feat: initialize direct session backend

compositor/src/backends/direct.rs

@@ -0,0 +1,65 @@
+use std::{error::Error, io};
+
+use smithay::{
+    backend::{
+        libinput::{LibinputInputBackend, LibinputSessionInterface},
+        session::{Event as SessionEvent, Session, libseat::LibSeatSession},
+        udev::{UdevBackend, UdevEvent},
+    },
+    reexports::{calloop::EventLoop, input::Libinput},
+};
+
+use crate::Ferese;
+
+pub fn init(event_loop: &mut EventLoop<Ferese>, state: &mut Ferese) -> Result<(), Box<dyn Error>> {
+    let (session, notifier) = LibSeatSession::new()?;
+    let seat_name = session.seat();
+    let udev_backend = UdevBackend::new(&seat_name)?;
+    let mut libinput_context =
+        Libinput::new_with_udev::<LibinputSessionInterface<LibSeatSession>>(session.clone().into());
+    libinput_context
+        .udev_assign_seat(&seat_name)
+        .map_err(|()| io::Error::other(format!("failed to assign libinput seat {seat_name}")))?;
+    let libinput_backend = LibinputInputBackend::new(libinput_context.clone());
+
+    state.direct_session = Some(session);
+    state.session_active = true;
+
+    event_loop
+        .handle()
+        .insert_source(libinput_backend, |event, _, state| {
+            state.process_input_event(event);
+        })?;
+    event_loop
+        .handle()
+        .insert_source(notifier, move |event, _, state| match event {
+            SessionEvent::PauseSession => {
+                state.session_active = false;
+                libinput_context.suspend();
+                tracing::info!("direct session paused");
+            }
+            SessionEvent::ActivateSession => {
+                if libinput_context.resume().is_err() {
+                    tracing::error!("failed to resume libinput");
+                }
+                state.session_active = true;
+                tracing::info!("direct session activated");
+            }
+        })?;
+    event_loop
+        .handle()
+        .insert_source(udev_backend, |event, _, _state| match event {
+            UdevEvent::Added { device_id, path } => {
+                tracing::info!(?device_id, ?path, "DRM device added");
+            }
+            UdevEvent::Changed { device_id } => {
+                tracing::debug!(?device_id, "DRM device changed");
+            }
+            UdevEvent::Removed { device_id } => {
+                tracing::info!(?device_id, "DRM device removed");
+            }
+        })?;
+
+    tracing::info!(seat = %seat_name, "initialized direct session input and device discovery");
+    Ok(())
+}