1// Take a look at the license at the top of the repository in the LICENSE file.
2
3// rustdoc-stripper-ignore-next
4//! Module for registering boxed types for Rust types.
5
6use crate::{ffi, gobject_ffi, prelude::*, translate::*};
7
8// rustdoc-stripper-ignore-next
9/// Trait for defining boxed types.
10///
11/// Links together the type name with the type itself.
12///
13/// See [`register_boxed_type`] for registering an implementation of this trait
14/// with the type system.
15///
16/// [`register_boxed_type`]: fn.register_boxed_type.html
17pub trait BoxedType: StaticType + Clone + Sized + 'static {
18 // rustdoc-stripper-ignore-next
19 /// Boxed type name.
20 ///
21 /// This must be unique in the whole process.
22 const NAME: &'static str;
23
24 // rustdoc-stripper-ignore-next
25 /// Allow name conflicts for this boxed type.
26 ///
27 /// By default, trying to register a type with a name that was registered before will panic. If
28 /// this is set to `true` then a new name will be selected by appending a counter.
29 ///
30 /// This is useful for defining new types in Rust library crates that might be linked multiple
31 /// times in the same process.
32 ///
33 /// A consequence of setting this to `true` is that it's not guaranteed that
34 /// `glib::Type::from_name(Self::NAME).unwrap() == Self::static_type()`.
35 ///
36 /// Optional.
37 const ALLOW_NAME_CONFLICT: bool = false;
38}
39
40// rustdoc-stripper-ignore-next
41/// Register a boxed `glib::Type` ID for `T`.
42///
43/// This must be called only once and will panic on a second call.
44///
45/// See [`Boxed!`] for defining a function that ensures that
46/// this is only called once and returns the type id.
47///
48/// [`Boxed!`]: ../../derive.Boxed.html
49pub fn register_boxed_type<T: BoxedType>() -> crate::Type {
50 unsafe extern "C" fn boxed_copy<T: BoxedType>(v: ffi::gpointer) -> ffi::gpointer {
51 let v = &*(v as *mut T);
52 let copy = Box::new(v.clone());
53
54 Box::into_raw(copy) as ffi::gpointer
55 }
56 unsafe extern "C" fn boxed_free<T: BoxedType>(v: ffi::gpointer) {
57 let v = v as *mut T;
58 let _ = Box::from_raw(v);
59 }
60 unsafe {
61 use std::ffi::CString;
62
63 let type_name = if T::ALLOW_NAME_CONFLICT {
64 let mut i = 0;
65 loop {
66 let type_name = CString::new(if i == 0 {
67 T::NAME.to_string()
68 } else {
69 format!("{}-{}", T::NAME, i)
70 })
71 .unwrap();
72 if gobject_ffi::g_type_from_name(type_name.as_ptr()) == gobject_ffi::G_TYPE_INVALID
73 {
74 break type_name;
75 }
76 i += 1;
77 }
78 } else {
79 let type_name = CString::new(T::NAME).unwrap();
80 assert_eq!(
81 gobject_ffi::g_type_from_name(type_name.as_ptr()),
82 gobject_ffi::G_TYPE_INVALID,
83 "Type {} has already been registered",
84 type_name.to_str().unwrap()
85 );
86
87 type_name
88 };
89
90 let type_ = crate::Type::from_glib(gobject_ffi::g_boxed_type_register_static(
91 type_name.as_ptr(),
92 Some(boxed_copy::<T>),
93 Some(boxed_free::<T>),
94 ));
95 assert!(type_.is_valid());
96
97 type_
98 }
99}
100
101#[cfg(test)]
102mod test {
103 // We rename the current crate as glib, since the macros in glib-macros
104 // generate the glib namespace through the crate_ident_new utility,
105 // and that returns `glib` (and not `crate`) when called inside the glib crate
106 use crate as glib;
107 use crate::prelude::*;
108 use crate::translate::{FromGlibPtrBorrow, FromGlibPtrFull, IntoGlibPtr};
109
110 #[derive(Clone, Debug, PartialEq, Eq, glib::Boxed)]
111 #[boxed_type(name = "MyBoxed")]
112 struct MyBoxed(String);
113
114 #[test]
115 fn test_register() {
116 assert!(MyBoxed::static_type().is_valid());
117 }
118
119 #[test]
120 fn test_value() {
121 assert!(MyBoxed::static_type().is_valid());
122
123 let b = MyBoxed(String::from("abc"));
124 let v = b.to_value();
125 let b2 = v.get::<&MyBoxed>().unwrap();
126 assert_eq!(&b, b2);
127 }
128
129 #[test]
130 fn test_from_glib_borrow() {
131 assert!(MyBoxed::static_type().is_valid());
132
133 let b = MyBoxed(String::from("abc"));
134 let raw_ptr = unsafe { MyBoxed::into_glib_ptr(b) };
135
136 // test that the from_glib_borrow does not take ownership of the raw_ptr
137 let _ = unsafe { MyBoxed::from_glib_borrow(raw_ptr) };
138
139 let new_b = unsafe { MyBoxed::from_glib_full(raw_ptr) };
140
141 assert_eq!(new_b.0, "abc".to_string());
142 }
143}
144