Trait wayland_backend::sys::server::GlobalHandler

pub trait GlobalHandler<D>: DowncastSync {
    fn bind(
        self: Arc<Self>,
        handle: &Handle,
        data: &mut D,
        client_id: ClientId,
        global_id: GlobalId,
        object_id: ObjectId
    ) -> Arc<dyn ObjectData<D>>;

    fn can_view(
        &self,
        _client_id: ClientId,
        _client_data: &Arc<dyn ClientData>,
        _global_id: GlobalId
    ) -> bool { ... }
    fn debug(&self, f: &mut Formatter<'_>) -> Result { ... }
}

Available on (crate features client_system or server_system) and crate feature server_system only.

A trait representing the handling of new bound globals

Required Methods

fn bind(
    self: Arc<Self>,
    handle: &Handle,
    data: &mut D,
    client_id: ClientId,
    global_id: GlobalId,
    object_id: ObjectId
) -> Arc<dyn ObjectData<D>>

A global has been bound

Given client bound given global, creating given object.

The method must return the object data for the newly created object.

Provided Methods

fn can_view(
    &self,
    _client_id: ClientId,
    _client_data: &Arc<dyn ClientData>,
    _global_id: GlobalId
) -> bool

Check if given client is allowed to interact with given global

If this function returns false, the client will not be notified of the existence of this global, and any attempt to bind it will result in a protocol error as if the global did not exist.

Default implementation always return true.

Examples found in repository

src/sys/server_impl/mod.rs (lines 1367-1371)

unsafe extern "C" fn global_filter<D: 'static>(
    client: *const wl_client,
    global: *const wl_global,
    _: *mut c_void,
) -> bool {
    if !HANDLE.is_set() {
        // This happens if we are invoked during the global shutdown
        // at this point, we really don't care what we send to clients,
        // the compositor is shutting down anyway so they're all going to be killed
        // thus return false, so that nothing is sent to anybody
        return false;
    }

    // Safety: skip processing globals that do not belong to us
    let is_known_global = HANDLE.with(|&(ref state_arc, _)| {
        let guard = state_arc.lock().unwrap();
        guard.is_known_global(global)
    });
    if !is_known_global {
        return true;
    }

    // Safety: if we are invoked here, the client is a valid client initialized by us
    let client_udata = match unsafe { client_user_data(client as *mut _) } {
        Some(id) => unsafe { &*id },
        None => return false,
    };

    let client_id = InnerClientId { ptr: client as *mut _, alive: client_udata.alive.clone() };

    // Safety: if we are invoked here, the global is a global client initialized by us
    let global_udata = unsafe {
        &*(ffi_dispatch!(WAYLAND_SERVER_HANDLE, wl_global_get_user_data, global)
            as *mut GlobalUserData<D>)
    };

    let global_id =
        InnerGlobalId { ptr: global as *mut wl_global, alive: global_udata.alive.clone() };

    global_udata.handler.can_view(
        ClientId { id: client_id },
        &client_udata.data,
        GlobalId { id: global_id },
    )
}

fn debug(&self, f: &mut Formatter<'_>) -> Result

Helper for forwarding a Debug implementation of your GlobalHandler type

By default will just print GlobalHandler { ... }

Examples found in repository

src/sys/../server_api.rs (line 96)

    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.debug(f)
    }

Implementations

impl<D> dyn GlobalHandler<D>where
    D: Any + 'static,

pub fn is<__T: GlobalHandler<D>>(&self) -> bool

Returns true if the trait object wraps an object of type __T.

pub fn downcast<__T: GlobalHandler<D>>(
    self: Box<Self>
) -> Result<Box<__T>, Box<Self>>

Returns a boxed object from a boxed trait object if the underlying object is of type __T. Returns the original boxed trait if it isn’t.

pub fn downcast_rc<__T: GlobalHandler<D>>(
    self: Rc<Self>
) -> Result<Rc<__T>, Rc<Self>>

Returns an Rc-ed object from an Rc-ed trait object if the underlying object is of type __T. Returns the original Rc-ed trait if it isn’t.

pub fn downcast_ref<__T: GlobalHandler<D>>(&self) -> Option<&__T>

Returns a reference to the object within the trait object if it is of type __T, or None if it isn’t.

pub fn downcast_mut<__T: GlobalHandler<D>>(&mut self) -> Option<&mut __T>

Returns a mutable reference to the object within the trait object if it is of type __T, or None if it isn’t.

pub fn downcast_arc<__T>(self: Arc<Self>) -> Result<Arc<__T>, Arc<Self>>where
    __T: Any + Send + Sync + GlobalHandler<D>,

Returns an Arc-ed object from an Arc-ed trait object if the underlying object is of type __T. Returns the original Arc-ed trait if it isn’t.

Trait Implementations

impl<D: 'static> Debug for dyn GlobalHandler<D>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

Implementors