Basic Principles

The wayland protocol is an asynchronous object oriented protocol. All requests are method invocations on some object. The request include an object id that uniquely identifies an object on the server. Each object implements an interface and the requests include an opcode that identifies which method in the interface to invoke.

The server sends back events to the client, each event is emitted from an object. Events can be error conditions. The event includes the object id and the event opcode, from which the client can determine the type of event. Events are generated both in response to requests (in which case the request and the event constitutes a round trip) or spontaneously when the server state changes.

• state is broadcast on connect, events are sent out when state changes. clients must listen for these changes and cache the state. there is no need (or mechanism) to query server state.

• the server will broadcast the presence of a number of global objects, which in turn will broadcast their current state.