Trait wayland_client::backend::ObjectData

pub trait ObjectData: DowncastSync {
    // Required methods
    fn event(
        self: Arc<Self>,
        backend: &Backend,
        msg: Message<ObjectId, OwnedFd>
    ) -> Option<Arc<dyn ObjectData>>;
    fn destroyed(&self, object_id: ObjectId);

    // Provided methods
    fn debug(&self, f: &mut Formatter<'_>) -> Result<(), Error> { ... }
    fn data_as_any(&self) -> &(dyn Any + 'static) { ... }
}

A trait representing your data associated to an object

You will only be given access to it as a & reference, so you need to handle interior mutability by yourself.

The methods of this trait will be invoked internally every time a new object is created to initialize its data.

Required Methods

fn event( self: Arc<Self>, backend: &Backend, msg: Message<ObjectId, OwnedFd> ) -> Option<Arc<dyn ObjectData>>

Dispatch an event for the associated object

If the event has a NewId argument, the callback must return the object data for the newly created object

fn destroyed(&self, object_id: ObjectId)

Notification that the object has been destroyed and is no longer active

Provided Methods

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

Helper for forwarding a Debug implementation of your ObjectData type

By default will just print ObjectData { ... }

fn data_as_any(&self) -> &(dyn Any + 'static)

Helper for accessing user data

This function is used to back the Proxy::data function in wayland_client. By default, it returns self (via Downcast), but this may be overridden to allow downcasting user data without needing to have access to the full type.

Implementations

impl dyn ObjectData

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

where __T: ObjectData,

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

pub fn downcast<__T>( self: Box<dyn ObjectData> ) -> Result<Box<__T>, Box<dyn ObjectData>>

where __T: ObjectData,

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>( self: Rc<dyn ObjectData> ) -> Result<Rc<__T>, Rc<dyn ObjectData>>

where __T: ObjectData,

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>(&self) -> Option<&__T>

where __T: ObjectData,

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>(&mut self) -> Option<&mut __T>

where __T: ObjectData,

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<dyn ObjectData> ) -> Result<Arc<__T>, Arc<dyn ObjectData>>

where __T: ObjectData + Any + Send + Sync,

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 Debug for dyn ObjectData

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

Formats the value using the given formatter.

Implementors

impl<I: Proxy + 'static, U: Send + Sync + 'static, State> ObjectData for QueueProxyData<I, U, State>

where State: Dispatch<I, U, State> + 'static,