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//
// DO NOT EDIT. THIS FILE IS GENERATED FROM $SRCDIR/xpcom/ds/nsIObserver.idl
//
/// `interface nsIObserver : nsISupports`
///
/// ```text
/// /**
/// * This interface is implemented by an object that wants
/// * to observe an event corresponding to a topic.
/// */
/// ```
///
// The actual type definition for the interface. This struct has methods
// declared on it which will call through its vtable. You never want to pass
// this type around by value, always pass it behind a reference.
#[repr(C)]
pub struct nsIObserver {
vtable: &'static nsIObserverVTable,
/// This field is a phantomdata to ensure that the VTable type and any
/// struct containing it is not safe to send across threads by default, as
/// XPCOM is generally not threadsafe.
///
/// If this type is marked as [rust_sync], there will be explicit `Send` and
/// `Sync` implementations on this type, which will override the inherited
/// negative impls from `Rc`.
__nosync: ::std::marker::PhantomData<::std::rc::Rc<u8>>,
// Make the rust compiler aware that there might be interior mutability
// in what actually implements the interface. This works around UB
// introduced by https://github.com/llvm/llvm-project/commit/01859da84bad95fd51d6a03b08b60c660e642a4f
// that a rust lint would make blatantly obvious, but doesn't exist.
// This prevents optimizations, but those optimizations weren't available
// before rustc switched to LLVM 16, and they now cause problems because
// of the UB.
// Until there's a lint available to find all our UB, it's simpler to
// avoid the UB in the first place, at the cost of preventing optimizations
// in places that don't cause UB. But again, those optimizations weren't
// available before.
__maybe_interior_mutability: ::std::cell::UnsafeCell<[u8; 0]>,
}
// Implementing XpCom for an interface exposes its IID, which allows for easy
// use of the `.query_interface<T>` helper method. This also defines that
// method for nsIObserver.
unsafe impl XpCom for nsIObserver {
const IID: nsIID = nsID(0xdb242e01, 0xe4d9, 0x11d2,
[0x9d, 0xde, 0x00, 0x00, 0x64, 0x65, 0x73, 0x74]);
}
// We need to implement the RefCounted trait so we can be used with `RefPtr`.
// This trait teaches `RefPtr` how to manage our memory.
unsafe impl RefCounted for nsIObserver {
#[inline]
unsafe fn addref(&self) {
self.AddRef();
}
#[inline]
unsafe fn release(&self) {
self.Release();
}
}
// This trait is implemented on all types which can be coerced to from nsIObserver.
// It is used in the implementation of `fn coerce<T>`. We hide it from the
// documentation, because it clutters it up a lot.
#[doc(hidden)]
pub trait nsIObserverCoerce {
/// Cheaply cast a value of this type from a `nsIObserver`.
fn coerce_from(v: &nsIObserver) -> &Self;
}
// The trivial implementation: We can obviously coerce ourselves to ourselves.
impl nsIObserverCoerce for nsIObserver {
#[inline]
fn coerce_from(v: &nsIObserver) -> &Self {
v
}
}
impl nsIObserver {
/// Cast this `nsIObserver` to one of its base interfaces.
#[inline]
pub fn coerce<T: nsIObserverCoerce>(&self) -> &T {
T::coerce_from(self)
}
}
// Every interface struct type implements `Deref` to its base interface. This
// causes methods on the base interfaces to be directly avaliable on the
// object. For example, you can call `.AddRef` or `.QueryInterface` directly
// on any interface which inherits from `nsISupports`.
impl ::std::ops::Deref for nsIObserver {
type Target = nsISupports;
#[inline]
fn deref(&self) -> &nsISupports {
unsafe {
::std::mem::transmute(self)
}
}
}
// Ensure we can use .coerce() to cast to our base types as well. Any type which
// our base interface can coerce from should be coercable from us as well.
impl<T: nsISupportsCoerce> nsIObserverCoerce for T {
#[inline]
fn coerce_from(v: &nsIObserver) -> &Self {
T::coerce_from(v)
}
}
// This struct represents the interface's VTable. A pointer to a statically
// allocated version of this struct is at the beginning of every nsIObserver
// object. It contains one pointer field for each method in the interface. In
// the case where we can't generate a binding for a method, we include a void
// pointer.
#[doc(hidden)]
#[repr(C)]
pub struct nsIObserverVTable {
/// We need to include the members from the base interface's vtable at the start
/// of the VTable definition.
pub __base: nsISupportsVTable,
/* void observe (in nsISupports aSubject, in string aTopic, in wstring aData); */
pub Observe: unsafe extern "system" fn (this: *const nsIObserver, aSubject: *const nsISupports, aTopic: *const libc::c_char, aData: *const u16) -> ::nserror::nsresult,
}
// The implementations of the function wrappers which are exposed to rust code.
// Call these methods rather than manually calling through the VTable struct.
impl nsIObserver {
/// ```text
/// /**
/// * Observe will be called when there is a notification for the
/// * topic |aTopic|. This assumes that the object implementing
/// * this interface has been registered with an observer service
/// * such as the nsIObserverService.
/// *
/// * If you expect multiple topics/subjects, the impl is
/// * responsible for filtering.
/// *
/// * You should not modify, add, remove, or enumerate
/// * notifications in the implemention of observe.
/// *
/// * @param aSubject : Notification specific interface pointer.
/// * @param aTopic : The notification topic or subject.
/// * @param aData : Notification specific wide string.
/// * subject event.
/// */
/// ```
///
/// `void observe (in nsISupports aSubject, in string aTopic, in wstring aData);`
#[inline]
pub unsafe fn Observe(&self, aSubject: *const nsISupports, aTopic: *const libc::c_char, aData: *const u16) -> ::nserror::nsresult {
((*self.vtable).Observe)(self, aSubject, aTopic, aData)
}
}