feat: add nested Phase 0 compositor

compositor/src/handlers/compositor.rs

@@ -0,0 +1,59 @@
+use smithay::{
+    backend::renderer::utils::on_commit_buffer_handler,
+    reexports::wayland_server::{
+        Client,
+        protocol::{wl_buffer, wl_surface::WlSurface},
+    },
+    wayland::{
+        buffer::BufferHandler,
+        compositor::{
+            CompositorClientState, CompositorHandler, CompositorState, get_parent,
+            is_sync_subsurface,
+        },
+        shm::{ShmHandler, ShmState},
+    },
+};
+
+use super::xdg_shell;
+use crate::{Ferese, state::ClientState};
+
+impl CompositorHandler for Ferese {
+    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>()
+            .expect("all clients have Ferese client state")
+            .compositor_state
+    }
+
+    fn commit(&mut self, surface: &WlSurface) {
+        on_commit_buffer_handler::<Self>(surface);
+        if !is_sync_subsurface(surface) {
+            let mut root = surface.clone();
+            while let Some(parent) = get_parent(&root) {
+                root = parent;
+            }
+            if let Some(window) = self.space.elements().find(|window| {
+                window
+                    .toplevel()
+                    .is_some_and(|toplevel| toplevel.wl_surface() == &root)
+            }) {
+                window.on_commit();
+            }
+        }
+        xdg_shell::handle_commit(&mut self.popups, &self.space, surface);
+    }
+}
+
+impl BufferHandler for Ferese {
+    fn buffer_destroyed(&mut self, _buffer: &wl_buffer::WlBuffer) {}
+}
+
+impl ShmHandler for Ferese {
+    fn shm_state(&self) -> &ShmState {
+        &self.shm_state
+    }
+}

compositor/src/handlers/mod.rs

@@ -0,0 +1,30 @@
+mod compositor;
+mod xdg_shell;
+
+use smithay::{
+    input::{Seat, SeatHandler, SeatState, pointer::CursorImageStatus},
+    reexports::wayland_server::protocol::wl_surface::WlSurface,
+    wayland::output::OutputHandler,
+};
+
+use crate::Ferese;
+
+impl SeatHandler for Ferese {
+    type KeyboardFocus = WlSurface;
+    type PointerFocus = WlSurface;
+    type TouchFocus = WlSurface;
+
+    fn seat_state(&mut self) -> &mut SeatState<Self> {
+        &mut self.seat_state
+    }
+
+    fn cursor_image(&mut self, _seat: &Seat<Self>, _image: CursorImageStatus) {}
+}
+
+impl OutputHandler for Ferese {}
+
+smithay::delegate_compositor!(Ferese);
+smithay::delegate_output!(Ferese);
+smithay::delegate_seat!(Ferese);
+smithay::delegate_shm!(Ferese);
+smithay::delegate_xdg_shell!(Ferese);

compositor/src/handlers/xdg_shell.rs

@@ -0,0 +1,129 @@
+use smithay::{
+    desktop::{
+        PopupKind, PopupManager, Space, Window, find_popup_root_surface, get_popup_toplevel_coords,
+    },
+    reexports::wayland_server::protocol::{wl_seat, wl_surface::WlSurface},
+    utils::Serial,
+    wayland::{
+        compositor::with_states,
+        shell::xdg::{
+            PopupSurface, PositionerState, ToplevelSurface, XdgShellHandler, XdgShellState,
+            XdgToplevelSurfaceData,
+        },
+    },
+};
+
+use crate::Ferese;
+
+impl XdgShellHandler for Ferese {
+    fn xdg_shell_state(&mut self) -> &mut XdgShellState {
+        &mut self.xdg_shell_state
+    }
+
+    fn new_toplevel(&mut self, surface: ToplevelSurface) {
+        self.space
+            .map_element(Window::new_wayland_window(surface), (0, 0), true);
+    }
+
+    fn new_popup(&mut self, surface: PopupSurface, _positioner: PositionerState) {
+        self.unconstrain_popup(&surface);
+        if let Err(error) = self.popups.track_popup(PopupKind::Xdg(surface)) {
+            tracing::warn!(?error, "failed to track xdg popup");
+        }
+    }
+
+    fn reposition_request(
+        &mut self,
+        surface: PopupSurface,
+        positioner: PositionerState,
+        token: u32,
+    ) {
+        surface.with_pending_state(|state| {
+            state.geometry = positioner.get_geometry();
+            state.positioner = positioner;
+        });
+        self.unconstrain_popup(&surface);
+        surface.send_repositioned(token);
+    }
+
+    fn move_request(&mut self, _: ToplevelSurface, _: wl_seat::WlSeat, _: Serial) {}
+
+    fn resize_request(
+        &mut self,
+        _: ToplevelSurface,
+        _: wl_seat::WlSeat,
+        _: Serial,
+        _: smithay::reexports::wayland_protocols::xdg::shell::server::xdg_toplevel::ResizeEdge,
+    ) {
+    }
+
+    fn grab(&mut self, _: PopupSurface, _: wl_seat::WlSeat, _: Serial) {}
+}
+
+pub fn handle_commit(popups: &mut PopupManager, space: &Space<Window>, surface: &WlSurface) {
+    if let Some(window) = space
+        .elements()
+        .find(|window| {
+            window
+                .toplevel()
+                .is_some_and(|toplevel| toplevel.wl_surface() == surface)
+        })
+        .cloned()
+    {
+        let configured = with_states(surface, |states| {
+            states
+                .data_map
+                .get::<XdgToplevelSurfaceData>()
+                .expect("xdg toplevel state exists")
+                .lock()
+                .expect("xdg toplevel state is not poisoned")
+                .initial_configure_sent
+        });
+        if !configured {
+            window
+                .toplevel()
+                .expect("mapped window has a toplevel")
+                .send_configure();
+        }
+    }
+
+    popups.commit(surface);
+    if let Some(PopupKind::Xdg(popup)) = popups.find_popup(surface)
+        && !popup.is_initial_configure_sent()
+    {
+        popup
+            .send_configure()
+            .expect("initial popup configure is valid");
+    }
+}
+
+impl Ferese {
+    fn unconstrain_popup(&self, popup: &PopupSurface) {
+        let Ok(root) = find_popup_root_surface(&PopupKind::Xdg(popup.clone())) else {
+            return;
+        };
+        let Some(window) = self.space.elements().find(|window| {
+            window
+                .toplevel()
+                .is_some_and(|toplevel| toplevel.wl_surface() == &root)
+        }) else {
+            return;
+        };
+        let Some(output) = self.space.outputs().next() else {
+            return;
+        };
+        let Some(output_geometry) = self.space.output_geometry(output) else {
+            return;
+        };
+        let Some(window_geometry) = self.space.element_geometry(window) else {
+            return;
+        };
+
+        let mut target = output_geometry;
+        target.loc -= get_popup_toplevel_coords(&PopupKind::Xdg(popup.clone()));
+        target.loc -= window_geometry.loc;
+        popup.with_pending_state(|state| {
+            state.geometry = state.positioner.get_unconstrained_geometry(target);
+        });
+    }
+}

compositor/src/input.rs

@@ -0,0 +1,125 @@
+use smithay::{
+    backend::input::{
+        AbsolutePositionEvent, Axis, AxisSource, ButtonState, Event, InputBackend, InputEvent,
+        KeyboardKeyEvent, PointerAxisEvent, PointerButtonEvent,
+    },
+    input::{
+        keyboard::FilterResult,
+        pointer::{AxisFrame, ButtonEvent, MotionEvent},
+    },
+    reexports::wayland_server::protocol::wl_surface::WlSurface,
+    utils::{SERIAL_COUNTER, Serial},
+};
+
+use crate::Ferese;
+
+impl Ferese {
+    pub fn process_input_event<I: InputBackend>(&mut self, event: InputEvent<I>) {
+        match event {
+            InputEvent::Keyboard { event, .. } => {
+                let keyboard = self.seat.get_keyboard().expect("seat has a keyboard");
+                keyboard.input::<(), _>(
+                    self,
+                    event.key_code(),
+                    event.state(),
+                    SERIAL_COUNTER.next_serial(),
+                    Event::time(&event) as u32,
+                    |_, _, _| FilterResult::Forward,
+                );
+            }
+            InputEvent::PointerMotionAbsolute { event, .. } => {
+                let Some(output) = self.space.outputs().next() else {
+                    return;
+                };
+                let Some(geometry) = self.space.output_geometry(output) else {
+                    return;
+                };
+                let position = event.position_transformed(geometry.size) + geometry.loc.to_f64();
+                let pointer = self.seat.get_pointer().expect("seat has a pointer");
+                pointer.motion(
+                    self,
+                    self.surface_under(position),
+                    &MotionEvent {
+                        location: position,
+                        serial: SERIAL_COUNTER.next_serial(),
+                        time: event.time() as u32,
+                    },
+                );
+                pointer.frame(self);
+            }
+            InputEvent::PointerButton { event, .. } => {
+                let pointer = self.seat.get_pointer().expect("seat has a pointer");
+                let serial = SERIAL_COUNTER.next_serial();
+                if event.state() == ButtonState::Pressed && !pointer.is_grabbed() {
+                    self.focus_window_under_pointer(serial);
+                }
+                pointer.button(
+                    self,
+                    &ButtonEvent {
+                        button: event.button_code(),
+                        state: event.state(),
+                        serial,
+                        time: event.time() as u32,
+                    },
+                );
+                pointer.frame(self);
+            }
+            InputEvent::PointerAxis { event, .. } => {
+                let source = event.source();
+                let horizontal = event.amount(Axis::Horizontal).unwrap_or_else(|| {
+                    event.amount_v120(Axis::Horizontal).unwrap_or(0.0) * 15.0 / 120.0
+                });
+                let vertical = event.amount(Axis::Vertical).unwrap_or_else(|| {
+                    event.amount_v120(Axis::Vertical).unwrap_or(0.0) * 15.0 / 120.0
+                });
+                let mut frame = AxisFrame::new(event.time() as u32).source(source);
+                if horizontal != 0.0 {
+                    frame = frame.value(Axis::Horizontal, horizontal);
+                    if let Some(value) = event.amount_v120(Axis::Horizontal) {
+                        frame = frame.v120(Axis::Horizontal, value as i32);
+                    }
+                }
+                if vertical != 0.0 {
+                    frame = frame.value(Axis::Vertical, vertical);
+                    if let Some(value) = event.amount_v120(Axis::Vertical) {
+                        frame = frame.v120(Axis::Vertical, value as i32);
+                    }
+                }
+                if source == AxisSource::Finger {
+                    if event.amount(Axis::Horizontal) == Some(0.0) {
+                        frame = frame.stop(Axis::Horizontal);
+                    }
+                    if event.amount(Axis::Vertical) == Some(0.0) {
+                        frame = frame.stop(Axis::Vertical);
+                    }
+                }
+                let pointer = self.seat.get_pointer().expect("seat has a pointer");
+                pointer.axis(self, frame);
+                pointer.frame(self);
+            }
+            _ => {}
+        }
+    }
+
+    fn focus_window_under_pointer(&mut self, serial: Serial) {
+        let pointer = self.seat.get_pointer().expect("seat has a pointer");
+        let keyboard = self.seat.get_keyboard().expect("seat has a keyboard");
+        if let Some((window, _)) = self.space.element_under(pointer.current_location()) {
+            let window = window.clone();
+            self.space.raise_element(&window, true);
+            let surface = window
+                .toplevel()
+                .expect("mapped window has a toplevel")
+                .wl_surface()
+                .clone();
+            keyboard.set_focus(self, Some(surface), serial);
+        } else {
+            keyboard.set_focus(self, Option::<WlSurface>::None, serial);
+        }
+        self.space.elements().for_each(|window| {
+            if let Some(toplevel) = window.toplevel() {
+                toplevel.send_pending_configure();
+            }
+        });
+    }
+}

compositor/src/main.rs

@@ -1,3 +1,49 @@
-fn main() {
+#![allow(irrefutable_let_patterns)]
-    println!("Ferese Phase 0 scaffold");
+
+mod handlers;
+mod input;
+mod state;
+mod winit;
+
+use std::{error::Error, process::Command};
+
+use smithay::reexports::{calloop::EventLoop, wayland_server::Display};
+pub use state::Ferese;
+use tracing::{info, warn};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    init_logging();
+
+    let mut event_loop: EventLoop<Ferese> = EventLoop::try_new()?;
+    let display: Display<Ferese> = Display::new()?;
+    let mut state = Ferese::new(&mut event_loop, display)?;
+    winit::init(&mut event_loop, &mut state)?;
+
+    // SAFETY: the backend has already read the host display and Ferese is
+    // single-threaded before the event loop and optional child start.
+    unsafe { std::env::set_var("WAYLAND_DISPLAY", &state.socket_name) };
+
+    info!(socket = ?state.socket_name, "Ferese is accepting Wayland clients");
+    spawn_client_from_args();
+    event_loop.run(None, &mut state, |_| {})?;
+    Ok(())
+}
+
+fn init_logging() {
+    let filter = tracing_subscriber::EnvFilter::try_from_default_env()
+        .unwrap_or_else(|_| tracing_subscriber::EnvFilter::new("ferese=info"));
+    tracing_subscriber::fmt().with_env_filter(filter).init();
+}
+
+fn spawn_client_from_args() {
+    let mut args = std::env::args_os().skip(1);
+    let Some(program) = args.next() else {
+        info!("no client requested; pass one after `--`, for example `-- foot`");
+        return;
+    };
+
+    match Command::new(&program).args(args).spawn() {
+        Ok(child) => info!(program = ?program, pid = child.id(), "spawned nested client"),
+        Err(error) => warn!(program = ?program, %error, "failed to spawn nested client"),
+    }
 }

compositor/src/state.rs

@@ -0,0 +1,122 @@
+use std::{error::Error, ffi::OsString, sync::Arc, time::Instant};
+
+use smithay::{
+    desktop::{PopupManager, Space, Window, WindowSurfaceType},
+    input::{Seat, SeatState},
+    reexports::{
+        calloop::{EventLoop, Interest, LoopSignal, Mode, PostAction, generic::Generic},
+        wayland_server::{
+            Display, DisplayHandle,
+            backend::{ClientData, ClientId, DisconnectReason},
+            protocol::wl_surface::WlSurface,
+        },
+    },
+    utils::{Logical, Point},
+    wayland::{
+        compositor::{CompositorClientState, CompositorState},
+        output::OutputManagerState,
+        shell::xdg::XdgShellState,
+        shm::ShmState,
+        socket::ListeningSocketSource,
+    },
+};
+
+pub struct Ferese {
+    pub start_time: Instant,
+    pub socket_name: OsString,
+    pub display_handle: DisplayHandle,
+    pub loop_signal: LoopSignal,
+    pub space: Space<Window>,
+    pub popups: PopupManager,
+    pub seat: Seat<Self>,
+    pub compositor_state: CompositorState,
+    pub output_manager_state: OutputManagerState,
+    pub seat_state: SeatState<Self>,
+    pub shm_state: ShmState,
+    pub xdg_shell_state: XdgShellState,
+}
+
+impl Ferese {
+    pub fn new(
+        event_loop: &mut EventLoop<Self>,
+        display: Display<Self>,
+    ) -> Result<Self, Box<dyn Error>> {
+        let display_handle = display.handle();
+        let compositor_state = CompositorState::new::<Self>(&display_handle);
+        let xdg_shell_state = XdgShellState::new::<Self>(&display_handle);
+        let shm_state = ShmState::new::<Self>(&display_handle, Vec::new());
+        let output_manager_state = OutputManagerState::new_with_xdg_output::<Self>(&display_handle);
+        let mut seat_state = SeatState::new();
+        let mut seat = seat_state.new_wl_seat(&display_handle, "ferese-winit");
+        seat.add_keyboard(Default::default(), 200, 25)?;
+        seat.add_pointer();
+        let socket_name = Self::init_wayland_listener(display, event_loop)?;
+
+        Ok(Self {
+            start_time: Instant::now(),
+            socket_name,
+            display_handle,
+            loop_signal: event_loop.get_signal(),
+            space: Space::default(),
+            popups: PopupManager::default(),
+            seat,
+            compositor_state,
+            output_manager_state,
+            seat_state,
+            shm_state,
+            xdg_shell_state,
+        })
+    }
+
+    fn init_wayland_listener(
+        display: Display<Self>,
+        event_loop: &mut EventLoop<Self>,
+    ) -> Result<OsString, Box<dyn Error>> {
+        let listening_socket = ListeningSocketSource::new_auto()?;
+        let socket_name = listening_socket.socket_name().to_os_string();
+        let loop_handle = event_loop.handle();
+
+        loop_handle.insert_source(listening_socket, |client_stream, _, state| {
+            if let Err(error) = state
+                .display_handle
+                .insert_client(client_stream, Arc::new(ClientState::default()))
+            {
+                tracing::warn!(%error, "failed to register Wayland client");
+            }
+        })?;
+        loop_handle.insert_source(
+            Generic::new(display, Interest::READ, Mode::Level),
+            |_, display, state| {
+                // SAFETY: this event source owns the display for the loop lifetime.
+                unsafe { display.get_mut().dispatch_clients(state)? };
+                Ok(PostAction::Continue)
+            },
+        )?;
+        Ok(socket_name)
+    }
+
+    pub fn surface_under(
+        &self,
+        position: Point<f64, Logical>,
+    ) -> Option<(WlSurface, Point<f64, Logical>)> {
+        self.space
+            .element_under(position)
+            .and_then(|(window, location)| {
+                window
+                    .surface_under(position - location.to_f64(), WindowSurfaceType::ALL)
+                    .map(|(surface, surface_location)| {
+                        (surface, (surface_location + location).to_f64())
+                    })
+            })
+    }
+}
+
+#[derive(Default)]
+pub struct ClientState {
+    pub compositor_state: CompositorClientState,
+}
+
+impl ClientData for ClientState {
+    fn initialized(&self, _client_id: ClientId) {}
+    fn disconnected(&self, _client_id: ClientId, _reason: DisconnectReason) {}
+}

compositor/src/winit.rs

@@ -0,0 +1,106 @@
+use std::{error::Error, time::Duration};
+
+use smithay::{
+    backend::{
+        renderer::{
+            damage::OutputDamageTracker, element::surface::WaylandSurfaceRenderElement,
+            gles::GlesRenderer,
+        },
+        winit::{self, WinitEvent},
+    },
+    output::{Mode, Output, PhysicalProperties, Subpixel},
+    reexports::calloop::EventLoop,
+    utils::{Rectangle, Transform},
+};
+
+use crate::Ferese;
+
+pub fn init(event_loop: &mut EventLoop<Ferese>, state: &mut Ferese) -> Result<(), Box<dyn Error>> {
+    let (mut backend, event_source) = winit::init()?;
+    let mode = Mode {
+        size: backend.window_size(),
+        refresh: 60_000,
+    };
+    let output = Output::new(
+        "ferese-winit".into(),
+        PhysicalProperties {
+            size: (0, 0).into(),
+            subpixel: Subpixel::Unknown,
+            make: "Ferese".into(),
+            model: "Nested".into(),
+        },
+    );
+    output.create_global::<Ferese>(&state.display_handle);
+    output.change_current_state(
+        Some(mode),
+        Some(Transform::Flipped180),
+        None,
+        Some((0, 0).into()),
+    );
+    output.set_preferred(mode);
+    state.space.map_output(&output, (0, 0));
+
+    let mut damage_tracker = OutputDamageTracker::from_output(&output);
+    event_loop
+        .handle()
+        .insert_source(event_source, move |event, _, state| match event {
+            WinitEvent::Resized { size, .. } => output.change_current_state(
+                Some(Mode {
+                    size,
+                    refresh: 60_000,
+                }),
+                None,
+                None,
+                None,
+            ),
+            WinitEvent::Input(event) => state.process_input_event(event),
+            WinitEvent::Redraw => {
+                let damage = Rectangle::from_size(backend.window_size());
+                let rendered = (|| -> Result<(), Box<dyn Error>> {
+                    {
+                        let (renderer, mut framebuffer) = backend.bind()?;
+                        smithay::desktop::space::render_output::<
+                            _,
+                            WaylandSurfaceRenderElement<GlesRenderer>,
+                            _,
+                            _,
+                        >(
+                            &output,
+                            renderer,
+                            &mut framebuffer,
+                            1.0,
+                            0,
+                            [&state.space],
+                            &[],
+                            &mut damage_tracker,
+                            [0.035, 0.04, 0.055, 1.0],
+                        )?;
+                    }
+                    backend.submit(Some(&[damage]))?;
+                    Ok(())
+                })();
+                if let Err(error) = rendered {
+                    tracing::error!(%error, "nested renderer failed");
+                    state.loop_signal.stop();
+                    return;
+                }
+                state.space.elements().for_each(|window| {
+                    window.send_frame(
+                        &output,
+                        state.start_time.elapsed(),
+                        Some(Duration::ZERO),
+                        |_, _| Some(output.clone()),
+                    );
+                });
+                state.space.refresh();
+                state.popups.cleanup();
+                if let Err(error) = state.display_handle.flush_clients() {
+                    tracing::debug!(%error, "failed to flush clients");
+                }
+                backend.window().request_redraw();
+            }
+            WinitEvent::CloseRequested => state.loop_signal.stop(),
+            _ => {}
+        })?;
+    Ok(())
+}