/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at
http://mozilla.org/MPL/2.0/. */
//! Objective-C bindings and helpers.
// Forward all exports from the `objc` crate.
pub use objc::*;
/// An objc class instance which contains rust data `T`.
#[derive(Clone, Copy)]
#[repr(transparent)]
pub struct Objc<T> {
pub instance: cocoa::id,
_phantom: std::marker::PhantomData<*mut T>,
}
impl<T> Objc<T> {
pub fn new(instance: cocoa::id) -> Self {
Objc {
instance,
_phantom: std::marker::PhantomData,
}
}
pub fn data(&self) -> &T {
let data = *unsafe { (*self.instance).get_ivar::<usize>("rust_self") } as *mut T;
unsafe { &*data }
}
pub fn data_mut(&mut self) -> &mut T {
let data = *unsafe { (*self.instance).get_ivar::<usize>("rust_self") } as *mut T;
unsafe { &mut *data }
}
}
impl<T> std::ops::Deref for Objc<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.data()
}
}
impl<T> std::ops::DerefMut for Objc<T> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.data_mut()
}
}
unsafe impl<T> Encode for Objc<T> {
fn encode() -> Encoding {
cocoa::id::encode()
}
}
/// Wrapper to provide `Encode` for bindgen-generated types (bindgen should do this in the fut
ure).
#[repr(transparent)]
pub struct Ptr<T>(pub T);
unsafe impl<T> Encode for Ptr<T> {
fn encode() -> Encoding {
cocoa::id::encode()
}
}
/// A strong objective-c reference to `T`.
#[repr(transparent)]
pub struct StrongRef<T> {
ptr: rc::StrongPtr,
_phantom: std::marker::PhantomData<T>,
}
impl<T> Clone for StrongRef<T> {
fn clone(&self) -> Self {
StrongRef {
ptr: self.ptr.clone(),
_phantom: self._phantom,
}
}
}
impl<T> std::ops::Deref for StrongRef<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
let obj: &cocoa::id = &*self.ptr;
unsafe { std::mem::transmute(obj) }
}
}
impl<T> StrongRef<T> {
/// Assume the given pointer-wrapper is an already-retained strong reference.
///
/// # Safety
/// The type _must_ be the same size as cocoa::id and contain only a cocoa::id.
pub unsafe fn new(v: T) -> Self {
std::mem::transmute_copy(&v)
}
/// Retain the given pointer-wrapper.
///
/// # Safety
/// The type _must_ be the same size as cocoa::id and contain only a cocoa::id.
#[allow(dead_code)]
pub unsafe fn retain(v: T) -> Self {
let obj: cocoa::id = std::mem::transmute_copy(&v);
StrongRef {
ptr: rc::StrongPtr::retain(obj),
_phantom: std::marker::PhantomData,
}
}
pub fn autorelease(self) -> T {
let obj = self.ptr.autorelease();
unsafe { std::mem::transmute_copy(&obj) }
}
pub fn weak(&self) -> WeakRef<T> {
WeakRef {
ptr: self.ptr.weak(),
_phantom: std::marker::PhantomData,
}
}
/// Unwrap the StrongRef value without affecting reference counts.
///
/// This is the opposite of `new`.
#[allow(dead_code)]
pub fn unwrap(self: Self) -> T {
let v = unsafe { std::mem::transmute_copy(&self) };
std::mem::forget(self);
v
}
/// Cast to a base class.
///
/// Bindgen pointer-wrappers have trival `From<Derived> for Base` implementations.
pub fn cast<U: From<T>>(self) -> StrongRef<U> {
StrongRef {
ptr: self.ptr,
_phantom: std::marker::PhantomData,
}
}
}
/// A weak objective-c reference to `T`.
#[derive(Clone)]
#[repr(transparent)]
pub struct WeakRef<T> {
ptr: rc::WeakPtr,
_phantom: std::marker::PhantomData<T>,
}
impl<T> WeakRef<T> {
pub fn lock(&self) -> Option<StrongRef<T>> {
let ptr = self.ptr.load();
if ptr.is_null() {
None
} else {
Some(StrongRef {
ptr,
_phantom: std::marker::PhantomData,
})
}
}
}
/// A macro for creating an objc class.
///
/// Classes _must_ be registered before use (`Objc<T>::register()`).
///
/// Example:
/// ```
/// struct Foo(u8);
///
/// objc_class! {
/// impl Foo: NSObject {
/// #[sel(mySelector:)]
/// fn my_selector(&mut self, arg: u8) -> u8 {
/// self.0 + arg
/// }
/// }
/// }
///
/// fn make_foo() -> StrongRef<Objc<Foo>> {
/// Foo(42).into_object()
/// }
/// ```
///
/// Call `T::into_object()` to create the objective-c class instance.
macro_rules! objc_class {
( impl $name:ident : $base:ident $(<$($protocol:ident),+>)? {
$(
#[sel($($sel:tt)+)]
fn $mname:ident (&mut $self:ident $(, $argname:ident : $argtype:ty )*) $(-> $rettype:ty)? $body:block
)*
}) => {
impl Objc<$name> {
pub fn register() {
let mut decl = declare::ClassDecl::new(concat!("CR", stringify!($name)), class!($base)).expect(concat!("failed to declare ", stringify!($name), " class"));
$($(decl.add_protocol(runtime::Protocol::get(stringify!($protocol)).expect(concat!("failed to find ",stringify!($protocol)," protocol")));)+)?
decl.add_ivar::<usize>("rust_self");
$({
extern "C" fn method_impl(obj: &mut runtime::Object, _: runtime::Sel $(, $argname: $argtype )*) $(-> $rettype)? {
Objc::<$name>::new(obj).$mname($($argname),*)
}
unsafe {
decl.add_method(sel!($($sel)+), method_impl as extern "C" fn(&mut runtime::Object, runtime::Sel $(, $argname: $argtype )*) $(-> $rettype)?);
}
})*
{
extern "C" fn dealloc_impl(obj: &runtime::Object, _: runtime::Sel) {
drop(unsafe { Box::from_raw(*obj.get_ivar::<usize>("rust_self") as *mut $name) });
unsafe {
let _: () = msg_send![super(obj, class!(NSObject)), dealloc];
}
}
unsafe {
decl.add_method(sel!(dealloc), dealloc_impl as extern "C" fn(&runtime::Object, runtime::Sel));
}
}
decl.register();
}
pub fn class() -> &'static runtime::Class {
runtime::Class::get(concat!("CR", stringify!($name))).expect("class not registered")
}
$(fn $mname (&mut $self $(, $argname : $argtype )*) $(-> $rettype)? $body)*
}
impl $name {
pub fn into_object(self) -> StrongRef<Objc<$name>> {
let obj: *mut runtime::Object = unsafe { msg_send![Objc::<Self>::class(), alloc] };
unsafe { (*obj).set_ivar("rust_self", Box::into_raw(Box::new(self)) as usize) };
let obj: *mut runtime::Object = unsafe { msg_send![obj, init] };
unsafe { StrongRef::new(Objc::new(obj)) }
}
}
}
}
pub(crate) use objc_class;
