wayland_client::wayland_env!

macro_rules! wayland_env {
    ($structname: ident, $($name: ident : $interface: ty),*) => { ... };
}

This macro allows you to create a simple wayland environment handler.

It will define a struct which upon creation communicates with the server to fetch the list of global objects and instanciate them with the newest interface version supported by both the server and the client library.

This struct comes with a static constructor init(display), which takes a display, and returns the created struct and an EventIterator associated with the display and all the global objects.

Note that none of the events associated with the newly created objects are dispatched (expect for the registry), allowing you to change the event iterators associated with them before dispatching them, if you want to.

The struct has these public fields:

• display: the WlDisplay provided as argument
• registry: a instance of the WlRegistry associated
• globals: a Vec containing the globals advertized by the server, in the format (global_id, interface_name, version) Note here that version is the version advertized by the server.
• One field for each of the objects you specified, of type Option<T, u32>, in the format (proxy, version). The value is None if this global was not advertized by the server.

Note that:

• If you specify several objects of the same interface, only the first one will be populated.
• If a global is advertized several times (like wl_seat or wl_output can be), only the first one will be automatically bound (but all will still be listed in the globals list).

The struct also provides two methods:

• fn rebind<T: Proxy>(&self) -> Option<(T, u32)> which will try to bind once more a global (this allows you to effectively clone a global, and is perfectly legal). It will match the first global of that type that was encountered. Returns None if this global type was not encountered.
• fn rebind_id<T: Proxy>(&self, id: u32) -> Option<(T, u32)> which will try to bind once more a global with given id as listed in globals. Returns None if given id is not known or if its interface does not match with the provided type.

Example of use:

#[macro_use] extern crate wayland_client;

use wayland_client::wayland::get_display;
use wayland_client::wayland::compositor::WlCompositor;
use wayland_client::wayland::shell::WlShell;

wayland_env!(WaylandEnv,
    compositor: WlCompositor,
    shell: WlShell
);

fn main() {
    let display = get_display().expect("Unable to connect to waylans server.");
    let (env, iter) = WaylandEnv::init(display);
    let shell = match env.shell {
        Some((ref comp, version)) if version >= 2 => comp,
        _ => panic!("This app requires the wayland interface wl_shell of version >= 2.")
    };
    // etc...
}