Split Wayland protocol handlers into dedicated modules

Move handler trait impls and delegate macros from state.rs into
handlers/{compositor,xdg_shell,input,output}.rs. Flesh out
CompositorHandler::commit with on_commit_buffer_handler and
XdgShellHandler::new_toplevel with window mapping. Add DataDeviceHandler,
SelectionHandler, ClientDndGrabHandler, and ServerDndGrabHandler impls
with DataDeviceState in the WayRay struct. State.rs now contains only
the struct definition and constructor.

crates/wrsrvd/src/handlers/compositor.rs

@@ -0,0 +1,65 @@
+use smithay::{
+    delegate_compositor, delegate_shm,
+    reexports::wayland_server::{
+        Client,
+        protocol::wl_surface::WlSurface,
+    },
+    wayland::{
+        buffer::BufferHandler,
+        compositor::{CompositorClientState, CompositorHandler, CompositorState},
+        shm::{ShmHandler, ShmState},
+    },
+};
+use tracing::trace;
+
+use crate::state::WayRay;
+
+/// Per-client state required by Smithay's compositor subsystem.
+///
+/// Must be stored in the client's `ClientData` so that `CompositorHandler`
+/// can retrieve it. Implements `wayland_server::backend::ClientData`.
+pub struct ClientState {
+    pub compositor_state: CompositorClientState,
+}
+
+impl smithay::reexports::wayland_server::backend::ClientData for ClientState {
+    fn initialized(&self, _client_id: smithay::reexports::wayland_server::backend::ClientId) {}
+    fn disconnected(
+        &self,
+        _client_id: smithay::reexports::wayland_server::backend::ClientId,
+        _reason: smithay::reexports::wayland_server::backend::DisconnectReason,
+    ) {
+    }
+}
+
+impl CompositorHandler for WayRay {
+    fn compositor_state(&mut self) -> &mut CompositorState {
+        &mut self.compositor_state
+    }
+
+    fn client_compositor_state<'a>(&self, client: &'a Client) -> &'a CompositorClientState {
+        &client.get_data::<ClientState>().unwrap().compositor_state
+    }
+
+    fn commit(&mut self, surface: &WlSurface) {
+        trace!(?surface, "surface commit");
+        smithay::backend::renderer::utils::on_commit_buffer_handler::<Self>(surface);
+    }
+}
+
+impl BufferHandler for WayRay {
+    fn buffer_destroyed(
+        &mut self,
+        _buffer: &smithay::reexports::wayland_server::protocol::wl_buffer::WlBuffer,
+    ) {
+    }
+}
+
+impl ShmHandler for WayRay {
+    fn shm_state(&self) -> &ShmState {
+        &self.shm_state
+    }
+}
+
+delegate_compositor!(WayRay);
+delegate_shm!(WayRay);

crates/wrsrvd/src/handlers/input.rs

@@ -0,0 +1,43 @@
+use smithay::{
+    delegate_data_device, delegate_seat,
+    input::{Seat, SeatHandler, SeatState, pointer::CursorImageStatus},
+    reexports::wayland_server::protocol::wl_surface::WlSurface,
+    wayland::selection::{
+        SelectionHandler,
+        data_device::{
+            ClientDndGrabHandler, DataDeviceHandler, DataDeviceState, ServerDndGrabHandler,
+        },
+    },
+};
+
+use crate::state::WayRay;
+
+impl SeatHandler for WayRay {
+    type KeyboardFocus = WlSurface;
+    type PointerFocus = WlSurface;
+    type TouchFocus = WlSurface;
+
+    fn seat_state(&mut self) -> &mut SeatState<Self> {
+        &mut self.seat_state
+    }
+
+    fn focus_changed(&mut self, _seat: &Seat<Self>, _focused: Option<&WlSurface>) {}
+
+    fn cursor_image(&mut self, _seat: &Seat<Self>, _image: CursorImageStatus) {}
+}
+
+impl SelectionHandler for WayRay {
+    type SelectionUserData = ();
+}
+
+impl ClientDndGrabHandler for WayRay {}
+impl ServerDndGrabHandler for WayRay {}
+
+impl DataDeviceHandler for WayRay {
+    fn data_device_state(&self) -> &DataDeviceState {
+        &self.data_device_state
+    }
+}
+
+delegate_seat!(WayRay);
+delegate_data_device!(WayRay);

crates/wrsrvd/src/handlers/mod.rs

@@ -0,0 +1,6 @@
+mod compositor;
+mod input;
+mod output;
+mod xdg_shell;
+
+pub use compositor::ClientState;

crates/wrsrvd/src/handlers/output.rs

@@ -0,0 +1,18 @@
+use smithay::{
+    delegate_output,
+    output::Output,
+    wayland::output::OutputHandler,
+};
+
+use crate::state::WayRay;
+
+impl OutputHandler for WayRay {
+    fn output_bound(
+        &mut self,
+        _output: Output,
+        _wl_output: smithay::reexports::wayland_server::protocol::wl_output::WlOutput,
+    ) {
+    }
+}
+
+delegate_output!(WayRay);

crates/wrsrvd/src/handlers/xdg_shell.rs

@@ -0,0 +1,43 @@
+use smithay::{
+    delegate_xdg_shell,
+    desktop::Window,
+    reexports::wayland_server::protocol::wl_seat,
+    utils::Serial,
+    wayland::shell::xdg::{
+        PopupSurface, PositionerState, ToplevelSurface, XdgShellHandler, XdgShellState,
+    },
+};
+use tracing::info;
+
+use crate::state::WayRay;
+
+impl XdgShellHandler for WayRay {
+    fn xdg_shell_state(&mut self) -> &mut XdgShellState {
+        &mut self.xdg_shell_state
+    }
+
+    fn new_toplevel(&mut self, surface: ToplevelSurface) {
+        let window = Window::new_wayland_window(surface);
+        self.space.map_element(window, (0, 0), false);
+        info!("new toplevel mapped");
+    }
+
+    fn new_popup(&mut self, _surface: PopupSurface, _positioner: PositionerState) {
+        // TODO: handle new popups
+    }
+
+    fn grab(&mut self, _surface: PopupSurface, _seat: wl_seat::WlSeat, _serial: Serial) {
+        // TODO: handle popup grabs
+    }
+
+    fn reposition_request(
+        &mut self,
+        _surface: PopupSurface,
+        _positioner: PositionerState,
+        _token: u32,
+    ) {
+        // TODO: handle popup reposition requests
+    }
+}
+
+delegate_xdg_shell!(WayRay);

crates/wrsrvd/src/main.rs

@@ -1,4 +1,5 @@
 mod errors;
+mod handlers;
 mod state;
 
 use crate::state::WayRay;

crates/wrsrvd/src/state.rs

@@ -1,41 +1,18 @@
 use smithay::{
-    delegate_compositor, delegate_output, delegate_seat, delegate_shm, delegate_xdg_shell,
     desktop::Space,
-    input::{Seat, SeatHandler, SeatState, pointer::CursorImageStatus},
-    output::Output,
-    reexports::wayland_server::{
-        Display, DisplayHandle, Client,
-        protocol::{wl_seat, wl_surface::WlSurface},
-    },
-    utils::{Clock, Monotonic, Serial},
+    input::{Seat, SeatState},
+    reexports::wayland_server::{Display, DisplayHandle},
+    utils::{Clock, Monotonic},
     wayland::{
-        buffer::BufferHandler,
-        compositor::{CompositorClientState, CompositorHandler, CompositorState},
-        output::{OutputHandler, OutputManagerState},
-        shell::xdg::{XdgShellHandler, XdgShellState, ToplevelSurface, PopupSurface, PositionerState},
-        shm::{ShmHandler, ShmState},
+        compositor::CompositorState,
+        output::OutputManagerState,
+        selection::data_device::DataDeviceState,
+        shell::xdg::XdgShellState,
+        shm::ShmState,
     },
 };
 use tracing::info;
 
-/// Per-client state required by Smithay's compositor subsystem.
-///
-/// Must be stored in the client's `ClientData` so that `CompositorHandler`
-/// can retrieve it. Implements `wayland_server::backend::ClientData`.
-pub struct ClientState {
-    pub compositor_state: CompositorClientState,
-}
-
-impl smithay::reexports::wayland_server::backend::ClientData for ClientState {
-    fn initialized(&self, _client_id: smithay::reexports::wayland_server::backend::ClientId) {}
-    fn disconnected(
-        &self,
-        _client_id: smithay::reexports::wayland_server::backend::ClientId,
-        _reason: smithay::reexports::wayland_server::backend::DisconnectReason,
-    ) {
-    }
-}
-
 /// Central compositor state holding all Smithay subsystem states.
 ///
 /// This is the "god struct" pattern required by Smithay — a single type that
@@ -47,6 +24,7 @@ pub struct WayRay {
     pub shm_state: ShmState,
     pub seat_state: SeatState<Self>,
     pub output_manager_state: OutputManagerState,
+    pub data_device_state: DataDeviceState,
     pub space: Space<smithay::desktop::Window>,
     pub seat: Seat<Self>,
     pub clock: Clock<Monotonic>,
@@ -60,6 +38,7 @@ impl WayRay {
         let compositor_state = CompositorState::new::<Self>(&dh);
         let xdg_shell_state = XdgShellState::new::<Self>(&dh);
         let shm_state = ShmState::new::<Self>(&dh, vec![]);
+        let data_device_state = DataDeviceState::new::<Self>(&dh);
 
         let mut seat_state = SeatState::new();
         let seat = seat_state.new_wl_seat(&dh, "wayray");
@@ -75,105 +54,10 @@ impl WayRay {
             shm_state,
             seat_state,
             output_manager_state,
+            data_device_state,
             space: Space::default(),
             seat,
             clock: Clock::new(),
         }
     }
 }
-
-// --- Minimal handler trait impls required by delegate macros ---
-// TODO: These will be expanded and moved to handlers/ in Task 4.
-
-impl CompositorHandler for WayRay {
-    fn compositor_state(&mut self) -> &mut CompositorState {
-        &mut self.compositor_state
-    }
-
-    fn client_compositor_state<'a>(&self, client: &'a Client) -> &'a CompositorClientState {
-        &client.get_data::<ClientState>().unwrap().compositor_state
-    }
-
-    fn commit(&mut self, _surface: &WlSurface) {
-        // TODO: handle surface commits (Task 4)
-    }
-}
-
-impl XdgShellHandler for WayRay {
-    fn xdg_shell_state(&mut self) -> &mut XdgShellState {
-        &mut self.xdg_shell_state
-    }
-
-    fn new_toplevel(&mut self, _surface: ToplevelSurface) {
-        // TODO: handle new toplevel windows (Task 4)
-    }
-
-    fn new_popup(&mut self, _surface: PopupSurface, _positioner: PositionerState) {
-        // TODO: handle new popups (Task 4)
-    }
-
-    fn grab(&mut self, _surface: PopupSurface, _seat: wl_seat::WlSeat, _serial: Serial) {
-        // TODO: handle popup grabs (Task 4)
-    }
-
-    fn reposition_request(
-        &mut self,
-        _surface: PopupSurface,
-        _positioner: PositionerState,
-        _token: u32,
-    ) {
-        // TODO: handle popup reposition requests (Task 4)
-    }
-}
-
-impl ShmHandler for WayRay {
-    fn shm_state(&self) -> &ShmState {
-        &self.shm_state
-    }
-}
-
-impl BufferHandler for WayRay {
-    fn buffer_destroyed(
-        &mut self,
-        _buffer: &smithay::reexports::wayland_server::protocol::wl_buffer::WlBuffer,
-    ) {
-        // TODO: handle buffer destruction (Task 4)
-    }
-}
-
-impl SeatHandler for WayRay {
-    type KeyboardFocus = WlSurface;
-    type PointerFocus = WlSurface;
-    type TouchFocus = WlSurface;
-
-    fn seat_state(&mut self) -> &mut SeatState<Self> {
-        &mut self.seat_state
-    }
-
-    fn focus_changed(&mut self, _seat: &Seat<Self>, _focused: Option<&WlSurface>) {
-        // TODO: handle focus changes (Task 4)
-    }
-
-    fn cursor_image(&mut self, _seat: &Seat<Self>, _image: CursorImageStatus) {
-        // TODO: handle cursor image updates (Task 4)
-    }
-}
-
-impl OutputHandler for WayRay {
-    fn output_bound(
-        &mut self,
-        _output: Output,
-        _wl_output: smithay::reexports::wayland_server::protocol::wl_output::WlOutput,
-    ) {
-        // TODO: handle output binding (Task 4)
-    }
-}
-
-// --- Delegate macros wiring Smithay's Dispatch impls ---
-// TODO: These will be moved to handlers/ in Task 4.
-
-delegate_compositor!(WayRay);
-delegate_xdg_shell!(WayRay);
-delegate_shm!(WayRay);
-delegate_seat!(WayRay);
-delegate_output!(WayRay);