Crate wayland_client

Client-side Wayland connector

Overview

Connection to the Wayland compositor is achieved by the default_connect() function, which provides you with a WlDisplay and an EventQueue.

From the display, you'll retrieve the registry, from which you can instantiate the globals you need. This step being really similar in most cases, this crate contains an utility struct EnvHandler which can do this job for you. See its documentation for details.

You then register your handlers for events to the event queue, and integrate it in your main event loop.

Implementations and event queues

This crate mirrors the callback-oriented design of the Wayland C library by using implementation structs: each wayland type defines an Implementation struct in its module, with one function field for each possible event this object can receive.

When registering an object on an event queue, you need to provide an implementation for this object. You can also provide some "implementation data": a value that will be provided as second argument to all the callback methods of your implementation.

A typical use of implementation data is to store here one or more state tokens to access some part of the shared state from your callback.

Example of implementation

You can register your wayland objects to an event queue:

event_queue.register(&my_object, implementation, impl_data);

A given wayland object can only be registered to a event queue at a given time, re-registering it will overwrite the previous configuration.

Objects can be registered to event queues using the &EventQueueHandle argument, available from withing an event callback.

Event loop integration

Once this setup is done, you can integrate the event queue to the main event loop of your program:

loop {
    // flush events to the server
    display.flush().unwrap();
    // receive events from the server and dispatch them
    // to handlers (might block)
    event_queue.dispatch().unwrap();
}

For more precise control of the flow of the event queue (and importantly non-blocking options), see EventQueue documentation.

Protocols integration

This crate provides the basic primitives as well as the core wayland protocol (in the protocol module), but other protocols can be integrated from XML descriptions.

The the crate wayland_scanner and its documentation for details about how to do so.

Modules

cursor	Cursor utilities
egl	EGL utilities
protocol	The wayland core protocol
protocol_interfaces	Interfaces for the core protocol
sys	Reexports of types and objects from wayland-sys

Macros

wayland_env

Create an environment handling struct

Structs

EnvHandler	Utility type to handle the registry and global objects
EventQueue	An event queue managing wayland events
EventQueueHandle	Handle to an event queue
ReadEventsGuard	A guard over a read intention.
State	A state store
StateToken	A token for accessing the state store contents

Enums

ConnectError	Enum representing the possible reasons why connecting to the wayland server failed
FatalError	Enum representing possible errors fatal to a wayland session
Liveness	Represents the state of liveness of a wayland object
RegisterStatus	Status of a registration attempt of a proxy.
RequestResult	Possible outcome of the call of a request on a proxy

Traits

Implementable	Common trait for wayland objects that can be registered to an EventQueue
Proxy	Common routines for wayland proxy objects.

Functions

connect_to	Connect to the compositor socket
default_connect	Connect to the compositor socket