input: add a default seat

jay-config/src/_private.rs

@@ -62,3 +62,5 @@ impl WireMode {
 
 #[derive(Serialize, Deserialize, Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub struct PollableId(pub u64);
+
+pub const DEFAULT_SEAT_NAME: &str = "default";

jay-config/src/_private/client.rs

@@ -576,6 +576,10 @@ impl Client {
         self.send(&ClientMessage::SetDoubleClickDistance { dist });
     }
 
+    pub fn disable_default_seat(&self) {
+        self.send(&ClientMessage::DisableDefaultSeat);
+    }
+
     pub fn connector_set_position(&self, connector: Connector, x: i32, y: i32) {
         self.send(&ClientMessage::ConnectorSetPosition { connector, x, y });
     }

jay-config/src/_private/ipc.rs

@@ -381,6 +381,7 @@ pub enum ClientMessage<'a> {
         env: Vec<(String, String)>,
         fds: Vec<(i32, i32)>,
     },
+    DisableDefaultSeat,
 }
 
 #[derive(Serialize, Deserialize, Debug)]

jay-config/src/input.rs

@@ -8,6 +8,7 @@ use {
         input::{acceleration::AccelProfile, capability::Capability},
         keyboard::Keymap,
         Axis, Direction, ModifiedKeySym, Workspace,
+        _private::DEFAULT_SEAT_NAME,
     },
     serde::{Deserialize, Serialize},
     std::time::Duration,
@@ -319,10 +320,20 @@ pub fn input_devices() -> Vec<InputDevice> {
 /// Returns or creates a seat.
 ///
 /// Seats are identified by their name. If no seat with the name exists, a new seat will be created.
+///
+/// NOTE: You should prefer [`get_default_seat`] instead. Most applications cannot handle more than
+/// one seat and will only process input from one of the seats.
 pub fn get_seat(name: &str) -> Seat {
     get!(Seat(0)).get_seat(name)
 }
 
+/// Returns or creates the default seat.
+///
+/// This is equivalent to `get_seat("default")`.
+pub fn get_default_seat() -> Seat {
+    get_seat(DEFAULT_SEAT_NAME)
+}
+
 /// Sets a closure to run when a new seat has been created.
 pub fn on_new_seat<F: FnMut(Seat) + 'static>(f: F) {
     get!().on_new_seat(f)
@@ -357,3 +368,14 @@ pub fn set_double_click_time(duration: Duration) {
 pub fn set_double_click_distance(distance: i32) {
     get!().set_double_click_distance(distance)
 }
+
+/// Disables the creation of a default seat.
+///
+/// Unless this function is called at startup of the compositor, a seat called `default`
+/// will automatically be created.
+///
+/// When a new input device is attached and a seat called `default` exists, the input
+/// device is initially attached to this seat.
+pub fn disable_default_seat() {
+    get!().disable_default_seat();
+}

jay-config/src/lib.rs

@@ -12,23 +12,19 @@
 //! config!(configure);
 //! ```
 //!
-//! This configuration will not allow you to interact with the compositor at all nor exit it.
+//! This configuration will not allow you to exit the compositor.
 //! To add at least that much functionality, add the following code to `configure`:
 //!
 //! ```rust
 //! use jay_config::{config, quit};
-//! use jay_config::input::{get_seat, input_devices, on_new_input_device};
+//! use jay_config::input::{get_default_seat, input_devices, on_new_input_device};
 //! use jay_config::keyboard::mods::ALT;
 //! use jay_config::keyboard::syms::SYM_q;
 //!
 //! fn configure() {
-//!     // Create a seat.
-//!     let seat = get_seat("default");
+//!     let seat = get_default_seat();
 //!     // Create a key binding to exit the compositor.
 //!     seat.bind(ALT | SYM_q, || quit());
-//!     // Assign all current and future input devices to this seat.
-//!     input_devices().into_iter().for_each(move |d| d.set_seat(seat));
-//!     on_new_input_device(move |d| d.set_seat(seat));
 //! }
 //!
 //! config!(configure);

src/compositor.rs

@@ -39,7 +39,7 @@ use {
     },
     ahash::AHashSet,
     forker::ForkerProxy,
-    jay_config::video::GfxApi,
+    jay_config::{_private::DEFAULT_SEAT_NAME, video::GfxApi},
     std::{cell::Cell, env, future::Future, ops::Deref, rc::Rc, sync::Arc, time::Duration},
     thiserror::Error,
     uapi::c,
@@ -207,6 +207,7 @@ fn start_compositor2(
         output_transforms: Default::default(),
         double_click_interval_usec: Cell::new(400 * 1000),
         double_click_distance: Cell::new(5),
+        create_default_seat: Cell::new(true),
     });
     state.tracker.register(ClientId::from_raw(0));
     create_dummy_output(&state);
@@ -254,6 +255,10 @@ async fn start_compositor3(state: Rc<State>, test_future: Option<TestFuture>) {
     config.configure(false);
     state.config.set(Some(Rc::new(config)));
 
+    if state.create_default_seat.get() && state.globals.seats.is_empty() {
+        state.create_seat(DEFAULT_SEAT_NAME);
+    }
+
     let _geh = start_global_event_handlers(&state, &backend);
     state.start_xwayland();
 

src/config/handler.rs

@@ -164,9 +164,7 @@ impl ConfigProxyHandler {
                 return;
             }
         }
-        let global_name = self.state.globals.name();
-        let seat = WlSeatGlobal::new(global_name, name, &self.state);
-        self.state.globals.add_global(&self.state, &seat);
+        let seat = self.state.create_seat(name);
         self.respond(Response::GetSeat {
             seat: Seat(seat.id().raw() as _),
         });
@@ -1516,6 +1514,7 @@ impl ConfigProxyHandler {
                 env,
                 fds,
             } => self.handle_run(prog, args, env, fds).wrn("run")?,
+            ClientMessage::DisableDefaultSeat => self.state.create_default_seat.set(false),
         }
         Ok(())
     }

src/it/tests/t0005_create_seat.rs

@@ -12,13 +12,13 @@ testcase!();
 async fn test(run: Rc<TestRun>) -> Result<(), TestError> {
     let client = run.create_client().await?;
 
-    tassert!(client.registry.seats.is_empty());
+    tassert_eq!(client.registry.seats.len(), 1);
 
-    let seat = run.get_seat("default")?;
+    let seat = run.get_seat("new-seat")?;
 
     client.sync().await;
 
-    tassert_eq!(client.registry.seats.len(), 1);
+    tassert_eq!(client.registry.seats.len(), 2);
 
     let client_seat = client.registry.seats.get(&seat.name());
     tassert!(client_seat.is_some());

src/state.rs

@@ -156,6 +156,7 @@ pub struct State {
     pub output_transforms: RefCell<AHashMap<Rc<OutputId>, Transform>>,
     pub double_click_interval_usec: Cell<u64>,
     pub double_click_distance: Cell<i32>,
+    pub create_default_seat: Cell<bool>,
 }
 
 // impl Drop for State {
@@ -924,4 +925,11 @@ impl State {
             capture.send_failed();
         }
     }
+
+    pub fn create_seat(self: &Rc<Self>, name: &str) -> Rc<WlSeatGlobal> {
+        let global_name = self.globals.name();
+        let seat = WlSeatGlobal::new(global_name, name, self);
+        self.globals.add_global(self, &seat);
+        seat
+    }
 }

src/tasks/input_device.rs

@@ -6,6 +6,7 @@ use {
         tasks::udev_utils::{udev_props, UdevProps},
         utils::asyncevent::AsyncEvent,
     },
+    jay_config::_private::DEFAULT_SEAT_NAME,
     std::{cell::Cell, rc::Rc},
 };
 
@@ -53,6 +54,12 @@ impl DeviceHandler {
             let ae = self.ae.clone();
             self.dev.on_change(Rc::new(move || ae.trigger()));
         }
+        for seat in self.state.globals.seats.lock().values() {
+            if seat.seat_name() == DEFAULT_SEAT_NAME {
+                self.data.seat.set(Some(seat.clone()));
+                break;
+            }
+        }
         if let Some(config) = self.state.config.get() {
             config.new_input_device(self.dev.id());
         }