ $get_type_expr,
428 @requires [$( $($requires),+ )?]
429 );
430 };
431
432 // ObjectInterface
433 (
434 $(#[$attr:meta])*
435 $visibility:vis struct $name:ident $(<$($generic:ident $(: $bound:tt $(+ $bound2:tt)*)?),+>)? (ObjectInterface<$iface_name:ty>) $(@requires $($requires:path),+)?;
436 ) => {
437 $crate::glib_object_wrapper!(
438 @object_interface [$($attr)*] $visibility $name $(<$($generic $(: $bound $(+ $bound2)*)?),+>)?, $iface_name,
439 @type_ $crate::translate::IntoGlib::into_glib(<$iface_name as $crate::subclass::interface::ObjectInterfaceType>::type_()),
440 @requires [$( $($requires),+ )?]
441 );
442 };
443}
444